Abstract:
Establishing maximal oxygen uptake in young people during a ramp cycle test to exhaustion

This study tested the hypotheses that (1) secondary criteria (respiratory exchange ratio (RER), heart rate, blood [lactate]) traditionally used to verify the determination of maximum oxygen uptake (VO₂(max)) in children can result in the acceptance of a 'submaximal' VO₂(max) or falsely reject a 'true' VO(₂max) and (2) the VO₂(peak) recorded during a ramp test in children is comparable to the VO₂(peak) achieved during supramaximal testing.

Abstract:
A protocol to determine valid V˙O2max in young cystic fibrosis patients.

OBJECTIVES: Measuring aerobic fitness (V˙O2max) via a maximal cardiopulmonary exercise test is an important clinical tool in cystic fibrosis. This study sought to establish: (1) the validity of traditional criteria to verify maximal efforts during a ramp cardiopulmonary exercise test; and (2) whether V˙O2 measured during an exhaustive cardiopulmonary exercise test represents a valid V˙O2max in paediatric patients, using a subsequent exhaustive supramaximal (Smax) exercise test. DESIGN: Cross-sectional. METHODS: Fourteen patients (7-18 years; 10 males) completed an exhaustive ramp test to determine V˙O2max. Following 15-min recovery, Smax (110% ramp peak power output) was performed. RESULTS: Ramp test V˙O2peak was significantly higher than V˙O2 documented at traditional endpoint criteria, including a RER of 1.00 (0.99±0.47Lmin(-1) vs. 1.83±0.78Lmin(-1), p<0.001) and 1.10 (1.36±0.59Lmin(-1) vs. 1.83±0.78Lmin(-1), p<0.001), despite 100% of patients satisfying these two criteria. Only 23% and 75% of patients satisfied the 95% age-predicted heart rate (HR) maximum and 180bmin(-1) criteria. Whilst mean ramp and SmaxV˙O2peak were not significantly different (1.83±0.78Lmin(-1) vs. 1.82±0.67Lmin(-1); p=0.88), at the individual level Smax elicited a 'meaningful' (>9%) increase in V˙O2peak (range 9.9-38.3%) compared with V˙O2peak from the ramp test in 3 of 14 cases (21.4%). CONCLUSIONS: Traditional criteria significantly underestimate V˙O2max in young cystic fibrosis patients. Conversely, Smax can confirm when 'true'V˙O2max is achieved. The use of Smax following cardiopulmonary exercise test represents an appropriate method to measure V˙O2max in young cystic fibrosis patients.

Abstract:
Glycaemic index of meals affects appetite sensation but not energy balance in active males.

BACKGROUND: Foods with low glycaemic index (LGI) are reported to suppress appetite mainly in overweight population but have not been investigated in athletic adults. OBJECTIVE: the aim of this study was to compare the short-term effects of LGI and high GI (HGI) meals over a day on subsequent subjective appetite sensation, energy intake, energy expenditure, energy balance and resting metabolic rate in physically active males. METHODS: This cross-sectional randomized crossover study included 14 active males (mean ± SD; age 34.5 ± 8.9 years, body mass index 22.8 ± 2.1 kg m(-2)) to consume LGI and HGI meals on two separate days. On each trial day, participants consumed a breakfast in the laboratory and then left with a packed lunch, dinner and snacks. Appetite scores, energy intake and expenditure were assessed. RESULTS: the area under the curve for appetite scores of the HGI trial was significantly smaller than that of the LGI trial during the laboratory period (p = 0.027) and throughout the day (p = 0.009). No significant differences in energy intake, energy expenditure, energy balance and resting metabolic rate were found between groups, between the trial days and between the corresponding post-trial days. CONCLUSIONS: These results show that frequent ingestion of the HGI meals, contrary to the previous reports, suppresses appetite more than that of LGI meals, but did not affect energy balance in physically active normal-weight males.

Abstract:
A systematic review of associations between the primary school built environment and childhood overweight and obesity.

This systematic review considers current literature on the association between childhood overweight and obesity and the primary school built environment. Bibliographic databases from the fields of medicine, social science, exercise science and education were systematically searched. The following elements of the built environment were found to have been investigated: playground availability and adequacy; gymnasium availability and adequacy; school field, showers and covered playground availability. One intervention study was identified which utilized the built environment as an adjunct to a behavior change intervention. This systematic review identified minimal research upon the association between the school built environment and weight status and the current results are inconclusive.

Abstract:
Cardiorespiratory fitness, fatness, and blood pressure associations in Nigerian youth.

This study aimed to examine the independent associations of cardiorespiratory fitness (CRF) and body fatness with resting blood pressure (BP) in children (9-11 yr) and adolescents (12-15 yr) in Benue State of Nigeria.

Abstract:
Critical power in adolescents: physiological bases and assessment using all-out exercise.

This study examined whether critical power (CP) in adolescents: (1) provides a landmark for maximal steady-state exercise; and (2) can be determined using 'all-out' exercise. Nine active 14-15 year olds (6 females, 3 males) performed five cycling tests: (1) a ramp test to determine VO(2peak); (2) up to four constant power output tests to determine CP; (3-4) constant power output exercise 10% above and 10% below CP; and (5) a 3 min all-out cycle test to establish the end power (EP) at 90 and 180 s of exercise. All participants completed 30 min of exercise below CP and were characterized by steady-state blood lactate and VO(2) profiles. In contrast, time to exhaustion during exercise above CP was 15.0 ± 7.0 min and characterized by an inexorable rise in blood lactate and a rise, stabilization (~91% VO(2peak)) and fall in VO(2) (~82% VO(2peak)) prior to exhaustion. Eight out of nine participants completed the 3 min test and their EPs at 90 s (148 ± 29 W) and 180 s (146 ± 30 W) were not different from CP (146 ± 27 W) (P = 0.98). The typical error of estimates for establishing CP using EP at 90 s or 180 s of the 3 min test were 25 W (19.7% CV) and 25 W (19.6% CV), respectively. CP in active adolescence provides a valid landmark for maximal steady-state exercise, although its estimation on an individual level using the 3 min all-out test may be of limited value. VO(2peak)

Abstract:
Effects of low and high cadence interval training on power output in flat and uphill cycling time-trials.

