SUBJECT: Protein: how much and when: Answers for athletes and exercisers -Notes from Roc Nutrition Investigator
Finally good answers about the protein you need to maintain your muscles, especially for athletes and exercisers - Journal of Nutrition Nov 2013 Supplement: Efficacy and Safety of Protein Supplement Use by Military and Other Physically Active Populations
A. Consensus statement - To provide evidence-based guidance regarding the efficacy and safety of dietary protein supplement (PS) use by members of the U.S. Armed Forces, a panel of internationally recognized experts in the fields of protein metabolism and dietary supplement research was convened...To maintain muscle mass, strength, and performance during periods of substantial metabolic demand and concomitant negative energy balance the panel recommended that warfighters consume 1.5–2.0 g · kg−1 · d−1 of protein. However, if metabolic demand is low, such as in garrison, protein intake should equal the current Military Dietary Reference Intake (0.8–1.5 g · kg−1 · d−1). To achieve recommended protein intakes, the panel strongly urges consumption of high-quality protein-containing whole foods. However, when impractical, the use of PSs (20–25 g per serving or 0.25–0.3 g · kg−1 per meal), particularly after periods of strenuous physical activity, is acceptable.
B. 20% of college athletes take protein supplements - Protein supplements (PSs) are, after multivitamins, the most frequently consumed dietary supplement by U.S. military personnel. Warfighters believe that PSs will improve health, promote muscle strength, and enhance physical performance. The estimated prevalence of regular PS use by military personnel is nearly 20% or more in active-duty personnel, which is comparable to collegiate athletes and recreationally active adults, but higher than that for average U.S. civilians. When dietary protein intake approaches 1.5 g · kg−1 · d−1, and energy intake matches energy expenditure, the use of PSs by most physically active military personnel may not be necessary.
C. Get carbs before your workout, protein afterwards - It was clear that if carbohydrate delivery was optimal either during or after an acute bout of exercise that additional protein will not increase exercise capacity. In contrast, with repeated exercise, use of protein supplementation was associated with reductions in muscle soreness and often a faster recovery of muscle function due to reductions in protein degradation. There was also good supportive evidence for long-term benefits of protein supplementation for gains in muscle mass and strength through accelerated rates of protein synthesis, as long as the training stimulus was of sufficient intensity, frequency, and duration.
D. The recommended range of protein intake is 1.2–1.8 g · kg − 1 · d − 1, which is 2-3x the RDA (ref). Like athletes, warfighters require nutrition support to optimize physical condition to maintain training, sustain performance, speed recovery, and prevent injury and illness. Specifically, energy and protein requirements have been tailored for these populations.
Risks involved with commercial protein supplements - There are significant risks associated with the use of unregulated dietary supplements. Risks include the absence of active ingredients, the presence of harmful substances (including microbiological agents and foreign objects), the presence of toxic agents, and the presence of potentially dangerous prescription-only pharmaceuticals. There is also growing evidence of risks to health and of serious adverse events, including a small number of fatalities, as a result of supplement use. The risk associated with the use of protein powders produced by major manufacturers is probably low, and the risk can be further reduced by using only products that have been tested under one of the recognized supplement quality assurance programs that operate in various countries.
F. Get your protein after the workout - At rest, intake of protein (optimal range between 20 and 40 g of high-quality protein) every ∼4–5 h is advocated due to the refractoriness of muscle protein synthesis in response to continuous supply. In relation to exercise, protein dosing (at a minimum of ∼20 g) both in close proximity to exercise and thereafter every 4–5 h during waking hours (including before bedtime) is likely optimal for adaptation/functional recovery.
G. Get 20-25g before sleep - Consumption of protein before sleep confers the anabolic responses required for the maintenance of lean mass and muscle recovery. A maximal response in muscle protein synthesis is achieved with the consumption of 20–25 g of protein alone.
H. Mature people need more protein - The demographic shift of the average age in the United States and worldwide mandates that careful attention be paid to the nutritional and health needs of all segments of our older adult population. A substantial proportion of adults over the age of 60 y consume less than the U.S.-recommended dietary allowance for protein and that greater dietary protein intake appears to reduce the decline in lean/muscle mass with aging. Studies of acute ingestion of high-quality dietary protein in healthy older adults suggest that the age-related blunting of protein synthetic capacity can be overcome with increased dietary protein intake.
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-Nutrition Investigator, Roc
Professor, Biochemistry, Beloit College