Caffeine Increases Work Done above Critical Power, but Not Anaerobic Work

ABSTRACTPurposeThe assumption that the curvature constant (W′) of the power–duration relationship represents anaerobic work capacity is a controversial, unresolved question. We investigated if caffeine ingestion could increase total work done above critical power (CP), and if this would be accompanied by greater anaerobic energy expenditure and by an enhanced maintenance of maximal oxidative metabolic rate.MethodsNine men (26.6 ± 5.3 yr, V˙O2max 40.6 ± 5.8 mL·kg−1·min−1) cycled until exhaustion at different exercise intensities on different days to determine the CP and W′. On separated days, participants cycled until exhaustion in the severe-intensity domain (136% ± 7% of CP) after ingesting either caffeine (5 mg·kg−1 body mass) or a placebo.ResultsTime to exhaustion was 34% longer with caffeine compared with placebo, and this was accompanied by a greater work done above CP (23.7 ± 5.7 vs 17.5 ± 3.6 kJ; 130% ± 30% vs 95% ± 14% of W′, P
Source: Medicine and Science in Sports and Exercise - Category: Sports Medicine Tags: Applied Sciences Source Type: research