Master athletes (40 years and over) can attain similar levels of fatigue resistance, muscle mass, strength and power to younger individuals. This helps to delay the onset of many adverse health events associated with ‘normal’ ageing. Nonetheless, despite the impressively high level of performance in Master athletes, musculoskeletal deterioration remains somewhat inevitable with advancing age. Thus, nutritional considerations to enhance the speed of recovery, optimize training adaptations and, ultimately, improve or maintain athletic performance are likely to differ between Master athletes and younger athletes.
An overview of current protein recommendations for athletes
It is widely acknowledged that dietary protein has a range of important effect for athletes including alleviating exercise-induced muscle soreness and inflammation, stimulating the synthesis and accretion of muscle proteins, and potentiating muscle hypertrophy, strength and aerobic performance. The majority of the available evidence on the ergogenic effects of dietary protein has been generated from studies in younger athletes and very few involved older athletes.
The most current recommendations for protein nutritional support for strength/power range from 1.2-1.7g/kg/per day and are analogous to those for endurance athletes. Although markedly higher than the current Recommended Daily Allowance (RDA) of 0.8g/kg/day for protein, this alternative range should be thought of as an ‘optimal’ amount to support the increased demands of muscle repair, remodeling and adaptation of individuals engaging in exercise training. It is advised that this recommended daily protein amount is evenly distributed over 4-5 daily meals/snacks. A meal should aim to supply a protein dose of ~0.3-0.4g/kg in close proximity to training completion (i.e. in the 1-2 h post-exercise window) and every 3-4 hours across the day to maximize the stimulation of muscle protein synthesis (see also this guest blog by Professor Stuart Phillips).
The optimal source of dietary protein for athletic populations is the subject of much debate. It is generally considered that proteins that supply a full complement of essential amino acids, particularly leucine, offer the greatest advantage for stimulating muscle protein synthesis. In this regard, animal-derived proteins (i.e. whey, milk, beef) are often reported to promote superior muscle remodeling responses to plant-based proteins, although consuming a higher dose of plant-based protein, or combining various plant-based proteins together may provide an amino acid profile that is sufficient to optimize muscle remodeling.
Do protein nutritional needs differ for Master athletes?
Age-related muscle loss begins in fourth decade of life and is a harbinger for the loss of strength and onset of disability. To mitigate this age-related musculoskeletal deterioration, it is recommended that daily protein intakes should be ~1.2g/kg/day for older individuals (~50% increase above the current RDA). This position is, in part, based on evidence that protein ingestion to stimulate muscle protein synthesis requires greater relative intakes in older individuals. Thus, given the already elevated requirement for dietary protein to support muscle mass maintenance in older age, it is intuitive to expect that the protein nutritional requirement to support net muscle protein synthesis in the ageing athlete may be greater than younger athletes. Indeed, whilst post-exercise rates of muscle protein synthesis are saturated with ~20-25g of leucine-rich whey protein in younger individuals, exercised muscles of untrained older individuals are responsive to a higher 40g protein dose (2).
Therefore, a key consideration in defining protein nutritional requirements for Master athletes is whether these highly trained older individuals display a similarly impaired muscle anabolic response to dietary protein and exercise as their sedentary counterparts. To investigate this, Doering and colleagues (1) recently compared the rate of muscle recovery following a 30-minute downhill ‘damaging’ treadmill run in Master (53 years) and younger triathletes (27 years). Cycle time trial performance over 3 days of recovery tended to be lower in Master triathletes, and was accompanied by lower rates of muscle protein synthesis compared with the younger triathletes. Importantly, all triathletes consumed 20g of whey protein immediately after the downhill run followed by a diet containing ~1.6g/kg/day of protein (0.3g/kg/per meal) during the 3-day recovery phase, yet this was still insufficient to optimize muscle recovery in Master athletes. These data strongly suggest that Master athletes may require dietary protein intakes in excess of the current recommendations for younger athletes to support post-exercise muscle protein synthesis, recovery of performance and long-term training adaptations (suggested range: 1.6-2.0g/kg/day).
Refining this advice further, the requirement for higher dietary protein intakes in Master athletes may be particularly beneficial during training bouts/phases that cause damage to muscle contractile and connective tissue (i.e. lengthening contractions, intensified training, return from injury), as master athletes display a slower rate of recovery compared to younger athletes in such scenarios. Finally, very high protein intakes (≥2g/kg/day) may offer an additive benefit for musculoskeletal health and performance in the ‘oldest old’ Master athletes (i.e. those aged 80 years and over).
What can we take away from all this?
From what we know we can come up with some broad guidelines for the master athlete. Master athletes nearing 50 should probably start with higher per meal protein intakes (0.4g/kg, 4-5 times daily). This certainly won’t be harmful and can only be beneficial. For individuals who find that tough to achieve and want avoid supplements, an additional 1-2 servings of dairy with each meal (i.e. glass of fat-free milk and low-fat yogurt) or nuts/grains can be the difference. Pre-sleep protein (discussed here) is likely to be beneficial for Master athletes. It seems that Master athletes should aim for 40g of casein protein to maximize overnight synthesis rates, which is superior to 20g.
Depending on the event the athlete is training for, it may mean cutting other macronutrients (fat and/or carbohydrate) in main meals to accommodate the extra protein. Master strength/power athletes should aim to reduce fat and carbohydrate intake marginally to accommodate the extra protein in order to maximize their power-to-weight ratio.
References
Doering TM, Jenkins DG, Reaburn PR, Borges NR, Hohmann E, and Phillips SM. Lower Integrated Muscle Protein Synthesis in Masters Compared with Younger Athletes. Med Sci Sports Exerc 48: 1613-1618, 2016.
Yang Y, Breen L, Burd NA, Hector AJ, Churchward-Venne TA, Josse AR, Tarnopolsky MA, and Phillips SM. Resistance exercise enhances myofibrillar protein synthesis with graded intakes of whey protein in older men. The British journal of nutrition 1-9, 2012.
Dr Leigh Breen is an Assistant Professor of Musculoskeletal Physiology and Metabolism in the School of Sport, Exercise and Rehabilitation
at the University of Birmingham. His research activity is conducted, primarily, under the auspices of the MRC-ARUK Centre for Musculoskeletal Ageing Research at UoB and centres on investigating mechanisms of age-related musculoskeletal deterioration and the development of exercise and nutritional countermeasures to this phenomenon.
