31 Oct 2013

We’re already enduring the warmest spring weather on record in Australia and summer is just around the corner, so hydration is a hot topic right now. A lot of people who work out, run or cycle regularly often wonder what they should drink to rehydrate after heavy exercise in hot weather.

Should they choose water? Or are sports drinks best?


Unfortunately, the answer isn’t always as clear as, say, water.

Even people who don’t exercise intensely would benefit from drinking an average of two litres – that’s about eight glasses – of water a day

If you do exercise, the benefits of consuming a sports drink depend on the duration and intensity of the exercise you do and how much you sweat

For example, when you’re exercising at high intensity or long duration (greater than 60 minutes), a sports drink is effective for rehydration because it contains a low amount of added sugars (compared to juice or soft drinks) and electrolytes (eg. sodium) – a combination proven to enhance absorption of fluid compared to drinking water alone.

Also, during sustained intense exercise of over 60 minutes, the added carbs (sucrose and glucose) have the benefit of providing fuel to the muscles. That’s because exercising at this level relies heavily on carbohydrates for energy.

However after about 60 to 90 minutes of intense activity, carbohydrate stores become depleted and muscles start to become reliant on burning fat for fuel, which isn’t as efficient as burning carbs.

The end result is poor performance, muscle soreness, fatigue and potentially delayed recovery.

The process of switching from carbohydrates to fat for fuel is known as ‘hitting the wall’, and sports drinks are a convenient way of preventing this by replenishing carbohydrates stores. Not only do they provide an alternative or additional source of fuel to sustain a high level of intensity, but sports drinks can be crucial for properly maintaining important body functions.

Another reason you should avoid guzzling huge amounts of water in this intense exercise situation is because it provides no sodium.

The sodium in sports drinks plays a valuable role in improving fluid absorption as well as stimulating the desire to drink larger volumes to ensure adequate rehydration.

Sodium can also play a role in replacing the large salt losses that can occur in long events when you’re sweating heavily.

The bottom line is that water is the best thirst quencher for anyone doing just a session at the gym or a jog under 30 minutes.

If you get bored with the flavourlessness of water, a refreshing alternative is to dilute a sports drink by mixing in extra plain water.

But for intense and prolonged exercise, sports drinks are a good option.

Kathleen Alleaume

Kathleen Alleaume is an accredited exercise physiologist and nutritionist and founder of The Right Balance