Vakgroep Menselijke fysiologie (MFYS)

Study Abstract: 

AIM: To examine the isolated and combined effects of severe hypoxia and a mild thermal challenge on performance, physiological measures, cognition and serum brain derived neurotrophic factor (BDNF).

METHODS: Nine trained male athletes (Age: 23±3y; Wmax: 333±45W) completed four experimental trials (CON: 15°C/0m, ALT: 15°C/3800m, TEMP: 25°C/0m, ALT+TEMP: 25°C/3800m) in a double blind, randomized, cross-over design. Subjects cycled for 30min in a self-paced test starting at 75%Wmax, their goal was to 'perform as much work as possible in 30min'. Power output, heart rate, blood lactate, pulse oximetry, core and skin temperature, thermal sensation, ratings of perceived exertion (RPE), reaction time (RT) and BDNF were assessed.

RESULTS: Subjects produced a significantly lower amount of work in 30min due to temperature (CON: 434±69kJ; TEMP: 420±75kJ; P=0.029) and altitude (CON: 434±69kJ; ALT: 298±51kJ; P<0.001). RPE-scores did not differ between trials (P>0.05). Altitude increased mean RT (P=0.022; 282±28ms at sea level; 289±32ms at altitude) and RT variability (P=0.020; 44±3ms at sea level: 50±4ms at altitude). Exercise increased BDNF (P=0.005; PRE: 21.8±8.4ng/mL; POST: 26.5±10.9ng/mL). However the altitude- and temperature-induced changes in performance, physiological measures, cognition and BDNF were independent (P>0.05).

CONCLUSION: Both a thermal challenge and altitude significantly decreased exercise capacity, but we did not observe an interaction effect. Altitude induced an increase in RT and an increase in RT variability, presenting a deterioration in cognitive functioning during acute hypoxia. Exercise significantly increased BDNF, but no effect of altitude on the BDNF concentration was observed.

More info? contact Jeroen van Cutsem.