A force equal to two or three times your body weight is exerted through your joints with every one of the 40,000 strides typically taken during a marathon - causing you to lose around 2cm in height. The muscle contractions cause small amounts of bleeding and swelling (microtrauma) in muscle tissues, while body weight can drop by 2% as a result of dehydration. But with the right approach, you'll be back on your feet in no time.

1 Pack a snack
Start to refuel within 15 minutes of reaching the finish line. Choose something high in carbohydrate with a little protein. Proprietary recovery drinks, such as Lucozade Sport Recovery, work fine, but strawberry Nesquik is also good. Salty foods, such as pretzels, help replace electrolytes as well as stimulating thirst, while fruit boosts antioxidant intake to help repair tissue damage. Drink little and often.

2 Get into tights afterwards
Research in the Journal of Sports Science and Medicine last year confirmed that they can help accelerate recovery, by aiding venous return and cell repair. For a double whammy, wear compression socks, a la Paula Radcliffe, in the race itself, and you'll have less muscle damage to recover from.

3 Say no to a hot bath
You may want nothing more than to sink into a hot bath post-race, but you need to cool down, not heat up. I've never managed to brave an ice bath, but I find that running a cold shower nozzle over my thighs and calves helps.

4 Pop some pills
Anti-inflammatories can help reduce pain and swelling. I take arnica tablets, but a non-steroidal anti-inflammatory such as ibuprofen does the job, too.

5 Give it a rest
Forget a celebratory night on the town. The best idea is to sleep. If you don't, you'll probably have a nasty cold by the end of the week.

· Sam Murphy will be running her 15th marathon on Sunday, and is author of Marathon: from Start to Finish, published by A&C Black at £11.89.