I'm a climber, so I'm talking specifically about forearms. I train regularly and have been for years, so I'm pretty familiar with how my body responds.

As I understand it, the "pumped" sensation in the forearms comes from the anaerobic energy usage; it's build of lactic acid. During my training session yesterday, I experienced more onset of a pump than usual. I would say it seemed that I was getting pumped, doing exactly my same warm ups and workout as I have been doing regularly for several weeks, at about 80% of the normal threshold.

I know that if I don't warm up good, it sets in faster. But my warm up was as complete as usual. What I want to know is what other parameters can affect this? Was I low on blood sugar? Were my muscles still fatigued from previous workouts? Did the cold I had just recovered from matter?

  • 4
    I'm not sure if I get your point, but as far as I know, the "pump" effect comes from accumulation af water in your muscles, and not from lactic acid. Dec 13, 2012 at 21:01

3 Answers 3


Muscle "pump" is nothing more than increased blood flow into a muscle from exertion. If you have a higher pump sensation than usual, then I'd look at something else as the cause. More caffeine or salt than usual, dehydration, other factors that would contribute to this.

  • +1 for salt/dehydration, I find that those levels drastically affects my feeling of pump.
    – John
    May 19, 2016 at 7:04

Lactic acid is a byproduct of the energy used in a muscle, like exhaust in an automobile. ATP or adenosine triphosphate comes in and removes the lactic acid. ATP is made up of calcium and creatine and adp. We can only get creatine from red meat or supplements. Could be something to look at.


In my experience the climbing "pump" has a lot of factors involved. I believe it is from too much blood staying in the forearms as JohnP said. I have found that hydration and anything that effects my overall strength impacts the quickness that I get pumped while climbing. If you are feeling a little weaker you tend to have to rely more on your hands and less on your core. I find that my climbing endurance is very sensitive to my overall health and mental state. I would say that the cause of your extra quick pump is probably related to your cold but I am not a doctor so I can not say for sure.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.