In my day job I recently interviewed the man in charge of new products at UK sport nutrition firm Science in Sport (SiS).

The firm, like rivals High5, specialises in producing energy gels, bars and drinks for endurance athletes – typically runners, triathletes and, yes, cyclists (thanks to SiS’ PR people for the opposite pic of Sir Chris Hoy with one of their drinks).

When interviewing SiS new products manager Luke Heeney, one thing that really stuck in my mind was what he said about maltodextrin – a glucose polymer that, in the UK at least, is typically derived from wheat starch. Heeney said maltodextrin is used in almost all endurance products because it is a slow-release carbohydrate and it is cheap. Which got me thinking...how cheap exactly?

I managed to buy a 2.5kg bag from bulkpowders.co.uk for £7.99…to put that in context, a 2.2kg tub of High5 energy drink powder is currently selling on Wiggle for £26.99.

Do it yourself

In our interview Heeney did point out that "not all maltodextrins are equal" and that his firm goes to great lengths to identify the best molecular weight of maltodextrin for maximising sporting performance. However, SiS unashamedly works with the likes of Hoy, Mark Cavendish and other top athletes to develop products that with give them the most marginal of advantages over their opponents.

I'm pretty sure that for us mere mortals, the following will suffice:

High5 makes its energy drinks and gels on the principle of a 2:1 ratio of two parts maltodextrin to one part fructose sugars, the idea being you get the quick energy hit of the fructose, and avoid a sugar crash with the slow release maltodextrin carbs.

Using this 2:1 ratio and the general principle that your body can absorb 60g of carbohydrate per hour (1g per minute), it is pretty easy to make your own energy drink.

What you need:
• Maltodextrin
• Sugary squash - my preference is Tesco’s Blackcurrant High Juice, with 36.7g of sugars per 100g, and costs just £1.49 per litre
• Lo Salt, e.g. Saxa So-Low at just £1.35. This is a 50% sodium and 50% potassium salt. Using these primary electrolytes will help replace some of the salts and minerals your body loses when sweating.
• Tap water

How to make it:
• Pour around 50ml of the squash into a 500ml or 700ml drinks bottle. Using High Juice this will give you between 18g and 20g of sugars.
• Add 40g of maltodextrin, a decent pinch of Lo salt, and fill the bottle up with tap water to the 500ml mark.
• Give the bottle a good shake and then taste. If it’s too sweet, add more water, not sweet enough (or slightly too salty) add a bit more high juice. Bear in mind that, if you’re like me, your sense of taste may become heightened during exercise…therefore always err towards the slightly weaker taste in the kitchen, because what might taste just right before exercise can taste sickly sweet during.

One other thing to mention is that it is only really worth making up an energy drink if you are going to be cycling for more than an hour. Anything under an hour and, assuming you have a reasonably balanced diet, your body should contain all the energy you need.

Other homemade sports drinks

If you are doing a particularly intense workout in under an hour, then you might want to make yourself a homemade “zero calories” electrolyte drink, like those made by High5. This is very simple: just add a splash of a “no added sugar" squash and a pinch of Lo-salt to a bottle and fill with water.

Many of the nutrition companies also sell “plus” versions of their drinks that include caffeine. The cheapest alternative is just to take a strip of Pro-plus or other caffeine pills with you (take them sparingly though – you don’t want to go to all the above effort of avoiding a sugar crash only to have a caffeine crash).

The other type of drink that firms like SiS and High5 sell are recovery drinks, both for straight after a big workout and later on for general muscle building. Again, go to a site like bulkpowders and buy some whey protein (or soy protein if you're a vegetarian). For immediately after exercise you’re going to need carbs to help you recover and replenish your depleted glycogen stores, and to help speed up the movement of the protein to your muscles to begin repairing them.

The easiest way to make your own “Rapid Recovery” drink is to repeat the above process for the energy drink, but halve the amount of maltodextrin to 20g and add 20g of whey protein. For an overnight recovery, just get some flavoured whey protein (chocolate’s my preference) and mix 30g with 300ml of semi-skimmed milk, and drink before bedtime (the milk helps slow down the release of the protein, helping spread out the absorption during sleep).

Homemade energy food

I’ve yet to find a way to make my own energy gels, but the cyclist’s classics all apply here as good alternatives, especially earlier on in the ride when the stomach finds it easier to digest solids; these classics include bananas, malt loaf, and fig rolls.

My personal favourites are flap jacks…especially as they are ridiculously cheap: you can get a 1kg bag of the main ingredient porridge oats (essential cycling breakfast) for just 75p. I use this BBC Good Food recipe, but reduce the brown sugar amount to 100g and use 4 tablespoons of golden syrup…this just helps them to be a bit more moist and stay together better when eating while cycling.

If you can't be arsed to bake, then Kellogs' Breakfast Bakes pack 31g of carbs into each bar, with a roughly 50/50 split between sugars and slow release carbs.

There's also always the humble Jelly Baby. Not great for slow-release energy, but perfect for a quick sugary pick-me-up if you're flagging, or facing a major hill climb in the next couple of miles.