lean legs

As an endurance athlete, I would guess that building muscle isn’t at the top of your priority list. Your priorities are more likely to be improving your endurance capacity, building speed, improving efficiency, and perhaps reducing body fat. But strength is an important component of endurance performance, eg for development of threshold power, and it’s important not to neglect this aspect of training along with the nutritional practices that support the development of lean muscle tissue. The aim is not to bulk up, which might indeed be counter-productive for an endurance athlete, but to increase the proportion of lean muscle mass within your body composition.

So where does nutrition fit into this? Isn’t building strength about resistance training and power workouts? Certainly undertaking these types of session on a regular basis are a fundamental part of developing lean muscle mass, and should be included in your training programme year round, perhaps to a greater extent in the off-season. But nutrition matters too, specifically consuming sources of protein. For development of muscle to occur, the synthesis of new muscle protein must exceed the rate of muscle breakdown. Both resistance training and eating protein triggers a rise in the physiological process called muscle protein synthesis (known as MPS), so combining the two is likely to give you the best results if you are looking to develop lean muscle mass.

One of the leading researchers on the topic of muscle protein synthesis is Professor Stuart Phillips from McMaster University in Canada. He recently published a paper in Sports Medicine 1 which gives a great summary of how to boost MPS. These are his key points:

  1. Combine resistance exercise and eating protein for the best effect.
  2. The boost to MPS is at its greatest shortly after exercise and declines over the next 24 to 48 hours.
  3. Consuming protein is not necessarily better. Research has shown that 20-25g (or around 0.25g/kg of body weight) is the optimal amount in young men, while older athletes (eg age 40 or over) may benefit from a larger amount, up to 40g.
  4. There’s good evidence to show that consuming protein that contains a high level of the amino acid leucine helps to trigger MPS. Leucine is particularly high in whey protein, which is available as a powdered supplement, found in dairy products such as milk and yogurt, or often included in recovery drinks and bars. Eggs are also a good source of leucine. Levels are lower in plant based proteins such as soya or rice.
  5. The current evidence doesn’t support the specific use of other amino acids such as glutamine or l-arginine to boost MPS.

While the importance of consuming protein to support MPS is not in doubt, whether that’s from food or supplements, the need to consume protein as soon as possible after training is still under debate. For example, researchers Alan Aragon and Brad Schoenfeld published a review paper in the Journal of the International Society of Sports Nutrition in 2013 2 which came to the conclusion that, on the basis of the current evidence, the much touted ‘post exercise anabolic window’ may last longer than previously thought, particularly when exercise was taken in a fed rather than a fasted state. It would appear that, for optimal results, consuming protein can occur within an hour or so of resistance exercise, or even later if you consumed protein at your last meal, and does not need to occur before you hit the shower! Data suggests that the body still responds to protein feeding up to 24 hours after a resistance training session.

So what does this mean for the endurance athlete who is looking to develop strength as part of their performance improvements? Here’s my practical guide:

  1. Include some resistance training in your weekly programme. It’s beyond the scope of this blog to advise further on this; please consult a strength and conditioning specialist or personal trainer.
  2. Think about your protein intake both before and after your workouts. If you do resistance training before breakfast, have that meal within one hour of finishing and include about 20g of protein from eggs, yogurt, fish, meat or nuts. If you do resistance training in the afternoons or early evenings, ensure that both your lunch and your supper contain 20-25g of protein, eg from meat, fish or dairy products.
  3. As a general rule on a daily basis, aim for 70-100g of protein spread out at regular intervals across your meals and snacks, depending on how much you weigh. 1.2-1.6g/kg is a good guide for endurance athletes to support both muscle recovery and muscle synthesis. It’s better to follow a ‘little and often’ approach than to have a large amount (eg 40g) at any one meal but none at others. Try to get most of your protein from solid foods, but 1-2 servings of whey protein in a recovery drink or a smoothie is fine too (a serving is 20g). Using whey protein with added leucine will be especially beneficial for MPS, according to a study published earlier this year on cyclists. 3

I hope you find this information helpful.

Jo Scott-Dalgleish BSc (Hons) is a BANT Registered Nutritionist, writing and giving talks about nutrition for endurance sportBased in London, she also works as a Registered Nutritional Therapist, conducting onetoone consultations with triathletes, distance runners and cyclists to help them eat well, be healthy and perform better through the creation of an individual nutritional plan. To learn more about these consultations, please visit www.nutritionforendurancesports.co.uk



1 Phillips SM (2014). A brief review of critical processes in exercise-induced muscular hypertrophy. Sports Medicine. 44 (Suppl 1): S71-77

2 Aragon AA and Schoenfeld BJ (2013): Nutrient timing revisited: is there a post-exercise anabolic window? JISSN. 10:5

3 Rowlands DS et al (2014). Protein-leucine fed dose effects on muscle protein synthesis after endurance exercise. Med Sci Sports Exerc. 14 July (published online ahead of print)