Purpose: The hyperbaric and hyperoxic effects of a dive have been demonstrated to elicit changes ... more Purpose: The hyperbaric and hyperoxic effects of a dive have been demonstrated to elicit changes in oxidative stress, endothelial function and microparticle (MP) release. Endothelial MP, which are small membrane vesicles shed from the endothelium, have been suggested as a valid in vivo marker of endothelial function. Furthermore, recent research has shown an increase in CD105 MP post-dive to be associated with a decline in endothelial function. The aim of this study was to ascertain whether antioxidant (AOX) pre-treatment can attenuate increased CD105 MP release post-dive. Methods: Five healthy, male, pressure-naive subjects completed two simulated dives (control and intervention) breathing compressed air to a depth of 18 metres' sea water for 80 min. For the intervention dive, all subjects received a commercially available AOX pill containing vitamins C and E, selenium and beta-carotene 2 h pre-dive. CD105 MP, total antioxidant capacity (TAC) and thiobarbituric reactive substances assay (TBARS) were determined pre-dive, at depth, immediately and 4 h post-dive. Results: In the control dive, there was a significant increase in CD105 MP immediately post-dive when compared with at depth (P < 0.001) and pre-dive (P = 0.039) values. Antioxidant pre-treatment significantly attenuated this release of CD105 MP post-decompression (P = 0.002). There were no significant changes in TBARS or TAC. Conclusion: These results may provide evidence of the potential use of AOX pre-treatment as an effective endothelial pre-conditioner for divers.
Introduction: Pacing can be defined as an ability to distribute available energy resources during... more Introduction: Pacing can be defined as an ability to distribute available energy resources during the race (Hettinga et al. , 2006). It’s a determinant of athletic performance, affected by an interaction between previous experience, performance feedback and individual risk-traits (Micklewright et al. , 2014). Selective processing of internal physiological and external feedback information is a complex process that informs pace decision-making (Renfree et al. , 2014), but little is known about how athletes seek-out and interpret information to make pacing decisions. This study compared information-seeking behavior between novice and experienced cyclists. Methods : Novice (n=10) and experienced (n=10) cyclists performed two 16.09 km self-paced time-trials (TT’s), one week apart. Time-trials were performed on a Velotron cycle ergometer using a video simulated course. Performance information (power, speed, cadence, distance and time), heart rate and the 6-20 RPE scale were displayed in front of participants during TT’s. A head-mounted eye-tracker was used to measure the frequency and duration of gazes towards each type of information. Gaze was coded as ‘other’ when participants were not looking at any of the information specified above. Cumulative gaze duration for each information source was calculated as a percentage of TT completion time. Between and within-subjects ANOVA’s were used to compare performance, fixation times and fixation frequencies between groups and trials. Results : Performance between TT’s did not change for experts (27:55±1:21 vs. 27:42±1:30 mins:secs) or novices (30:53±3:14 vs. 30:16±2:56 mins:secs). Cycling speed in each segment was faster among experts compared to novices, but both groups maintained an even pace through the TT’s. In TT1, experts primarily looked at speed (30.1%) followed by other (19.3%) then distance (18.3%). Novices were less selective during TT1, looking at distance (21.6%), video (15.3%), other (14.3%), and power (13.4%) (Fig 1A). Experts looked at speed more in TT2 (Speed 33.4%, Distance 17.7%, and other 16%) and novices looked at the video less (Distance 23.1%, Speed 14.4%, Power 13.8%, Other 13.6% and Video 10.5%) (Fig1B). Differences in fixation time were found between groups for primary (P=0.003) and secondary sources of information (P=0.043) (Fig 2A). Differences were also found in frequency for primary (P=0.003) and secondary source of information (P=0.04) respectively (Fig. 2B) . Discussion: Experts were found to look at speed as their primary source of information compared to novices who looked at distance. This may indicate a preference for performance related decision-making in experts compared to a focus on task completion among novices.
Heat shock proteins play an important role as molecular chaperones of the cell. Inducible heat sh... more Heat shock proteins play an important role as molecular chaperones of the cell. Inducible heat shock protein 70 is rapidly synthesised in response to numerous stressors and monocytes are sensitive to changes in core temperature resulting in a circadian variation of Hsp70 expression. Monocytes were isolated via density centrifugation from nine healthy male volunteers at 5 am, 1 pm and 9 pm, representing the nadir (5 am), peak (9 pm) and intermediate (1 pm) of Hsp70 expression in the 24-h cycle. Analysis of freshly isolated monocytes for Hsp70 expression confirmed Hsp70 levels at the three selected time points. Monocytes were subjected to in vitro heat shock at 40 degrees C (+/-0.1) for 90 min with a 90 min 37 degrees C (+/-0.1) exposure acting as a control. A significant increase in Hsp70 was observed at 5 am (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) and 1 pm (p = 0.028) at 40 degrees C when compared to 37 degrees C but not at 9 pm (p = 0.19). A significant increase was also observed from the basal levels of Hsp70, measured on freshly isolated monocytes and the levels detected after heat shock at 40 degrees C at 5 am (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) and 1 pm (p = 0.001), which was not observed at 9 pm (p = 0.15). Furthermore, a significant correlation was observed in the heat shock response at 40 degrees C and that obtained at 37 degrees C (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). In conclusion, the heat shock response in monocytes is directly proportional to the amount of Hsp70 present in the cells and the stress response may be much higher at different times of the day.
