Just like a car, the quality of fuel you put into your engine will dictate how well it performs. This is especially important on long distance cycle rides. This article explains the types of fuels you need, how they are used and why carbohydrate is best.

For the most part, energy production during a long-distance ride happens at a relatively low rate, and it comes mostly from carbohydrate and fat with a small contribution from protein. Carbohydrate is the preferred fuel for working muscles and is stored in the muscles and liver as glycogen. If you have not consumed carbohydrate before a ride, and replaced it during the ride and at the end of each day of a multi-day ride, this can be a limiting factor on a long-distance ride.

Good foods for cycling

The involvement of protein in energy production is never more than 10% of total energy expenditure, but it does result in a significant amount of protein being used from your body's protein stores. Protein is used as an energy source during the latter stages of a ride - when your body's carbohydrate stores have been depleted.

During long exercise it is more likely that you'll use protein as an energy source. When protein is used, it can exacerbate dehydration, as urine production is stimulated to speed the excretion of the waste products from protein (amino acid) breakdown.

It is advisable to eat some form of protein (meat, fish, and vegetarian alternative) twice a day, with lunch and dinner to meet your protein requirements. You do not need huge amounts of protein, even if you are trying to put on muscle mass. Female endurance athletes in particular are sometimes lacking in protein in their diet.
  During exercise your body will actually attempt to keep its muscle glycogen stores intact and use some fat instead of burning carbohydrate whenever possible. However, during a long-distance ride at a steady pace, you will not be able to continue at the same pace if your carbohydrate stores run low. Fortunately, with training you can delay the point at which this occurs.

Most cycling is aerobic and it uses both glycogen and fat but, perhaps when climbing a steep hill, anaerobic energy provision may momentarily replace it when the aerobic energy production is not quick enough in providing the necessary fuel. Anaerobic activity uses just glycogen.

Importance of Hydration

During a four-hour ride it is easy for you to lose 4-8 litres of sweat, which if not replaced will have a huge detrimental affect on your cycling performance. Isotonic sports drinks (i.e. those 'in balance' with your body fluids) will provide fluid faster than any other type of drink. If you do not like these then you could alternate between sips of water and sips of a higher energy drink but you will also need a source of salt from a snack to facilitate fluid absorption. Don't wait until you feel thirsty before having a drink, you will already be dehydrated by then.

Balanced diet

Fat intake needs to be kept low for two reasons:

• It is not necessary to replace fat stores between bouts of activity.
• Less fat in the diet means that you are more likely to eat more carbohydrate foods and avoid unwanted weight gain.
• Unless you are following a vegetarian or low-energy diet, it is more likely that you are eating too much, rather than too little, protein. It is important that you do not consume an excess of protein over a long period since the excess protein calories are stored as fat it can easily lead to unwanted weight gain.
• Do eat plenty of carbohydrate rich foods.
• Avoid too much fat.
• Eat 'normal' amounts of protein, i.e. not large quantities of meat, eggs and milk.
• You do not need to supplement minerals lost in sweat. These can be replaced with a normal, balanced diet.

Suggested food and drink for training/riding

During long-distance rides you have a greater choice of foods, as you will be consuming a greater proportion of your energy consumption for the day on the bike. Suitable foods include banana, jam or other low-fat sandwiches, cereal bars, flapjack, malt loaf, scones, bagels, low-fat cake bars, low-fat biscuits, Snack-a-Jacks, currant buns and teacakes. Milkshakes can also be useful if you find it difficult to eat on the bike. 
Timing of eating  

Aim to eat and average of 30-60g of carbohydrate per hour, to maintain your performance level. This is equivalent to 1-2 cereal bars, or 1-2 large bananas, or 500-1000ml of an isotonic sports drink. 'Carbohydrate loading' is an eating regime, which aims to pack muscle glycogen stores to the brim before exercise. This involves tapering training over the days leading up to an event, to cut down on muscle glycogen utilisation. At the same time the amount of carbohydrate in the diet is increased to supply the muscles with glycogen. However, athletes do report mixed reports on its effectiveness. Foods to avoid

High energy  drinks do not cause problems in small quantities, or when interspersed with water but too much can dehydrate you and upset your stomach. Drinks lower in carbs like fruit squash or an isotonic drink are better. These will not only provide fluid quickly, but will also supply some carbohydrate. It's worth trying out different brands on shorter rides before you embark on a long ride to decide which ones you can tolerate.

Foods such as pasties, sausage rolls, pork pies and Scotch eggs are not good choices for snacks, as they are high in fat and do not provide any carbohydrate. Fizzy drinks and cola, or any drink containing caffeine should be avoided, as they will dehydrate you.