This week, we explore safe and effective strategies in ‘making weight’ for combat sport athletes.
An athlete’s weight cut can be broken down into two phases: chronic and acute.

During a chronic phase, the main emphasis is to reduce body fat slowly at a rate of 0.5-1% body mass loss per week.

The acute phase is further divided into two processes: rapid weight loss (RWL) and rapid weight gain (RWG).

Many combat sport athletes experience large adverse physical, mental, and emotional issues when they (1) haven’t achieved target body fat loss during the chronic fat loss phase, and (2) must accelerate weight loss during the acute phase to ‘make weight’.

Ultimately, athletes are healthiest and perform at their best when they are at baseline – the issue with RWL is that they experience extreme disruptions in homeostasis when moving further away from their ‘optimal’ baseline.

Reported issues range from RED-S, acute kidney injury, and in some cases, fatality – This issue further compounds when done multiple times per year.

Therefore, there’s a high need to educate and change the culture in all weight making athletes/sports.

A 2020 study by Cannataro et al examined the health, hormonal, and body composition changes of 21 Muay Thai fighters over the course of a RWL and RWG phase when done under professional.

RWL Overview: 3 Days

– Carbohydrate restriction <30g/day to deplete both muscle and liver glycogen stores. In doing so will reduce associated water. i.e. for every 1g of glycogen depleted, 3g of water will be dropped.

RWG Overview: 8 Hours

– Carbohydrate replenishment of 4.5g/kg consumed through high GI, energy dense carbs in addition to 250mL water every 45 mins.

Results:

– Both male and female fighters dropped 4.4% and 3.5% body mass during the RWL phase.
– Bodymass was restored fully post RWG in males, but not females, indicative of glycogen and water replenishment.
– No negative impact on kidney health was observed as ‘active dehydration/sweating out’ wasn’t performed.
– Males experiences a significant decrease in testosterone and remained supressed after RWG.
– Thyroid-stimulating hormone also declined and took 15 and 25 days to return full in males and females respectively.

This study explored the impact of one method that many weight making athletes use. Of which, losing <5% body mass in the acute phase doesn’t appear to be overly detrimental to health.

However, RWL, especially if more aggressive could cause longer term issues if repeated multiple times per year. i.e. what is the true compounding effect over the course of an athletes career?

Therefore, the athlete and coach have the responsibility to enter fight week no more than 5% off target weight (in a replenished/hydrated state) to reduce the likeliness of adverse physical and psychological issues going into fight night.

The ideal scenario – to MAINTAIN weight year-round through improving eating and lifestyle habits, then adopting a small cut IF needed on fight week. Therefore, avoiding large cutting cycles and yo-yo dieting.