It’s one of the hallmarks of ageing; reduced muscle mass. In the absence of preventative measures, normal ageing is said to result in a loss of skeletal muscle mass at a rate of 0.5-2% per annum1. When the muscle loss gets really bad it’s called sarcopenia (in scientific terms). But scientific gobbledygook aside, we’ve all witnessed the frailty of certain elderly people; hunched over, unstable and less mobile. These features of frail elderly are all underpinned in part by significant reductions in muscle mass. Muscle is literally what holds our frame up. Without muscle, our skeleton frame would simply fall to the ground in a heap.
The frailty of the elderly places a significant burden on our health care system which is why there are concerted efforts by many research and government organisations to uncover the mechanisms behind these changes and develop measures to prevent them.
Anabolic Resistance in Elderly
Fascinating studies over the last few years have discovered that concerning protein intake and muscle protein synthesis, the elderly have what is termed ‘anabolic resistance’4. In a nutshell, this phenomenon has identified that the elderly (i.e. >65 years), relative to young individuals (i.e. <30 years), require a higher protein intake following resistance exercise to maximally stimulate muscle protein synthesis (MPS)4. More specifically, they require higher amounts of the branched-chain amino acid leucine to maximally stimulate MPS4. For more information on this phenomenon, please refer to this our article on ‘Protein for the Elderly’.
Weight Training Variables for Elderly
Apart from nutrition, the other major factor affecting muscle in elderly is exercise4. In recent years, scientists have been looking more closely at the different variables of exercise, such as type, volume and intensity and how these affect MPS in elderly. A group of researchers from the University of Nottingham have completed two key studies which shed light on the comparative effect of volume versus intensity in young and old subjects.
Weight Training Intensity Important For Elderly
Their first study published in 2009 showed that intensity was a key factor in increasing muscle protein synthesis in both young and old, with exercises at higher intensities (60%-90% 1RM) producing larger increases in MPS than exercises at low intensities (20%-40% 1RM)2. However, younger subjects showed a greater MPS response than the elderly subjects, thus confirming that in elderly subjects (i.e. >65 years) the MPS response to weight training is suppressed2.
Weight Training Volume in Elderly
The next question the researchers set out to answer was whether the total work performed (i.e. number of reps of a given weight) during a weight’s session was an important factor in modulating the MPS response. To answer this question, the researchers subjected both young and old subjects to either: a high-intensity (i.e. 75% 1RM) or low-intensity (i.e. 40% 1RM) weight training session on two separate occasions; separated by a 3-month interval. On each occasion the subjects worked out at the same intensity, with the sessions differing only in volume; with one having double the other3.
As an example, subjects assigned to the high-intensity group completed 2 sessions of unilateral leg-extensions. One session comprised of 3 sets of 8 repetitions @ 75% 1RM while the next session comprised double the amount of work, namely, 6 sets of 8 repetitions @ 75% 1RM3.
What the researchers found was pretty fascinating. In a nutshell the study found that doubling the volume at both intensities had a significant impact on MPS only in elderly subjects4. In the young men, doubling the volume of exercise at 40% 1RM had no additional effects and at 75% 1RM only small additional effects on the MPS response4. It would seem that in older individuals, increasing the volume of weight lifted is a very important factor in maximally stimulating MPS, compared with young individuals.
Weight Training Guidelines for Elderly
These research findings are very new so ideally more studies are needed before they can be considered fact. But if you are an elderly individual who makes the effort to work out with weights regularly, you would be well-advised to consider increasing the volume of your workout to 6-8 sets if you are not already. Happy training!
1. Baumgartner RN, et al. Epidemiology of sarcopenia among the elderly in New Mexico. Am J Epidemiol. 1998;147, 755–763.
2. Kumar V, et al. Age-related differences in the dose–response relationship of muscle protein synthesis to resistance exercise in young and old men. J Physiol. 2009;587(1):211–217.
3. Kumar V, et al. Muscle protein synthetic responses to exercise: effects of age, volume, and intensity. J Gerontol A Biol Sci Med Sci. 2012 Aug 2. [Epub ahead of print]
4. Koopman R. Dietary protein and exercise training in ageing. Proc Nutr Soc. 2011;70(1):104-113.