https://vo2maxpro.com/blog/does-caffeine-improve-vo2-max https://vo2maxpro.com/blog/does-caffeine-improve-vo2-max They list a study and more info on that page.

https://vo2maxpro.com/blog/does-caffeine-improve-vo2-max https://vo2maxpro.com/blog/does-caffeine-improve-vo2-max They list a study and more info on that page. Probably why almost all pre-workouts include caffeine. Some push for 300mg per serving. Yohimbe gives some weird heart effects also.