Effects of pre- or post-exercise whey protein supplementation on body fat and metabolic and inflammatory profile in pre-conditioned older women: A randomized, double-blind, placebo-controlled trial.

BACKGROUND AND AIM: Protein supplementation and resistance training (RT) are interventions that may counteract decline in muscle mass and increase in fat mass, thus reducing the risk of developing chronic diseases during the aging process. The objective of this study was to investigate the effect of whey protein (WP) pre- or post-RT on metabolic and inflammatory profile in pre-conditioned older women. METHODS AND RESULTS: Seventy older women participated in this investigation and were randomly assigned to one of three groups: WP pre-RT and placebo post-RT (WP-PLA, n = 24), placebo pre-RT and WP post-RT (PLA-WP, n = 23) and placebo pre and post-RT (PLA-PLA, n = 23). Each group ingested 35 g of PLA or WP pre- and post-RT. RT was carried out over 12 weeks (three times/week; 3 x 8-12 repetition maximum). Body composition, blood pressure, blood samples and dietary intake were assessed pre- and post-intervention. After the intervention, WP groups showed greater improvements in appendicular lean soft tissue (ALST: WP-PLA, 3.1%; PLA-WP, 3.9%; PLA-PLA, 1.8%) and total cholesterol/high density lipoprotein cholesterol ratio (TC/HDL-C: WP-PLA, -12.11%; PLA-WP, -13.2%; PLA-PLA, -0.7) when compared with PLA-PLA. WP post-RT also showed improvements (P < 0.05) in ALST/appendicular fat mass ratio (PLA-WP, 5.8%; PLA-PLA, 1.3%), total body fat (PLA-WP, -3.8%; PLA-PLA: -0.1) and trunk fat mass (PLA-WP, -3.1%; PLA-PLA, -0.3%) when compared with PLA-PLA. CONCLUSION: WP pre- or post- RT promotes improvements in ALST and TC/HDL-C ratio in pre-conditioned older women. WP administered after RT was more effective in improving metabolic health Z-score and in reducing body fat compared to placebo group.

Correlations between resistance training-induced changes on phase angle and biochemical markers in older women.

The main purpose of this study was to investigate the effects of 12 weeks of resistance training (RT) on phase angle (PhA), inflammatory and oxidative stress biomarkers, and to evaluate whether these RT-induced adaptations are related to PhA changes. Fifty-one older women (70.6 ± 5.1 years; 26.9 ± 4.2 kg/m2 ) were randomly allocated into a training group (TG) that performed 12-week RT or a nonexercising control group (CG). The PhA (Xitron), body composition (DXA), and blood sample measurements (after a 12 hours fast) were performed before and after the intervention. The TG showed a significant (P < .05) increase in PhA (TG: +7.4±5.9% vs CG: -3.6 ± 8.8%), and interleukin-10 (IL-10; TG: +51.8 ± 71.1% vs CG: -46.6 ± 38.0%), and a decrease in tumor necrosis factor alpha (TNF-α; TG: -15.2 ± 11.1% vs CG: +6.9±17.7%), interleukin-6 (IL-6; TG: -17.9 ± 17.8% vs CG: +6.1 ± 24.8%), and C-reactive protein (CRP; TG: -24.1 ± 19.9% vs CG: +43.8 ± 31.1%). Moreover, TG upregulated catalase (TG: +11.4 ± 15.0% vs CG: -6.7 ± 10.2%). Changes in TNF-α (r = -.71), CRP (r = -.65), lower advanced oxidation protein products (r = -.55), and catalase (r = +.73) after RT were correlated with changes in PhA (P < .05). These results suggest that RT improves PhA, inflammatory and oxidative stress biomarkers, and the changes in inflammatory and oxidative damage markers are correlated with changes in PhA.

Effect of resistance training on phase angle in older women: A randomized controlled trial.

Phase angle (PhA) is an angular-derived bioelectrical impedance parameter based on resistance and reactance that has been widely used in different populations as an objective indicator of cellular health. The purpose of this study was to analyze the effect of resistance training (RT) on PhA in older women. Forty-one older women (67.2 ± 4.5 years, 64.0 ± 12.3 kg, 154.7 ± 5.2 cm, and 26.6 ± 4.8 kg/m2 ) were randomly assigned to one of two groups: a training group (TG, n = 19) that underwent progressive RT for 12 weeks (eight exercises, three sets of 10-15 repetitions maximum, three times per week) or a control group (CG, n = 22) that did not perform any type of exercise during the intervention period. Resistance, reactance, PhA, total body water (TBW), intracellular (ICW) and extracellular (ECW) water were assessed by spectral bioelectrical impedance. There was a significant group by time interaction (P < 0.05) for PhA, TBW, and ICW in which only the TG increased their scores after the intervention period (PhA = +6.5%, TBW = +2.8%, and ICW = +5.1%). The results suggest that progressive RT promotes an increase in PhA in older women. Therefore, the PhA seems to be a good parameter to assess changes in cellular health during RT intervention.

Phase angle predicts physical function in older adults.

BACKGROUND: Phase angle (PhA) is recognized as an indicator of cellular health and may be a useful marker of physical functions in geriatric populations. AIMS: We aim to analyse the ability of the Phase angle (PhA) to predict the physical function in older adults. METHOD: 113 healthy older adults (67 female and 46 male) performed physical tests using the Fullerton Battery - Senior Fitness Test, to assess their physical fitness. Bioelectrical impedance spectroscopy was used to determine PhA at 50KHz and dual-energy x-ray absorptiometry to assess body composition. RESULTS: PhA was positively associated with functional fitness composite, chair stand, arm curl and 6 min walk test and negatively related with chair sit-and-reach and 8-foot and go (p < 0.05). Even after adjusting for potential confounding variables such as age, sex and appendicular lean soft tissue, PhA showed an association with arm curl (ß = 0.23,p = 0.038), and 8-foot and go (ß=-0.214,p = 0.042). CONCLUSIONS: Higher values of PhA are related with a better physical function. Regardless of sex, age, and skeletal muscle, PhA predicts body strength, agility and dynamic balance in healthy older adults.