This study tested the effects of low-cadence (60 rev min(-1)) uphill (Int(60)) or high-cadence (100 rev min(-1)) level-ground (Int(100)) interval training on power output (PO) during 20-min uphill (TT(up)) and flat (TT(flat)) time-trials. Eighteen male cyclists ([Formula: see text]: 58.6 ± 5.4 mL min(-1) kg(-1)) were randomly assigned to Int(60), Int(100) or a control group (Con). The interval training comprised two training sessions per week over 4 weeks, which consisted of six bouts of 5 min at the PO corresponding to the respiratory compensation point (RCP). For the control group, no interval training was conducted. A two-factor ANOVA revealed significant increases on performance measures obtained from a laboratory-graded exercise test (GXT) (P (max): 2.8 ± 3.0%; p < 0.01; PO and [Formula: see text] at RCP: 3.6 ± 6.3% and 4.7 ± 8.2%, respectively; p < 0.05; and [Formula: see text] at ventilatory threshold: 4.9 ± 5.6%; p < 0.01), with no significant group effects. Significant interactions between group and uphill and flat time-trial, pre- versus post-training on PO were observed (p < 0.05). Int(60) increased PO during both TT(up) (4.4 ± 5.3%) and TT(flat) (1.5 ± 4.5%). The changes were -1.3 ± 3.6, 2.6 ± 6.0% for Int(100) and 4.0 ± 4.6%, -3.5 ± 5.4% for Con during TT(up) and TT(flat), respectively. PO was significantly higher during TT(up) than TT(flat) (4.4 ± 6.0; 6.3 ± 5.6%; pre and post-training, respectively; p < 0.001). These findings suggest that higher forces during the low-cadence intervals are potentially beneficial to improve performance. In contrast to the GXT, the time-trials are ecologically valid to detect specific performance adaptations.

Abstract:
Hydration status, fluid intake, and electrolyte losses in youth soccer players.

The purpose of the study was to determine the hydration status, fluid intake, and electrolyte losses of 21 male professional youth soccer players (age 17.1 ± 0.7 y) training in a cool environment. Pretraining and posttraining measurements of body mass, urine (freezing-point osmolality method), and sweat concentration (flame-emission spectroscopy) were collected. Fourteen players were found to be hypohydrated before training. The amount of fluid lost due to exercise equated to a 1.7% loss in body mass, which equated to a gross dehydration loss of 0.5%. Overall, the soccer players replaced 46% ± 88% of sweat loss during training, and only 4 remained hypohydrated after training. No significant correlations between sweat loss and sweat concentrations of Na+ (r = -.11, P =. 67) or K+ (r =. 14, P =. 58) were found, but there was a significant correlation with Mg2+ (r = -.58, P <. 009). This study found large variability in pretraining hydration status that the players were able to rehydrate during the training sessions. However, given the numbers starting training in a hypohydrated state, adequate hydration status before training should be considered by youth players, coaches, and sports-science support staff.

Abstract:
Kicking velocity and physical, technical, tactical match performance for U18 female football players--effect of a new ball.

We investigated kicking velocity and physical, technical, and tactical match performance for under-18 (U18) female football players and evaluated the effect of using a newly developed lighter smaller ball. Ten regional league teams participated. Maximal ball velocity was 4±1% higher when kicking the new ball (NB) compared with the standard ball (SB) in a laboratory testing situation (23.2±0.4 vs. 22.4±0.3 ms(-1); p<.05). Mean HR was similar during games with NB and SB (169±2 vs. 170±2 bmin(-1); p>.05), but lower-limb muscular RPE was lower with NB (4.2±0.4 vs. 5.2±0.3; p<.05). The number of activity changes (1387±76 vs. 1401±55), total distance covered (9.09±0.25 vs. 9.11±0.25 km) and high-intensity running (1.04±0.08 vs. 1.11±0.07 km) were not different between NB and SB (p>.05). High-intensity running decreased (p<.05) from 0-20 to 60-80 min with NB (34%) and SB (37%). The number and success rate of long and short passes did not differ between NB and SB (p>.05). In conclusion, physiological demands were high in youth female football games, and decrements in running performance occurred towards the end of games. The players kicked faster and reported lower muscular exertion during games played with a lighter smaller ball, but locomotor activities, heart rate and overall technical-tactical game performance remained unaffected.

Abstract:
The effect of baseline metabolic rate on pulmonary O₂ uptake kinetics during very heavy intensity exercise in boys and men.

This study tested the hypothesis that pulmonary VO₂ kinetics would be slowed during 'work-to-work' exercise in adults but not in children. Eight boys (mean age=12.5 ± 0.5 years) and nine men completed very heavy step transitions initiated from either 'unloaded' pedalling (U→VH) or unloaded-to-moderate cycling (i.e. U→M to M→VH). The phase II τ was significantly (p<0.05) lengthened in M→VH compared to U→M and U→VH in boys (30 ± 5 vs. 19 ± 5 vs. 21 ± 5 s) and men (49 ± 14 vs. 30 ± 5 vs. 34 ± 8 s). In U→VH, a greater relative VO₂ slow component temporally coincided with an increased linear iEMG slope in men compared boys (VO₂ slow component: 16 ± 3 vs. 11 ± 4%; iEMG slope: 0.19 ± 0.24 vs. -0.06 ± 0.14%, p<0.05). These results suggest that an age-linked modulation of VO₂ kinetics might be influenced by alterations in muscle fibre recruitment following the onset of exercise.

Abstract:
The effects of 4-weeks of plyometric training on reactive strength index and leg stiffness in male youths.

Although previous pediatric research has reported performance improvements in muscular power, agility, speed, and rate-of-force development after exposure to plyometric training, the effects on reactive strength index (RSI) and leg stiffness remain unclear. One hundred and twenty-nine boys from 3 different age groups (9, 12, and 15 years) participated and were divided into either an experimental (EXP) or control (CON) group within their respective age groups. The EXP groups followed a twice-weekly, 4-week plyometric training program, whereas the CON groups participated in their normal physical education lessons. Preintervention and postintervention measures were collected for RSI (during maximal hopping) and leg stiffness (during submaximal hopping). Both 12- and 15-year-old EXP groups made significant improvements in both absolute and relative leg stiffness (p < 0.05). The 9-year-old EXP group and CON groups for all ages did not make significant changes in leg stiffness. The 12-year-old EXP cohort also made significant improvements in RSI (p < 0.05). Both 15- and 9-year-old EXP cohorts, and CON groups for all ages, failed to show any significant improvements in RSI. The study concludes that improvements in RSI and leg stiffness after a 4-week plyometric training program are age dependent during childhood.

Abstract:
Environmental factors affecting elite young athletes.

