Fat supplements, es-pecially conjugated linoleic acid (CLA), are increasingly popularergogenic aids among endurance athletes. To evaluate the im-portance of fat supplementation in the practice of endurancesports, we investigated the effects of CLA supplementation onbody weight, muscle hypertrophy, peripheral blood composition,and bone marrow composition in healthy, young, endurance-trained mice. Young, healthy mice were subdivided into control,trained, and treated groups, according to their running atti-tudes. Training was performed over a period of 6 weeks on atreadmill, at a gradually increasing duration and speed. CLA-treated groups were gavaged with 0.425 mg·d1CLA supplementfor the entire training period. The exercise protocol induced asignificant decrease in body weight (p0.003) and a consistentmuscle hypertrophy (p0.003). A morphological evaluation ofbone marrow from trained mice revealed an accelerated turn-over of the erythroid lineage, i.e., a relative increase in proeryth-roblasts. Conjugated linoleic acid supplementation did not in-duce a further decrease in total body weights in either untrainedor trained mice (p0.747), but induced a further increase inmuscle hypertrophy in trained mice (p0.009). Furthermore,CLA feeding induced an important lymphopenia in peripheralblood of CLA-fed trained mice (p0.05). These findings suggestthat CLA may improve the performance of endurance athletesby increasing muscle hypertrophy, and, at the same time, thatit may cause oxidative stress damage, leading to a peripheralblood lymphopenia and a consequent neutrophilia as a defensiveresponse. Despite the positive increase in muscle hypertrophyclaimed by the pharmaceutics companies, we suggest that en-durance athletes and those looking to improve their own skeletalmuscle mass refrain from CLA supplementation, because itseems to intensify the oxidative stress caused by exhaustive ex-ercise.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2007|
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