Contents of Research Review

1. Background & Objective
2. What They Did
3. What They Found
4. Practical Takeaways
5. Reviewer’s Comments
6. About the Reviewer
7. Comments

Background & Objective

Weight making-sports require athletes to reach a certain body mass on a scale before they can qualify to then compete in the respective weight category. The pressure to reach certain weights to gain a competitive advantage over opponents is reaching new extremes, so much so that certain weight making strategies are resulting in athlete deaths as recent as June this year (see HERE) and is discussed by one of the authors of this case-study in the video and podcast below.

With this in mind, the weight-making research group at Liverpool John Moores University aimed to describe the strategies of an individual male athlete as he made weight before competition and quantify the physiological and metabolic impact of the extreme weight cut.

What They Did

The athlete presented was a 22-year-old professional male MMA fighter, with the contest under investigation for the case study being the defence of his featherweight championship. At the beginning of the camp he weighed 80.2 kg and was required to make weight at 65.7 kg over an 8-week period.

They assessed the athlete at regular periods before and after the contest for body composition using DXA and skinfolds, resting metabolic rate, and peak oxygen uptake with blood samples taken and analysed at a local hospital.

The protocol of the 8-week weight-making period included the following phases:

1) 7-week energy restriction period.

2) 6-day water loading period.

3) An acute weight cut strategy.

4) Rehydration and refuel strategy

5) Ad libitum recovery period following the fight.

What They Found

During phase 1, the athlete lost 4.4kg. During the “cut”, the athlete exhibited clear symptoms of the relative energy deficiency in sport syndrome, reductions in resting metabolic rate, the inability to complete the maximal oxygen uptake test and perturbations to endocrine status and hypercholesterolemia (high cholesterol).

In phase 3 during the cut to make-weight (weight-loss of 7.3 kg), the athlete experienced a significant stress response:

⇒ 3-fold increase in plasma cortisol

⇒ Evaluations in serum proteins

⇒ Elevations in plasma osmolality

⇒ Elevations in plasma sodium concentrations

The plasma sodium observed (148 mmol.L-1) was near to severe levels of hypernatremia (>150 mmol.L-1) where mortality may occur. Similarly, the relative and absolute changes in serum creatinine levels during the final phase of the weight cut are consistent with acute kidney injury.

Finally, following the 32-h rehydration and refueling strategy, the athlete gained 10.6 kg in absolute mass and 2 weeks after the competition, resting metabolic rate, markers of endocrine status, lipid profile, hydrations status and kidney function had all returned towards normative ranges.

Practical Takeaways

For practitioners and coaches working with athletes that are required to make-weight for competition, this case-study provides clear data showing the potentially harming effects of making weight poorly (specific to this individual). The athlete showed clear signs of relative energy deficiency, evidenced by:

⇒ Reduced metabolic rate.

⇒ Inability to complete performance tests.

⇒ Alterations to endocrine hormones.

⇒ High cholesterol.

⇒ Dehydration induced hypernatremia.

⇒ Acute kidney injury.

Although based on one individual, this case study shows the harmful (and potentially fatal) effects of extreme weight cutting in MMA athletes and represents a call for action to governing bodies to safeguard the welfare of MMA athletes. Similar habits of making weight are reported elsewhere (refer to the article below).

Practically, athletes and coaches should seek help and advice from qualified dieticians and sport nutritionists before attempting to make weight. A list of accredited sport nutritionists can be seen HERE.

Reviewer’s Comments

“Personally, working with professional boxers and Olympic level Judo athletes, I know how important it is for them to make weight safely and allow them to perform to the best of their ability. For me, the data presented from this research group is alarming, and shows just how close the athlete was to potentially fatal outcomes, in particular to the acute kidney damage.

Although more and more research is now being performed on these athletes who are required to make weight for competition, it worries me that the people who can control the rules and regulations of such weigh in’s are not willing to listen and thus change the rules around weight categories for the better. Will we see another fatal outcome this year like the one mentioned above?”

Want to learn more?

Then check these out…

Watch this video

Read this article

Read this article

Listen to this podcast

The full study can be read here.

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About the Author

Do you work in weight category sports? Let us know how you ensure healthy weight loss below…