Publications by category
Journal articles
Jack J, Woodgates A, Smail O, Felix B, Lynam K, Lester A, Williams G, Bond B (In Press). Cerebral blood flow regulation is not acutely altered after a typical number of headers in women footballers.
Frontiers in Neurology,
NeurotraumaAbstract:
Cerebral blood flow regulation is not acutely altered after a typical number of headers in women footballers
Background: the repeated act of heading has been implicated in the link between football participation and risk of neurodegenerative disease, and acutely alters cerebrovascular outcomes in men. This study assessed whether exposure to a realistic number of headers acutely influences indices of cerebral blood flow regulation in female footballers. Methods: Nineteen female players completed a heading trial and seated control trial on two separate days. The heading trial involved six headers in one hour (one every 10 minutes), with the ball travelling at 40 ± 5 km/h. Cerebrovascular reactivity to hypercapnia and hypocapnia was determined using serial breath holding and hyperventilation attempts. Dynamic cerebral autoregulation (dCA) was assessed by scrutinizing the relationship between cerebral blood flow and mean arterial blood pressure during 5 minutes of squat stand maneuvers at 0.05 Hz. Neurovascular coupling (NVC) was quantified as the posterior cerebral artery blood velocity response to a visual search task. These outcomes were assessed before and one hour after the heading or control trial. Results: No significant time by trial interaction was present for the hypercapnic (P=0.48, ηp2=0.05) and hypocapnic (P=0.47, ηp2=0.06) challenge. Similarly, no significant interaction effect was present for any metric of dCA (P>0.12, ηp20.14, ηp2
Abstract.
Bond B, Koep J, Weston M, Barker A, Sansum K (In Press). The acute and postprandial effects of sugar moiety on vascular and metabolic health outcomes in adolescents. Applied Physiology, Nutrition and Metabolism
Bond B, Barker A, Koep J, Weston M, Lester A, Coombes J, Bailey T (In Press). The within and between-day reliability of cerebrovascular reactivity using traditional and novel analytical approaches.
Experimental PhysiologyAbstract:
The within and between-day reliability of cerebrovascular reactivity using traditional and novel analytical approaches
Cerebrovascular reactivity of the middle cerebral artery velocity (CVR MCAv) to carbon dioxide (CO2) is a common method to assess cerebrovascular function. Yet, the approaches used to calculate CVR outcomes vary. The aim of this study was to explore the within and between-day reliability of traditional CVR outcomes. The second aim was to explore the reliability of novel kinetic-based analyses. Healthy adults (n=10, 22.3±3.4 years) completed assessments of CVR over four minutes using a fixed fraction of inspired CO2 (6%). This was repeated across four separate visits (between-day), and on one visit measures were repeated 2.5 hours later (within-day). No mean biases were present between assessments for traditional CVR metrics, expressed as absolute (cm/s/mmHg) or relative (%/mmHg) outcomes (minute-3, minute-4, peak 1 second, peak 30 second) (between-day: P>0.14, ηp20.22, d>0.27). Absolute, rather than relative CVR, yielded the most reproducible parameters (coefficient of variation: 8.1-13.2% versus 14-83% respectively). There were significant differences between CVR outcomes (P0.89) dependent on the time point used to determine CVR, as a steady state MCAv response was rarely observed. Furthermore, the MCAv response was not reproducible within an individual (kappa=0.15, P=0.09). No mean differences were present for novel kinetic outcomes (amplitude, time-delay, time constant) (between-day: P>0.05, d0.38, d
Abstract.
Weston M, Koep J, Lester A, Barker A, Bond B (2022). The acute effect of exercise intensity on peripheral and cerebral vascular function in healthy adults.
Journal of applied physiologyAbstract:
The acute effect of exercise intensity on peripheral and cerebral vascular function in healthy adults
The acute effect of exercise intensity on cerebrovascular reactivity, and whether this mirrors changes in peripheral vascular function, has not been investigated. The aim of this study was to explore the acute effect of exercise intensity on cerebrovascular reactivity (CVR) and peripheral vascular function in healthy young adults (n=10, 6 females, 22.7 ± 3.5 years). Participants completed four experimental conditions on separate days: high intensity interval exercise (HIIE) with intervals performed at 75% maximal oxygen uptake (V̇O2max; HIIE1), HIIE with intervals performed at 90% V̇O2max (HIIE2), continuous moderate intensity exercise (MIE) at 60% V̇O2max and a sedentary control condition (CON). All exercise conditions were completed on a cycle ergometer and matched for time (30 min) and average intensity (60% V̇O2max). Brachial artery flow-mediated dilation (FMD) and CVR of the middle cerebral artery were measured before exercise, and one- and three hours post-exercise. CVR was assessed using transcranial Doppler ultrasonography to both hypercapnia (6% carbon dioxide breathing) and hypocapnia (hyperventilation). FMD was significantly elevated above baseline one and three hours following both HIIE conditions (P0.33). CVR to both hypercapnia and hypocapnia, and when expressed across the end-tidal CO2 range, was unchanged in all conditions, at all time points (all P>0.14). In conclusion, these novel findings show that the acute increases in peripheral vascular function following HIIE, compared to MIE, were not mirrored by changes in cerebrovascular reactivity, which was unaltered following all exercise conditions in healthy young adults.
Abstract.
Lester A, Vickers GL, Macro L, Gudgeon A, Bonham‐Carter A, Campbell JP, Turner JE (2021). Exercise‐induced amplification of mitogen‐stimulated oxidative burst in whole blood is strongly influenced by neutrophil counts during and following exercise. Physiological Reports, 9(17).
