6 Tips on Protein Intake for Athletes: Clearing Up the Confusion

Protein intake is important to build and repair muscle – and ultimately aids an improvement in sporting performance. However, as I am sure many of you athletes have found, the information out there on how protein can be consumed effectively is pretty confusing. So, here are 6 tips to consider with regards to your protein consumption:

  1. Consumption before sessions: if protein is eaten before a short session (less than 1 hour), this will help muscle synthesis after the session.

The protein consumed before a session may contribute to increasing the amino acid pool for muscle synthesis after the session, as the digestion time for the proteins will release the amino acids in the body post-session[1].

If the training session is longer than an hour, protein ingested is more likely to be used as a fuel rather than for muscle synthesis. 

  1. Consumption during sessions: in endurance sessions, muscle breakdown without synthesis will be limited if protein is consumed during continuous exercise (above 1.5hrs). With regards to resistance sessions, protein synthesis may be aided by protein eaten during the session (if longer than 2 hours).

Endurance athletes training for longer periods of time – 1.5+ hours – may benefit from protein consumption to limit amino acids from being used as a fuel[2]. It is debated as to whether this protein enhances synthesis4, or just maintains protein balance[3], but it is clear that this consumption doesn’t cause a negative protein balance and may prime the amino acid pool for post-exercise muscle synthesis.

In reference to resistance exercise (comprising of reps and sets) the rest periods may be used for muscle synthesis in sessions lasting longer than 2 hours[4]. If the sessions are shorter, there is limited opportunity for skeletal muscle remodelling as it usually occurs in the hours after the session, not in the minutes between reps.

  1. Consumption after sessions: if athletes are training every day, they should focus more on regular protein consumption rather than an increase in intake ONLY after a session.

Recent research suggests that protein ingestion directly after exercise stimulates muscle protein synthesis for up to 4 hours after the session[5]. However, most sources suggest that consumption up to 24 hours after a session can contribute to synthesis[6].

  1. Amount and timing of consumption: for optimal consumption, 0.25g/kg body weight every 3 hours is most effective in allowing muscle synthesis[7]. Athletes training in the evening may consider increasing this to 0.5g/kg of body weight in pre-bedtime snacks due to the protein deficiency occurring in the night[8].

THERE IS NO POINT IN EATING LARGE AMOUNTS OF PROTEIN ALL AT ONCE… in fact new research says that eating more than 20g of protein at once (for an 80kg person) results in the amino acids being used as a fuel rather than contributing to muscle synthesis[9]

So, optimal doses should be at around 0.25g/kg of body weight to stimulate muscle synthesis and induce a positive protein balance. Intakes of 10-16g (lower) can also stimulate synthesis even though body protein balance is negative[10].

General daily requirements for athletes differ from regular individuals who want to offset deficiency. General requirements are around 0.8kg/kg body weight/day[11]– it is important to ignore this figure as athletes consume protein to better performance rather than to stop deficiency.

  1. Type of protein to consume: both wholefood and isolated protein options aid muscle synthesis, however isolated sources may be best to consume post-session for athletes wanting to make muscle gains. Good wholefood options include eggs, milk, beef, fish, soy and beans; and the best isolated protein options are leucine-rich, including whey for initial muscle synthesis and casein for prolonged synthesis.

The best protein sources are impacted by two things:

  • Good amino acid composition – this can be worked out by looking at the biological valueof proteins (the higher the BV, the better the amino acid composition).
    • Egg has the highest BV of any wholefood, with most animal proteins like beef, milk and fish following suit[12].
    • Vegetarian options like soy protein and beans are also high12.
  • High rate of digestion – as this means the amino acids appear in the blood faster.
    • Casein has the slowest digestibility and is found in soy proteins. Animal products however have high digestibility [12].

Sources with both a high biological value and high rate of digestion increase muscle synthesis post-exercise[13].

Mixed protein sources vs isolated protein sources:

Mixed protein sources consist of wholefoods (not supplements) and they have a different amino acid composition compared to isolated sources[14]. THIS IS NOT A BAD THING… wholefoods still cause a positive protein balance. Actually, it has been found that milk, or sources containing large amounts of dairy (high in whey and casein protein), enhance protein synthesis and improve lean body mass10.

However, it is recommended that athletes wanting to initiate rapid post-exercise muscle synthesis should consume leucine-rich rapidly digested isolated protein[15].