To date, much of the research concerning the performance of elite young athletes has focused on physical and physiological factors and how these relate to age and maturation. Little attention has been paid to other factors which might limit performance such as nutrition or environmental stressors. The paucity of research on the environmental effects on performance in young athletes is unsurprising given the need for experimental studies, the ethics of which would generally be untenable. As an outcome, there is a reliance on observational and case study data, e.g. observing the stressors which occur during jet lag and effects on sleep patterns, altitude and pollution. The effects of environmental factors have been predominantly researched from a health context in youngsters rather than a performance context. However, the evidence of those few empirical studies combined with coach and/or sports science support teams' experience have provided professionals with some guidelines. These applied guidelines include sleep patterns, jet lag, pollution and altitude research, to aid those preparing young athletes for training and competition in environments that present potential challenges to performance. The limitations of data extrapolated from adults are acknowledged and in all cases it is emphasised that recommendations and implementing practice should be based on data collected from young people.

Abstract:
Exercise metabolism during moderate-intensity exercise in children with cystic fibrosis following heavy-intensity exercise.

Muscle metabolism is increased following exercise in healthy individuals, affecting exercise metabolism during subsequent physical work. We hypothesized that following heavy-intensity exercise (HIE), disease factors in children with cystic fibrosis (CF) would further exacerbate exercise metabolism and perceived exertion during subsequent exercise. Nineteen children with CF (age, 13.4 ± 3.1 years; 10 female) and 19 healthy controls (age, 13.8 ± 3.5 years; 10 female) performed 10 bouts of HIE interspersed with 1 min of recovery between each bout. Three minutes later participants completed a 10-min moderate-intensity exercise (MIE) test (test 1). The MIE test was subsequently repeated 1 h (test 2) and 24 h (test 3) later. Each MIE test was identical and participants exercised at individualized work rates, calibrated by an initial graded maximal cardiopulmonary exercise test, while metabolic and perceived exertion measurements were taken. Following HIE, mixed-model ANOVAs showed a significant difference in oxygen uptake (VO₂) and rating of perceived exertion (RPE) between the 2 groups across the MIE tests (p < 0.01). In controls, VO₂ (L·min⁻¹) and RPE decreased significantly from test 1 to test 2 (p < 0.01) and test 2 to test 3 (p < 0.05). However, in children with CF, VO₂ (L·min⁻¹) increased significantly from test 1 to test 2 (p < 0.01), while RPE did not differ, both VO₂ and RPE decreased significantly from test 2 to test 3 (p < 0.01). In conclusion, following HIE the metabolic and perceptual responses to MIE in both groups decreased 24 h later during test 3. These data show that children with mild-to-moderate CF have the capability to perform HIE and 24 h allows sufficient time for recovery.

Abstract:
Longitudinal monitoring of power output and heart rate profiles in elite cyclists.

Power output and heart rate were monitored for 11 months in one female (V(.)O(2max): 71.5 mL · kg⁻¹ · min⁻¹) and ten male (V(.)O(2max): 66.5 ± 7.1 mL · kg⁻¹ · min⁻¹) cyclists using SRM power-meters to quantify power output and heart rate distributions in an attempt to assess exercise intensity and to relate training variables to performance. In total, 1802 data sets were divided into workout categories according to training goals, and power output and heart rate intensity zones were calculated. The ratio of mean power output to respiratory compensation point power output was calculated as an intensity factor for each training session and for each interval during the training sessions. Variability of power output was calculated as a coefficient of variation. There was no difference in the distribution of power output and heart rate for the total season (P = 0.15). Significant differences were observed during high-intensity workouts (P < 0.001). Performance improvements across the season were related to low-cadence strength workouts (P < 0.05). The intensity factor for intervals was related to performance (P < 0.01). The variability in power output was inversely associated with performance (P < 0.01). Better performance by cyclists was characterized by lower variability in power output and higher exercise intensities during intervals.

Abstract:
Prevalence of nonfunctional overreaching/overtraining in young English athletes.

Nonfunctional overreaching and overtraining (NFOR/OT) in adults can lead to significant decrements in performance, combined with physical and psychological health problems. Little is known about this condition in young athletes by comparison; thus, the aim of the study was to assess the incidence and symptomatology of NFOR/OT in young English athletes.

Abstract:
Seasonal monitoring of sprint and jump performance in a soccer youth academy.

The aim of the study was to longitudinally assess speed and jump performance characteristics of youth football players over a 3 y period.

Abstract:
The effect of non-contingent and accurate performance feedback on pacing and time trial performance in 4-km track cycling.

To determine whether the provision of comparative performance feedback during 4 km track cycling affects completion time.

Abstract:
The effect of pedal rate on pulmonary O2 uptake kinetics during very heavy intensity exercise in trained and untrained teenage boys.

This study tested the hypothesis that the VO2 kinetic response would be slowed in untrained (UT) but not trained (T) teenage participants whilst cycling at 115 rev min(-1) compared to 50 rev min(-1). Eight UT and seven T boys completed two square-wave transitions to very heavy-intensity exercise pedalling at 50 rev min(-1) and 115 rev min(-1). In UT at the higher pedal rate, the phase II VO2 was significantly (P < 0.01) slower (50 rev min(-1): 32 ± 5 vs. 115 rev min(-1): 42 ± 11 s) and the relative VO2 slow component was significantly (P < 0.01) elevated (50 rev min(-1): 10 ± 3 vs. 115 rev min(-1): 16 ± 5%). The phase II VO2 (50 rev min(-1): 26 ± 4 vs. 115 rev min(-1): 22 ± 6s) and relative VO2 slow component (50 rev min(-1): 14 ± 5 vs. 115 rev min(-1): 17 ± 3%) were unaltered by pedal rate in T (P > 0.05). These data are consistent with the notion that VO2 kinetics are influenced by muscle fibre recruitment in youth but this effect is attenuated in endurance trained teenage boys.

Abstract:
The influence of chronological age on periods of accelerated adaptation of stretch-shortening cycle performance in pre and postpubescent boys.

