As adults, with each passing decade, our capacity to synthesize new muscle declines up to 40%, the amount of anabolic hormones in circulation decrease by at least 25%, inflammatory markers increase by at least 15% and the expression of muscle growth-specific genes decrease by 10-50%.1,2,3 Our ability to metabolize fats and carbohydrates decreases by 12% each year.4 If that isn’t enough, maximum muscle strength and power can also diminish by an alarming 35%.5 And remember, these changes become evident from the third decade of life.
If you’re on the wrong side of 30, before you go pack your gym bag for the geriatrics home, I’m going to offer some research-based strategies that will help offset the muscle aging process. In fact, the research suggest that under the correct conditions, adults in their 50, 60s and older can reignite muscle anabolic responses back to those seen in 20 year-olds.
The good news…
Recent studies confirm that a lifelong commitment to exercise offers real protection against the ever-increasing levels of oxidative stress that damage cellular structures and cause aging.6 In particular, resistance exercise has been identified as an integral part of this for two reasons.
Firstly, high-overload resistance exercise is the most effective form of mechanical loading and therefore, a potent stimulus to increase the rate of protein synthesis within muscles.7
Secondly, the stimulation of muscle protein synthesis (MPS) is now recognized as the underlying anabolic mechanism for changing the size of muscle mass.8 That means, a high stimulation of MPS is critical not only for building muscle mass but also, cellular regeneration and muscle preservation as we age.
Based on these reasons, rule #1 is, stay committed to high-overload resistance training. Fascinatingly, this type of exercise is capable of reversing (or at least improving) many of the metabolic and neuro-musclular degenerative aspects associated with aging.9-12
The age-related loss of muscle and concurrent gain in body fat appears to be associated with a systemic (chronic) inflammatory response and increased levels of cytokines (such as TNF and IL-6). However, unlike other types of exercise, high-overload resistance training reduces cytokine levels in the muscles of older adults.11
Additionally, this reduction is associated with an increased rate of basal (resting) MPS. Other studies show that a consistent approach to resistance training can induce favourable changes in heat-shock proteins (Hsp70) in adults.12 The Hsp’s are important as they protect cell integrity during stressful situations such the presence of excessive free radicals (that damage cells and promote aging). In particular, Hsp70 is thought to play a role in the muscle regeneration process. High-overload resistance training is most effective at triggering a positive response in these anti-aging muscle proteins.12
Where did my anabolic response go?
Unfortunately, there are some facts about aging we can’t escape. One is the diminished anabolic response to feeding and workouts.7 Remember, anabolism means regeneration and synthesis of new tissue. The older you get, the anabolic response to meals and workouts is shorter-lived.7 This is also accompanied by a greater release of amino acids from muscle and a more vigorous acute-phase (immune) response of plasma proteins after a workout.13 The bottom line is the older we get, the more recovery is required between workouts and the muscle gains come even slower.
Frustratingly, no studies have attempted to assess at what stage in life this change in anabolic processes starts to take place. Also, it is not known what the main instigators are that cause these chemical and physical alterations, physical activity, or quality of nutrition? It is also uncertain if these aspects have a combined effect on gene regulation that determine muscle and body fat changes.
To add further annoyance, it seems that aging per se does not diminish the capacity to build muscle – the mechanisms are fully intact, even in people over 90 years of age. For example, while a major contributor to the age-related decline in muscle mass is thought to be the loss of alpha-motor neuron input, the research available suggests that the muscles of a 90-year-old can respond with strength and power improvements in a similar manner to a person in their 20’s.14,15
Protein metabolism: the key differences in aging
- The essential amino acids are the building blocks of protein; they are vital to stimulating a high rate of MPS. However, aging ensures a diminished anabolic sensitivity to workouts but also, meals.7 In comparison to younger adults, studies show that older adults require a higher dose (concentration) to optimize MPS rates and the anabolic/recovery response to exercise.16
- One reason is splanchnic extraction of dietary amino acids. That is, as we age, more amino acids are taken up by organs and less actually get delivered to muscles. This key difference in intestinal absorption maybe due to the increased importance of the splanchnic tissues in the regulation of protein metabolism during aging.17
- This finding is important, it means that not only is the concentration but also the absorption kinetics of the protein is critical for restoring the anabolic response to more youthful levels.16,17
- Of all the essential amino acids, leucine appears to be the most potent for activating muscle recovery and regeneration at the molecular level. However, with aging leucine is metabolized more so for energy production and to manufacture glutamine; the primary fuel of the immune system. When less leucine is available, muscle breakdown becomes the dominant pathway of whole-body protein metabolism.17 This makes muscle gains impossible.
Correcting the problem
If you’re on the wrong side of 30 this is where it all gets pretty exciting. The latest research shows us that if the correct bio-environment is created during high-overload resistance training, many of the age-related diminished responses can actually be reversed.
