Intermittent fasting and martial arts: does it work?

The question everyone asks in the changing room

At some point, almost everyone in the gym has heard about intermittent fasting. Some say they lost five kilos in two weeks. Others swear they became slow, drained, unable to survive three rounds without hitting the wall. The truth, as almost always, lies somewhere in the middle, and depends heavily on how and when you apply this eating strategy to your training routine.

At BadAzz Station, in Santa Maria da Feira, we train athletes of every profile: people doing Muay Thai early in the morning, others training MMA in the late afternoon, and some arriving for Kickboxing after a full day of work. Each person has a different routine, which is exactly why there is no single answer to this question. But there is solid information to help you make a smart, grounded decision.

What intermittent fasting actually means in practice

Intermittent fasting, or IF, is not a diet in the traditional sense. It does not tell you what to eat, only when to eat. The most common protocol is 16:8, where you go 16 hours without consuming calories and fit all your meals into an 8-hour window. There are more aggressive variations, like 18:6 or OMAD (one meal a day), but for most martial arts athletes these options are unnecessarily restrictive.

During the fasting period, the body depletes its glycogen stores and begins using fat as fuel. On top of that, mechanisms like autophagy are activated, a cellular clean-up process that has been linked to improvements in recovery and long-term metabolic health. These are precisely the effects that draw so many combat sports athletes towards this approach.

The real benefits for martial arts practitioners

Let's get to what matters. Intermittent fasting can bring concrete advantages for combat athletes, but it is important to be honest about what the science actually says, without overstating the promises.

• Weight management and cutting: For athletes who need to make weight for competition, IF is a useful tool for keeping body mass closer to fight weight throughout the year. Fewer extreme last-minute cuts mean less physical and mental wear.
• Improved body composition: With a well-structured eating window, it is possible to maintain or even build muscle while losing fat. The key is ensuring sufficient protein intake, especially after training.
• Mental clarity and focus: Many practitioners report a sharper cognitive edge during the fasting period. For technical disciplines like Luta Livre or Wrestling, where concentration matters as much as physical strength, this effect is worth taking seriously.
• Metabolic adaptation: Over time, the body becomes more efficient at using fat as fuel, which can benefit moderate-intensity training sessions of longer duration.
• Simplified routine: Fewer meals to prepare means less time in the kitchen and fewer decisions throughout the day. For anyone juggling work, family and training, that is not a small thing.

The risks you cannot ignore

IF is not for everyone, nor for every phase of an athlete's journey. There are situations where this approach can do more harm than good.

The main problem arises when high-intensity training coincides with deep fasting hours. Doing hard sparring, an intense grappling session or a wrestling workout in an advanced fasted state can compromise performance and, in more serious cases, lead to hypoglycaemia, dizziness and a drop in technical output precisely when you need to be at your sharpest.

Another real risk is muscle catabolism. If your eating window does not provide enough protein and calories to support your training volume, the body may start breaking down muscle for energy. That is the opposite of what any combat athlete wants.

There is also the psychological dimension: fasting can increase irritability and difficulty concentrating during the first weeks of adaptation. Training in a team requires communication, patience and mental presence, and showing up to class tired and on edge is not good for you or your training partners.

How to adapt intermittent fasting to your training schedule

The golden rule is straightforward: your most demanding training session should never happen at the end of a long fast. Your eating window must be built around your training, not the other way around.

There are two main scenarios that work well for most athletes:

• Morning training: If you train early, consider a lighter fast (6 to 8 hours of overnight fasting, not 16), take in protein immediately after, and open your eating window from there. This is a gentle form of IF that does not compromise performance.
• Late-day training: This is the most favourable scenario for a classic 16:8 protocol. Break your fast at midday with a meal rich in protein and carbohydrates, train in the late afternoon or evening, and have your final meal after the session. The fast restarts naturally overnight.

In either case, hydration during the fasting period is essential. Water, black coffee and unsweetened teas are allowed and help control hunger and maintain focus.

What to eat in the eating window: don't undo the effort

There is no point in fasting for 16 hours and then filling your eating window with ultra-processed food. IF works when nutritional quality is present. For martial arts athletes, the priorities are clear:

• Protein in sufficient quantity: A minimum of 1.6 to 2.2 grams per kilogram of body weight per day. Chicken, fish, eggs, legumes and Greek yoghurt are essential allies.
• Strategic carbohydrates: Rice, sweet potato, oats and fruit should be concentrated around your pre- and post-training meals to ensure energy and muscle recovery.
• Quality fats: Olive oil, avocado, nuts and oily fish support hormonal production, which is critical for athletes training at high volume.
• Micronutrients and fibre: Vegetables with every meal, in abundance. Non-negotiable.

Check our training schedule and plan your meals around your sessions. Nutrition is just as trainable as an armbar or a left hook.

Who should avoid intermittent fasting

Some profiles should genuinely avoid this approach, or at least consult a sports nutritionist before going ahead:

• Young athletes still in a growth phase
• People with a history of eating disorders
• Those training twice a day at very high volume
• Athletes in an active muscle-building phase
• Anyone with diagnosed metabolic or hormonal conditions

If you have doubts about your specific situation, talk to our team. You can get in touch or come by the academy for a no-commitment conversation.

FAQ: intermittent fasting and martial arts

Can I train while fasting without losing performance?

It depends on the intensity and the duration of the fast. Moderate-intensity and technical sessions can go well during a short fast (8 to 10 hours). For high-intensity sessions, sparring or competition, make sure you have had a proper meal beforehand. With time, the body adapts and you can sustain more effort in a fasted state.

Does intermittent fasting help with weight cutting for competition?

Yes, it can be a useful tool for keeping your weight closer to the limit throughout the year, reducing the need for aggressive last-minute cuts. However, competition weight cuts should always be supervised and done gradually. Check our pricing page to learn more about our programmes and speak with the coaches before making any decision.

How long does it take to adapt to intermittent fasting?

Most people feel the effects of adaptation during the first two to four weeks. Intense hunger, some irritability and energy dips are normal during this phase. After that, the body regulates ghrelin levels (the hunger hormone) and the whole experience becomes much easier to manage.

Do I need supplements to do intermittent fasting while training?

It is not mandatory, but some supplements can help. Creatine, post-workout whey protein and BCAAs (for those training in a longer fast) are the most common. What you cannot compromise on is the quality of food inside your eating window. Supplements complement, they do not replace.

Is intermittent fasting compatible with all disciplines at BadAzz Station?

Yes, with the right timing adjustments. Whether you train Muay Thai, MMA, Kickboxing, Wrestling or Luta Livre, IF can be integrated intelligently as long as your meal timing aligns with your training sessions. The secret is consistency and patience to let your body adapt.