Updated 20th April 2016
What you eat and drink the day before the marathon as well as on the day can have a big effect on your performance. You’ll be burning approximately 2,600 calories over the course so consuming the right foods, avoiding dehydration and getting the timing right are all-important when it comes to sustaining a high-energy output for several hours. Of course, everyone’s different and there’s no single nutrition or hydration strategy that suits all but here are some simple rules to make sure you run your best race.
Your main focus should be on fueling and hydrating, getting your body ready for the race. This means eating a balanced diet, with a mixture of healthy carbs, protein , plenty of fresh fruit and veg and minimising highly processed foods. This is not the time for experimenting with new foods or drinks.
As glycogen depletion is a limiting factor in your marathon performance it ,makes sense to maximise your glycogen stores before the race set off with as much fuel as possible. Most runners benefit from carbohydrate loading, which is a dietary protocol for increasing your carbohydrate stores (glycogen).
There no need to do a depletion phase at the start of the week. Studies have shown that tapering your training for the last 2 – 3 weeks plus increasing carbs (8 – 12g/ kg BW/ day) for at least 2 days before race – Friday and Saturday – achieves just as good results.
The day before
By now, your muscle glycogen stores should be almost fully stocked and you should be feeling rested. Your goals are to top-up your glycogen stores, stay well-hydrated and avoid any pitfalls that may jeopardise your performance the next day.
Eat little and often throughout the day and avoid big meals so you don’t over-burden your stomach. It’s not a good idea to over-indulge the night before a race as this can play havoc with your digestive system and keep you awake at night. You may also feel sluggish the next day.
Stick with familiar foods. Eat only foods that you know agree with you and eat them in normal-sized amounts. Avoid gas-forming foods (or combinations of food) such as beans, lentils, cruciferous vegetables (broccoli, Brussels sprouts, cauliflower), bran cereals and spicy foods the night before the race. They may make you feel uncomfortable.
Aim to stay well-hydrated. Keep a water bottle handy so you remember to drink regularly throughout the day. This is especially important if you are travelling to the race venue on this day, as it is easy to forget to drink.
The most simple method to assess hydration status is to look at urine colour. From a practical point of view, you should be producing a dilute, pale-coloured urine. Concentrated, dark-coloured urine of a small volume indicates you are dehydrated and is a signal that you should drink more
Alcohol is a diuretic so it’s better to avoid it completely. If you overindulge, you may feel below par the next day.
By now, your muscle glycogen stores should be fully stocked and you should feel ready to go! All that remains to be done before the race is to top-up your liver glycogen stores at breakfast time (liver glycogen is normally depleted during the overnight fast) without feeling bloated, and replace fluids lost overnight.
You need to get up early enough to eat and digest your pre-race meal. Ideally, schedule your breakfast 3 – 4 hours before the race start time. So, if your race starts at 10 am, have breakfast at 6 – 7 am. Consume 25–50 g of carbohydrate for each hour before the start of the race, depending on your body weight (the heavier you are, the more carbohydrate you’ll need). So, that’s roughly 75 – 150g.
Stick with what you’re used to. Carbohydrate-rich foods, such as porridge, cereal, toast and fruit, are good choices . Include a little protein or healthy fat to increase satiety and provide a more sustained energy release. If you find it difficult to eat because of pre-race nerves, try a liquid meal (for example, a smoothie, milk or milkshake) or semi-solid meal such as yoghurt or pureed/ mashed fruit. Bananas or porridge pots are good options if you need to eat on the go.
Have a small carb-rich snack (50 – 75g) about 1 hour before the race. A banana, handful of dried fruit or a fruit & nut bar are good options. During the race, keep blood sugar levels topped up by consuming 30 – 60g carbohydrate per hour – use whatever you trained with and can stash easily in your pockets. Examples include dried fruit, date and nut energy bars, jelly beans or babies, sports drinks or gels.
Hydration is a fine balance. Don’t start the race dehydrated, but nor do you need to aggressively overhydrate beforehand. As a rule, the ASCM advise 5 – 10ml of water/ kg BW in the 2 – 4 hours before the race. You can then have another 125–250 ml or just enough to satisfy your thirst during the warm up or about 45 minutes before the gun goes off.
During the marathon, there are no strict rules about how much to drink as this depends on how much fluid you lose through sweat. The International Marathon Medical Directors Association suggest 400-800ml of fluid per hour, depending on your seat rate.
If you’ve practised a drinking strategy in training, you probably have a good idea how much to drink but if the temperature soars on race day then you must drink more.
But don’t drink excessively. Drinking more than you’ve lost increases the risk of hyponatraemia (low levels of sodium in the blood), which is a serious and potentially fatal condition. As a rough guide, aim to drink 125–250 ml –about two or three big swigs – every 15 to 20 minutes or according to thirst. Avoid drinking large amounts in one go.
You don’t need to drink at every aid station but don’t be tempted to miss out the early fluid stations to gain valuable time, particularly on a warm humid day – dehydration later on will slow you down even more. Slowing a little as you run through the stops while drinking may add 1 or 2 minutes to your time but it can repay you with 10 or 20 minutes gained by the finish of the marathon.
Stick with whatever you have used in training and don’t try anything new. Continue drinking until the last few miles.
If you’ve been drinking according to your thirst and taking in carbohydrates throughout the race, you should be able to maintain the pace to the finish line.
After the race
Before you go off and celebrate, you need to replace the fluid you have lost. Drink around 500 ml, little and often, in the first 30 minutes after the race, and then keep sipping every 5 to 10 minutes until you are passing pale coloured urine again.
You also need to start replenishing glycogen stores – consume 1g carbohydrate/ kg BW. To speed muscle recovery, consume around 20g protein. Milk or other milk-based drinks or recovery drinks, yogurt, home-made super-flapjacks, blueberry muffins or fruit and nut loaf are good options.
Signs that you MAY BE dehydrated during the race:
- A dry mouth
- Extreme thirst
- Unusually lacking in energy
- Fatiguing early during the race
- Feeling excessively hot
- A bad headache
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