b'THE MASTERS ATHLETEMasters athlete is a term used to describe the ageing athlete who regularly trains and competes in a given sport. Over the past few decades, there have been increasing numbers of high-level recreational athletes, as well as retired elite athletes, who are competing well into their 60s and 70s 36 . As with the general population, there are specific nutritional requirements that need to be addressed with advancing age amongst masters athletes. Further consideration also needs to be given to the nutritional demands brought on with training and competition.Both endurance capacity and muscular strength decline with age 37 . Cardiovascular fitness, as measured by VO, peaks 2maxduring the third decade of life and steadily declines thereafter, likely as a product of reduced maximal heart rate and cardiac output. Similarly, muscle size and strength peak around the age of 25-30 years and begins to decline in middle age (~50 years). It appears that muscle loss is associated with i) overall decrease in muscle fibres, ii) reduction in muscle fibre size, and iii) decreased fibre recruitment due to loss of motor neurons.Changes to our microbiota and immune function also occur as we age 38 . Over the course of our lifetime, the gut microbiota evolves in response to different circumstances. As infants, the mode of delivery, whether we were breast or formula fed, and when we were weaned and onto which foods, all shape our early microbiota profile. On the other end of the spectrum, we see lower numbers of important SCFA producers, and more protein breakdown (proteolysis) in elderly populations. There is also an age-related decline in immune function, characterised by a decline in T-cell function, reductions in B-cells and natural killer cells, impaired antigen presenting and chronic inflammation. It should be noted that age-associated decline in immune and GI function have not been systematically researched amongst masters athletes. Much like anabolic resistance, age-related decline in immune function appears to be mitigated by regular participation in physical activity. NUTRIENTS TO NOTEProtein CalciumGiven the widely recognised decrements in skeletalIn addition to vitamin D, calcium is essential to muscle mass with age, protein intake and dailyattenuate age-related bone mineral loss, particularly for distribution is particularly important for mastersfemale athletes. athletes. Generally, a daily intake of ~1.2 g/kg bodyHydrationmass/day is recommended for masters athletes. This value may be higher for those looking to gain muscleOlder adults may experience decreased thirst mass or for endurance/ultra-endurance athletes. Intakeperception, so a hydration plan should be implemented of ~0.4 g/kg BM of high-quality protein (e.g., meat,for training and events where excessive fluid losses are dairy, eggs or soy) immediately after training appearsexperienced.to promote skeletal muscle synthesis. Daily proteinLive microbes and microbe-accessible nutrientsdistribution is also important, as 20-30g boluses consumed 3-4 times per day helps to promote aAs mentioned above, gut microbial diversity has been positive net protein balance. shown to decrease with age. Consumption of microbe-Vitamin D accessible nutrients, particularly prebiotics, have been shown to increase microbial diversity and attenuate With age we experience loss of bone minerals andimmunosenescence in older adults, while probiotics decreased ability to synthesise vitamin D from sunlightmay help to increase populations of beneficial bacteria. exposure. As previously discussed, vitamin D is essential for bone growth and mineralisation, immune response and muscle function. These important functions in conjunction with increased requirements and decreased capacity for synthesis, make vitamin D a key nutrient to note amongst masters athletes. 21'