Lifting weights shifts a cellular health marker in over-60s

As we age, body composition shifts in unwelcome directions, and tracking those shifts usually means focusing on muscle mass or fat. Bioelectrical impedance analysis offers another window: raw electrical measurements of the body's tissues, summarised in a value called phase angle, which reflects the state of the cells themselves and tends to deteriorate with age and inactivity. Resistance training is already the standard prescription for preserving muscle in later life. This review asked whether it also moves phase angle, which would suggest the benefits of lifting run all the way down to cellular level.

The authors searched four electronic databases up to January 2022 for randomised controlled studies in adults aged 60 and over, in which resistance training lasted at least eight weeks and raw bioelectrical values were measured. The outcomes of interest were phase angle, resistance and reactance, the raw readings an impedance device produces. Seven studies qualified, covering 344 participants in total, and methodological quality across them was rated at 71.3% on the scale used. Results from the trials were then pooled to estimate the overall effect of training.

Resistance training increased phase angle by 0.52 degrees compared with control conditions. That change was driven by both underlying components moving in the healthy direction: reactance rose by 3.58 ohms while resistance fell by 28.50 ohms. In the bioimpedance vector analysis the authors describe, resistance-trained people showed a beneficial leftward displacement on the chart of those two readings, whereas inactivity induced a shift the other way. All three pooled changes were statistically clear.

Phase angle has been gaining ground as a simple marker of cellular health and ageing, and this review connects it to the best-established intervention for ageing bodies, strength work. It supports the view that resistance training counteracts the ageing effect on body mass and its components, measured here without scans or blood tests. The evidence base is small at seven trials, and the authors call for more sophisticated studies to identify which equipment and protocols optimise the effect. How much a 0.52 degree change matters for hard health outcomes is not something this analysis can answer.

If you are over 60 and lifting, or deciding whether to start, this adds a quieter benefit to the familiar ones of strength and muscle: a measurable shift in a marker tied to the condition of your cells. It is also worth knowing if you use a body composition device that reports phase angle, since regular resistance training is one thing that appears to move that number in the right direction. The trials here all ran for at least eight weeks, so this reflects sustained training rather than a quick response.