Exercise is great for your health; it helps you to control your weight, improves your cardiovascular health and releases endorphins which make you feel good, but to get the most out of your exercise sessions you need to know what to eat.
The body needs fuel for the muscles to work, and for this the body prefers carbohydrates. When carbohydrates have been consumed they are digested and absorbed into the bloodstream. Once the glucose (simple carbohydrate) is in the bloodstream it is circulated around the body. The muscles and liver are able to take some of this glucose and store it as glycogen (a simple term for stored carbohydrate). If you are consuming a balanced high carbohydrate diet you should have enough glycogen stored for 90 – 120 minutes of exercise.
As well as ensuring that you have enough fuel for exercise you also need to be hydrated. For every 2% of fluid that you lose, your performance can decrease by up to 20%. The body can lose a lot of fluid due to sweat loss and fluid lost while breathing. Dehydration in severe situations can cause death. In milder cases it is can cause a decreased mental performance with a reduced reaction time, an inability to concentrate and a feeling of fatigue. The body also finds it harder to regulate its temperature when dehydrated.
Before an exercise session it is important to eat a high carbohydrate snack to ensure that your muscle and liver glycogen stores are topped up. If you do not have enough carbohydrate stored as fuel for use you will fatigue early. High carbohydrate meal or snack options include; breakfast cereal with milk or yoghurt and fruit, pancakes with banana and natural yoghurt, a wholegrain sandwich with lean meat (or an egg) and salad, a roll/wrap with salad and lean meat or a pasta or rice based meal.
It is important to be hydrated before you exercise as once you start exercising you start to lose even more fluid through sweat loss. To make sure that you are hydrated you should consume enough fluid to have clear and plentiful urine. It also helps if you try to stay hydrated on a day-to-day basis.
If you are exercising for less than an hour in duration you should not need to consume extra carbohydrates. This is because your body can store enough fuel for this length of exercise, providing you eat a balanced diet high in carbohydrates each day. If you are exercising for longer than one hour in duration you should consider consuming extra carbohydrates as you may start to run out of fuel. In this instance you may like to consume a sports drink as these contain water, electrolytes and carbohydrate, or you may like to consume a food source of carbohydrate (for example a banana or honey or jam sandwich).
During exercise the amount of fluid that you need will depend on how much you sweat and how hydrated you were when you started. For most, 600 – 750mLs per hour of fluid is needed to maintain hydration. If you sweat a lot, or are exercising in a hot environment you may need more. If you sweat less or you are exercising in a cold environment you may need less. For exercise less than one hour in duration plain water is fine but for exercise over one hour you may like to use a sports drink.
Although it can be easy to forget about eating well after exercise, recovery is a very important time. The period immediately after you have finished exercise is very important as there is still a large amount of blood moving through your muscles. This high blood flow means that more nutrients can be delivered to the muscles. If you eat a high carbohydrate meal or snack immediately after a workout you provide more carbohydrate quickly to replace what has been lost during exercise. If you wait too long to eat you may find that the reduced blood flow does not allow as much carbohydrate to be taken up by the muscles. This then restricts the amount of carbohydrate available for your next workout. The recovery meal should also contain protein as this has been shown to help your muscles recover and increase in size. Good ideas for a recovery snack or meal include; breakfast cereal with milk or yoghurt and fruit, peanut butter on toast with a fruit and yoghurt smoothie, a rice salad with lean meat and vegetables, a burger with salad and a lean meat patty (or chickpea patty), a sandwich with lean meat, an egg and salad or a smoothie made with plenty of fruit, yoghurt and fruit juice.
It is also important to drink fluid after your workout to ensure that you rehydrate. If you are dehydrated when you finish your workout you need to consume more fluid to ensure that you do not risk your mental and physical performance and overall health.
Eating around a workout is vitally important as the fuel that you consume is used as energy for exercise. If you do not eat correctly, you will not perform well.