Octacosanol supplementation increases running endurance time and improves biochemical parameters after exhaustion in trained rats

This study evaluated the effects of octacosanol on running performance and related biochemical parameters in exercise-trained rats run to exhaustion on a treadmill. Male Sprague-Dawley rats were randomly assigned to one of three groups - sedentary control group (SC), exercise-trained control group (EC), and exercise-trained, octacosanol-supplemented group (EO) - and raised on either control or octacosanol (0.75%)-supplemented diet with (or without for SC rats) exercise-training for 4 weeks. EC rats ran 184% longer until exhaustion than SC rats (P <.01), while octacosanol-supplemented trained rats ran 46% longer than EC rats (P <.05). Under the exhausted state immediately following the running performance test, EO rats exhibited significantly higher plasma ammonia and lactate concentrations compared with the values for EC rats (P <.05). Although EO rats ran significantly longer until exhausted, their plasma glucose level and gastronecmius muscle glycogen concentration were not significantly different from those of EC rats. Dietary supplementation of octacosanol resulted in significantly higher creatine phosphokinase activity in plasma (44% increase, P <.01) and citrate synthase activity in muscle (16% increase, P<.01) of exercise-trained rats. These results suggest that the ergogenic properties of octacosanol include the sparing of muscle glycogen stores and increases in the oxidative capacity in the muscle of exercise-trained rats.