Background and aim Attempts at personalisation of exercise programmes in head and neck cancer (Ha... more Background and aim Attempts at personalisation of exercise programmes in head and neck cancer (HaNC) have been limited. The main aim of the present study is to investigate the feasibility and acceptability of introducing a remotely delivered, fully personalised, collaborative, and flexible approach to prescribing and delivering exercise programmes into the HaNC usual care pathway. Methods This is a single arm, feasibility study. Seventy patients diagnosed with HaNC will be recruited from two regional HaNC centres in the United Kingdom. Patients will undertake an 8-week exercise programme designed and delivered by cancer exercise specialists. The exercise programme will start any time between the time of diagnosis and up to 8 weeks after completing treatment, depending on patient preference. The content of the exercise programme will be primarily based on patient needs, preferences, and goals, but guided by current physical activity guidelines for people with cancer. The primary outc...
Objectives:To investigate whether a single bout of mixed circuit training (MCT) can elicit acute ... more Objectives:To investigate whether a single bout of mixed circuit training (MCT) can elicit acute blood pressure (BP) reduction in chronic hemiparetic stroke patients, a phenomenon also known as post-exercise hypotension (PEH).Methods:Seven participants (58 ± 12 years) performed a non-exercise control session (CTL) and a single bout of MCT on separate days and in a randomized counterbalanced order. The MCT included 10 exercises with 3 sets of 15-repetition maximum per exercise, with each set interspersed with 45 s of walking. Systolic (SBP) and diastolic (DBP) blood pressure, mean arterial pressure (MAP), cardiac output (Q), systemic vascular resistance (SVR), baroreflex sensitivity (BRS), and heart rate variability (HRV) were assessed 10 min before and 40 min after CTL and MCT. BP and HRV were also measured during an ambulatory 24-h recovery period.Results:Compared to CTL, SBP (∆-22%), DBP (∆-28%), SVR (∆-43%), BRS (∆-63%), and parasympathetic activity (HF; high-frequency component:...
This study extends our earlier studies in rats by applying our heatstroke model to a new species.... more This study extends our earlier studies in rats by applying our heatstroke model to a new species. Additionally, transgenic mice are used to examine the role of heat shock protein (HSP) 72 in experimental heatstroke. Transgenic mice that were heterozygous for a porcine HSP70i gene ([+]HSP72), transgene-negative littermate controls ([−]HSP72), and normal Institute of Cancer Research strain mice (ICR) under pentobarbital sodium anesthesia were subjected to heat stress (40°C) to induce heatstroke. In [−]HSP72 or ICR, the values for mean arterial pressure, the striatal blood flow, and the striatal Po2after the onset of heatstroke were significantly lower than those in preheat controls. The core and brain temperatures, the extracellular concentrations of ischemic and injury markers in the striatum, and the striatal neuronal damage scores were significantly greater than those in the preheat controls. In [−]HSP72 or ICR, the body temperatures, cell ischemia content, and injury marker in the...
International Journal of Sports Physiology and Performance, 2016
Purpose:To assess the acute alterations in triaxial accelerometry (PlayerLoad [PLVM]) and its ind... more Purpose:To assess the acute alterations in triaxial accelerometry (PlayerLoad [PLVM]) and its individual axial planes (anteroposterior PlayerLoad [PLAP], mediolateral PlayerLoad [PLML], and vertical PlayerLoad [PLV]) during a standardized 90-min soccer match-play simulation (SAFT90). Secondary aims of the study were to assess the test–retest reliability and anatomical location of the devices.Methods:Semiprofessional (n = 5) and university (n = 15) soccer players completed 3 trials (1 familiarization, 2 experimental) of SAFT90. PlayerLoad and its individual planes were measured continuously using micromechanical-electrical systems (MEMS) positioned at the scapulae (SCAP) and near the center of mass (COM).Results:There were no between-halves differences in PLVM; however, within-half increases were recorded at the COM, but only during the 1st half at the SCAP. Greater contributions to PLVM were provided by PLV and PLML when derived from the SCAP and COM, respectively. PLVM (COM 1451 ± ...
