Background:
The UK, as with most of the Western World, has an ageing population due to decades of improving life expectancy. However, this increase in lifespan has not been matched by an increase in healthy life expectancy (“health span”), and as such an increased number of people are living in poor health in later life. Declines in cardiorespiratory fitness (CRF) and muscle mass are both associated with advancing age and each of these declines are associated with worse health outcomes. Resistance exercise training (RET) has previously been shown to improve muscle mass and function in both young and older adults. However, if RET is also able to improve the CRF of older adults, as it has been shown to do in younger populations, it has the potential to improve multiple health outcomes in the expanding older population.
Methods:
This systematic review aimed to identify the role of RET for improving CRF in healthy (i.e., not disease-specific cohorts) older (>60 y) adults. A search across CINAHL, MEDLINE, EMBASE, and EMCARE databases was conducted using a PICO (population, intervention, comparison, outcome) protocol, with meta-analysis performed on eligible papers (randomised control trials only) to identify improvements in established CRF parameters (VO2 peak, anaerobic threshold (AT), blood pressure and peak heart rate) following RET-only interventions. Search terms used included “healthy ageing”, “resistance training”, “weightlifting”, “muscle strengthening”, “aged”, and “cardiorespiratory fitness”, and only papers published in the English language were included.
Results:
Thirteen eligible studies were identified, the majority of which used weight machines or free-weights to provide resistance. Three studies used resistance bands and 1 study used water-based resistance. Meta-analysis revealed a significant improvement in VO2 peak (MD 2.59 ml/kg/min; 95% CI 1.73 ml/kg/min to 3.45 ml/kg/min) and AT (MD 1.40 ml/kg/min; 95% CI 0.06 ml/kg/min to 2.74 ml/kg/min) when RET was compared to control (no intervention). Blood pressure (systolic: MD 2.32 mmHg; 95% CI -5.76 mmHg to 10.41 mmHg; diastolic: MD -0.38 mmHg; 95% CI -4.19 mmHg to 3.43 mmHg) and peak heart rate (MD 2.05 bpm; 95% CI 0.73 bpm to 3.36 bpm) were not altered by RET compared to control.
Discussion:
The predominant finding of this systematic review is a clear benefit of RET on both VO2 peak and AT when compared to habitual activity controls. This review also highlights that despite exercise being well recognised as beneficial to human health, including for older adults, there is limited high-quality evidence for one of the most common forms of exercise; RET, to improve a known significant contributor to whole body health i.e., CRF. The main finding of this review adds to a growing body of evidence supporting the implementation of RET in the older population for improving whole-body health across the life course.