Separate and Combined Effects of Caffeine and Sodium-Bicarbonate Intake on Judo Performance.

UNLABELLED: The combined supplementation of caffeine (CAF) and sodium bicarbonate (NaHCO3) may have a potential ergogenic effect during intermittent-exercise tasks such as judo; however, its effect in this sport has not been tested. PURPOSE: To investigate the isolated and combined effects of CAF and NaHCO3 on judo performance. METHODS: Ten judokas performed 4 supplementation protocols-NaHCO3, CAF, NaHCO3 + CAF, and placebo (PLA) (cellulose)-followed by 3 Special Judo Fitness Tests (SJFTs) interspaced with 5 min rest. RESULTS: In the first SJFT, the combined supplement (NaHCO3 + CAF) resulted in a higher number of throws than with PLA (24.4 ± 0.9 and 23.2 ± 1.5 throws, respectively, P = .02). There was no significant difference between conditions for the 2nd SJFT (P = .11). In the 3rd SJFT, NaHCO3 and NaHCO3 + CAF resulted in more throws than with PLA (23.7 ± 1.6, 24.4 ± 1.0, and 22.0 ± 1.6 throws, P = .001 and P = .03, respectively). When the total throws performed in the 3 SJFTs were summed, they were higher than PLA only for NaHCO3 + CAF (68.8 ± 4.4 and 72.7 ± 3.1 throws, respectively, P = .003). Postexercise plasma lactate after each SJFT was higher in all experimental conditions than with PLA (P = .001). There was no significant difference in rating of perceived exertion across the conditions (P = .18). CONCLUSION: The results of the current study show that the combined supplementation of NaHCO3 + CAF increases judo performance compared with PLA.

Does antioxidant vitamin supplementation protect against muscle damage?

The high forces undergone during repetitive eccentric, or lengthening, contractions place skeletal muscle under considerable stress, in particular if unaccustomed. Although muscle is highly adaptive, the responses to stress may not be optimally regulated by the body. Reactive oxygen species (ROS) are one component of the stress response that may contribute to muscle damage after eccentric exercise. Antioxidants may in turn scavenge ROS, thereby preventing or attenuating muscle damage. The antioxidant vitamins C (ascorbic acid) and E (tocopherol) are among the most commonly used sport supplements, and are often taken in large doses by athletes and other sportspersons because of their potential protective effect against muscle damage. This review assesses studies that have investigated the effects of these two antioxidants, alone or in combination, on muscle damage and oxidative stress. Studies have used a variety of supplementation strategies, with variations in dosage, timing and duration of supplementation. Although there is some evidence to show that both antioxidants can reduce indices of oxidative stress, there is little evidence to support a role for vitamin C and/or vitamin E in protecting against muscle damage. Indeed, antioxidant supplementation may actually interfere with the cellular signalling functions of ROS, thereby adversely affecting muscle performance. Furthermore, recent studies have cast doubt on the benign effects of long-term, high-dosage antioxidant supplementation. High doses of vitamin E, in particular, may increase all-cause mortality. Although some equivocation remains in the extant literature regarding the beneficial effects of antioxidant vitamin supplementation on muscle damage, there is little evidence to support such a role. Since the potential for long-term harm does exist, the casual use of high doses of antioxidants by athletes and others should perhaps be curtailed.