Stuart Best

Exercise-heat acclimation in young and older trained cyclists

OBJECTIVESnThe purpose of this study was to investigate the effect of age on the capacity to acclimatise to exercise-heat stress. This study hypothesised that age would not affect body temperature and heat loss effector responses to short-term exercise-heat acclimation in trained subjects.nnnDESIGNnSeven young subjects (19-32 years) were matched with 7 older subjects (50-63 years). Subjects were highly trained but not specifically heat acclimated when they exercised for 60 min at 70%VO2max in hot-dry (35 °C, 40%RH) and thermoneutral (20 °C, 40%RH) conditions, pre and post 6 days of exercise-heat acclimation (70%VO2max, 35 °C, 40%RH).nnnMETHODSnRectal temperature (Tr), skin temperature (Tsk), heart rate (HR), cutaneous vascular conductance (CVC) and whole body sweat loss (Msw) were measured during each testing session and Tr and HR were measured during each acclimation session.nnnRESULTSnTr, Tsk, %HRmax, CVC and Msw were similar across age groups both pre and post heat acclimation. Following heat acclimation relative decreases and increases in Tr and Msw, respectively, were similar in both subject groups. There was a significant reduction in heart rate (%HRmax) and increase in final CVC following the acclimation programme in the young group (all p < 0.05) but not the older group.nnnCONCLUSIONSnWhen comparing young and older well trained adults we found age affected the cardiovascular adaptation but not body temperature or whole body sweat loss to exercise-heat acclimation. These data suggest age does not affect the capacity to acclimatise to exercise-heat stress in highly trained adults undergoing short-term heat acclimation.

The effect of ageing and fitness on thermoregulatory response to high‐intensity exercise

There are conflicting reports as to whether ageing causes a decreased thermoregulatory response, or if observed differences in previous studies are related to maximal aerobic capacity or training status. This study hypothesized that thermoregulatory response to severe exercise‐heat stress is maintained with ageing when both young and older subjects are well trained. Seven older highly trained (OHTu2009=u200951–63 years) cyclists were matched with two groups of young cyclists (19–35 years); one group matched for training status [young highly trained (YHT) participants, nu2009=u20097] and another for V ˙ O 2 max [young moderately trained (YMT), nu2009=u20097]. Each participant exercised at 70% V ˙ O 2 max in hot (35°C, 40% relative humidity) and thermoneutral (20°C, 40% relative humidity) conditions for 60u2009min. Final rectal temperature in the thermoneutral and heat (YHTu2009=u200939.13u2009±u20090.33°C, YMTu2009=u200939.11u2009±u20090.38°C, OHTu2009=u200939.11u2009±u20090.51°C) tests were similar between all three groups. %HRmax (heat test: YHTu2009=u200992.5u2009±u20096.0%, YMTu2009=u200991.6u2009±u20094.4%, OHTu2009=u200988.6u2009±u20095.1%), skin temperature, and cutaneous vascular conductance during cycling in both environments were similar between groups. Lower sweat loss and evaporative heat loss in the heat test in the OHT and YMT groups when compared with the YHT group reflected lower metabolic heat production. The findings of the present study suggest that thermoregulatory response is maintained with age among highly trained subjects.

Plasma and lymphocyte Hsp72 responses to exercise in athletes with prior exertional heat illness

We investigated the effect of exercise in the heat on both intracellular and extracellular Hsp72 in athletes with a prior history of exertional heat illness (EHI). Two groups of runners, one consisting of athletes who had a previous history of EHI, and a control group (CON) of similar age (29.7xa0±xa01.2 and 29.1xa0±xa02xa0years CON vs. EHI) and fitness [maximal oxygen consumption

A Box lift and place assessment is related to performance of several military manual handling tasks

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Predicting endurance time in a repetitive lift and carry task using linear mixed models

(V˙O2max) 65.7xa0±xa02 and 64.5xa0±xa03xa0mlxa0kg−1xa0min−1 CON vs. EHI] were recruited. Seven subjects in each group ran on a treadmill for 1xa0h at 72xa0%

A method for developing organisation-wide manual handling based physical employment standards in a military context

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