Although it is suggested that periods of naturally occurring accelerated adaptation may exist for various physical parameters, it would appear that no such evidence exists for stretch-shortening cycle (SSC) development. Two hundred and fifty male youths aged 7-17 years were tested for squat (SJ) and countermovement jump (CMJ) height, reactive strength index (RSI), and leg stiffness, with analyses of variance used to establish any significant between-group differences. Additionally, to ascertain the existence of periods of accelerated adaptation, inferences were made about the magnitudes of change between consecutive chronological age groups in relation to the smallest worthwhile change. The largest mean differences (±90% confidence limits) occurred between age groups 10 and 11 (G10-G11) for squat jump (SJ) height (21.61 ± 12.08-31.94%), CMJ height (20.80 ± 11.1-44.1%), and RSI (26.51 ± 11.07-44.10%); and between G12 and G13 for SJ (15.31 ± 7.47-23.73%) and CMJ (16.09 ± 7.50-25.38%) height. Negative mean differences occurred between G11 and G12 for SJ height (-1.32 ± -9.30 to 7.37%), CMJ jump height (-7.68 ± -15.15 to 0.45%) and RSI (-11.48 ± -22.21 to 0.74%); and between G10 and G11 for leg stiffness (-8.87 ± -18.85 to 2.34%). It would appear almost certain that windows of accelerated adaptation may exist for SJ and CMJ height and RSI in male youths; however, leg stiffness results would suggest that fast-SSC function may follow a different developmental trend.

Abstract:
A survey of exercise testing and training in UK cystic fibrosis clinics.

Exercise testing is a valuable prognostic tool and exercise training has many health benefits in cystic fibrosis (CF). The objective of this study was to survey the provision of exercise testing and training in UK CF clinics.

Abstract:
Age- and sex-related differences in muscle phosphocreatine and oxygenation kinetics during high-intensity exercise in adolescents and adults.

The aim of this investigation was to examine the adaptation of the muscle phosphates (e.g. phosphocreatine (PCr) and ADP) implicated in regulating oxidative phosphorylation, and oxygenation at the onset of high intensity exercise in children and adults. The hypotheses were threefold: primary PCr kinetics would be faster in children than adults; the amplitude of the PCr slow component would be attenuated in children; and the amplitude of the deoxyhaemoglobin/myoglobin (HHb) slow component would be reduced in children. Eleven children (5 girls, 6 boys, 13 +/- 1 years) and 11 adults (5 women, 6 men, 24 +/- 4 years) completed two to four constant work rate exercise tests within a 1.5 T MR scanner. Quadriceps muscle energetics during high intensity exercise were monitored using (31)P-MRS. Muscle oxygenation was monitored using near-infrared spectroscopy. The time constant for the PCr response was not significantly different in boys (31 +/- 10 s), girls (31 +/- 10 s), men (44 +/- 20 s) or women (29 +/- 14 s, main effects: age, p = 0.37, sex, p = 0.25). The amplitude of the PCr slow component relative to end-exercise PCr was not significantly different between children (23 +/- 23%) and adults (17 +/- 13%, p = 0.47). End-exercise [PCr] was significantly lower, and [ADP] higher, in females (18 +/- 4 mM and 53 +/- 16 microM) than males (23 +/- 4 mM, p = 0.02 and 37 +/- 11 microM, p = 0.02), but did not differ with age ([PCr]: p = 0.96, [ADP]: p = 0.72). The mean response time for muscle tissue deoxygenation was significantly faster in children (22 +/- 4 s) than adults (27 +/- 7 s, p = 0.01). The results of this study show that the control of oxidative metabolism at the onset of high intensity exercise is adult-like in 13-year-old children, but that matching of oxygen delivery to extraction is more precise in adults.

Abstract:
Evaluation of a field test to assess performance in elite cyclists.

The study aimed to assess the reproducibility of power output during a 4 min (TT4) and a 20 min (TT20) time-trial and the relationship with performance markers obtained during a laboratory graded exercise test (GXT). Ventilatory and lactate thresholds during a GXT were measured in competitive male cyclists (n=15; (.)VO (2max) 67+/-5 ml x min (-1) x kg (-1); P (max) 440+/-38W). Two 4 min and 20 min time-trials were performed on flat roads. Power output was measured using a mobile power-meter (SRM). Strong intraclass-correlations for TT4 ( R=0.98; 95% CL: 0.92-0.99) and TT20 ( R=0.98; 95% CL: 0.95-0.99) were observed. TT4 showed a bias+/-random error of - 0.8+/-23W or - 0.2+/-5.5%. During TT20 the bias+/-random error was - 1.8+/-14W or 0.6+/-4.4%. Both time-trials were strongly correlated with performance measures from the GXT (p<0.001). Significant differences were observed between power output during TT4 and GXT measures (p<0.001). No significant differences were found between TT20 and power output at the second lactate-turn-point (LTP2) (p=0.98) and respiratory compensation point (RCP) (p=0.97). In conclusion, TT4 and TT20 mean power outputs are reliable predictors of aerobic endurance. TT20 was in agreement with power output at RCP and LTP2.

Abstract:
Exercise training in children and adolescents with cystic fibrosis: theory into practice.

Physical activity and exercise training play an important role in the clinical management of patients with cystic fibrosis (CF). Exercise training is more common and recognized as an essential part of rehabilitation programmes and overall CF care. Regular exercise training is associated with improved aerobic and anaerobic capacity, higher pulmonary function, and enhanced airway mucus clearance. Furthermore, patients with higher aerobic fitness have an improved survival. Aerobic and anaerobic training may have different effects, while the combination of both have been reported to be beneficial in CF. However, exercise training remains underutilised and not always incorporated into routine CF management. We provide an update on aerobic and anaerobic responses to exercise and general training recommendations in children and adolescents with CF. We propose that an active lifestyle and exercise training are an efficacious part of regular CF patient management.

Abstract:
Influence of acetaminophen on performance during time trial cycling.

To establish whether acetaminophen improves performance of self-paced exercise through the reduction of perceived pain, 13 trained male cyclists performed a self-paced 10-mile (16.1 km) cycle time trial (TT) following the ingestion of either acetaminophen (ACT) or a placebo (PLA), administered in randomized double-blind design. TT were completed in a significantly faster time (t(12) = 2.55, P < 0.05) under the ACT condition (26 min 15 s +/- 1 min 36 s vs. 26 min 45 s +/- 2 min 2 s). Power output (PO) was higher during the middle section of the TT in the ACT condition, resulting in a higher mean PO (P < 0.05) (265 +/- 12 vs. 255 +/- 15 W). Blood lactate concentration (B[La]) and heart rate (HR) were higher in the ACT condition (B[La] = 6.1 +/- 2.9 mmol/l; HR = 87 +/- 7%max) than in the PLA condition (B[La] = 5.1 +/- 2.6 mmol/l; HR = 84 +/- 9%max) (P < 0.05). No significant difference in rating of perceived exertion (ACT = 15.5 +/- 0.2; PLA = 15.7 +/- 0.2) or perceived pain (ACT = 5.6 +/- 0.2; PLA = 5.5 +/- 0.2) (P > 0.05) was observed. Using acetaminophen, participants cycled at a higher mean PO, with an increased HR and B[La], but without changes in perceived pain or exertion. Consequently, completion time was significantly faster. These findings support the notion that exercise is regulated by pain perception, and increased pain tolerance can improve exercise capacity.

