An athlete's body has different fuel demands than someone living a sedentary lifestyle — more carbohydrate for glycogen, more protein for repair, and precise timing around training. This article covers how sports nutrition builds on everything else in this strand to support performance and recovery.
Sports nutrition applies the same core principles covered throughout this strand — macronutrients, hydration, energy balance — but scales and times them around the specific demands of training. An endurance runner, a strength athlete, and a casual gym-goer all draw on the same nutritional science, just tuned to very different fuel and repair needs.
During exercise, the body relies heavily on carbohydrate stored in muscle and liver as glycogen. Carbohydrate needs scale directly with training volume and intensity:
These figures are grams per kilogram of body weight, per day. Deliberately cutting carbohydrate intake is generally discouraged for athletes in heavy training, since it directly limits available glycogen — and available fuel.
Exercise, especially resistance training, creates small amounts of muscle damage that protein helps repair and rebuild. Athlete protein needs run notably higher than the general adult guideline:
Spreading protein across three to five meals across the day, including a serving after training, is generally favoured over consuming it all in one large meal.
Fat is rarely the primary energy source during intense exercise, but it remains essential — supplying fat-soluble vitamins, essential fatty acids, and a meaningful share of daily energy. Athletes generally don't need a fat intake dramatically different from the standard adult range covered earlier in this strand; it usually fills in whatever calories remain after carbohydrate and protein targets are met.
An easily digestible, carbohydrate-focused meal, generally eaten a few hours beforehand, tops up glycogen without causing digestive discomfort during exercise.
Water alone is generally sufficient for sessions under an hour. For longer or more intense sessions, a carbohydrate-electrolyte drink helps sustain performance.
A combination of carbohydrate and protein — often cited around a 3:1 or 4:1 carb-to-protein ratio — supports glycogen refilling and muscle repair.
Chocolate milk is a commonly cited post-workout option not because of any special ingredient, but because it happens to naturally combine carbohydrate and protein in roughly the ratio research supports for recovery — a practical, low-cost option rather than a specialised product.
As covered in the earlier Hydration article, even mild fluid loss affects performance — a loss of around 2% of body weight in fluid has been shown to measurably reduce aerobic performance. For sessions under an hour, water is generally adequate. Beyond about 60 minutes, or in hot and humid conditions, replacing electrolytes — particularly sodium — alongside fluid becomes increasingly important, since sweat carries both water and sodium out of the body.
Many products marketed to athletes promise a performance edge, but the evidence base varies enormously between them. Creatine monohydrate is among the most consistently well-researched supplements for supporting strength and power output. Others, including various herbal extracts, have far more limited or mixed evidence. As with any supplement, an athlete's foundation should be food-based nutrition first — supplements fill genuine gaps, they don't replace the basics covered throughout this strand.
Athletes, particularly in sports emphasising leanness, face a specific risk called low energy availability — not eating enough to support both training demands and normal body function. Sustained low energy availability can affect hormone balance, bone health, and long-term performance, and is a recognised concern within sports medicine, sometimes referred to as Relative Energy Deficiency in Sport (RED-S). This is a genuine health consideration best assessed by a qualified sports medicine professional or sports dietitian, not something to self-diagnose or manage through informal online guidance.
Sports nutrition isn't a separate discipline from general nutrition — it's the same science, scaled and timed around specific training demands. Carbohydrate for fuel, protein for repair, careful hydration, and attention to overall energy balance form the foundation; from there, an individualised plan built with a sports dietitian accounts for the specific sport, body, and goals involved.
14 questions. Select an answer for each, then submit to see your score instantly.