For years, fasted training has been sold as either a fat-loss cheat code or a gains-killing disaster, depending on which corner of the internet you wander into. As usual, the truth is somewhere in the middle – with new research suggesting there could be less to worry about than you might have been ‘influenced’ to believe.

A new study on well-trained athletes found that Ramadan fasting had no negative effect on maximal strength or power. The athletes were tested during the final week of Ramadan, after around 13 hours without food or fluid, then again a week after Ramadan, when they’d eaten a standardised meal before training.

Across tests including isometric mid-thigh pulls, bench press, loaded jump squats and throws, there were no significant drops in peak force, rate of force development or power. That’s despite the athletes sleeping almost an hour less during Ramadan, showing lower blood glucose and even with mild dehydration.

In other words, their circumstances were far from optimal, but their performance didn’t fall apart. The takeaway is that while many of us are quick to conflate feeling flat, hungry or fatigued with being physically incapable – that’s not necessarily always the case.

This doesn’t mean fuelling is irrelevant. Previous fasting studies have found reductions in performance markers, while other researchers found that lifters training after breaking their fast improved their squat and deadlift more than those training fasted. Endurance work is a different beast, too. Longer sessions rely more heavily on available fuel, hydration and glycogen – meaning the idea that ‘training fasted is fine’ stops holding true over a long enough timeline.

Individual tolerance is important here, too. Some people feel sharp training on empty. Others feel like they’ve been unplugged at the wall. Your mileage may very, literally.

For fat loss, the big rock is still energy balance. Whether you train fasted or fed, you lose body fat by sustaining a calorie deficit. But in that deficit – if your goal is to maintain performance and keep muscle loss at bay – then a banana, coffee, yoghurt or proper pre-workout meal, if it helps you lift better or run harder is just common sense fuelling.

An important bit of context here is that the study was conducted during Ramadan. Why is that so important? Because it highlights that sometimes fasted training isn’t a preference – it’s a necessity, or at least hard to avoid. This study suggests that, in the short term, strength and power can be maintained when conditions are far from perfect. Which you should keep in mind the next time you decide to skip the gym because you’re not ‘optimally fuelled’.

So fuel properly when you can. Put carbs and protein around the sessions that matter. But don’t sack off training altogether every time your nutritional stars aren’t aligning.

Our take is that the real flex is being smart enough to fuel when possible – but flexible enough to still get a good session in, even when you can’t.

With almost 18 years in the health and fitness space as a personal trainer, nutritionist, breath coach and writer, Andrew has spent nearly half of his life exploring how to help people improve their bodies and minds.    

As our fitness editor he prides himself on keeping Men’s Health at the forefront of reliable, relatable and credible fitness information, whether that’s through writing and testing thousands of workouts each year, taking deep dives into the science behind muscle building and fat loss or exploring the psychology of performance and recovery.   

Whilst constantly updating his knowledge base with seminars and courses, Andrew is a lover of the practical as much as the theory and regularly puts his training to the test tackling everything from Crossfit and strongman competitions, to ultra marathons, to multiple 24 hour workout stints and (extremely unofficial) world record attempts.   

 You can find Andrew on Instagram at @theandrew.tracey, or simply hold up a sign for ‘free pizza’ and wait for him to appear.