Caffeine improves performance in double poling during acute exposure to 1 2 , 000 m altitude
نویسنده
چکیده
24 There is limited research on the physiological effects of caffeine (CAF) ingestion on exercise 25 performance during acute hypoxia. The aim of the present study was therefore to test the 26 effect of placebo (PLA) and CAF (4.5 mg·kg) on double poling (DP) performance during 27 acute hypoxia. Methods: Thirteen male sub-elite cross-country skiers ( O2max72.6 ± 5.68 28 mL·kg·min) were included. Performance was assessed as 1) an 8 km cross-country DP 29 time-trial (C-PT), and 2) time until task failure at a set workload equal to ~90% of DP O2max. 30 Testing was carried out in a hypobaric chamber, at 800 mBar, (PIO2 ~125 mmHg) 31 corresponding to ~2000 m above sea level in a randomized double-blinded, placebo32 controlled, cross-over design. Results: CAF improved time to task failure from 6:10 ±1:40 33 min to 7:22 ±1:30 min (p<0.05), and velocity the first 4 km (p<0.05), but not overall time 34 usage for the 8 km C-PT. During submaximal exercise subjects reported lower pain in arms 35 and rate of perceived exertion (RPE) following CAF ingestion. Throughout C-PTs similar 36 RPE and pain was shown between treatments. However, higher heart rate was observed 37 during the CAF 8 km (187±7 vs. 185±7; p<0.05) and 90 % C-PT (185±7 vs.181±9) associated 38 with increased ventilation, blood lactate, glucose, adrenaline, decreased pH, and bicarbonate. 39 Conclusion: The present study demonstrates for the first time that CAF ingestion improves 40 DP time to task failure although not consistently time-trial performance during acute exposure 41 to altitude. Mechanisms underpinning improvements seem related to reduced pain, RPE and 42 increased HR during CAF C-PTs. 43
منابع مشابه
Caffeine improves performance in double poling during acute exposure to 2,000-m altitude.
There is limited research on the physiological effects of caffeine (CAF) ingestion on exercise performance during acute hypoxia. The aim of the present study was therefore to test the effect of placebo (PLA) and CAF (4.5 mg/kg) on double poling (DP) performance during acute hypoxia. Thirteen male subelite cross-country skiers (V̇o2max 72.6 ± 5.68 ml·kg(-1)·min(-1)) were included. Performance was...
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