You may have had a great summer, so why do you feel exhausted, 10lb heavier and as though your liver is thoroughly pickled? What should you be doing to get back into work mode?

▶ First, you won't have put on as much weight as you think. Studies show that most people only put on 1lb over the Christmas period and the worst offenders put on 5lb. You won't have exceeded that over a summer break. But it is sensible to start an exercise regime straight away because any weight gain won't drop off on its own. Start small and build up – brisk walking first for 20-30 minutes three to four times a week and then your exercise of choice – a mixture of running, cycling, swimming and gym is good. Exercise with a friend – it feels sociable instead of a sweaty chore, and it's more likely to happen.

▶ Eat smaller meals but up to five a day. Cut some carbs and eat lots of fruit and vegetables.

▶ Get back into good sleep habits – have some downtime before you get ready for bed. That means no laptops or BlackBerrys under your duvet as you try to catch up on work. Go for seven or eight hours sleep and start no later than 11pm.

▶ Cut back on your drinking. Those extra glasses of wine in the sun might have made you feel fab, but in real life they make you depressed and play havoc with your sleep. Listen to your liver sighing and try not to drink every night.

▶ Get organised before you start work. I would chip away at emails, and label ones you need to deal with. But be kind to yourself and don't expect to catch up in one day.

▶ The biggest problem after holidays is feeling down. However much you like your job, the chances are you'll have liked your holiday more. Organise things to look forward to. Arranging your next holiday can often brighten the darkest mood.