  1. MOST IMPORTANTLY… how does this help you?

As an athlete wanting to maintain muscle mass – eating protein regularly whilst making sure that the calories you eat equal the calories that you burn will ensure that protein synthesis and breakdown is equal… it will reduce chance of injury and helps to make your body leaner and stronger.

As an athlete wanting to increase muscle mass – eating protein regularly whilst making sure that the calories you eat exceed the calories that you burn will ensure that protein synthesis is larger than breakdown… it means that the weight that you put on will most likely be muscle, making you fitter, stronger and faster.

Read more on why athletes need protein in one of my previous posts:

https://cookandcontemplate.com/2018/06/17/the-science-why-do-athletes-need-protein/

I hope that this post has been useful… please comment your thoughts and questions underneath and I will try to get back to you!

[1]Tipton, K.D., Elliot, T.A., Cree, M.G. et al. (2007) ‘Stimulation of net muscle protein synthesis by whey protein ingestion before and after exercise’, AM J Physiology Endocrinology Metabolism, 292, pp. 71-76.

[2]Beelen, M., Zorenc, A., Pennings, B., et al. (2011) ‘Impact of protein coingestion on muscle protein synthesis during continuous endurance type exercise’, American Journal of Physiology: Endocrinology and Metabolism, 300, pp. 945-954.

[3]Hulston, C.J., Wolsk, E., Grondahl, T.S., Yfanti, C. and Van, H.G. (2011) ‘Protein intake does not increase vastus lateralis muscle protein synthesis during cycling’, Medicine and Science in Sports and Exercise, 43, pp. 1122-1130.

[4]Beelen, M., Koopman, R., Gijsen, A.P., et al. (2008) ‘Protein coingestion stimulates muscle protein synthesis during resistance-type exercise’, American Journal of Physiology: Endocrinology and Metabolism, 295, pp. 70-77.

[5]Tang, J.E., Perco, J,G., Moore, D.R., Wilkinson, S.B. and Phillips, S.M. (2008) ‘Resistance training alters the response of fed state mixed muscle protein synthesis in young men’, American Journal of Physiology, 294, pp. 172-178.

[6]Burd, N.A., West, D.W., Moore, D.R., et al. (2011) ‘Enhanced amino acid sensitivity of myofibrillar protein synthesis persists up to 24 h after resistance exercise in young men’, Journal of Nutrition, 141, pp. 568-573.

[7]Moore, D.R., Areta, J., Coffey, V.G., et al. (2012) ‘Daytime pattern of post-exercise protein intake affects whole-body protein turnover in resistance-trained males’, Nutrition and Metabolism, 9, p. 91.

[8]Res, P.T., Goen, B., Pennings, B., et al.(2012) ‘Protein ingestion before sleep improves postexercise overnight recovery’, Medical Science Sport and Exercise, 44, pp. 1569-1569.

[9]Moore, D.R., Robinson, M.J., Fry, J.L., et al. (2009) ‘Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men’, American Journal of Clinical Nutrition, 89, pp. 161-168.

[10]Lunn, W.R., Pasiakos, S.M., Colletto, M.R., et al. (2012) ‘Chocolate milk and endurance exercise recovery: protein balance, glycogen, and performance’, Medical Science Sport and Exercise, 44, pp. 682-691.

[11]Phillips, S.M. (2012) ‘Dietary protein requirements and adaptive advantages in athletes’, British Journal of Nutrition, 108(2), pp. 158-167.

[12]Hoffman, J.R. and Falvo, M.J. (2004) ‘Protein – which is best?’, Journal of Sports Science and Medicine, 3, pp. 118-130.

[13]Tang, J.E., Moore, D.R., Kujbida, G.W., Tarnoplosky, M.A., and Phillips, S.M. (2009) ‘Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men’, Journal of Applied Physiology, 107, pp. 987-992.

[14]Burke, L.M., Winter, J.A., Cameron-Smith, D., et al. (2012) ‘Effect of intake of different dietary protein sources on plasma amino acid profiles at rest and after exercise’, Journal of Sport Nutrition and Exercise Metabolism, 22, pp. 452-462.

[15]Moore, D., Phillips, S. and Slater, G. (2015) ‘Protein’, in Burke, L. and Deakin, V. (eds.) Clinical Sports Nutrition. North Ryde: McGraw-Hill Education Ltd, pp. 94-110.

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