I get plenty of questions in various comments throughout the website, but I also get comments and questions via the contact form.
In the past I have address those questions through e-mail, but often I do not have the time to reply to each and every question personally. I want to take a more proactive approach to answering Your Questions by posting them in the blog. This way we can be sure that everyone benefits from the Q & A.
“I have heard that too much caffeine can be detrimental to muscle growth because of its tendency to increase cortisol which has catabolic effects. That being said, it also stimulates testosterone production, so its actual effects are a little unclear. Here’s a little medical study I found on the web to back it up:
Just curious if you’ve heard anything along these lines and I’m interested to hear your take on it.”
As you can see from the image to the right, coffee does have its ways of increasing testosterone levels, but I’m pretty sure that’s not what you are talking about. For most folks you probably prefer to make your own cup of liquid fuel early in the morning. So instead, lets look at the effects of caffeine in general, on the hormones that affect muscle growth.
A study to determine the hormonal effects of caffeine on resistance training has not conclusively proven that caffeine can help you build muscle, but it has proven that caffeine does effect both testosterone and cortisol levels.
The participants consisted of 24 professional rugby players. They ingested caffeine in doses of 0, 200, 400, and 800 mg, in random order, 1 hr before a resistance-exercise session. Samples of saliva were taken before, during, and after exercise to measure levels of testosterone and cortisol.
Some facts about the effects of caffeine on testosterone and cortisol:
- During exercise, testosterone concentration increases by about 15% without caffeine. This is good.
- Ingesting caffeine causes an additional increase in testosterone levels of about 21% at the highest dose. This is great!
- Cortisol increased by about 52% at the highest dose of caffeine. This is bad.
- Therefore at the highest dose, the testosterone:cortisol ratio decreased by about 14%. This is not good but not terrible either.
In conclusion, we can say that the benefits of increased testosterone from ingesting caffeine before a resistance training session are offset by a more substantial increase in cortisol and thus a decrease in the testosterone:cortisol ratio. On the other hand, caffeine has been linked somewhat to performance enhancement such as increased energy and increased endurance.
Should You Take Caffeine Before Training?
Ultimately you will have to make your own decision based on how caffeine makes you feel during a workout – whether ingesting caffeine significantly improves your athletic performance.
If caffeine does not impact your performance at all, then we can clearly see that ingesting caffeine has a slightly negative effect on hormone levels, so you should avoid it.
If caffeine does enhance your athletic performance, then you can justify using it despite the increase in cortisol considering that the decrease in your testosterone:cortisol ratio is minimal.
To answer the original question: no, caffeine does not appear to directly help you build muscle, at least not directly through an increase in the testosterone:cortisol ratio.