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Diet and Training: What to Eat and When

When you’re training, what you eat and when you eat it can make the difference between powering through your workout and feeling like throwing in the towel half way through. Indeed, one of the reasons you may not feel like exercising is that you’re simply too tired – which is often the result of not giving your body the fuel it needs to be active.

The first step towards eating to achieve peak physical performance is to have an overall healthy diet – not just on the days you’re exercising, but on non-training days too. In the UK, this means following the Eatwell Guide (i), which recommends at least five portions of a variety of fruit and vegetables a day as well as a good balance of starchy carbohydrates (wholegrain where possible), low-fat and low-sugar dairy (or dairy alternatives), protein and small amounts of unsaturated fats.

Meanwhile, if you’re in training there are other considerations to keep in mind…

Eat carbs for energy

Eating as few carbohydrates as possible may be fashionable right now, but whether you’ve just started exercising to improve your fitness level, you’re training as a bodybuilder or preparing for an important sporting or fitness event, you need carbs to keep going. Carbs provide your body with energy – if you’re exercising and trying to follow a low-carb diet, it’s more than likely you’ll feel tired and unable to concentrate, and your recovery after exercise may be slower too.

The Eatwell Guide confirms that starchy carbohydrates are a good source of energy as well as the main source of a range of nutrients in our diet. They provide around four calories of energy in every gram, and are often referred to as the body’s preferred fuel source for people involved in high-intensity activities.

When you eat carbohydrate foods, they break down into glucose and other simple sugars in the bloodstream. Your body then burns glucose to produce heat and a molecule that stores and releases energy into the cells called adenosine triphosphate (ATP). Any remaining glucose is stored in your muscles and liver as glycogen.

Aim to have some carbs with every meal, and increase the amount on heavy training days where you have two or more sessions or one long session of two hours or more. According to the NHS, healthy sources of carbs include:

  • Whole grain bread and breakfast cereals

  • Brown rice

  • Whole wheat pasta

  • Potatoes with skins on

  • Fruit (including dried and tinned fruit)

Fill up on protein to build muscle

Interestingly, protein gives you glucose too, but the conversion takes longer compared to eating carbs. However, protein is thought to be important if you want to maintain or increase your muscle size as well as reduce muscle breakdown and damage caused by exercising.

Eat some protein with most of your main meals if your focus is on muscle building. According to the Eatwell Guide you should eat some beans, pulses, fish, eggs, meat and other protein, and aim for at least two portions of oily fish every week, (such as salmon or mackerel). Aim to have less red and processed meat such as bacon, ham and sausages – instead choose lean cuts of meat and mince. Meanwhile, beans and pulses are also good meat substitutes because they’re lower in fat and higher in fibre and protein.

Other plant-based alternatives that provide protein include tofu, Quorn, seitan and tempeh. Milk, cheese, yoghurt and fromage frais are also good sources of protein and some vitamins, plus they provide calcium to help keep your bones strong.

What to eat before

It’s a good idea to have a main meal some time before you exercise to make sure your body has the fuel it needs. Timing your meal is important, as eating too much too close to exercising can cause stomach discomfort, especially if you have a meal with lots of fat, protein and fibre – all of which tend to take longer to digest than other foods.

You may need to experiment a bit with your meal timings, but start by having a main meal about three or four hours before you start training. Have a healthy combination of carbs and protein, but less fat and fibre to make sure your meal has been absorbed fully by the time you start to exercise (food before exercise is only beneficial when it has been digested).

You may also want to try having a light snack an hour or two beforehand (this is particularly advisable if you train early in the morning and don’t have time for a main meal several hours before you start). Ideally, this should contain carbs for energy and some protein to help with muscle building and recovery. Try one of the following:

  • Protein drink that provides both protein and carbs an hour or two before your workout.

  • Breakfast cereal with milk (porridge, for instance)

  • Banana with peanut butter

  • Crackers with cottage cheese

  • Apple with half a palmful of walnuts

Avoid anything fatty this close to your workout session – such as full-fat cheese, chips, avocados or lots of nuts – as well as snacks with too much fibre (such as raw veggies, nuts, seeds or high-fibre cereals).

What to eat during

If your exercise session lasts an hour or less, you usually don’t need anything other than water to stay hydrated while you’re working out. Also drink water regularly before your session begins, so that you start well hydrated.

But if you’re training for longer – or if your session is a particularly heavy one or you’re training in hot temperatures – having some fast-absorbing carbs may replenish your energy levels, prevent dehydration and improve your performance.

Try having a sports drink that contains electrolytes (mineral salts such as potassium, calcium and magnesium that are lost through perspiration), a sports bar, a glass of milk, banana or some dried fruit for a quick energy boost.

Having some protein while training – such as a  protein drink or a protein bar – can be a good idea for certain people, such as athletes doing intense or multiple daily sessions and body builders aiming to gain large amounts of muscle mass.

What to eat after

Post-exercise nutrition can help you recover more quickly from your workout session too. According to the NHS you should drink plenty of water and eat as soon as you can after working out, ideally within an hour or two – this could be your next main meal. Meanwhile if you train intensely or several times a day, having some carbs and protein – such as a glass of milk and a banana – within 60 minutes of finishing your session may help you recover faster.

Having protein after exercise can also help if you’ve had a heavy or long session or you’re looking to increase or maintain muscle mass. Try some grilled chicken, an omelette, peanut butter on whole grain toast or a tuna fish sandwich. A whey protein drink is a good example, as whey contains fast-acting proteins that get into your muscles quickly. A protein drink is also ideal if you tend not to feel particularly hungry after exercising.

Drinking sour cherry concentrate after your workout may also help you to recover, especially if you’ve had an intense session. One study suggests it may help reduce muscular pain brought on by excessive exercise (ii), while another found it helps with muscle recovery in marathon runners after drinking it for just five days before a race (iii). A 2014 study involving cyclists also claims drinking sour cherry concentrate may help reduce inflammation and oxidative stress brought on by intensive exercise (iv). Look for high-strength cherry concentrate products, as these are thought to offer the best results.



  1. The Eatwell Guide. produced by Public Health England in association with the Welsh government, Food Standards Scotland and the Food Standards Agency in Northern Ireland.

  2. , . , , et al. Efficacy of a tart cherry juice blend in preventing the symptoms of muscle damage. Br J Sports Med. ;40:679-83

  3. , , , et al. Influence of tart cherry juice on indices of recovery following marathon running. Scand J Med Sci Sports. ;20(6):843-852.

  4. , , , , . Montmorency cherries reduce the oxidative stress and inflammatory responses to repeated days of high-intensity stochastic cycling. Nutrients. ;6(2):829-843.

Our Author - Keri Filtness


Keri Filtness has worked in the Nutrition Industry for 19 years. She is regularly called upon for her professional comments on health and nutrition related news. Her opinions have been featured by BBC3, Prima, Vitality, The Mirror, Woman’s Own and Cycling Weekly, amongst others. She has also worked one to one with journalists, analysing their diets and health concerns and recommending changes and additions, where appropriate.

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