Power or Resistance Training in Older People

older mans arm lifting a weight

Power or Resistance Training in Older People

older mans arm lifting a weight

A systematic review by researchers in the UK shows that high-velocity power training had similar effects to traditional resistance training on the Short Physical Performance Battery and the Timed Up and Go test.

First author Robert Morrison answers some questions about the review.

Your recent systematic review sought to compare higher and lower velocity resistance training in older people.

How are these two types of resistance training defined?

When defining these two types of resistance training, concentric movement speeds and external resistance are considered.

High-velocity power training (HVPT) refers to exercise where the concentric portion of a movement is completed as quickly as possible.

Traditional moderate velocity resistance training (TRT) is any exercise regimen that does not explicitly aim to maximise concentric velocity—commonly, with a concentric phase that lasts two seconds or more.

While TRT is performed using 60–80 per cent of a one repetition maximum, HVPT uses lower external resistances of 40–60 per cent of a one repetition maximum.

What does theoretical reasoning indicate about whether we should expect HVPT or TRT to be the more effective intervention?

Functional performance requires the integration of several health-related and skill-related components of physical fitness.

Muscular strength is a health-related component that predicts functional decline in older adults.

By contrast, muscle power, a skill-related component, declines faster than strength throughout life, up to six per cent annually in those over 70 years of age. Strength (force) or power (force x velocity) deficits can be addressed with training to improve functional performance.

The goal of HVPT is to enhance the rate of force development and peak muscular power, whereas TRT focuses on developing maximal muscle force at slower velocities.

Both HVPT and TRT are therefore beneficial training modalities for functional performance.

Although both TRT and HVPT can improve muscle strength, muscle power is thought to be a more important predictor of functional performance and the ability to carry out activities of daily living.

This has led to the theory that emphasising muscle power through HVPT may be a more effective intervention for functional performance in older people.

Did the review find much evidence? The objective was to synthesise randomised controlled trials that performed a head-to-head comparison of HVPT and TRT in functional performance in adults over 60 years of age.

We conducted a search of five databases, followed by a search of theses and grey literature. There were 21 trials that met our inclusion criteria and 19 of them were included in the meta-analysis, totalling 1055 individuals.

All trials were published between 2003 and 2020 and most were conducted in a university setting. Most of the participants were healthy and 70 per cent were female. Outcomes included the Short Physical Performance Battery (SPPB), Timed Up and Go (TUG), five- times sit-to-stand (5-STS), 30-second sit-to-stand (30-STS), static balance, dynamic balance, usual gait speed, fast gait speed, long walking and stair climb tests.

Our assessment rated 16 of the trials as having a high risk of bias.

We also evaluated the quality of reporting using the consensus on exercise reporting template (CERT).

Common reasons for downgrading included trials not reporting the qualifications or experience of those delivering the intervention or details of exercise supervision, along with deficiencies in intervention adherence, study replication and study fidelity.

What did the evidence show overall about the relative efficacy of the two types of resistance training?

In general, the relative efficacy of either training modality was equivocal.

The effect estimates for the 5-STS, static balance, dynamic balance, usual gait speed, fast gait speed, long walking and stair climb outcomes were very uncertain.

There were weak to moderate effects that favoured HVPT for the SPPB and TUG outcomes, with some imprecision.

It is unknown whether these effect estimates have clinical relevance. Sensitivity analysis of the SPPB and TUG showed that the removal of studies rated as at ‘high’ risk of bias or ‘low’ in CERT resulted in greater imprecision.

The certainty of evidence in all outcomes was low to very low.

Were there any clear differences?

According to our analysis, resistance training at both higher and lower velocities is similarly effective in improving the functional performance of older adults, although the estimated difference in effect was uncertain. The true effect of either modality may have been masked by the wide range of training protocols used and the lack of training specificity.

The generalisability of the findings was limited by the fact that most of the participants were reportedly healthy, female and without functional impairment.

Given the similar effects on functional outcomes, physiotherapists can prescribe either modality based on individual patient requirements or goals.

What further research is needed in this area?

Further research should consider a wider range of baseline functional capacity in participants.

There is a need to conduct more studies with similar protocols (eg, using machines and resistance bands) and more targeted training for specific outcomes. More rigorous investigations, including preregistration and transparency in the research process for randomisation and assessor blinding, are required.

Robert Morrison is an exercise physiologist based in Limerick, Ireland whose research interests lie in human performance and ageing. He is commencing doctoral research to explore the concept of physical literacy as applied to older populations.

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