In this regard, nutritional intervention with the correct dietary proteins holds the key and we know that a higher concentration of essential amino acids and rapid absorption kinetics are required to restore anabolic mechanism to more youthful levels. With this knowledge, here is a research-based, step-by-step approach to reigniting muscle anabolic responses to more youthful levels.
Step 1: I recommend utilizing VP2 Whey Isolate just before and after every workout. VP2’s peptide profile is biochemically tailored to optimize the anabolic response of resistance exercise. The results obtained with VP2 in clinical trials has made this protein a focal point of anti-aging research.18
One reason is, whey peptides are absorbed faster and in greater amounts compared to other proteins.19 When taken close to resistance training, VP2 seems to really amplify the anabolic response which results in significantly better gains in strength, lean mass and less body fat.20 Outside the workout, the addition of whey peptides to meals results in a higher net gain in muscle protein during a training program and this is evident in both young and older adults.19 In line with the clinical trials I’ve been involved with, to speed recovery, strength gain and fat loss I recommend one 15-30 gram dose before and after intense exercise plus a serving in liquid meals, 3 or 4 times a day.18
As noted earlier, one of the key differences with aging muscle in response to a workout is the greater release of amino acids and a more vigorous acute-phase (immune) response.
Step 2: Glutamine is the primary fuel of the immune system.21 Supplementation at this time will help reduce the “leak” of key amino acids from muscles and boost immune function. Research shows a 5-10 gram dose gets into circulation quickly. I recommend 2 servings (5-10 grams) one at the start and the other at the end of the 3 hour post-workout window.
Step 3: Aging reduces the expression of muscle-specific genes involved in growth and strength development. The only supplement shown in research to up regulate the expression of muscle-specific genes is creatine monohydrate.22 Be sure to supplement with Micronized Creatine before and after intense exercise. The clinical trials I’ve completed suggest this is a highly effective way to increase muscle creatine concentrations which activate better strength and lean mass gains.20
Step 4: Finally, as we age, the concentration of BCAA and in particular, leucine in the diet becomes more and more important for activation of anabolic pathways.23 At least one study has shown that leucine is so potent, when older adults (over 60 yrs) increased the concentration of leucine in their protein supplements, anabolic responses to training were restored to similar to levels seen in people in their 20’s – now that’s pretty cool.24
Therefore, the addition of BCAAs to meals and protein shakes may become more and more important to help off-set the age-related decline in anabolic responses to training.
References:
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2. Toth MJ, Matthews DE, Tracy RP, Previs MJ. Age-related differences in skeletal muscle protein synthesis: relation to markers of immune activation. Am J Physiol Endocrinol Metab 288(5):E883-91, 2005.
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6. Rosa EF, Silva AC, Ihara SS, Mora OA, Aboulafia J, Nouailhetas VL. Habitual exercise program protects murine intestinal, skeletal, and cardiac muscles against aging.J Appl Physiol. 99(4):1569-75, 2005.
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17. Layman DK, Walker DA Potential importance of leucine in treatment of obesity and the metabolic syndrome. J Nutr. 136(1):319S-23S, 2006.
18. Hayes A, Cribb PJ. Effect of whey protein isolate on strength, body composition and muscle hypertrophy during resistance training. Curr Opin Clin Nutr Metab Care. 2008 Jan;11(1):40-4.
19. Dangin M, Guillet C, Garcia-Rodenas C, Gachon P, Bouteloup-Demange C, Reiffers-Magnani, Fauquant J, Ballèvre O and Beaufrère B. The rate of protein digestion affects protein gain differently during aging in humans. J. Physiol 549.2: 635-644, 2003.
20. Cribb PJ, Hayes A. Effects of supplement timing and resistance exercise on skeletal muscle hypertrophy. Med Sci Sports Exerc. 2006 Nov;38(11):1918-25.
21. Curi R, Lagranha CJ, Doi SQ. Molecular mechanisms of glutamine action. J Cell Physiol 28; 2005.
22. Safdar A, Yardley NJ, Snow R, Melov S, Tarnopolsky MA. Global and targeted gene expression and protein content in skeletal muscle of young men following short-term creatine monohydrate supplementation. Physiol Genomics. 2008 17;32:219-28.
23. Rennie MJ. A role for leucine in rejuvenating the anabolic effects of food in old rats. J Physiol. 1;569:357, 2005.
24. Koopman R, Wagenmakers AJ, Manders RJ, Zorenc AH, Senden JM, Gorselink M, Keizer HA, van Loon LJ. Combined ingestion of protein and free leucine with carbohydrate increases postexercise muscle protein synthesis in vivo in male subjects. Am J Physiol Endocrinol Metab. 288(4):E645-53, 2005.
