New Findings
What is the central question of this study?
This study examined the effects of 20 weeks of administration of conjugated linoleic acids/omega‐3 fatty acids with or without programed resistance exercise training on body composition, skeletal muscle properties and functional capacity in middle‐aged mice fed a high‐fat diet.
What is the main finding and its importance?
Chronic daily administration of conjugated linoleic acids/omega‐3 fatty acids with resistance exercise training can help to blunt fat gain, alleviate loss of myogenic capacity and sensorimotor function and lower tissue inflammation in middle‐aged mice during chronic high‐fat diet‐induced catabolism.
This study investigated the effects of 20 weeks of combined conjugated linoleic acid (CLA)/omega‐3 fatty acid (n‐3) administration independently or combined with resistance exercise training (RET) on skeletal muscle in middle‐aged mice consuming a high‐fat diet (HFD). Nine‐month‐old C57BL/6 mice were randomly assigned into four experimental groups (H, high‐fat diet; HE, H + RET; HCN, H + CLA/n‐3; and HECN, H + CLA/n3 + RET). Body composition and functional capacity were assessed pre‐ and post‐intervention. Muscle tissues were collected at 14 months of age. ANOVA was used, with significance set at P ≤ 0.05. Fat mass significantly increased in H (+74%), HE (+142%) and HECN (+43%) but not in HCN. Muscle wet weights were significantly lower in H and HCN than in HE and HECN. Grip strength substantially declined in H (−15%) and HCN (−17%), whereas sensorimotor function significantly declined only in H (−11%). HECN exhibited improvement in strength (+22%) and sensorimotor coordination (+17%). In comparison to H, muscle tumour necrosis factor‐α mRNA expression was significantly lower in HE (−39%), HCN (−24%) and HECN (−21%), respectively. Mean myofibre cross‐sectional areas were markedly lower in H and HCN than in HE and HECN. H showed significantly lower satellite cell abundance and numbers of myonuclei than all other groups. Our findings suggest that long‐term daily CLA/n‐3 intake with resistance training improved sensorimotor function, ameliorated fat gain and prevented loss of myogenic capacity while lowering tumour necrosis factor‐α expression during chronic HFD.