Your diet can be instrumental in overcoming performance-related issues and in an extract from her new book, Renee McGregor explains how

The human body is extremely efficient and clever, but it’s not perfect. Although participating in sport is important for good health, sport itself is not always beneficial for our bodies. Indeed, rates of injury are usually high in athletes.

Whether it is a twisted joint, a pulled muscle or ligament, or something more serious, training for sport puts a huge strain on the body and, inevitably, that can lead to overuse and injury.

Nutrition is a continually evolving science, with new studies and research being published on a daily basis. An area that is of real interest to researchers is how nutrition can impact on injury prevention and how it can improve recovery rates from injury. As with all studies, results are mixed and, although further research is required, overall we can note some key nutritional strategies that may be beneficial:


A common phenomenon in athletes is DOMS, or delayed onset muscle soreness, especially in those who have taken on a new form of training, such as adding strength to weekly running mileage, or those who have trained or competed particularly hard.

The soreness is most commonly felt 24-72 hours after training and is the result of micro-trauma, which is mechanical damage at a very small scale to the exercised muscles, leading to inflammation and oxidative stress.

Usually if you repeat a certain exercise pattern sufficiently, your body will get used to it and the soreness will stop. However, we also know that to improve performance, muscles need to be ‘overloaded’ continually and so DOMS is a training inevitability from time to time.

Much research has been done into ways in which we can reduce inflammation and oxidative stress on the body through nutrition, with the best findings coming from the use of powerful antioxidants.

Some examples include:

  • Curcumin: found in the spice cumin
  • Isoflavanoids: found in soya beans
  • Vitamin C: found widely in fresh fruit and vegetables
  • Polyphenols: most of the data has come from studies using tart cherry juice, which does seem to show a significant reduction in inflammatory markers in endurance athletes after strenuous sessions; I recommend tart cherry juice capsules or shots after all high-intensity training or races as a way to reduce oxidative stress on the body. You can buy these at health food stores or online.

The most important thing to remember when you are injured is that you need to rest. Depending on the severity of your injury, you may need as little as a few days to more than 6 months. Nutrition can also be instrumental in your recovery and return to exercise.

A lot of athletes understandably worry about weight gain when they become injured. Research has demonstrated that decreasing your overall energy intake, but increasing your protein intake (to as high as 2.3g/kg bodyweight daily) is a useful way to recover without gaining weight.

For bone injuries, such as a stress fracture, supplementing with vitamin D has been shown to be effective; and new research emerging is also looking at the role of vitamin C and collagen as supplements.


When you are training hard, you are bound to feel some residual fatigue.

However, if tiredness does not disappear after a few days’ rest, it is important to take note and consider what else could be contributing. Ask yourself:

1. Have I increased or changed my training significantly recently?

2. Am I recovering appropriately nutritionally?

3. Am I hydrated?

4. Am I eating enough before I train?

5. Is it possible I am coming down with a virus or other illness?

If your answers to these five questions don’t seem to reveal what might be contributing to your fatigue, consider whether there are other medical or nutritional reasons that could be at the root. We do know that a vitamin D deficiency is linked to chronic fatigue and poor muscle recovery.

Similarly deficiencies in other micro-nutrients can pose problems. Don’t imagine that the prefix ‘micro’ means these nutrients have only small effects and are therefore less significant for your well-being than macronutrients. Micro means that we need to consume them in ‘micro’ amounts, but they are no less essential to good health. Examples are:

  • Vitamins: A, B, C, D, E and K
  • Minerals: calcium, iron and phosphorus
  • Electrolytes: sodium and potassium
  • Trace elements: iodine, zinc and magnesium

Micronutrients are essential for many metabolic processes within the body and, although we can manufacture a few of them within the body, most have to come from the diet.

Most function as co-enzymes or co-factors within the body — that is, they aid enzymes and proteins in their function. For example, the B vitamins are very important for carbohydrate and fat metabolism, while vitamin C, along with zinc, is important for a healthy immune system; you need magnesium and calcium for good muscle contraction. Each and every micronutrient has a significant part to play in your training success. Make sure your diet contains them.

Runner’s trots

A very common and unpleasant side-effect most runners will experience at some stage is the phenomenon often known as “runner’s trots” — an urgent need to defecate. This has a number of possible causes:

1. Leaving little time between eating and running. When you start running, the body directs blood flow to the working muscles, and away from the digestive system. This, combined with the actual physical movement of running, causes the contents of the stomach to be thrown up and down, thus leading to that all-too-familiar immediate need to go to the toilet.

2. Similarly, in longer endurance events, when you are most likely to be using sports gels and drinks, becoming dehydrated and/or taking on more energy than you need causes the contents of the stomach to become very concentrated and this in turn causes stomach issues.

3. Caffeine is well known for causing an increase in speed of food through the digestive system. This can be advantageous as you can be sure that your digestive system is ‘empty’ prior to running. Some energy gels and products contain caffeine and, while this can have positive effects on your performance, if you are not used to using caffeine with your running, it may cause you some issues, so it is best to always practise taking on caffeine in training.

4. Too much fluid. Some runners panic about becoming dehydrated and so aim to take on fluid before and often during their run, even if it is short. Again drinking too much can cause an increase in speed of food through the gut, once again leading to stomach issues.

» Renee McGregor is a performance and clinical nutritionist, accredited by Health and Care Professions Council and the Sport and Exercise Nutrition Register. She is a member of the British Dietetic Association and the author of Fast Fuel: Food For Running Success ( £9.99)

» Check out some of Renee McGregor’s recipes for recovery and pre-session fuelling here