You've heard it " No pain, no gain" the exercise motto that is annoying as "do you feel the burn". It just makes you want to punch the person saying it, even if that person is yourself. How true is it though? Do you really need to push so hard until you feel that burn from the muscles at lactate threshold? Well the interesting thing yes, you need the pain, and no you can block it out and get it gains...kinda
It turns out that taking the common pain reliever Tylenol before you exercise might have performance-enhancing benefits. A couple of Lab Coats at the University of Bedfordshire in the United Kingdom took 13 trained cyclists, gave them either a placebo or 1500 mg of acetaminophen, and made them cycle a 10-mile time trial. The ones that took the drug were 2%faster, rode harder at higher heart rate, and produced more lactate. All while their perceived level of effort was the same or lower than the riders on the placebo.
How and why this could be important to you depends on your sport. In a Sprint, or Olympic Triathlon you could use acetaminophen in your race strategy. I'm not sure how long 1500 mg would last in a half or full Iron Man, but a 2 % gain is a very significant performance boost. A 5Km - you could potentially cut a large portion of your time on race day.
I'm have not yet researched the performance gain on weight-bearing sports such as powerlifting or bodybuilding, but if you could manage pain though those intense workouts I'm sure you would see positive gains.
Of course, I'm not saying you should be popping tons of Tylenol before exercise all the time, just some of the time ;). Pain is actually important, and I'll get to that in a different article. But the results are compelling for an over-the-counter drug.
Mauger, Alexis R., et al. “Influence of Acetaminophen on Performance during Time Trial Cycling.” Journal of Applied Physiology, 1 Jan. 2010, https://www.physiology.org/doi/full/10.1152/japplphysiol.00761.2009?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed.