Sports nutrition advice arrives wrapped in jargon. This glossary explains the common terms, from electrolytes to the recovery window, so you can read a label or a tip sheet and work out what actually applies to you.

Sports nutrition labels and advice love their jargon, and half the confusion for new exercisers is not knowing what the words mean. Once you can tell a gel from an oral rehydration solution, or an electrolyte from a macronutrient, most product claims become much easier to judge. Here is a plain-English glossary of the terms you are most likely to come across, along with what each one actually means for your training.

Macronutrient terms: the energy in your food

Macronutrient The nutrients your body needs in the largest amounts: carbohydrate, protein and fat. These are the energy-yielding nutrients, the ones your body breaks down for fuel.

Carbohydrate The macronutrient with the strongest evidence behind it for exercise. Reviews of research stretching back decades consistently point to carbohydrate as the primary macronutrient for sustaining and improving physical performance, particularly for high-intensity efforts.

Protein Found in every living cell, with both structural and functional jobs in the body, protein makes up roughly 15 to 20 per cent of your total body mass. It also supports muscle repair after training.

Fat The third energy-yielding macronutrient. Expert panels note that dietary fat can sustain an active person through lower-intensity training bouts, while carbohydrate remains the go-to fuel for hard efforts.

Micronutrient Vitamins and minerals, needed in much smaller amounts than macronutrients. They do not provide energy themselves, but they are involved in the metabolic processes that let your body get energy from carbohydrate, protein and fat. Many B-group vitamins, for example, help your body use those energy-yielding nutrients, and most B vitamins cannot be stored, so they need to be eaten regularly through a varied diet.

Electrolytes: what they actually do

Electrolyte A mineral that carries an electric charge when dissolved in water or body fluids, including blood. You have electrolytes in your blood, urine and tissues, and you get them from the foods you eat and the fluids you drink.

Sodium An electrolyte that helps keep the volume of blood and tissue fluids in your body at the right level. A small amount is essential, yet the average Australian consumes almost double the sodium they need for good health.

Potassium Another of the body’s main electrolytes, and one of the two, alongside sodium, that sweat-loss products are designed to replace.

Calcium The most abundant mineral in our diets and one of the main electrolytes. It helps make and keep bones and teeth strong, which is where about 99 per cent of it sits, while around 1 per cent supports metabolic functions including muscle contraction.

Glycogen, fuelling and the recovery window

Glycogen The form in which your body stores carbohydrate, held in the muscles and drawn on for energy as you exercise. Long or hard sessions use up these stores, which is why regular carbohydrate intake matters most for anyone training on consecutive days.

Recovery window The period straight after a workout when eating and drinking helps your body bounce back. Sports dietitians suggest eating a meal or snack with some protein in the hour after you finish, along with fluid. Shortchange yourself on both and you may feel tired and lethargic, your muscle recovery can suffer, and your next workout becomes harder than it needs to be.

Hydration terms

Your body cannot store water, so it needs fresh supplies every day to replace losses from the lungs, skin and urine. Most mature adults lose about 2.5 to 3 litres of water per day, and losses climb in hot weather and with prolonged exercise. Food helps more than people expect: most foods contain some water, and the body can get about 20 per cent of its total water needs from what is on your plate.

Sweat rate How much fluid you lose for each hour of exercise, which varies with the weather, your clothing, your health, your intensity and your fitness, since fitter people start sweating sooner and sweat more heavily during a session. You can estimate it by weighing yourself in light clothing just before you begin, recording any fluid you drink and any urine losses during the session, then working out your weight change plus fluids consumed minus urine losses and dividing the total by the hours you exercised.

Thirst A surprisingly unreliable guide to your fluid needs. By the time you feel thirsty, dehydration has already set in, so make fluid replacement a priority when you are active rather than waiting for the signal.

Over-hydration The opposite problem: drinking more than your body actually needs. You can overdo fluid intake during a workout, and in rare but severe cases over-hydration can lead to death, which is why knowing your sweat rate beats forcing down bottles on a timer.

Words you will see on supplement labels

Sports drink Also called a carbohydrate-electrolyte drink. Designed to deliver a balanced amount of carbohydrate and fluid so you can rehydrate and refuel at the same time during and after exercise. Standard versions contain roughly 10 to 30 mmol of sodium per litre.

Sports gel A highly concentrated source of carbohydrate, around 65 to 75 g per 100 ml, in a honey-like consistency that is easy to consume and quickly digested. Built for long endurance events, not a casual gym session.

Sports chews Concentrated carbohydrate in a chewy, jelly-bean form that is easy to eat and digest mid-activity. Same job as a gel, different texture.

Electrolyte replacement supplement Powders, tablets or ready-to-drink products designed to replace the fluid and electrolytes, particularly sodium and potassium, lost through sweat or other body fluids. Some come with carbohydrate added, others without.

Oral rehydration solution Often shortened to ORS. These are manufactured to World Health Organization guidelines for treating dehydration associated with diarrhoea and gastroenteritis, with sodium typically around 50 to 60 mmol per litre and a low-moderate carbohydrate content aimed at helping the gut absorb fluid rather than at fuelling exercise.

Endurance formula A marketing label for sports drinks with higher amounts of both carbohydrate and electrolytes than standard versions, typically 30 to 50 mmol of sodium per litre. Useful in specific situations, but not automatically better for every workout.

ABCD classification The Australian Institute of Sport’s system for ranking sports foods and supplement ingredients into four groups according to scientific evidence and practical considerations, including whether a product is safe, effective and permitted for use in sport. Even for high performance athletes, the AIS frames sports foods and supplements as playing a small but important role, and it recommends engaging a sports dietitian when considering any supplement.

Putting the terms into simple everyday habits

For most people exercising for health, plain water and balanced meals cover the job. Plain water is the most effective way to quench thirst and top up the fluid lost through sweat, and it is worth drinking some before you start as well. After a session, aim for a meal or snack with a source of protein within the hour, and keep a water bottle handy throughout the day.

Food first is also the sensible reading of the label terms above. A balanced plate, with half filled with vegetables or fruit, one quarter lean protein and one quarter wholegrains, gives your body what it needs without the price tag of shakes and powders. Sugary drinks, including many sports drinks, add kilojoules without other essentials, so there is no need to rely on them.

Salt deserves a note too. The National Health and Medical Research Council advises Australian adults to aim for no more than one teaspoon, or 5 grams, of salt a day, which is about 2,000 mg of sodium. An adult body only needs around 1 to 2 grams of salt daily to function, and intake above 2,000 mg of sodium a day is associated with high blood pressure, a risk factor for kidney and cardiovascular disease.

Where to go from here

Fuelling works best alongside a routine you can actually keep. If you are building one, our guide to a 20-minute bodyweight workout for beginners shows how little equipment a solid session needs, and our explainer on why rest days matter and how to use them covers the recovery side of the equation. And if your sessions leave you more sore than expected, our article on what DOMS is and what helps separates normal post-exercise soreness from something worth getting checked. For personal advice about your own fluid and nutrition needs, a GP or an accredited sports dietitian is the right person to ask.

Questions we get

Do I need sports drinks or electrolyte supplements for casual workouts?

For most people exercising for health, plain water and balanced meals are enough. Sports drinks are designed to deliver carbohydrate and fluid together for people refuelling during and after harder or longer sessions.

What is the recovery window?

It is the period soon after exercise when eating and drinking helps your body recover. Sports dietitians suggest having a meal or snack with a source of protein within the first hour after you finish, along with fluid.

Does sweating mean I need extra salt?

Not usually. Cramps that follow a bout of sweating are generally due to dehydration rather than a lack of salt, and a genuine sodium shortage from exercise is extremely rare. Drinking water before, during and after activity is the better fix.

How do I work out my sweat rate?

Weigh yourself in light clothing just before a session, record any fluid you drink and estimate any urine losses during it, then divide your total fluid loss by the hours you exercised. Your GP or an accredited sports dietitian can help you build a fluids plan.

This article is general information, not personalised medical or fitness advice. Talk to your GP, a physiotherapist or an accredited exercise physiologist before starting a new exercise program if you have a health condition or injury, are pregnant or haven’t been active for a while. In an emergency, call 000.