Abstract:
Critical power is not attained at the end of an isokinetic 90-second all-out test in children.

The purpose of this study was to establish whether critical power, as traditionally determined from the performance of three constant-load tests to exhaustion, is attained at the end of a 90-s all-out test in children. Sixteen healthy children (eight males and eight females; mean age 12.3 years, s(x) = 0.1; body mass 39.6 kg, s(x) = 1.8; peak VO(2) 2.0 litres. min(-1), s(x) = 0.1) completed an incremental test to exhaustion to determine peak oxygen uptake (peak VO(2)), three separate constant-load tests to exhaustion to calculate critical power, and an isokinetic 90-s all-out test. The end power of the 90-s test averaged over the last 10 s (140 W, s(x) = 8) was significantly higher than critical power (105 W, s(x) = 6; t = 6.8; P < 0.01), yet the two parameters were strongly correlated (r = 0.74; P < 0.01). After 60 s, there were no further reductions in power output during the 90-s test (P < 0.0001). In conclusion, at the end of a 90-s all-out test, children are able to produce power outputs well above critical power. This suggests that 90 s is not long enough to completely exhaust the anaerobic work capacity in children.

Abstract:
Early oxygen uptake recovery following exercise testing in children with chronic chest diseases.

The value of exercise testing as an objective measure of disease severity in patients with chronic chest diseases (CCD) is becoming increasingly recognized. The aim of this study was to investigate changes in oxygen uptake (VO2) during early recovery following maximal cardiopulmonary exercise testing (CPXT) in relation to functional capacity and markers of disease severity. Twenty-seven children with CCD (age 12.7 +/- 3.1 years; 17 female) [19 children with Cystic fibrosis (CF) (age 13.4 +/- 3.1 years; 10 female) and 8 with other stable non-CF chest diseases (NON-CF) (age 11.1 +/- 2.2 years; 7 female)] and 27 healthy controls (age 13.2 +/- 3.3 years; 17 female) underwent CPXT on a cycle ergometer. On-line respiratory gas analysis measured VO2 before and during CPXT to peak VO2) (VO2(peak)), and during the first 10 min of recovery. Early VO2 recovery was quantified by the time (sec) to reach 50% of the VO2 (peak) value. Early VO2 recovery was correlated against spirometry [forced expiratory volume in 1 sec (FEV(1)) and forced expiratory flow between 25% and 75% of the forced vital capacity (FEF(25-75))] and aerobic fitness (VO2)(peak)) as a measure of functional capacity. Disease severity was graded in the CF patients by the Shwachman score (SS). Compared to controls, children with CCD demonstrated a significantly reduced VO2(peak) (P = 0.011), FEV(1) (P < 0.001), FEF(25-75) (P < 0.001), and a significantly prolonged early (VO2) recovery (P = 0.024). In the CF patients the SS was significantly correlated with early VO2 recovery (r = -0.63, P = 0.004), FEV(1) (r = 0.72, P = 0.001), and FEF(25-75) (r = 0.57, P = 0.011). In the children with CCD, FEV(1), FEF(25-75), and BMI were not significantly correlated with VO2(peak) or early VO2 recovery. Lung function does not necessarily reflect aerobic fitness and the ability to recover from exercise in these patients. A significant relationship was found between VO2(peak) and early VO2 recovery (r = -0.39, P = 0.044) in the children with CCD, showing that a greater aerobic fitness corresponded with a faster recovery.

Abstract:
Influence of feedback and prior experience on pacing during a 4-km cycle time trial.

To determine the importance of distance knowledge, distance feedback, and prior experience on the setting of a pacing strategy.

Abstract:
Critical power in adolescent boys and girls--an exploratory study.

The purpose of the study was to identify critical power (CP) in boys and girls and to examine the physiological responses to exercise at and 10% above CP (CP+10%) in a sub-group of boys. Nine boys and 9 girls (mean age 12.3 (0.5) y performed 3 constant-load tests to derive CP. Eight of the boys then exercised, in random order, at CP and CP+10% until volitional exhaustion. CP was 123 (28) and 91 (26) W for boys and girls, respectively (p < 0.02), which was equivalent to 75 (6) and 72 (10) % of peak oxygen uptake, respectively (p > 0.47). Boys' time to exhaustion at CP was 18 min 37 s (4 min 13 s), which was significantly longer (p < 0.007) than that at CP+10% (9 min 42 s (2 min 31 s)). End-exercise values for blood lactate concentration (B[La]) and maximal oxygen uptake were higher in the CP+10% trial (5.0 (2.4) mmol.L-1 and 2.15 (0.4) L.min-1, respectively) than in the CP trial, (B[La], 4.7 (2.1) mmol.L-1; maximal oxygen uptake, 2.05 (0.35) L.min-1; p > 0.13). Peak oxygen uptake (expressed as a percentage of the peak value) was not attained at the end of the trials (94 (12) and 98 (14) % for CP and CP+10%, respectively). These results provide information about the boundary between the heavy and severe exercise intensity domains in children, and have demonstrated that CP in a group of boys does not represent a sustainable steady-state intensity of exercise.

Abstract:
Muscle phosphocreatine and pulmonary oxygen uptake kinetics in children at the onset and offset of moderate intensity exercise.

