Fighting Fatigue

Most people will experience tiredness or fatigue at some stage during training. And, in most cases, this may be due to increases in the amount or intensity of training, stress-related or simply due to lack of sleep (although it’s always a good idea to see your GP to check for any underlying medical conditions as well). However, adequate nutrition is often overlooked as a contributing factor to fatigue. In many cases, a simple change in eating habits can increase energy levels and improve performance.

Symptoms of fatigue

Symptoms vary between individuals but can include:

  • Increased resting heart rate
  • Reduced performance and poor recovery
  • Increased perception of effort
  • Sudden weight loss
  • Loss of appetite
  • Increased risk of illness
  • Loss of enjoyment in training
  • Sleep and/or mood disturbances

Nutritional factors that can contribute to fatigue

Poor food choices

Active people and athletes lead busy lifestyles and often have little time for shopping and food preparation. Insufficient wholegrains, lean meats and dairy, and too few fruit and vegetables and a reliance on processed snack foods can lead to fatigue. Using caffeine-containing food and beverages to suppress fatigue can lead to chronic tiredness as caffeine can interfere with sleep patterns.

Inadequate carbohydrate

Carbohydrate is an important energy source during exercise and daily needs to reflect training load. Eating insufficient carbohydrates combined with regular training can result in gradual depletion of muscle fuel (glycogen) stores leading to fatigue, lack of energy to train, loss of muscle mass and poor recovery. As carbohydrate is also needed to fuel the brain, low carbohydrate diets can result in poor concentration, depression and mood swings.

Poorly timed carbohydrate intake

After moderate to high intensity exercise, effective recovery of muscle glycogen (stored carbohydrate) only starts after eating a carbohydrate based snack or meal. This is most important when there is less than 8-12 hours between exercise sessions. If there more time between training sessions, total carbohydrate intake over the whole day is most important.

Insufficient energy intake

Many active people with busy schedules simply don’t eat enough during the day. Active people with a large lean body mass, high training loads, trying to increase muscle mass or are still growing may struggle to eat enough food if not well organised. Having energy rich foods and drinks available during and after exercise is important to meet additional needs. Some athletes also deliberately restrict their energy intake to maintain a low body weight for their sport or to achieve a particularly weight category to compete. If this is not well planned it can lead to fatigue.


Dehydration impacts on exercise performance and may reduce decision making ability and skill level. Possible signs of ongoing dehydration are general lethargy, dry skin, headaches, nausea and poor concentration. Individuals with high sweat rates should be particularly careful about meeting their fluid needs and taking note of urine colour and volume can be useful for monitoring hydration levels. Including a drink with every meal and snack will assist with daily fluid needs.

Iron deficiency

Athletes, particularly females, adolescents and those who avoid red meat, have an increased risk of iron deficiency. Low iron stores result in general tiredness with can impair recovery and immune function. Monitoring changes to iron levels through regular blood tests through your GP will give a clear indication of whether insufficient iron is the cause of fatigue.

Will vitamin and mineral supplements cure fatigue?

Fatigue is largely caused by an imbalance of energy, carbohydrate, protein and fat. Unless addressing a specific deficiency (e.g. iron), supplements will do little to reverse the problem. A broad spectrum multivitamin and mineral may be useful for athletes who are travelling and can’t eat their normal meals. Elite athletes with a heavy competition schedule and disrupted meals may also benefit from a broad spectrum multivitamin and mineral supplement to ‘top up’ dietary intake.

An Accredited Sports Dietitian can help active individuals design a nutritious eating plan that will provide the right balance of carbohydrate, protein, fat and sufficient vitamins and minerals to maximise exercise performance at training and competition and promote recovery between exercise sessions.

For more information on this or other sports nutrition topics, subscribe to our newsletter or book to see an Accredited Sports Dietitian.