Exercise and physical activity are quite variable over the lifespan. In general, there is a decline in both with age. As a result there is progressive loss in lean muscle mass (sarcopenia) and gain in body fat. The degree to which this is programmed in the DNA is debatable and cause for further study. It is clear, however, that these changes are best associated with lifestyle changes. Not only does physical activity decline (we typically see this begin in the mid-twenties and increase—i.e., decline faster—in the 50s and beyond), but so does exercise intensity. Whilst the younger adult is more inclined to lift heavy/high volume and do more HIIT-style training, the older adult is more likely to participate in lower intensity cardiorespiratory exercise (e.g., steady-state walking) and minimal resistance (most likely machine-based) training. While any activity is better than no activity, intensity does matter in the long run.
Any loss in muscle mass suggests a decline in performance. Of course, there is a limit as to what might be considered essential muscle mass for the older adult. It is not likely or feasible for an elite powerlifter or an NFL lineman to maintain the level of muscle mass and strength attained at the peak of the career beyond retirement. How much strength is determined to be an appropriate maintenance level is individual and dependent upon the desired activity level. For most of us, we have never been close to our peak genetic-potential. As such, we have room for improvement—even into our 50s and older.
Sarcopenia causes us to lose abilities—i.e., function. This loss of function leads to greater loss as the principle of reversibility (i.e., “use it or lose it”) kicks in. The less we do the less capable of doing we become. This leads to an accelerated decline.
It is often a matter of social expectation and a poor understanding of human physiology. Walking is a “healthy activity” (and it is, however…). Any physical activity that is less than the maintenance level for performance will result in a progressive decline in performance. (Note: we can’t call it exercise because it does not meet the criteria intent of improving one’s health, physical performance, and/or physical appearance.) So, the suggestion that one must do less based on the observation that physical abilities decline as one ages is built on a false pretext. In reality, one can improve performance at any age. Improvement, however, requires progressive overload—that the body system progressively do more than that to which it is accustomed. It need not be an extreme amount of effort. Nor must it involve extensive time at the gym. For most individuals, it simply requires a greater intensity of effort (within the constraints of one’s current health).
The decline in physical activity and subsequent increase in body fat has more important implications than simply performance and appearance. Flynn et al.1 coined the term “inflamm-inactivity” in consideration of the effects of inactivity on the hyper-inflammatory state seen with increasing age. There is a close association between sarcopenia and obesity and the pro-inflammatory responses by the immune system. Among other benefits, exercise improves immune function, lowers inflammation, and improves insulin sensitivity (i.e., decrease the risk of diabetes). Thus, maintaining (and, if possible and/or necessary, gaining) muscle mass and deceasing body fat are essential to longevity.
One is never too old to train. Don’t let exercise to become just another physical activity. Give it purpose and intensity. If noticeably aging relative to your peers you are not exercising enough—i.e., with sufficient intent and intensity. Challenge yourself—your physical capacity—to improve. Put the brakes on the aging process and change the definition of “healthy”. Try lifting “heavy” weights (“heavy” is relative; it is based on a percentage of one’s maximum strength). Fatigue the neuromuscular system in your training sessions. Don’t just move the weight. Do cardio with the intent of improving performance. Don’t be afraid to sweat.
In our 20s, we exercised to look good. In our 50s and beyond, we life to look better than our aging peers, of course, but more importantly, we exercise for longevity.
Be your best today; be better tomorrow.
Carpe momento!
1Flynn, M.G., Markofski, M.M., & Carrillo, A.E. (2019). Elevated inflammatory status and increased risk of Chronic disease in chronological aging: inflamm-aging or inflamm-inactivity? Aging and Disease, 10(1):147-156. http://dx.doi.org/10.14336/AD.2018.0326