A review of studies: Stretching before strengthening can decrease gains
This is not medical advice.
This is not a hit piece on stretching. There are many times when we need to stretch. There are sports that require increased flexibility to help decrease risk of injury, and there are rehab protocols that absolutely require aggressive stretching to prevent joints from becoming permanently frozen.
This is a hit piece on the notion that we “must stretch” without regard for context, circumstance or specific reasons.
I’ve written about this previously, however I came across a new study on the effects of stretching before strength training.
This study was published in the Journal of Strength and Conditioning Research, 37(5):p 1145-1156, May 2023. It is a meta analysis, meaning they reviewed the results of many studies at once, 35 in this case. Studies can be flawed, or have varying conclusions, so reviewing many at one time helps to improve validity. No conclusions are ever 100% certain.
I have included the link to the study if you wish to read it. One line in the summary was this,
“Performing stretching before RT (resistance training, i.e. weight lifting) and for a prolonged time (>8 weeks) can blunt the strength gains to a small-to-moderate magnitude.”
There are different kinds of stretches. These studies looked at the effects of 4-8 week stretching programs in conjunction with strengthening routines. Most of the stretches were 1 minute in duration.
The new way of warming up
It is now universally accepted that active warm ups are better than stretching before sports, to help prevent injury and improve performance.
There is a 2 minute video link in this article of some active warm ups.
Implications for sport
These studies were very specific measuring decreased strength gains when stretching was performed beforehand. I am especially interested in this because I equate sports with strength. Whether you squat a heavy load, or push against someone in football, in both cases, it involves strength. So in theory, too much static stretching before football would not be advantageous. Sports also involve power, which means moving your body weight very quickly. Passive stretching has also been shown to decrease sprinting speeds.