The process of aging is associated with a decline in total body water (TBW) and its intracellular fraction (ICW), besides an increase in extracellular water (ECW). Additionally, phase angle is a key indicator of nutritional status, sarcopenia, functional capacity, and mortality risk. A reduction in phase angle has also been tied to a decline in muscle mass in the elderly.

A recent study, therefore, evaluated the effects of a combined whey protein (WP) and resistance training (RT) intervention on cellular health in pre-conditioned older women.

This randomized controlled clinical trial included a sample of seventy older women, divided into 3 groups. The study conducted over a period of 26 weeks, was divided in two phases. The first phase was an eight-week period where participants were subjected to a pre-conditioning RT program (weeks 3–10). The second phase (supplementation phase) randomized the participants into three groups who were then subjected to WP plus RT for 12 weeks (weeks 13–24).

Twenty four women constituted the WP-placebo (WP-PLA) group, 23 formed the placebo-WP (PLA-WP) group, and another 23 constituted the placebo-placebo (PLA-PLA) group. Each group was given 35 g of the product - placebo or WP - pre- and post- training. The RT program was conducted over a 12 week period. Investigators assessed total body water (TBW), intra (ICW) and extracellular (ECW) water, resistance (R), reactance (Xc), and phase angle (PhA). Lean soft tissue (LST) was also measured, and food consumption was assessed using the average of two 24-hour recalls.

There was a group by time interaction (P < 0.05) for LST, ICW and the ECW/ICW ratio. The WP groups exhibited higher increases in comparison with the placebo-placebo group. A time effect (P <  0.05) was noted for TBW, Xc, and PhA. Furthermore, there was a reduction (P <0.05) in R only in the WP-PLA and PLA-WP groups.

Whey protein supplementation (pre- or post-), in association with RT, facilitated an increase in ICW and LST, and a reduction in ECW/ICW ratio in pre-conditioned older women. Whey protein supplementation is therefore an effective strategy to enhance the response to RT in pre-conditioned older adult woman, especially in terms of cellular hydration.

Reference

1. Nabuco HCG, Tomeleri CM, Sugihara P Junior, et al. Effect of whey protein supplementation combined with resistance training on cellular health in pre-conditioned older women: A randomized, double-blind, placebo-controlled trial. Arch Gerontol Geriatr. 2019 May - Jun;82:232-237.