Purpose: The hyperbaric and hyperoxic effects of a dive have been demonstrated to elicit changes ... more Purpose: The hyperbaric and hyperoxic effects of a dive have been demonstrated to elicit changes in oxidative stress, endothelial function and microparticle (MP) release. Endothelial MP, which are small membrane vesicles shed from the endothelium, have been suggested as a valid in vivo marker of endothelial function. Furthermore, recent research has shown an increase in CD105 MP post-dive to be associated with a decline in endothelial function. The aim of this study was to ascertain whether antioxidant (AOX) pre-treatment can attenuate increased CD105 MP release post-dive. Methods: Five healthy, male, pressure-naive subjects completed two simulated dives (control and intervention) breathing compressed air to a depth of 18 metres' sea water for 80 min. For the intervention dive, all subjects received a commercially available AOX pill containing vitamins C and E, selenium and beta-carotene 2 h pre-dive. CD105 MP, total antioxidant capacity (TAC) and thiobarbituric reactive substances assay (TBARS) were determined pre-dive, at depth, immediately and 4 h post-dive. Results: In the control dive, there was a significant increase in CD105 MP immediately post-dive when compared with at depth (P < 0.001) and pre-dive (P = 0.039) values. Antioxidant pre-treatment significantly attenuated this release of CD105 MP post-decompression (P = 0.002). There were no significant changes in TBARS or TAC. Conclusion: These results may provide evidence of the potential use of AOX pre-treatment as an effective endothelial pre-conditioner for divers.
Introduction: Pacing can be defined as an ability to distribute available energy resources during... more Introduction: Pacing can be defined as an ability to distribute available energy resources during the race (Hettinga et al. , 2006). It’s a determinant of athletic performance, affected by an interaction between previous experience, performance feedback and individual risk-traits (Micklewright et al. , 2014). Selective processing of internal physiological and external feedback information is a complex process that informs pace decision-making (Renfree et al. , 2014), but little is known about how athletes seek-out and interpret information to make pacing decisions. This study compared information-seeking behavior between novice and experienced cyclists. Methods : Novice (n=10) and experienced (n=10) cyclists performed two 16.09 km self-paced time-trials (TT’s), one week apart. Time-trials were performed on a Velotron cycle ergometer using a video simulated course. Performance information (power, speed, cadence, distance and time), heart rate and the 6-20 RPE scale were displayed in front of participants during TT’s. A head-mounted eye-tracker was used to measure the frequency and duration of gazes towards each type of information. Gaze was coded as ‘other’ when participants were not looking at any of the information specified above. Cumulative gaze duration for each information source was calculated as a percentage of TT completion time. Between and within-subjects ANOVA’s were used to compare performance, fixation times and fixation frequencies between groups and trials. Results : Performance between TT’s did not change for experts (27:55±1:21 vs. 27:42±1:30 mins:secs) or novices (30:53±3:14 vs. 30:16±2:56 mins:secs). Cycling speed in each segment was faster among experts compared to novices, but both groups maintained an even pace through the TT’s. In TT1, experts primarily looked at speed (30.1%) followed by other (19.3%) then distance (18.3%). Novices were less selective during TT1, looking at distance (21.6%), video (15.3%), other (14.3%), and power (13.4%) (Fig 1A). Experts looked at speed more in TT2 (Speed 33.4%, Distance 17.7%, and other 16%) and novices looked at the video less (Distance 23.1%, Speed 14.4%, Power 13.8%, Other 13.6% and Video 10.5%) (Fig1B). Differences in fixation time were found between groups for primary (P=0.003) and secondary sources of information (P=0.043) (Fig 2A). Differences were also found in frequency for primary (P=0.003) and secondary source of information (P=0.04) respectively (Fig. 2B) . Discussion: Experts were found to look at speed as their primary source of information compared to novices who looked at distance. This may indicate a preference for performance related decision-making in experts compared to a focus on task completion among novices.
Heat shock proteins play an important role as molecular chaperones of the cell. Inducible heat sh... more Heat shock proteins play an important role as molecular chaperones of the cell. Inducible heat shock protein 70 is rapidly synthesised in response to numerous stressors and monocytes are sensitive to changes in core temperature resulting in a circadian variation of Hsp70 expression. Monocytes were isolated via density centrifugation from nine healthy male volunteers at 5 am, 1 pm and 9 pm, representing the nadir (5 am), peak (9 pm) and intermediate (1 pm) of Hsp70 expression in the 24-h cycle. Analysis of freshly isolated monocytes for Hsp70 expression confirmed Hsp70 levels at the three selected time points. Monocytes were subjected to in vitro heat shock at 40 degrees C (+/-0.1) for 90 min with a 90 min 37 degrees C (+/-0.1) exposure acting as a control. A significant increase in Hsp70 was observed at 5 am (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) and 1 pm (p = 0.028) at 40 degrees C when compared to 37 degrees C but not at 9 pm (p = 0.19). A significant increase was also observed from the basal levels of Hsp70, measured on freshly isolated monocytes and the levels detected after heat shock at 40 degrees C at 5 am (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) and 1 pm (p = 0.001), which was not observed at 9 pm (p = 0.15). Furthermore, a significant correlation was observed in the heat shock response at 40 degrees C and that obtained at 37 degrees C (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). In conclusion, the heat shock response in monocytes is directly proportional to the amount of Hsp70 present in the cells and the stress response may be much higher at different times of the day.
