Caffeine and Blood Flow

Clearing up the confusion

Written By Jim Stoppani, PhD

Updated November 29, 2018

One question I get asked a LOT lately is, "Why is caffeine included in preworkout supplements that include nitric oxide (NO) boosters when caffeine is a well-known vasoconstrictor that reduces blood flow?"

Unfortunately, there is a LOT of misinformation out there. Caffeine for some reason has been tagged as a supplement that constricts blood vessels and reduces blood flow to muscles. However, nothing could be further from the truth.

Caffeine is actually an NO booster that dilates blood vessels and increases blood flow to muscles.

But I am not just spouting off some info that I think is true. I am telling you this because research confirms that this is true. Take one study from Japan that reported that subjects receiving 300 mg of caffeine increased NO levels, dilated blood vessels and increased blood flow to the muscles.

So not only shouldn't you worry about caffeine in your preworkout supplement, but you should worry that your preowkrout supp DOES contain caffeine.

After all, not only will caffeine boost NO levels and increase blood flow to muscles, but it will amp you up for a tougher workout, immediately increase your muscle strength, provide you more energy for the workout, burn more fat, and blunt muscle pain during exercise, which helps you train harder.

So go with preworkout supplement products that supply about 200-30 mg of caffeine. Or simply take a caffeine pill about 1 hour before workouts. Coffee will not do, as it contains other phytochemicals that appear to interfere with caffeine's benefits.