Depression and muscle

A new study finds that leg muscle mass and depression are inversely correlated.

Welcome to the first post of Mirrors, Signal, Blind Spot! Many thanks to my very first subscribers. In this newsletter, I'll summarize new studies that strike me as interesting and important. I hope you'll find it to be worth reading.

This is not a health blog. However, since humans care about our health, conduct a lot of research about it, and cherry pick that research, my content will often relate to health.

Without further ado, today's study was published on May 31, 2024 in the journal PLOS ONE.

Researchers in the Czech Republic found an inverse correlation between muscle mass and clinical depression.

In a longitudinal study of central Europeans aged 27 to 31, the researchers found that participants with weak quadriceps were 4.65 times (with a confidence interval of 95%) more likely to be experiencing clinical depression than those with average or strong quadriceps.

The participants were half male, half female. The association was more pronounced in female participants, but it was still notable in the male participants.

Limitations

Since the study design only makes possible an association, we don't know if any causation exists.

Furthermore, if there is causation, we don't know if muscle mass lowers our chances of getting depression or if depression lowers our chances of building muscle.

For example, maybe depression deprives survivors of the motivation to do squats.

Discussion

The researchers speculate that the production of seratonin, a consequence of building muscle, may explain the results.

Thanks to PLOS ONE for making their journal free to the public.

A tangential note

In case anyone's interested, here are a few playlists of my favorite videos for strength training. A gym is not essential.

• Strength training I

• Strength training II

• Strength training targeting hip and low back pain