To further understand the mechanism(s) explaining the faster pulmonary oxygen uptake (p(VO)(2)) kinetics found in children compared to adults, this study examined whether the phase II p(VO)(2) kinetics in children are mechanistically linked to the dynamics of intramuscular PCr, which is known to play a principal role in controlling mitochondrial oxidative phosphorylation during metabolic transitions. On separate days, 18 children completed repeated bouts of moderate intensity constant work-rate exercise for determination of (1) PCr changes every 6 s during prone quadriceps exercise using (31)P-magnetic resonance spectroscopy, and (2) breath by breath changes in p(VO)(2) during upright cycle ergometry. Only subjects (n = 12) with 95% confidence intervals <or=+/-7 s for all estimated time constants were considered for analysis. No differences were found between the PCr and phase II p(VO)(2) time constants at the onset (PCr 23 +/- 5 vs. p(VO)(2) 23 +/- 4 s, P = 1.000) or offset (PCr 28 +/- 5 vs. p(VO)(2) 29 +/- 5 s, P = 1.000) of exercise. The average difference between the PCr and phase II p(VO)(2) time constants was 4 +/- 4 s for the onset and offset responses. Pooling of the exercise onset and offset responses revealed a significant correlation between the PCr and p(VO)(2) time constants (r = 0.459, P = 0.024). The close kinetic coupling between the p(VO)(2) and PCr responses at the onset and offset of exercise in children is consistent with our current understanding of metabolic control and suggests that an age-related modulation of the putative phosphate linked controller(s) of mitochondrial oxidative phosphorylation may explain the faster p(VO)(2) kinetics found in children compared to adults.

Abstract:
Muscle metabolism during constant- and alternating-intensity exercise around critical power.

Few studies have focused on the metabolic responses to alternating high- and low-intensity exercise and, specifically, compared these responses to those seen during constant-load exercise performed at the same average power output. This study compared muscle metabolic responses between two patterns of exercise during which the intensity was either constant and just below critical power (CP) or that oscillated above and below CP. Six trained males (mean +/- SD age 23.6 +/- 2.6 y) completed two 30-minute bouts of cycling (alternating and constant) at an average intensity equal to 90 % of CP. The intensity during alternating exercise varied between 158 % CP and 73 % CP. Biopsy samples from the vastus lateralis muscle were taken before (PRE), at the midpoint and end (POST) of exercise and analysed for glycogen, lactate, PCr and pH. Although these metabolic variables in muscle changed significantly during both patterns of exercise, there were no significant differences (p > 0.05) between constant and alternating exercise for glycogen (PRE: 418.8 +/- 85 vs. 444.3 +/- 70; POST: 220.5 +/- 59 vs. 259.5 +/- 126 mmol x kg (-1) dw), lactate (PRE: 8.5 +/- 7.7 vs. 8.5 +/- 8.3; POST: 49.9 +/- 19.0 vs. 42.6 +/- 26.6 mmol x kg (-1) dw), phosphocreatine (PRE: 77.9 +/- 11.6 vs. 75.7 +/- 16.9; POST: 65.8 +/- 12.1 vs. 61.2 +/- 12.7 mmol x kg (-1) dw) or pH (PRE: 6.99 +/- 0.12 vs. 6.99 +/- 0.08; POST: 6.86 +/- 0.13 vs. 6.85 +/- 0.06), respectively. There were also no significant differences in blood lactate responses to the two patterns of exercise. These data suggest that, when the average power output is similar, large variations in exercise intensity exert no significant effect on muscle metabolism.

Abstract:
Aerobic fitness and visceral adipose tissue in children.

To determine the relationship between aerobic fitness (peak VO2) and the volume of visceral adipose tissue (VAT) in children.

Abstract:
Effects of age and recovery duration on performance during multiple treadmill sprints.

The aim of this study was to investigate the effects of age and recovery duration on performance during multiple treadmill sprints. Twelve boys (11.7 +/- 0.5 y) and thirteen men (22.1 +/- 2.9 y) performed ten consecutive 10-s sprints on a non-motorised treadmill separated by 15-s (R15) and 180-s (R180) passive recovery intervals. Mean power output (MPO), mean force output (MFO), running velocity, step length, and step rate were calculated for each sprint. Capillary blood samples were drawn from the fingertip at rest and 3 min after the tenth sprint to measure the lactate accumulation (Delta [La]). With R15, all mechanical parameters decreased significantly less in the boys than in the men over the ten sprints (MPO: - 28.9 vs. - 47.0 %, MFO: - 13.1 vs. - 25.6 %, running velocity: - 18.8 vs. - 29.4 %, p < 0.001, respectively). With R180, all mechanical values remained unchanged in the boys. In the men, MPO and MFO significantly decreased over the ten sprints (- 7.8 % and - 4.6 %, p < 0.05, respectively). The running velocity, however, did not decrease because the decrease in step rate (p < 0.001) was compensated by an increase in step length. For either recovery interval, Delta [La] values were higher in the men compared to the boys (R15: 12.7 vs. 7.7 mmol. L (-1), p < 0.001, R180: 10.7 vs. 7.7 mmol. L (-1), p < 0.05). To conclude, the boys maintained more easily their running performance than the men during repeated treadmill sprints with R15. Three-minute recovery periods were sufficient in the boys to repeat short running sprints without substantial fatigue. Despite the decrease in power and force outputs with R180, the young men were able to maintain their running velocity during the test.

Abstract:
Reliability of 31P-magnetic resonance spectroscopy during an exhaustive incremental exercise test in children.

This study examined the reliability of (31)P-magnetic resonance spectroscopy (MRS) to measure parameters of muscle metabolic function in children. On separate days, 14 children (7 boys and 7 girls) completed three knee-extensor incremental tests to exhaustion inside a whole-body scanner (1.5 T, Phillips). The dynamic changes in the ratio of inorganic phosphate to phosphocreatine (Pi/PCr) and intracellular muscle pH were resolved every 30 s. Using plots of Pi/PCr and pH against power output (W), intracellular thresholds (ITs) for each variable were determined using both subjective and objective procedures. The IT(Pi/PCr) and IT(pH) were observed subjectively in 93 and 81% of their respective plots, whereas the objective method identified the IT(Pi/PCr) in 88% of the plots. The IT(pH) was undetectable using the objective method. End exercise (END) END(Pi/PCr), END(pH), IT(Pi/PCr) and IT(pH) were examined using typical error statistics expressed as a % coefficient of variation (CV) across all three exercise tests. The CVs for the power output at the subjectively determined IT(Pi/PCr) and IT(pH) were 10.6 and 10.3%, respectively. Objective identification of the IT(Pi/PCr) had a CV of 16.3%. CVs for END(pH) and END(Pi/PCr) were 0.9 and 50.0%, respectively. MRS provides a valuable window into metabolic changes during exercise in children. During knee-extensor exercise to exhaustion, END(pH) and the subjectively determined IT(Pi/PCr) and IT(pH) demonstrate good reliability and thus stable measures for the future study of developmental metabolism. However, the objectively determined IT(Pi/PCr) and END(Pi/PCr) displayed poor reliability.

