The aging process (AKA 30 years of age onwards), in the presence of high ROS (reactive oxygen species) and/or damaged mitochondrial DNA, can induce widespred mitochondrial dysfunction. In the healthy cell, mitophagy results in the removal of dysfunctional mitochondria and related material. In the abscence of functional removal of unwanted mitochondrial material, a retrograde and anterograde signalling process is potentially instigated, which results in both motor neuronal and muscle fibre apoptosis (death) (Alway, Mohamed, Myers 2017, Ex Sp Sc Rev, 45, 2, 58-69). This process is irreversible. Investigations in healthy populations, have shown that regular exercise improves the ability to cope with regular oxidative stress by the buffering and 'mopping up' of ROS agents which are induced as a result of exercise. It is plausible and highly probable that regular exercise throughout life can mitigate against muscle fibre death (Sarcopenia). Importantly, this process of muscle fibre death can commence in the 4th decade of life, and be as much as 1% per year. Reduction of muscle mass can result in immune and metabolic compromise, including subclinical inflammation, type II diabetes as well as the obvious reduction in functional capacity for activities of daily living.
Optimal approach to load progression during strength training in older adults
Three dominant approaches exist to progression and exercise training
- perceived exertion (RPE)
- target repetitions (incl. repetitions to failure (RM), repetitions in reserve (RiR)
- % of maximum (%1RM)
It has been established that repetitions to failure for sports specific training is highly effective in some populations, however in older adults it may induce DOMS or worse still function-limiting-injuries. Older peoples perception of exercise are among the major determinants whether a person will continue their exercise program. Too slow progression or too little load can be as unmotivating as an injury from repetitions to failure. Lower intensities may lead to higher adherence rates and feelings of pleasure. But what is too little and too much? Buskard etal (2019, Med Sc Sp Ex, 51, 11, 2224-2233) determined that all forms of progressive exercise improved muscular strength and functional capacity. Moreover the RPE method was significantly more tolerable and enjoyable than the RM, RiR, and %1RM methods. However, this may only hold true for the first 6 months of a training regime, after which time, the individual has become accustomed to the routine of exercise and hence may perceive greater loads as more beneficial with reduced side effects. The latter is speculative but anecdotally appears to be true in some sub-populations involved in competitve exercise.
See : Sarcopenia and Aging
Published 11 July 2017
Updated : 26 November 2019