Fight camp nutrition: how to eat around MMA training

This guide summarizes the ISSN's 2025 position stand on nutrition and weight cut strategies for MMA and other combat sports, plus a peer-reviewed review on the risks of weight cutting. It is general education, not a weight cut plan. If you are cutting for a fight, work with a qualified sports dietitian or sports nutrition professional who can monitor you.

Start camp close to your division

The ISSN position stand suggests that between camps, a fighter's walk-around weight should sit no more than about 12 to 15 percent above the weight class, and the authors note these numbers have not been fully proven by research. The practical point is simple: the further you drift between fights, the more you have to lose in camp, and the more tempting a dangerous fight-week cut becomes. Staying reasonably close to your division is the single best thing you can do for your next camp.

Lose weight slowly during camp

Most of the weight you lose in camp should be body fat, lost through a modest calorie deficit over weeks. The ISSN stand cites a common target of 0.5 to 1 kg of body mass per week, and elsewhere describes 0.5 to 1 percent of body mass per week over an 8-week camp. Slow loss protects muscle and keeps training quality up. Crash dieting in the last two weeks does the opposite.

Daily targets during camp

The ISSN gives these ranges for combat athletes during a weight descent:

Protein. Protein should be prioritized during a weight descent to preserve lean mass. Spreading it across the day, rather than loading it into one meal, makes the target easier to hit.

Carbohydrate. Carbs fuel the high-output rounds, sparring and conditioning that MMA demands. The ISSN notes that carbohydrate needs vary with body size, the type of workout and its intensity. In practice, that means eating more carbohydrate on hard sparring and conditioning days and less on light technical or rest days, while staying above the 3 to 4 g per kg floor.

Fat. Fat is where most of the calorie cut can come from once protein and training carbs are set, but not below the minimum.

Eating around training sessions

• Before hard sessions: a meal built on carbohydrate and protein, eaten early enough that it sits well when you train.
• During long or hot sessions: the ISSN suggests a carbohydrate drink at a 6 to 8 percent concentration to help maintain blood glucose and hydration.
• After training: protein and carbohydrate to start recovery, especially if you train twice a day.
• Track sweat loss: the ISSN recommends monitoring fluid loss during camp, for example by weighing before and after sessions, so you know how much to drink back.

Fight week and the weigh-in

Fight week is where most of the risk sits. The ISSN describes short-term methods such as reducing fiber, sodium and carbohydrate, and in some cases supervised water manipulation. It is clear that extreme methods such as diet pills, laxatives, enemas and purging are not endorsed, and that acute water-loss methods should only be used with appropriate supervision. It also states that the long-term effects of frequent weight cuts on health and performance are unknown.

A 2019 review in Sports (Barley, Chapman and Abbiss) adds the case for caution. It reports that several athletes have died while cutting weight, that dehydration for weight loss raises the risk of acute cardiovascular problems, that heat-based methods such as saunas increase the risk of heat illness including heat stroke, and that a rapid loss of about 5 percent of body mass in under 24 hours impairs repeat-effort performance. The ISSN also notes that a 2.5 percent drop in body weight from dehydration can impair performance.

Do not attempt a large dehydration cut on your own. Sauna sessions, sweat suits, fluid restriction and diuretics can become dangerous quickly. If your plan relies on losing a large share of your body weight as water in the final days, the plan needs to change, and a qualified sports dietitian or physician should be involved.

After the weigh-in

Rehydration and refueling come first. The ISSN suggests starting with an oral rehydration solution, then fast-digesting carbohydrates, while limiting fiber so your stomach stays settled. How much you need depends on how much you cut and how long you have: professional MMA, boxing and kickboxing typically allow 24 to 36 hours between weigh-in and the fight, while wrestling and jiu-jitsu can allow as little as 1 to 2 hours. A smaller cut is easier to recover from in either case.

Putting it into a week

A simple way to run camp is to set protein the same every day and let carbohydrate move with the schedule: higher on sparring and double-session days, lower on technique and rest days, with fat filling the rest of the calorie budget. Siloh plans meals around your training days, so an MMA program and the food that fuels it sit in the same plan.