Power versus endurance: What goes first in the ageing stakes?

A fascinating US study based on world record statistics has made it clear that ageing diminishes muscle power considerably sooner and more dramatically than endurance in both men and women.

The researchers compared age-related changes in athletic performance, as reflected in world records for stationary rowing and power-lifting, to test the theory that ageing affects activities requiring short bursts of muscle power more than those based on endurance.

World-record performance data were plotted for each event across the age groups, from under-12 to 80-89 for one-hour stationary rowing, and from 20-35 to 80-plus for Olympic power-lifting. Heavyweight and lightweight-class world records were plotted for men and women in each age group.

Key findings were as follows:

• In the heavyweight-class men’s rowing event, performance rises rapidly and peaks in the third decade. From age 25 to 85 performance decreases by 29%, with a gradual decline of just 4% from 25 to 55 and a more rapid decline thereafter of 0.83% per year. These values indicate a strong relation between performance and age for the entire age range, with the curve for lightweight-class men’s records following a similar trend but at 0-6% lower performance;
• Data for women in the same age groups show similar trends but at a lower level. Notably, however, whereas men’s performance peaks in the third decade, women’s peaks in the fourth decade. From age 35-55 there is a gradual (5%) decline in rowing performance, after which it declines more rapidly by 0.80% per year;
• For power-lifting, men’s records show a performance peak in the third decade, rapidly decreasing by 3% per year until age 37 and then steadily declining by 0.9% per year from age 37.5 to age 85;
• Women’s power-lifting performance also peaks in the third decade, rapidly decreasing by 3.4% per year until age 37.5 and then steadily decreasing by 1.2% per year until age 52.

‘Our findings suggest,’ say the researchers, ‘that a statistically significant difference exists in the effect of ageing on the ability to engage in activities requiring explosive movements over short time intervals versus activities requiring greater endurance capacity. Moreover, rates of men’s and women’s age-related changes in these activities are similar.

The findings also indicate, they add, that there is ‘an inherent loss of ability to produce powerful muscle contractions with increasing age, despite persistent training and otherwise good health. In other words, the effectiveness of training for development and maintenance of muscle strength decreases progressively with age’.

Although the biological mechanisms underlying this effect remain to be clarified, the researchers speculate that preferential loss of fast-twitch muscle fibre function with age – as reported in previous studies – may play a role.

From their particular viewpoint as orthopaedic surgeons and rehabilitation specialists, they suggest that some form of regular resistance training should be advocated for orthopaedic patients over 30 in an attempt to offset age-associated strength loss.

Am J Orthop 2002 Feb;31(2):93-98