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This 2015 article from nutritionist Lee Rickards will discuss how to optimise rehydration, following weigh ins and intense training sessions.

Quick Facts
  • Boxers can expect to lose 3-5% of their body mass during a 90 minute training session. This can impair physical and mental performance.
  • If you lose 1kg in body mass during a training session, you should replace this by 150% (1.5 L) over 90 – 120 minutes.
  • Useful drinks to rehydrate with are isotonics, skimmed milkshakes, and coconut water.

Rehydration and refuelling of carbohydrates are vital for boxing to optimise physical performance and avoid fatigue.

On the night before and morning of a weigh-in, many combat sport athletes dehydrate themselves, using hot baths, saunas and sweat suits to lose the last few pounds they need to make weight.

Note: we’ll use the terms dehydration and hydration because it’s simple to understand. But you should remember that really all we’re trying to do is keep our body fluid balanced – equal what’s going in and out – to keep our cells and chemical reactions happy. Scientifically there are no such things are dehydrated or hydrated, but we can have negative and positive fluid balance.

It’s well known that dehydration is dangerous in combat sports because it can lead to loss of fluid surrounding the brain increasing the risk of severe brain injuries.

Some boxers dehydrate and restrict food intake before the weigh-in. If you’re doing this, after the weigh you should drink more fluid than you’ve lost.  However, it be might hard for you to determine what amount of fluid you’ve lost. So jump on the scales and look at how much you weigh. 1 L of water is equivalent to 1 kg. So if you’ve lost 1 kg of body mass, try to drink around 1.5 L of fluid (150%) to replace this.

When rehydrating, don’t drink the fluid you need all at once. Sip little and often and spread out your fluid intake over 90 to 120 minutes. If you drink too much straight away, your kidneys will likely filter this and you’ll pee it out.


Replace fluid with 150% of what was lost during a session.

If your weight is going up sensibly and gradually towards your fighting weight and you’re feeling OK, then your doing your job. Ideally, you’ll have practised your weight making strategy and you’ll have a good idea about your fluid requirements.

To help absorb and retain fluid a 6% carbohydrate solution with added electrolytes is generally more effective than water alone. In other words, a sports drink.

Typical drinks I’d recommend include isotonics with a pinch of salt, skimmed-milkshakes and coconut water. Watery fruits and vegetables will also contribute to fluid intake. The fructose (fruit sugar) and electrolytes will also help absorption and water-retention. Banana’s, apricots, sweet potatoes and spinach are good options but again, you should test whether these are kind to your gut before you use them after the weigh in.

An in-depth webinar is available for Boxing Science members to watch instantly, discussing hydration strategies for boxing in the context of a training session. For a limited time, a seven-day free trial is available on our Boxing Science Membership.