The more physical activity you do, the more glucose your body uses, the more carbohydrates you need to consume to replenish your fuel stores. If there's no fuel for the engine it's not going anywhere!"

Unfortunately, in reality, sexual activity doesn't burn many calories. But seeing as Valentine's Day is looming and so love may be in the air, let's have a fun look at five possible scenarios for Valentine's night and what fuel each may require...

1. Not getting any
Think of it as being 'in-training' and get yourself down to the local gym. Why? Well, there are at least three good reasons. Firstly, physical activity will make you feel better about yourself and will help you get in shape ready for action. Secondly, it's a more productive way to work-off any sexual frustration. Last, but certainly not least, the gym is the most common place for meeting a new partner.

And, if you want to get the best out of your work-outs, then you need the best nutrition advice. So invest in a copy of the new book 'Fuelling Fitness for Sports Performance' - it's based on the latest scientific information and is designed to help anyone who exercises on a regular basis improve their performance through their diet.

2. A kiss and a cuddle
The warm-up for hopefully more to come... But don't expect to get warm - the energy cost is very low. In fact you might as well be asleep as you'll burn the same amount of calories per hour just sleeping.

For example, if you weigh 80kg (about 12½ stone), you'll burn about 72kcal per hour - that's only equivalent to an apple, 6 jelly beans or 2 squares of chocolate. A chocolate option is probably best comfort-wise!

3. A 'quickie'
The sprinter of the love-making world. No point looking at calories burned per hour - this workout will only last a few minutes. And, if that's all you've got time for then you've probably not got much time to eat.

But, if you need a quick energy fix then go for some jelly sweets or dried fruit.

4. A night of passion
The endurance athlete of the bedroom. But with only a small energy cost for general sexual activity it's hardly an endurance exercise - a marathon runner burns 10 times the amount of calories! But, let's indulge ourselves and have a carbohydrate rich meal for starters - try a delicious plate of fresh pasta, tossed in lemon juice & olive oil, topped with warm baked salmon or goats cheese, served with a fiery rocket & parmesan salad.

Prepare a platter of fresh fruit like strawberries, mango & pineapple and a decadent bowl of warm chocolate to dip them into for afters or 'between courses'!

5. A vigorous horizontal workout!
The power athlete - only burning a few calories per hour - but you'll have to be fit to keep vigorous sexual activity up for an hour! So eat a nutrient-packed carbohydrate-rich diet to fuel your training program.

Pre-bedroom activity you'll want to opt for a carbohydrate-rich meal that's light - so no baked tatties tonight!

Opt for cous cous flavoured with lemon & coriander and served with warm-coloured vegetables like tomatoes & peppers and don't forget your protein - some grilled chicken or haloumi cheese should do the trick.