ABSTRACT
Chromium is one of the essential dietary trace elements that an important role in regulating whole body metabolism and energy utilization. However, there is a strong argument about chromium supplementation during exercise training programs, as some authors recommend it and others consider it illegal. Therefore, this work was planned to assess the metabolic responses to exercise training program in conjunction with chromium supplementation. Four rat groups were studied; rats subjected to swim exercise 2 hours/day for 2 weeks, rats supplemented with chromium picolinate in a dose of 90 micro g/kg body weight/day by gavage for 2 weeks and rats exposed to both regimens as well as their control non-exercised non-supplemented rats. Results of the present study revealed improvement in glucose tolerance with insignificant changes in serum insulin concentrations and a remarkable hypolipidemic responses in the three studied rat groups compared to the control. Unexpectedly the metabolic responses of the combination of chromium and exercise training did not exceed those obtained either chromium supplementation alone or exercise alone. Such non-additive effect could be ascribed to the common pathway shared by both chromium and exercise to exert their actions; and either chromium or exercise could, on its own, achieve the maximal response that cannot be further increased by their combination. The beneficial effects of chromium supplementation on increasing insulin sensitivity and improving blood lipid profile makes it an effective agent in treating non-insulin dependent diabetes and arteriosclerosis. Also, chromium has favorable effects in sparing protein use during exercise, decreasing lactate production with conservation of high glycogen content that enables prolongation of strenuous muscular exercise and much delaying the exhaustion point. In conclusion, it is evident from this study that chromium is instrumental in mediating metabolic effects of exercise and its role, in this respect, is physiological not pharmacological. Therefore, it is wrong to deal with chromium as one of the ergogenic substances that considered illegal to use with exercise