Old age is associated with lower physical activity levels, suboptimal protein intake, and sarcopenia. Although resistance exercise (RE) and protein supplementation partially protect against sarcopenia under controlled conditions, the efficacy of home-based, unsupervised RE (HBRE) and multi-ingredient supplementation (MIS) is largely unknown.
In this randomised, placebo-controlled and double-blind trial, a team of researchers from McMaster University Medical Center, Canada, undertook a 12-week randomised, placebo-controlled clinical trial, to test the efficacy of daily intake of a five-ingredient supplement including whey, micellar casein, creatine, vitamin D3, and n-3 PUFAs (‘Muscle5’; M5), combined with three days per week low-intensity HBRE, for improving SM mass, strength, and function in free-living elderly.
They hypothesised that 12 weeks of HBRE would be beneficial for all participants, while the Muscle5 supplement would improve muscle integrity to a greater extent versus placebo.
Thirty-two sedentary men underwent twelve weeks of home-based resistance band training (three days per week), in combination with daily intake of a five-nutrient supplement (‘Muscle5’; M5, n = 16, 77.4 ± 2.8 y) containing whey, micellar casein, creatine, vitamin D, and omega-3 fatty acids, or an isocaloric/isonitrogenous placebo (PLA; n = 16, 74.4 ± 1.3 y), containing collagen and sunflower oil.
Their results suggested that lean mass to fat ratios, maximal strength, and function were significantly improved in the M5 group following HBRE/MIS therapy. Quadriceps muscle size was also significantly increased in the M5 group post intervention. Sub-group analysis indicated even greater gains in total lean mass in sarcopenic individuals following HBRE/MIS therapy.
The authors concluded that the supplement was a safe, well-tolerated, and effective complement to low-intensity, home-based resistance exercise and improves lean mass, strength, and overall muscle quality in old age.
Despite the profound benefits of RE across all age groups, there is some evidence of a blunted anabolic response to contractile activity with ageing (e.g., anabolic resistance). Therefore creating the notion that a combination of RE with other interventional strategies may be necessary to maintain muscle health in old age.
For example, the synergism between branched-chain amino acids (BCAAs) and contractile activity is well-established, with leucine being the most potent of all BCAAs in activating anabolic pathways, although the majority of essential amino acids (EAAs) are necessary for muscle protein synthesis (MPS).
The literature suggests that a higher single dose (≥40 g whey), multiple daily dosing, increases total protein intake (1.2–1.6 g protein/day), or provision of additional anabolic nutrients are necessary to maximize MPS and maintain SM in old age. Beyond protein supplementation, vitamin D, polyunsaturated fatty acids, and creatine have all documented SM benefits.
The authors of the current study explain the idea of using multi-ingredient supplementation (MIS) mainly rests on the simultaneous targeting of several metabolic and signalling pathways to potentiate SM gains, including the major growth regulatory processes within the muscle cell (e.g., protein synthesis, protein degradation, and satellite cells), energy production, contractile function, and/or recovery.
The report states: "As MIS stimulates several processes simultaneously, it theoretically ‘circumvents’ the main limitation of using traditional, single-nutrient strategies to maintain SM in old age, e.g., anabolic resistance.
"A myriad of supplements are purported to provide significant benefits for SM strength, performance, and recovery, but relatively few are supported by sound evidence from randomised clinical trials (RCTs). "Ultimately, there is a need for RCTs to assess the safety and efficacy of a vast majority of supplements due to the lax regulatory framework generally surrounding these products, increasing the risk of false advertising, unsubstantiated claims, and health side-effects."
Tarnopolsky. M. A., et al
"A Five-Ingredient Nutritional Supplement and Home-Based Resistance Exercise Improve Lean Mass and Strength in Free-Living Elderly"