Resistance Training, Regardless Of Protein Supplementation, Improves Muscular Phenotypes In Women Long-term After Bariatric Surgery

Abstract

PURPOSE: This double-blind placebo-controlled study investigated the effects of resistance training (RT), with and without protein supplementation (PRO), on body composition, muscle strength and physical function in long term Roux-en-Y bypass (RYGB) female patients. METHODS: A total of 45 women (age 40.4 ± 8.5 yrs, BMI 29.0 ± 4.7 kg/m2) with 4.1 ± 1.4 yrs after RYGB surgery were divided into four groups: Control + Placebo (CON+PL; n = 11), Control + PRO (CON+PRO; n = 10), RT+PL (n = 12), and RT+PRO (n = 12). Patients were evaluated before and after the 12-weeks study protocol for body composition (Tetrapolar Bioelectrical Impedance), knee extensors isokinetic strength and physical function (timed up and go [TUG], 30-seconds sit to stand, and 6-minutes walking). PRO and PL were administrated in a double-blind fashion and respectively consisted of daily 0.5 g of whey protein powder per kg of ideal body weight and an isocaloric placebo powder, both throughout the study period. Training protocol comprised 3 sets of 8-12 reps for 8 exercises targeting all major muscle groups and with progressive loads. ANOVA was used to assess time by group interactions. RESULTS: No significant between-groups differences were observed for any variable at baseline (all P > .05). Significant improvements were observed in the exercised groups, but not in the nonexercised groups, for skeletal muscle mass (RT+PL 0.6 ± 0.3, P = .02; RT+PRO 0.8 ± 0.2, P <.01; CON+PL -0.1 ± 0.3, P = .68; and CON+PRO 0.3 ± 0.3 kgs, P = .31), isokinetic peak torque (RT+PL 12.9 ± 3.1, P<.01; RT+PRO 8.7 ± 2.6, P < .01; CON+PL -4.4 ± 2.9, P = .15; and CON+PRO -3.1 ± 2.9 Nm, P = .30), TUG (RT+PL -1.1 ± 0.2, P < .01; RT+PRO -0.7 ± 0.2, P < .01; CON+PL -0.2 ± 0.2, P = .38; and CON+PRO -0.3 ± 0.2 seconds, P = .23), six-minutes walking (RT+PL 48.4 ± 20.6, P = .02; RT+PRO 37.4 ± 17.8, P = .04; CON+PL -0.9 ± 21.9, P = .97; and 4.4 ± 19.5 meters, P = .82) and seat to stand test (RT+PL 3.2±0.7, P<.01; RT+PRO 1.7±0.6, P<.01; CON+PL 1.1±0.7, P=.13; and CON+PRO 0.7 ± 0.6 repetitions, P = .25). No differences for the improvements were observed between exercised groups (all P > .05). Also, no significant alteration occurred for percent body fat in any group (all P > .05). CONCLUSIONS: A 12-weeks RT program, regardless of PRO, improves muscle mass, knee extensors isokinetic strength and physical function in long term RYGB female patients.