Abstract:
Achievement of peak VO2 during a 90-s maximal intensity cycle sprint in adolescents.

The aim of this study was to determine whether peak oxygen uptake (PVO2) attained in a 90-s maximal intensity cycle sprint is comparable to that from a conventional ramp test. Sixteen participants (13 boys and 3 girls, 14.6 +/- 0.4 yr) volunteered for the study. On Day 1 they completed a PVO2 test to exhaustion using a 25 W x min(-1) ramp protocol beginning at 50 W. Peak VO2 was defined as the highest VO2 value achieved, and aerobic power (Wmax) as the power output of the final 30 s. On Day 2 the participants completed two 90-s maximal sprints (S1 and S2). A 45-min recovery period separated each sprint. Mean oxygen uptake over the last 10 s of each sprint was determined as PVO2, and minimum power (MinP-30 s) as the mechanical power attained in the final 30 s. A one-way ANOVA was used to analyse differences between S1, S2, and the ramp test for PVO2 and MinP-30 s. Peak VO2 was not significantly different between the ramp, S1, or S2 (2.64 +/- 0.5, 2.49 +/- 0.5, and 2.53 +/- 0.5 L x min(-1), respectively, p > 0.68). The S1 and S2 PVO2 scores represented 91 +/- 10% and 92 +/- 10% of the ramp aerobic test. The MinP-30 s for S1 and S2 were significantly lower than the Wmax of the ramp test, p < 0.05. Hence, for researchers solely interested in PVO2 values, a shorter but more intensive protocol provides an alternative method to the traditional ramp aerobic test.

Abstract:
Prediction of visceral adipose tissue using air displacement plethysmography in children.

To determine the ability of air displacement plethysmography (ADP) to predict visceral adipose tissue (VAT) volume in children.

Abstract:
The reproducibility of an endurance performance test in adolescent cyclists.

The purpose of the study was to measure the reproducibility of a performance test in well-trained adolescent cyclists. Eight male and one female cyclist [mean age 15.7 (0.7) y] participated in the study. Lactate threshold (LT) and peak VO2 were assessed. The performance test was repeated on three separate days and consisted of 30 min of steady state (SS) cycling at 80% of individual LT. Immediately after the SS cycling a time trial (TT) started with the cyclists having to complete a fixed amount of work as fast as possible. Reliability was assessed for the TT with the coefficient of variation (CV) as the (SD/mean)*100 for each participant, intraclass correlation coefficients (ICC) and typical error (SD of the difference in mean /radical2). The group mean (SD) times for the TT were TT1 1889 (306), TT2 1857 (283) and TT3 1953 (279) s respectively. Individual CV varied from 0.25% to 10%. The ICC for TT1/2 and 2/3 were r = 0.78 and 0.93 (P<0.05). The typical errors, expressed as a CV% on the log transformed performance times, were 7.3 and 3.7% for TT1/2 and TT2/3 respectively. The largest individual CVs were observed between TT1 and TT2. The differences in CV and SD among the three TTs indicate that trial two and three were more reliable than TT1, suggesting a habituation trial is needed. It is concluded that the present performance test is reliable in adolescent cyclists with lower variation between trials 2 and 3.

Abstract:
Effects of age and mode of exercise on power output profiles during repeated sprints.

The aim of this study was to compare power output profiles during repeated cycling and running sprints in children and adults. On two separate visits, 12 boys [11.7 (0.5) years] and 13 men [22.1 (2.9) years] performed ten consecutive 10-s sprints interspersed with 15-s recovery intervals on a non-motorised treadmill and cycle ergometer. Peak (PPO) and mean (MPO) power outputs were measured during each sprint. Capillary fingertip blood samples were drawn at rest and 3 min after the final sprint to measure lactate accumulation (Delta[La]). PPO and MPO decreased significantly more in adults compared to children over the ten sprints irrespective of the mode of exercise (P<0.001). PPO decreased by a similar amount during running and cycling in children (-17.7 versus -14.3%, P>0.05, respectively) and adults (-43.3 versus -40.0%, P>0.05, respectively). In contrast, MPO decreased significantly more during running compared to cycling both in children (-28.9 versus -18.7%, P<0.05) and adults (-47.0 versus -36.7%, P<0.05). The greater decrease in MPO during running compared to cycling was accompanied in children by significantly higher Delta[La] values (7.7 versus 4.1 mmol l(-1), P<0.001). In adults, blood lactate accumulation tended to be higher during running than cycling (12.7 versus 10.8 mmol l(-1), P=0.06). To conclude, adults displayed a greater decrement in power output compared to children over the ten repeated running and cycling sprints. Furthermore, children and adults experienced greater fatigue during running compared to cycling. This last result may be attributed to additional muscle recruitment during sprint running.

Abstract:
Oxygen uptake kinetics during treadmill running in boys and men.

The purpose of this study was to compare the kinetics of the oxygen uptake (VO(2)) response of boys to men during treadmill running using a three-phase exponential modeling procedure. Eight boys (11-12 yr) and eight men (21-36 yr) completed an incremental treadmill test to determine lactate threshold (LT) and maximum VO(2). Subsequently, the subjects exercised for 6 min at two different running speeds corresponding to 80% of VO(2) at LT (moderate exercise) and 50% of the difference between VO(2) at LT and maximum VO(2) (heavy exercise). For moderate exercise, the time constant for the primary response was not significantly different between boys [10.2 +/- 1.0 (SE) s] and men (14.7 +/- 2.8 s). The gain of the primary response was significantly greater in boys than men (239.1 +/- 7.5 vs. 167.7 +/- 5.4 ml. kg(-1). km(-1); P < 0.05). For heavy exercise, the VO(2) on-kinetics were significantly faster in boys than men (primary response time constant = 14.9 +/- 1.1 vs. 19.0 +/- 1.6 s; P < 0.05), and the primary gain was significantly greater in boys than men (209.8 +/- 4.3 vs. 167.2 +/- 4.6 ml. kg(-1). km(-1); P < 0.05). The amplitude of the VO(2) slow component was significantly smaller in boys than men (19 +/- 19 vs. 289 +/- 40 ml/min; P < 0.05). The VO(2) responses at the onset of moderate and heavy treadmill exercise are different between boys and men, with a tendency for boys to have faster on-kinetics and a greater initial increase in VO(2) for a given increase in running speed.

Abstract:
Aerobic responses of prepubertal boys to two modes of training.

To investigate the effects of two contrasting eight week training programmes on the aerobic performance of 39 prepubescent boys (mean age 10.1 years).

