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Cycling Nutrition

Your body needs fuel.  More precisely it needs the energy contained in the fuel.  The proper unit of measure for this energy is a kilojoule but a more commonly known unit is a calorie, expressed as cal or kcal.  There are 4.2 kilojoules in a calorie.

The estimated average daily energy requirement for a normally active woman is 2,000 kcal or 2,500 for a man.  These are figures for ‘average’ people and will vary depending on your size but can be used as good ball park figures.

Your body stores energy in the form of fat and as glycogen in the muscles and liver.  The glycogen store, when fully topped up, equates to about 2,000 calories.  The amount stored as fat varies from person to person but for most of us it is too much!  The energy in fat is not as easily accessible as that stored as glycogen and to optimize energy release from your fat stores you need to be exercising at fairly low levels of intensity.
When exercising your body requires more energy.  It will obtain this energy from the most available source, which is food being processed by the stomach.  If this is insufficient it will then deplete the glycogen supplies and then move on to either fat or protein (produced by breaking down muscle mass), depending on how much effort is being expended and how rapidly the energy is needed.  Okay, it’s not actually that simple but that linear view will be sufficient for our purposes: we’re not top flight athletes.
The amount of additional energy you need will depend on the amount of effort you are putting in.  On a fairly gentle ride you might need an extra 3-400 calories per hour of riding.  If you are powering along at maximum speed in hilly terrain the figure could be more like 800-1,000 per hour.
If you were to ride for 4 hours at a gentle pace you might burn an extra 1,200 -1,600 calories.  This is a significant amount, being half an average man’s normal intake and about three quarters of a woman’s.  You need to put these calories back in during the ride, otherwise you run the risk of bonking.
Where do the calories come from?  Well, from what we eat.  More specifically from: 



400 kcal



400 kcal



900 kcal



700 kcal


Good new!  That liquid lunch break at the pub is a brilliant way of topping up the glycogen supplies. 


Sadly not.


Although alcohol contains a lot of energy per gram and is rapidly absorbed by the body, the available evidence suggests these Calories are not used significantly during exercise.


And unfortunately there are also negative effects:


  • it is a diuretic and contributes to dehydration
  • it slows down glycogen production and release from the liver so energy is slow to get to the muscles and the stores are not topped up quickly enough
  • it can make you wobbly!


In fact studies have shown that cycling after taking alcohol requires more energy, produces a higher heart rate, and stimulates a higher cardiovascular demand.  And you fall off a lot.


So what should I eat?


You should eat a normal well balanced diet combining carbohydrates (about 60%), protein (about 15%) and fat (about 25%) [and maybe a little alcohol].  You will need to eat more of it though to replenish the extra energy you are using.


Carbohydrates – 60%


Carbohydrates are the cyclist’s main source of energy.  They are basically either simple carbohydrates which the body can break down and utilise very quickly or complex ones that take a little longer.  Put another way, some get used up very quickly and others are slow burners. 


A useful tool is the Glycemic Index.  This gives a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after eating.   The higher the GI a food has, the more rapidly digested and absorbed its energy is.  Below is a table of some common food types but if you want to find the GI value of other foods visit http://www.glycemicindex.com/ which has an extensive database.  Most people are surprised at the GI value of some foods the first time they come across them.  For instance grapefruits, which are sweet and sugary are low GI and white rice, viewed by many as a bulk slow burner, is one of the highest GI foods going.


In general we should eat foods with low GI values to help maintain a steady blood sugar level.  However, whilst on the bike we might need to use high GI food to provide a quick boost, especially if close to bonking.  If you are going on a long ride a good tactic is to to pack in some low GI foods before you start and then keep up a regular supply of medium/high GI foods interspersed with low GI foods whilst on the move.  After the ride pack in more low GI foods to provide sustained energy for recovery.


Glycemic Index (0-100)

Low GI Foods

Medium GI Food

High GI Foods



Boiled potatoes


Mashed potato






White bread


Red lentils


Pitta bread




Whole milk


Basmati Rice




Dried apricots






Skimmed milk


Digestive biscuit




Low-fat fruit yoghurt


New potatoes




Wholemeal spaghetti


Coca cola


French fries






Coco Pops




Shortbread biscuit


Jelly beans


White spaghetti




Rice cakes


All Bran


Rye bread


Rice Krispies




Pineapple, fresh




Porridge made with water




Jacket potato


Baked beans in tomato sauce


Shredded wheat


Puffed wheat


Milk chocolate


Mars bar




Stoneground wholemeal bread




Parsnips, boiled






White rice, steamed




Wholemeal bread






Fat – 25%


Fat has long been labelled as an evil in dietary terms but it is an essential part of our nutritional needs.  A lack of fat in the diet can adversely affect blood pressure and blood clotting, inhibit the body’s ability to control inflammation and lead to low energy levels and poor recovery from exercise.


Fats come in three varieties:


Saturated - If any fats are ‘evil’ then these are they.  These major contributors to heart disease have no known positive benefits for sporting performance or even health generally.  Typically these fats are animal based, such as cheese and butter, and are widely used in processed foods.  Of course most of us find them to be the tastiest fats as well.


Monounsaturated  - Generally monounsaturated fats are widely believed to be the healthiest of all the fats.   They are said to help reduce the bad form of cholesterol in the body and to increase the amount of good cholesterol.  Sources of monounsaturated fats include nuts, seeds, avocados, olives and oils made from these products.


Polyunsaturated - These contain ‘essential fatty acids’ which the body cannot produce by itself and have to come from food.  Whilst they can also reduce the harmful kind of cholesterol in the body they can also reduce the good cholesterol so need to be balanced with monounsaturated fats.  Good sources of polyunsaturated fats are vegetable oils and oily fish.

Protein – 15%


The major consideration for a long distance cyclist is that protein’s role in maintaining and replacing the tissues in your body.  Your muscles, organs and many of your hormones are made up of protein, and it is also used in the manufacture of hemoglobin, the red blood cells that carry oxygen to your body. Protein is also used to manufacture antibodies that fight infection and disease and is integral to your body's blood clotting ability.


So you need protein to help your muscles repair after you have been punishing them all day, to maintain your red blood cell count so you don’t need a transfusion every evening, to help fight off illness and to make sure you don’t bleed to death from minor road rash.


Good sources of protein include:


  • Meat – e.g. beef, poultry, pork and lamb
  • Fish and shellfish
  • Dairy products – e.g. cheese, yogurt and milk
  • Eggs
  • Beans, peas, oats and legumes
  • Tofu and soy products
  • Nuts and seeds


For post ride recovery try a yoghurt after a short ride or a milkshake after a longer effort. It can be worth trying a carbohydrate and protein recovery drink after an all day effort to maximise recovery before the next day.  There are a number of proprietary drinks available but they are all best consumed within 20 minutes of finishing your ride to maximise muscle recovery. 


There is also evidence to suggest that protein can help the body in the processing of glycogen and that consuming protein and carbohydrate in a ration of 1:4 optimises the absorption rate.  Again you can buy sports drinks made up in this proportion.  Alternatively you can make sure whatever you are eating during the ride is in roughly those proportions.

Micro Nutrients and Vitamins


Whilst carbohydrates, proteins and fats provide the body with fuel (as well as other things) it also needs a variety of other things in order to function properly.  These are broadly termed micronutrients and include things like vitamins, minerals and enzymes.  The body needs these to maintain the body’s immune and hormone system (you’ll need some adrenalin to get you up those hills), to repair body tissues and to control nerve and muscle function and fluid levels.


The best way to make sure you are getting the micro nutrients you need is to eat your ‘five a day’ fruit and vegetable portions.  Although, when you are training hard and using twice as much energy as usual, you will also need to up your micro nutrients.  So you may have to eat ten a day.  [Please note that whilst wine is made from grapes it does not count as one of your five a day.  Nor does cider.  Or any other alcoholic beverage.]



You should strive to maintain the balance of 60/15/25 (or so) at each meal to provide the body with a steady stream of all the things it needs.  Of course this may not be easy if you are on the bike all day.  Even if you stop for proper meals ideally you should maintain a steady supply between stops if you do not want to suffer from peaks and troughs in performance. 


Final Word on Nutrition


Training when dehydrated and with low energy levels can be a wasted effort or even detrimental.  Yes, there are many riders who pride themselves on being able to complete a 100 mile ride on one 500ml water bottle and a lick of a flapjack wrapper.  But just think how much better they would feel and how much fitter they would become if they weren’t so hard.



Bonking on the Bike

[excellent bike handling skills required]


If you have every suddenly become completely exhausted on a ride (suffered from ‘the bonk’ - also called ‘crashing’ or ‘hitting the wall’) it is because you have depleted your glycogen supply and your body is switching to back up energy supplies which it cannot access as fast as you are demanding it.  It’s back up energy sources are fat and muscle protein.  Unfortunately your body will find it easier and quicker to break down the protein in your muscles for energy than to release the energy from fat stores.  You need to put calories in quickly with high GI carbohydrates and combine this with low GI carbohydrates to start filling the glycogen tanks again.




Mystery Superfood


And the superfood is – milk!  No really.  Not only is it an excellent source of protein, it contains good levels of carbohydrate, packs a range of vitamins and minerals and hydrates you as well.  When you’re training hard, drink one to two pints a day. This sounds a lot, but you’ll feel the difference when you recover quicker and whizz through that training.





Top tips:

  • eat little and often.  Set a timer to remind you to eat if necessary.  Eat even if you are not hungry – you have a lot of calories to consume!
  • listen to your body.  If it starts craving bacon its probably after protein, if it’s chocolate you need carb energy fast.  Get a sugary fix AND eat some slower burners otherwise you will ‘crash’ again quickly.
  • down protein after your ride each day to improve your recovery.  Try to do it as soon after the end of the ride as possible.  There is an optimum window of between 10-20 minutes after the ride when the body can make best use of the protein to repair muscles and aid recovery.
  • on long rides consume carbs and protein in a 4:1 ration.  This will aid energy levels and boost recovery.
  • caffeine can help your concentration levels towards the end of a long ride but don’t overdo it.  Carry emergency caffeine gels.
  • things can taste sweeter towards the end of a long ride so if you are using energy drinks dilute them a little more as the day progresses.