Publications by year
In Press
Jack J, Woodgates A, Smail O, Felix B, Lynam K, Lester A, Williams G, Bond B (In Press). Cerebral blood flow regulation is not acutely altered after a typical number of headers in women footballers.
Frontiers in Neurology,
NeurotraumaAbstract:
Cerebral blood flow regulation is not acutely altered after a typical number of headers in women footballers
Background: the repeated act of heading has been implicated in the link between football participation and risk of neurodegenerative disease, and acutely alters cerebrovascular outcomes in men. This study assessed whether exposure to a realistic number of headers acutely influences indices of cerebral blood flow regulation in female footballers. Methods: Nineteen female players completed a heading trial and seated control trial on two separate days. The heading trial involved six headers in one hour (one every 10 minutes), with the ball travelling at 40 ± 5 km/h. Cerebrovascular reactivity to hypercapnia and hypocapnia was determined using serial breath holding and hyperventilation attempts. Dynamic cerebral autoregulation (dCA) was assessed by scrutinizing the relationship between cerebral blood flow and mean arterial blood pressure during 5 minutes of squat stand maneuvers at 0.05 Hz. Neurovascular coupling (NVC) was quantified as the posterior cerebral artery blood velocity response to a visual search task. These outcomes were assessed before and one hour after the heading or control trial. Results: No significant time by trial interaction was present for the hypercapnic (P=0.48, ηp2=0.05) and hypocapnic (P=0.47, ηp2=0.06) challenge. Similarly, no significant interaction effect was present for any metric of dCA (P>0.12, ηp20.14, ηp2
Abstract.
Bond B, Koep J, Weston M, Barker A, Sansum K (In Press). The acute and postprandial effects of sugar moiety on vascular and metabolic health outcomes in adolescents. Applied Physiology, Nutrition and Metabolism
Bond B, Barker A, Koep J, Weston M, Lester A, Coombes J, Bailey T (In Press). The within and between-day reliability of cerebrovascular reactivity using traditional and novel analytical approaches.
Experimental PhysiologyAbstract:
The within and between-day reliability of cerebrovascular reactivity using traditional and novel analytical approaches
Cerebrovascular reactivity of the middle cerebral artery velocity (CVR MCAv) to carbon dioxide (CO2) is a common method to assess cerebrovascular function. Yet, the approaches used to calculate CVR outcomes vary. The aim of this study was to explore the within and between-day reliability of traditional CVR outcomes. The second aim was to explore the reliability of novel kinetic-based analyses. Healthy adults (n=10, 22.3±3.4 years) completed assessments of CVR over four minutes using a fixed fraction of inspired CO2 (6%). This was repeated across four separate visits (between-day), and on one visit measures were repeated 2.5 hours later (within-day). No mean biases were present between assessments for traditional CVR metrics, expressed as absolute (cm/s/mmHg) or relative (%/mmHg) outcomes (minute-3, minute-4, peak 1 second, peak 30 second) (between-day: P>0.14, ηp20.22, d>0.27). Absolute, rather than relative CVR, yielded the most reproducible parameters (coefficient of variation: 8.1-13.2% versus 14-83% respectively). There were significant differences between CVR outcomes (P0.89) dependent on the time point used to determine CVR, as a steady state MCAv response was rarely observed. Furthermore, the MCAv response was not reproducible within an individual (kappa=0.15, P=0.09). No mean differences were present for novel kinetic outcomes (amplitude, time-delay, time constant) (between-day: P>0.05, d0.38, d
Abstract.
2022
Weston M, Koep J, Lester A, Barker A, Bond B (2022). The acute effect of exercise intensity on peripheral and cerebral vascular function in healthy adults.
Journal of applied physiologyAbstract:
The acute effect of exercise intensity on peripheral and cerebral vascular function in healthy adults
The acute effect of exercise intensity on cerebrovascular reactivity, and whether this mirrors changes in peripheral vascular function, has not been investigated. The aim of this study was to explore the acute effect of exercise intensity on cerebrovascular reactivity (CVR) and peripheral vascular function in healthy young adults (n=10, 6 females, 22.7 ± 3.5 years). Participants completed four experimental conditions on separate days: high intensity interval exercise (HIIE) with intervals performed at 75% maximal oxygen uptake (V̇O2max; HIIE1), HIIE with intervals performed at 90% V̇O2max (HIIE2), continuous moderate intensity exercise (MIE) at 60% V̇O2max and a sedentary control condition (CON). All exercise conditions were completed on a cycle ergometer and matched for time (30 min) and average intensity (60% V̇O2max). Brachial artery flow-mediated dilation (FMD) and CVR of the middle cerebral artery were measured before exercise, and one- and three hours post-exercise. CVR was assessed using transcranial Doppler ultrasonography to both hypercapnia (6% carbon dioxide breathing) and hypocapnia (hyperventilation). FMD was significantly elevated above baseline one and three hours following both HIIE conditions (P0.33). CVR to both hypercapnia and hypocapnia, and when expressed across the end-tidal CO2 range, was unchanged in all conditions, at all time points (all P>0.14). In conclusion, these novel findings show that the acute increases in peripheral vascular function following HIIE, compared to MIE, were not mirrored by changes in cerebrovascular reactivity, which was unaltered following all exercise conditions in healthy young adults.
Abstract.
2021
Lester A, Vickers GL, Macro L, Gudgeon A, Bonham‐Carter A, Campbell JP, Turner JE (2021). Exercise‐induced amplification of mitogen‐stimulated oxidative burst in whole blood is strongly influenced by neutrophil counts during and following exercise. Physiological Reports, 9(17).