Abstract:
Effect of endurance training on oxygen uptake kinetics during treadmill running.

The purpose of this study was to examine the effect of endurance training on oxygen uptake (VO(2)) kinetics during moderate [below the lactate threshold (LT)] and heavy (above LT) treadmill running. Twenty-three healthy physical education students undertook 6 wk of endurance training that involved continuous and interval running training 3-5 days per week for 20-30 min per session. Before and after the training program, the subjects performed an incremental treadmill test to exhaustion for determination of the LT and the VO(2 max) and a series of 6-min square-wave transitions from rest to running speeds calculated to require 80% of the LT and 50% of the difference between LT and maximal VO(2). The training program caused small (3-4%) but significant increases in LT and maximal VO(2) (P<0.05). The VO(2) kinetics for moderate exercise were not significantly affected by training. For heavy exercise, the time constant and amplitude of the fast component were not significantly affected by training, but the amplitude of the VO(2) slow component was significantly reduced from 321+/-32 to 217+/-23 ml/min (P<0.05). The reduction in the slow component was not significantly correlated to the reduction in blood lactate concentration (r = 0. 39). Although the reduction in the slow component was significantly related to the reduction in minute ventilation (r = 0.46; P<0.05), it was calculated that only 9-14% of the slow component could be attributed to the change in minute ventilation. We conclude that the VO(2) slow component during treadmill running can be attenuated with a short-term program of endurance running training.

Abstract:
Longitudinal changes in young people's short-term power output.

The influences of age, body size, skin-fold thickness, gender, and maturation on the short-term power output of young people were examined using multilevel modelling.

Abstract:
Oxygen uptake kinetics in treadmill running and cycle ergometry: a comparison.

The purpose of the present study was to comprehensively examine oxygen consumption (VO(2)) kinetics during running and cycling through mathematical modeling of the breath-by-breath gas exchange responses to moderate and heavy exercise. After determination of the lactate threshold (LT) and maximal oxygen consumption (VO(2 max)) in both cycling and running exercise, seven subjects (age 26.6 +/- 5.1 yr) completed a series of "square-wave" rest-to-exercise transitions at running speeds and cycling power outputs that corresponded to 80% LT and 25, 50, and 75%Delta (Delta being the difference between LT and VO(2 max)). VO(2) responses were fit with either a two- (<LT) or three-phase ( >LT) exponential model. The parameters of the VO(2) kinetic response were similar between exercise modes, except for the VO(2) slow component, which was significantly (P < 0.05) greater for cycling than for running at 50 and 75%Delta (334 +/- 183 and 430 +/- 159 ml/min vs. 205 +/- 84 and 302 +/- 154 ml/min, respectively). We speculate that the differences between the modes are related to the higher intramuscular tension development in heavy cycle exercise and the higher eccentric exercise component in running. This may cause a relatively greater recruitment of the less efficient type II muscle fibers in cycling.

Abstract:
Bias and limits of agreement between hydrodensitometry, bioelectrical impedance and skinfold calipers measures of percentage body fat.

Previous research has often used correlations as a statistical method to show agreement; however, this is not a valid use of the statistic. The purpose of this study was to investigate the bias and limits of agreement for three methods of estimating percentage body fat for 117 male and 114 female university athletes: hydrodensitometry (HYD), bioelectrical impedance (BIA) and skinfold calipers (SKF). The mean (SD) percentage body fat for males as assessed by HYD, BIA and SKF methods, respectively, were 13.2 (3.3)%, 14.1, (3.3)% and 13.0 (3.2)%. Female body fat measurements were 22.5 (3.9)%, 23.7 (4.3)% and 23.8 (4.2)%, respectively. Pearson product moment correlations for male and female body fat percentages between the three methods were high, ranging from 0.81 to 0.86 (P < 0.05). However, compared to the criterion measure of body fat percentage (HYD), the magnitude of agreement BIA and SKF revealed a different pattern. The mean absolute difference between HYD and BIA measurements of body fat for males was -0.8 (2.0)% fat, and between HYD and SKF was it was 0.2 (1.7)% fat. The mean absolute difference for females between HYD and BIA was -1.2 (2.5)%; for HYD and SKF it was -1.4 (2.2)%. Compared to the HYD measures for males and females, the BIA and SKF measures were as much as a 3.8% underestimation and a 6.2% overestimation of body fat. This study provides evidence that the strength of a correlation does not indicate agreement between two methods. In future, reliability and validity studies should examine the absolute differences between two variables and calculate limits of agreement around which a practitioner can appreciate the precision of the methodologies.

Abstract:
Dynamic trunk strength of Canadian football players, soccer players, and middle to long distance runners.

Muscle strength data for sports which have varying demands on the trunk musculature are needed. The purpose of this study was to measure the trunk strength of three different sports groups of male varsity athletes and a recreationally active but nontrained group. Forty-six athletes (soccer: N = 16, Canadian football: N = 15, and middle and long distance runners: N = 15) and 15 recreationally active subjects were studied. Three consecutive concentric and eccentric contractions through a range of 60 degrees at an angular velocity of 30 degrees per second (0.5236 rad/sec) were performed to measure the strength of the trunk flexors and extensors. Results showed peak concentric and eccentric flexor torque for football and soccer players to be significantly greater than the other two groups (p < or = 0.05). Peak concentric and eccentric extensor torque was significantly greater for football players than runners (p < or = 0.05). Soccer players' eccentric flexor peak torque relative to body mass was significantly greater than runners and the recreationally active subjects (p < or = 0.05). This study compares trunk flexor and extensor data for specific sports populations.

Abstract:
Effect of training on the aerobic power and anaerobic performance of prepubertal girls.

The purpose of this study was to investigate the effects of two, three times a week, 8-week training programmes on the aerobic power and anaerobic performance of 30 prepubescent girls, with a mean age of 9.6 y. Peak oxygen uptake assessed by an incremental discontinuous treadmill test, and peak power in 5 s and mean power over 30 s estimated from a Wingate anaerobic test were used as the criterion measures. Twelve girls trained using a continuous cycle ergometer programme, 11 girls followed a sprint running programme and the control group consisted of 7 girls. Both training groups significantly (p < 0.05) increased their peak oxygen uptake and peak power in 5 s. However, the increase reported here are lower than those generally observed in adolescents following training. The control group demonstrated no significant (p > 0.05) change in either variable. No significant (p > 0.05) changes in mean power over 30 s were observed in any group.