Stimulants And Performance: Animal Model For Evaluating The Effect Of Caffeine On Aerobic Exercise

Abstract

In pursuit of success in sports, physical educators, nutritionists, and trainers employ 'energy drinks'. Several effects of such stimulants depend on the presence of caffeine in the composition. PURPOSE: To compare the effect of caffeine on exercise to the effect of drinks adding other compounds to caffeine. METHODS: The present study compared the effect of pure caffeine (PC), cola (CC) drinks, and caffeine + taurine + glucuronolactone (CTG) drinks on the performance of mice in a running wheel. Two groups of six two-month-old male C57/bl mice were housed in cages fitted with running wheels and a monitoring system. Animals were introduced to the wheel individually until all six mice were familiarized to the setting. In a second stage, all six mice were allowed to exercise ad libitum simultaneously and received, in sequence, the three stimulants to drink during two days with two-day intervals receiving water. Caffeine concentrations in the stimulant drinks were: PC= 0.125 mg/ml; CC= 0.1 mg/ml; CTG= 0.32 mg/ml. RESULTS: The distance run during the days of water ingestion (3.9 ± 1.6 km) was significantly shorter than during the periods of CC ingestion (7.6 ± 0.6 km; P = 0.003) and CTG ingestion (8.3 ± 1.6 km; P < 0.001), but not during PC ingestion (4.4 ± 2.6 km; P > 0.05). CONCLUSION: The model here described is a viable way to measure performance of mice in exercise wheel. This study confirms the dose-independent contribution of caffeine to performance without suggestion of synergistic action by added compounds.