N-3 polyunsaturated fatty acids and progressive resistance training does not increase muscle mass and muscle strength in obese individuals compared to placebo
Introduction: Obesity induces many physiological changes that harm muscular function. Usual treatment for obesity is exercise and diet. N-3 PUFA have shown to have a certain benefit as to increasing muscle mass and strength. The goal of this study was to examine the effect of 23 weeks of n-3 PUFA supplementation combined with 13 weeks of progressive resistance training on muscle mass and strength in obese individuals.
Method: Thirty-five middle-aged obese participants (age 48.3 ± 6.4, BMI 34.3 ± 3.9) participated in the study. They were allocated into one of two groups; PUFA (n= 17; 1000mg n-3 PUFA) or CON (n=18; 1000mg of high oleic sunflower oil). Both groups combined their 23 weeks of supplementation with 13 weeks of 2 weekly supervised resistance training sessions. DXA, ultrasound and HUMAC were measured at three time-points: baseline (T1), pre-training (T2) and post-test (T4).
Results: Between the groups, there was no significant difference in isometric strength, lean body mass and muscle thickness after 7 weeks of supplementation (resp; p = 0.99, p = 0.87, p = 0.81). After 13 weeks of combined resistance training, CON increased significantly in isometric strength (17.01 ± 11.67%, p = 0.006) and PUFA did not (12.14 ± 14.52%, p = 0.18). In muscle thickness, PUFA showed a significant change (12.03 ± 10.23%, p = 0.001) and CON showed no significant change (6.68 ± 8.78%, p = 0.2). None of the groups increased in lean body mass (p = 0.90), and there was no significant difference in any test parameters between the groups (isometric strength: p >0.99, lean body mass: p = 0.90, muscle thickness: p = 0.41).
Conclusion: 7 weeks of n-3 PUFA supplementation does not increase muscle mass or muscle strength. After 13 weeks of combined resistance training, there was no significant difference observed between PUFA and CON. The effect of n-3 PUFA is still unclear and should be investigated further