Forskning
February 1, 2016
Caffeine attenuates decreases in leg power without increased muscle damage
B G Ribeiro et al, 2016, Caffeine attenuates decreases in leg power without increased muscle damage, Journal of Strength and Conditioning Research, published online ahead of print.
ABSTRACT
Caffeine ingestion has been shown to be an effective ergogenic aid in several sports. Caffeine administration may increase exercise capacity, which could lead to a greater degree of muscle damage after exercise. This was a randomized, double-blind, placebo-controlled crossover study. Six male handball athletes ingested placebo (PLA) or caffeine (CAF; 6 mg.kg body mass) capsules on two different occasions. 60 min after the ingestion the capsules, was to evaluate serum caffeine levels. Thereafter, all participants performed a protocol of vertical jumps. The protocol consisted of four sets of 30 sec of continuous vertical jumps with 60 sec of recovery between sets. Blood lactate (LAC) and creatine kinase (CK) were determined before and after the protocol. We found significant differences in serum caffeine levels between PLA 0.09±0.18 µg/mL vs. CAF 6.59±4.44 µg/ mL (p<0.001). CAF elicited a 5.23% (p<0.05) improvement in the leg power compared to PLA. The CAF trial displayed higher (LAC) (p<0.05) compared to PLA (6.26±2.01 vs. 4.39±2.42 mmol.L, respectively) after protocol of vertical jumps’, while no difference in CK was observed between trials (p>0.05). These results indicate that acute ingestion of caffeine (6 mg.kg body weight) can reduce the level of muscle fatigue and preserved leg power during the test, possibly resulting in increase in blood lactate levels. There was no increase in muscle damage, leading to believe that acute administration of (6 mg.kg body weight) caffeine is safe. Thus, nutritional interventions with caffeine could help athletes in supporting a greater physiological overload during high intensity training sessions. Sports and activities that require repetitive leg power would be applicable to the results of the study.
