This third and final part of my series looking at the importance of carbohydrates to Thai boxers, explains how carbs affect your final weight cut the week before a fight. Your body composition should already be on point (less than 10% body fat) by managing your calorie intake (especially carbs) for the previous 4-weeks or so.

In the last post I said, “Unlike fat storage, your body can store only a limited amount of carbohydrate in both the muscles and the liver.”

This equates to approximately 300-700g of muscle glycogen (carbohydrate) and 80-110g of glycogen in the liver, providing a storage capacity 400-800g. But this is only a portion of the associated weight resulting from stored carbohydrate or glycogen. For every 1g of stored glycogen, your body also stores about 3-4g of water, which makes a big difference to your body weight. Glycogen and associated water stores could be adding between 1-3kg to your weight; and that’s without reducing water intake and dehydrating in any way, just running down your muscle glycogen stores.

It takes at least 20-hours to fully restore muscle glycogen (provided sufficient carbohydrate is consumed in that period), so this method of weight reduction is not for fights with the weigh-in on the same day. Your performance will be greatly reduced if you compete with low glycogen levels. Only consider running down muscle glycogen if your weigh-in is the day before the fight.

Larger, more muscular fighters have a greater muscle mass and therefore a greater capacity for muscle glycogen storage, and can therefore drop more weight using this method. This final cut is a temporary glycogen  and water weight dumping process. If done correctly, you’ll have regained your full weight again by fight time.

Minimising your carbohydrate intake in the final week of training will run down your glycogen stores quickly and strip off the weight. Bare in mind that toward the end of the week, when your glycogen stores are virtually depleted, training is going to be very tough. It’s important that you don’t train for too long. Your training programme should be periodised for short, high-intensity sessions in this last week to provide optimum peaking for the fight; this also allows you to train effectively despite running low on glycogen.

Glycogen depletion, combined with controlled dehydration through water loading is the most effective way to temporarily drop weight the day before the fight. Getting the weight off is only half the job. It’s crucial that you understand how to pack back on all that temporarily lost body weight before stepping into the ring, or you’ll squander your advantage.

If you missed the first two parts in this blog series, you can check them out here:


    Don Heatrick BSc. (Hons) Level 4 Strength & Conditioning Coach, Muay Thai Coach

    Don Heatrick

    Founder of Heatrick Strength and Conditioning

    Don Heatrick is a family man from the UK, former mechanical design engineer, European Muay Thai silver medallist, former pro Thai boxer (ranked 4th in UK while aged 40-years), and now a podcast host and the go-to expert on Muay Thai performance training with over 25 years of coaching experience.

    Don helps committed Thai boxers organise training for accelerated self development & Muay Thai performance.

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