By Susannah Reid,
What do you picture when you imagine good health and fitness in old age? Is it the 90 year-old marathon runner shuffling across the finish line; is it the retired 70 year-old man who can still out-squat most 20 year olds; or do you picture a group of seniors doing seated exercises in a care home? With these images in mind, let’s look at the three traits that may be predictors of who will enjoy life the longest, best quality life.
As the first example of the marathon runner suggests, VO2 max, or the maximal rate of oxygen one can consume, is a strong predictor of longevity. Those with poor VO2 max scores may lose their ability to live independently sooner (7). Aerobic capacity creates a foundation for the use of the higher intensity energy systems and allows for better recovery (5). A study of middle-aged men found lower levels of inflammatory markers in those with higher aerobic capacities (3). With this said, aerobic capacity isn’t the only important fitness indicator for health and longevity.
Leg strength makes everything easier, as strength trainees can attest. Tasks that involve getting up from the floor, climbing stairs and jumping over puddles are no big deal and feel easy in comparison to the weights lifted in the gym. In those who are so weak that standing up from the floor or a chair is a near max effort, not only will their muscles feel shaky, but their heart will race in response to such a seemingly innocuous task. As the person is out of breath, one may assume that they have a “bad heart”. However, if they are unable to use their muscle mass and be strong relative to their size, the concern may certainly extend further than a lack of aerobic fitness and heart health. When someone is incapable of getting out of a chair without pushing themselves up with their arms, they are said to be on the dependence threshold (7). Again, this means their days of living on their own are limited.
Leg strength is best developed with bodyweight and free-weight exercises that also develop balance and body awareness (5). Strong leg muscles have a mix of power and endurance fibres. This fibre ratio is optimal for allowing a movement to be carried out at the needed intensity and duration. With age, the rate of muscle loss accelerates dramatically. This muscle loss is particularly pronounced in type 2 muscle fibres, which produce the largest amounts of force and power and do not use oxygen (anaerobic). As humans age, they gradually convert existing muscle fibres to type 1 fibres (6). Type 1 fibres use oxygen efficiently and produce low force and power relative to their type 2 counterparts. Type 1 fibres are smaller in diameter and require a strong aerobic system in order to use them efficiently (2). Muscle fibre conversion is partially due to loss of neural connection to the type 2 fibres (6). At the onset of loss of fibre connection, the fibres either die or they become reconnected with another nerve, typically a type 1 nerve (2). The result of this is smaller muscles that can contract for long periods of time, but with less strength. Exercises that progress from high rep sets, to low rep sets will recruit more type 2 fibres which will help preserve their function.
Lean muscle mass is another predictor of longevity. Not only does muscle help you to perform better in sports and life, it ensures your cells and hormones continue to work properly (5). Muscle tissue is very important in the regulation of glucose signalling in the body (4). Having more muscle mass that can be activated during daily movement has been suggested to benefit metabolic function. It is not known how much lean mass is optimal, however what’s more clear is that those with more muscle mass tend to have less body fat and fewer metabolic diseases (5).
As we live longer, more people are seeking out ways of living quality lives into their old age. Research has long supported VO2 max as an indicator of longevity. More recently there has been evidence for leg strength and lean muscle as important factors in quality of life and longevity. As more studies are done, this may change how we view exercise, training and fitness into our old age.
Faff, J. (2004). Physical activity, physical fitness, and longevity. Biology of Sport, 21(1), 3-24.
Jones, D. A., Round, J. M., & Haan, A. . (2004). Skeletal muscle from molecules to movement: A textbook of muscle physiotherapy for sport, exercise and physiotherapy. Edinburgh: Churchill Livingstone.
Kullo, I. J., Khaleghi, M., & Hensrud, D. D. (2007). Markers of inflammation are inversely associated with VO2 max in asymptomatic men. Journal of Applied Physiology, 102(4), 1374-1379
Long, Y. C., & Zierath, J. R. (2006). AMP-activated protein kinase signaling in metabolic regulation. The Journal of clinical investigation, 116(7), 1776-1783.
Proctor, D. N., Singh, M. A. F., Salem, G. J., & Skinner, J. S. (2009). POSITION STAND.
Rolland, Y., Czerwinski, S., Van Kan, G. A., Morley, J. E., Cesari, M., Onder, G., … & Chumlea, W. M. C. (2008). Sarcopenia: its assessment, etiology, pathogenesis, consequences and future perspectives. The Journal of Nutrition Health and Aging, 12(7), 433-450.
Warburton, D. E., Nicol, C. W., & Bredin, S. S. (2006). Health benefits of physical activity: the evidence. Canadian medical association journal, 174(6), 801-809.