Background and aim Attempts at personalisation of exercise programmes in head and neck cancer (Ha... more Background and aim Attempts at personalisation of exercise programmes in head and neck cancer (HaNC) have been limited. The main aim of the present study is to investigate the feasibility and acceptability of introducing a remotely delivered, fully personalised, collaborative, and flexible approach to prescribing and delivering exercise programmes into the HaNC usual care pathway. Methods This is a single arm, feasibility study. Seventy patients diagnosed with HaNC will be recruited from two regional HaNC centres in the United Kingdom. Patients will undertake an 8-week exercise programme designed and delivered by cancer exercise specialists. The exercise programme will start any time between the time of diagnosis and up to 8 weeks after completing treatment, depending on patient preference. The content of the exercise programme will be primarily based on patient needs, preferences, and goals, but guided by current physical activity guidelines for people with cancer. The primary outc...
Objectives:To investigate whether a single bout of mixed circuit training (MCT) can elicit acute ... more Objectives:To investigate whether a single bout of mixed circuit training (MCT) can elicit acute blood pressure (BP) reduction in chronic hemiparetic stroke patients, a phenomenon also known as post-exercise hypotension (PEH).Methods:Seven participants (58 ± 12 years) performed a non-exercise control session (CTL) and a single bout of MCT on separate days and in a randomized counterbalanced order. The MCT included 10 exercises with 3 sets of 15-repetition maximum per exercise, with each set interspersed with 45 s of walking. Systolic (SBP) and diastolic (DBP) blood pressure, mean arterial pressure (MAP), cardiac output (Q), systemic vascular resistance (SVR), baroreflex sensitivity (BRS), and heart rate variability (HRV) were assessed 10 min before and 40 min after CTL and MCT. BP and HRV were also measured during an ambulatory 24-h recovery period.Results:Compared to CTL, SBP (∆-22%), DBP (∆-28%), SVR (∆-43%), BRS (∆-63%), and parasympathetic activity (HF; high-frequency component:...
This study extends our earlier studies in rats by applying our heatstroke model to a new species.... more This study extends our earlier studies in rats by applying our heatstroke model to a new species. Additionally, transgenic mice are used to examine the role of heat shock protein (HSP) 72 in experimental heatstroke. Transgenic mice that were heterozygous for a porcine HSP70i gene ([+]HSP72), transgene-negative littermate controls ([−]HSP72), and normal Institute of Cancer Research strain mice (ICR) under pentobarbital sodium anesthesia were subjected to heat stress (40°C) to induce heatstroke. In [−]HSP72 or ICR, the values for mean arterial pressure, the striatal blood flow, and the striatal Po2after the onset of heatstroke were significantly lower than those in preheat controls. The core and brain temperatures, the extracellular concentrations of ischemic and injury markers in the striatum, and the striatal neuronal damage scores were significantly greater than those in the preheat controls. In [−]HSP72 or ICR, the body temperatures, cell ischemia content, and injury marker in the...
International Journal of Sports Physiology and Performance, 2016
Purpose:To assess the acute alterations in triaxial accelerometry (PlayerLoad [PLVM]) and its ind... more Purpose:To assess the acute alterations in triaxial accelerometry (PlayerLoad [PLVM]) and its individual axial planes (anteroposterior PlayerLoad [PLAP], mediolateral PlayerLoad [PLML], and vertical PlayerLoad [PLV]) during a standardized 90-min soccer match-play simulation (SAFT90). Secondary aims of the study were to assess the test–retest reliability and anatomical location of the devices.Methods:Semiprofessional (n = 5) and university (n = 15) soccer players completed 3 trials (1 familiarization, 2 experimental) of SAFT90. PlayerLoad and its individual planes were measured continuously using micromechanical-electrical systems (MEMS) positioned at the scapulae (SCAP) and near the center of mass (COM).Results:There were no between-halves differences in PLVM; however, within-half increases were recorded at the COM, but only during the 1st half at the SCAP. Greater contributions to PLVM were provided by PLV and PLML when derived from the SCAP and COM, respectively. PLVM (COM 1451 ± ...
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Papers by Adrian Midgley