Can you increase strength in a calorie deficit?

Yes, you can absolutely gain strength in a calorie deficit! All you who work with me and are currently cutting are a testament to this – consistently smashing new lifting personal bests. The scientific literature also supports this with a new meta-analysis (a study of studies) done by Murphy and Koehler.

Prefer to watch than read? Then please check out the video below:

Meta-analysis findings

The meta-analysis found that energy restriction impaired muscle growth but not strength development. These findings didn't surprise me, as I'm yet to see a client who didn't continue to gain strength when in a deficit. Muscle-building does take a hit, as naturally, you're going to gain more muscle in a surplus than in a deficit, as you'll be much more effectively fueling the muscle-building process. Though, that's not to say you CAN'T also build muscle during energy restriction; in this analysis, several studies found muscle growth in an energy deficit. Losing fat while simultaneously building muscle is known as body recomposition, and I've done a very in-depth article explaining how this is not only possible but, with the right plan, probable!

Recommendations

Avoid extreme calorie restriction

This analysis showed that lean mass gains scaled with the severity of the energy deficit – the larger the deficit, the less gains you make. So, as I point out in my body recomposition article, it's important not to participate in EXTREME calorie restriction if you want to continue building muscle while cutting. 

Track your strength development

One big thing that I wanted to make sure I mentioned when explaining these findings and providing take-home points is that strength gains, especially in the short term, are largely due to neural improvements in the neuromuscular system and our brain. This is why many can see astronomical strength gains while visual muscle gain takes its sweet time. If you're not making the expected strength gains while in a deficit, especially if you're relatively new to training, then you're likely losing muscle mass. This is why I use strength development and progressive overload as a key metrics when tracking progress – not only for strength but also for muscle gain and maintenance.

Summary

Your fat loss endeavours shouldn't impact your strength gains – you can make some serious strength gains while in a calorie deficit. Muscle building will take a hit, but it's not as bad as many think – you can still build muscle during energy restriction. If you're not gaining strength, then the expected positive neural adaptations must be overshadowed by muscle loss; if this is the case, you might need to bump up your calories slightly. You want to be in a slight deficit to lose weight, not an extreme one – this will allow you to increase strength and even muscle when shredding. 

Reference

Murphy C, Koehler K. Energy deficiency impairs resistance training gains in lean mass but not strength: A meta-analysis and meta-regression. Scand J Med Sci Sports. 2022 Jan;32(1):125-137. doi: 10.1111/sms.14075. Epub 2021 Oct 13. PMID: 34623696.