Sport and exercise

Advised

• Vitamin D

  A vitamin the body makes when skin is in sunlight. Oily fish, eggs and fortified foods have some; supplements come as D3 or D2.

  • NHS: Everyone should consider 10 micrograms a day in autumn and winter.
  • British Dietetic Association: People in regular training and competition should be aware of their vitamin D needs.

  What vitamin D is, and the forms it comes in

Limited evidence

• BCAAs

  Three amino acids, leucine, isoleucine and valine, found in protein foods such as meat, fish and milk.

  • NIH ODS: Not much scientific evidence for BCAA supplements.
  • NIH ODS: Taking up to 20g a day of BCAA supplements seems safe.

• Beta-alanine

  An amino acid found in meat, poultry and fish, sold as powder or capsules.

  • NIH ODS: Sports-medicine experts disagree on its value; studies have not all agreed.
  • NIH ODS: 800mg or more can cause tingling or prickling skin, not considered harmful.

• Beetroot and nitrate

  Beetroot powder, extract or concentrate, sold for its nitrate. Beetroot is among the best food sources of nitrate.

  • NIH ODS: Studies mostly used beet juice; whether powder supplements compare is not known.
  • NIH ODS: Moderate amounts of beet juice are safe but can turn urine pink or red.

• Citrulline

  An amino acid the body makes, also present in some foods. Supplements come as L-citrulline or citrulline malate.

  • NIH ODS: Research is limited, and the few studies found mixed results.
  • NIH ODS: Not enough research to know whether it is safe; some report stomach discomfort.

• HMB

  A compound the body makes in small amounts from leucine, an amino acid in protein foods. Supplements come as calcium HMB or free acid.

  • NIH ODS: Hard to judge: studies varied widely in age, fitness, dose and length.
  • NIH ODS: No side effects reported at 3g a day for up to 8 weeks.

• Glutamine

  An amino acid the body makes, also eaten in protein foods such as meat, fish, eggs, dairy and pulses.

  • NIH ODS: Only a few studies, and little scientific evidence for glutamine in exercise or sport.
  • NIH ODS: No side effects reported at up to 45g a day for several weeks.

• Protein powder

  Powdered protein from milk (whey or casein), egg, beef, soya, pea, rice or hemp, mixed into shakes.

  • NIH ODS: High protein intakes seem quite safe, but more than the recommended amount has no advantage.

  Also covered by British Dietetic Association.

• Sports drinks and electrolytes

  Salts such as sodium and potassium, sold as tablets or powders to mix with water, or in ready-made sports drinks.

  • BHF: For most people, electrolyte drinks are no more hydrating than plain water.
  • British Dietetic Association: Water is best for most activities; regular strenuous exercisers may find sports drinks useful.

Things to check

• UKAD: No supplement is guaranteed free of banned substances; athletes should use only batch-tested products and check batch numbers.
• UKAD: Labels can be inaccurate and products contaminated during manufacture; be wary of fakes bought online.
• FSA: Healthy adults: no more than 200mg of caffeine a serving, and 400mg a day from all sources.
• FSA: Deaths have been reported where pure caffeine was measured incorrectly; measure powders precisely and avoid dry scooping.
• NIH ODS: Creatine usually causes some weight gain from water retention; rare reactions include cramps and stomach upset.
• NIH ODS: In most cases, only adults should use performance supplements.
• BHF: Electrolyte drinks are not suitable for people with heart failure or kidney disease.
• NHS: Do not take more than 100 micrograms (4,000 IU) of vitamin D a day.

If you take medication, are pregnant, or have a health condition, check with a pharmacist or GP first.