Analysis of combinatory effects of free weight resistance training and a high-protein diet on body composition and strength capacity in postmenopausal women - A 12-week randomized controlled trial.
Study Goal
The researchers aimed to determine the effects of resistance training (RT) and a high-protein diet (HPD) on body composition, muscle thickness, and strength capacity in postmenopausal women.
Results Summary
RT significantly increased skeletal muscle mass, reduced fat mass in one group, and improved muscle thickness and strength (grip strength, squat, and deadlift). HPD alone had minimal effects on strength but no impact on body composition.
Population
Healthy postmenopausal women (age 58.2 ± 5.6 years).
Effective Dosage
RT: 3 sessions/week, 5 exercises each; HPD: 2.5 g/kg fat-free mass.
Duration
12 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
Resistance training (RT) | increase | skeletal muscle mass (SMM) | postmenopausal women | Δ+1.4 ± 0.9 kg (TP group); Δ+1.2 ± 1.3 kg (T group) | significantly increased | #1 |
Resistance training (RT) (T group only) | decrease | fat mass (FM) | postmenopausal women | Δ-2.4 ± 2.9 kg | reduced | #2 |
Resistance training (RT) | increase | muscle thickness of the M. biceps brachii | postmenopausal women | Δ+0.4 ± 0.3 cm (TP group); Δ+0.3 ± 0.3 cm (T group) | significant increase | #3 |
Resistance training (RT) + high-protein diet (HPD) (TP group only) | increase | muscle thickness of the M. biceps femoris | postmenopausal women | Δ+0.3 ± 0.4 cm | significant increase | #4 |
High-protein diet (HPD) without training | no change | body composition | postmenopausal women | - | does not affect | #5 |
Resistance training (RT) | increase | grip strength | postmenopausal women | Δ+4.7 ± 2.4 kg (TP group); Δ+3.6 ± 3.0 kg (T group) | significant increase | #6 |
Resistance training (RT) | increase | 1-RM in the squat (BBS) | postmenopausal women | Δ+30.0 ± 14.2 kg (TP group); Δ+34.0 ± 12.0 kg (T group) | significant increase | #7 |
Resistance training (RT) | increase | 1-RM in the deadlift (DL) | postmenopausal women | Δ+20.8 ± 10.3 kg (TP group); Δ+22.1 ± 7.6 kg (T group) | significant increase | #8 |
High-protein diet (HPD) without training (CP group) | increase | 1-RM in the squat (BBS) | postmenopausal women | Δ+7.5 ± 5.4 kg | significant increase | #9 |
High-protein diet (HPD) without training (CP group) | increase | 1-RM in the deadlift (DL) | postmenopausal women | Δ+5.5 ± 7.7 kg | significant increase | #10 |
Resistance training (RT) | increase | body composition and strength capacity | postmenopausal women | - | enhances | #11 |
High-protein diet (HPD) without training | increase | BBS and DL | postmenopausal women | - | has a trivial significant effect | #12 |
High-protein diet (HPD) with resistance training (RT) | no change | body composition and strength capacity | postmenopausal women | - | has no clear additive effect | #13 |
BACKGROUND: Menopause has a significant impact on the endocrine system of middle-aged women, resulting in a loss of skeletal muscle mass (SMM), changes in fat mass (FM) and a reduction in strength capacity. Resistance training (RT) and a high-protein diet (HPD) are effective methods for maintaining or increasing SMM. This study aims to determine the effects of HPD and RT on body composition, muscle thickness and strength capacity in postmenopausal women. METHODS: In total 55 healthy postmenopausal women (age: 58.2 ± 5.6 years, weight 69.1 ± 9.6 kg, height 166.5 ± 6.5 cm) successfully participated in the study. The women were randomly assigned to either group: training + protein (2.5 g/kg fat-free mass (FFM)) (n = 15; TP); only training (n = 12; T); only protein (2.5 g/kg FFM) (n = 14; CP) or control (n = 14; C). TP and T performed RT for 12 weeks with three training sessions and five exercises each. CP and C were prohibited from training during the period. The main parameters analysed for body composition were FFM, SMM, FM, muscle thickness of the M. rectus femoris, M. biceps femoris, M. triceps brachii and M. biceps brachii muscles. Strength was tested using a dynamometer for grip strength and 1-RM in the squat (BBS) and deadlift (DL). RESULTS: The SMM significantly increased by RT (TP: (Δ+1.4 ± 0.9 kg; p < 0.05; d = 0.4; T: Δ+1.2 ± 1.3kg; p < 0.05; d = 0.3) and FM could be reduced only in T: (Δ-2.4 ± 2.9 kg; p < 0.05; d = 0.3). In muscle thickness a significant increase in the M. biceps brachii in both training groups (TP: (Δ+0.4 ± 0.3 cm; p < 0.05; d = 1.6; T: (Δ+0.3 ± 0.3 cm; p < 0.05; d = 0.9) and in M. biceps femoris only in TP (Δ+0.3 ± 0.4 cm; p < 0.05; d = 0.9) were observed. HPD without training does not affect body composition, A significant increase in grip strength (TP: Δ+4.7 ± 2.4 kg; (p < 0.05; d = 1.5; T: (Δ+3.6 ± 3.0 kg; p < 0.05; d = 0.8), in BBS (TP: (Δ+30.0 ± 14.2 kg; p < 0.05; d = 1.5; T: (Δ+34.0 ± 12.0 kg; p < 0.05; d = 2.4) and in DL (TP: (Δ+20.8 ± 10.3 kg; p < 0.05; d = 1.6; T: (Δ+22.1 ± 7.6 kg; p < 0.05; d = 2.0) was observed in both training groups. The CP also recorded a significant increase in the BBS (Δ+7.5 ± 5.4 kg; p < 0.05; d = 0.4) and in DL (Δ+5.5 ± 7.7 kg; p < 0.05; d = 0.5). No significant differences were detected for TP and T for any of the parameters. CONCLUSION: The results indicate that RT enhances body composition and strength capacity in postmenopausal women and is a preventive strategy against muscle atrophy. Besides HPD without training has a trivial significant effect on BBS and DL. HPD with RT has no clear additive effect on body composition and strength capacity. Further studies are needed to confirm these observations.