King Grub
2012-02-22, 12:05
INTRODUCTION:
This study aimed to determine whether caffeine ingestion would increase the workload voluntarily chosen by athletes in a limited sleep state.
METHODS:
In a double-blind, crossover study, sixteen professional rugby players ingested either a placebo or 4 mg·kg-1 caffeine 1 h before exercise. Athletes classified themselves into non-deprived (8 h+) or sleep-deprived states (6 h or less). Exercise comprised four sets of bench press, squats, and bent rows at 85% 1-RM. Athletes were asked to perform as many repetitions on each set as possible without failure. Saliva was collected prior to administration of placebo or caffeine, and again prior to and immediately after exercise and assayed for testosterone and cortisol.
RESULTS:
Sleep deprivation produced a very large decrease in total load (p = 1.98 x 10-7). Caffeine ingestion in the non-deprived state resulted in a moderate increase in total load with a larger effect in the sleep deprived state resulting in total load similar to those observed in the non-deprived placebo condition. Eight of the sixteen athletes were identified as caffeine responders. Baseline testosterone was higher (p < 0.05) and cortisol trended lower in non-sleep deprived states. Changes in hormones from pre-dose to pre-exercise correlated to individual workload responses to caffeine. Testosterone response to exercise increased with caffeine compared to placebo, as did cortisol response.
CONCLUSIONS:
Caffeine increased voluntary workload in professional athletes, emphasised further under conditions of self-reported limited sleep. Caffeine may prove worthwhile when athletes are perceived as tired, especially in individuals identified as responders.
Int J Sport Nutr Exerc Metab. 2012 Feb 15. Acute caffeine ingestion increases voluntarily chosen resistance training load following limited sleep.
http://journals.humankinetics.com/journals-login
This study aimed to determine whether caffeine ingestion would increase the workload voluntarily chosen by athletes in a limited sleep state.
METHODS:
In a double-blind, crossover study, sixteen professional rugby players ingested either a placebo or 4 mg·kg-1 caffeine 1 h before exercise. Athletes classified themselves into non-deprived (8 h+) or sleep-deprived states (6 h or less). Exercise comprised four sets of bench press, squats, and bent rows at 85% 1-RM. Athletes were asked to perform as many repetitions on each set as possible without failure. Saliva was collected prior to administration of placebo or caffeine, and again prior to and immediately after exercise and assayed for testosterone and cortisol.
RESULTS:
Sleep deprivation produced a very large decrease in total load (p = 1.98 x 10-7). Caffeine ingestion in the non-deprived state resulted in a moderate increase in total load with a larger effect in the sleep deprived state resulting in total load similar to those observed in the non-deprived placebo condition. Eight of the sixteen athletes were identified as caffeine responders. Baseline testosterone was higher (p < 0.05) and cortisol trended lower in non-sleep deprived states. Changes in hormones from pre-dose to pre-exercise correlated to individual workload responses to caffeine. Testosterone response to exercise increased with caffeine compared to placebo, as did cortisol response.
CONCLUSIONS:
Caffeine increased voluntary workload in professional athletes, emphasised further under conditions of self-reported limited sleep. Caffeine may prove worthwhile when athletes are perceived as tired, especially in individuals identified as responders.
Int J Sport Nutr Exerc Metab. 2012 Feb 15. Acute caffeine ingestion increases voluntarily chosen resistance training load following limited sleep.
http://journals.humankinetics.com/journals-login