Doing Cardio First Lowers Your Testosterone and GH

Strength first or cardio first? A new study looks at hormone levels 24 and 48 hours post workout and finds lower testosterone, growth hormone, and TSH when athletes did cardio first.

A few weeks ago I presented a study that looked at exercise order. It asked the question, “If you plan to perform both strength and conditioning workouts, which should come first?” The study found that performing your conditioning workout first kept testosterone levels higher immediately after the workout. This would suggest that performing conditioning first, then strength might be the way to go.

A new study from the Journal of Strength and Conditioning Research looks at the same question. But today’s study examined the issue even further, looking at hormone levels 24 and 48 hours post exercise. And the results show that exercise order causes drastic differences in hormone levels during your recovery.

The study examined 42 untrained men, all close to 30 years old. While the men didn’t regularly perform strength or conditioning work, they were all somewhat active in casual sports. All men performed the same total volume of work. Half performed their strength workout first, then conditioning. And the other half performed their conditioning workout first, then strength. The strength work was several sets of leg press. The conditioning work was 30 minutes of cycling on a stationary bike.

Researchers measured hormone levels at every possible stage: before the workouts, between the two workouts, after the workouts, 24 hours post-workout, and 48-hours post-workout. They looked at the primary hormones that affect growth and recovery: testosterone, cortisol, growth hormone, and thyroid-stimulating hormone (TSH).

The results? Performing conditioning work before strength work left testosterone, growth hormone, and TSH hormones depressed at 24 and 48 hours post exercise. This is a big deal. Those are important anabolic hormones that help determine how well your body will recover and how much muscle you will gain as a result of your workout. Since performing conditioning first depressed those hormones for 48 hours, while performing strength first did not, then performing strength work first may be the way to go.

This is an important finding, but here are a few caveats to keep in mind. First, both workouts used the same muscle groups. The effect might not have been experienced if the strength work had focused on the upper body before cycling toasted the lower body. Next, the conditioning work lasted 30 minutes. Many programs primarily use conditioning workouts of less than 20 minutes. The depressed hormonal affect at 48 hours post-exercise might have been less severe for shorter conditioning workouts. Finally, the conditioning work was a single activity: 30 minutes of cycling. Had the conditioning workout contained a few different movements, then we might have seen different results.

But today’s study makes it clear that performing strength work prior to endurance work is optimal for recovery, as compared to the opposite order. Remember that next time you’re considering which part of your workout to get after first.


1. Moritz Schumann, et. al. Acute Neuromuscular and Endocrine Responses and Recovery to Single-Session Combined Endurance and Strength Loadings: “Order Effect” in Untrained Young Men. Journal of Strength & Conditioning Research: February 2013 – Volume 27 – Issue 2 – p 421–433. doi: 10.1519/JSC.0b013e31827f4a10

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