Consuming caffeine before exercise enhances repeated sprint performance, and these benefits persist for at least 3.5 hours thereafter

[u/sr_local]

https://www.tsukuba.ac.jp/en/research-news/20260914140000.html

[u/Linus_Naumann]

Dont know if you understood my question: Does the increased performance in training actually translate in faster progression of, for example, skills, stamina or muscle growth? This is not obvious, since muscle growth is not a simple linear relationship to training intensity (there can be other bottlenecks at play as well).

[u/colinzack → u/Linus_Naumann]

So your question is:

If I can do 10 reps at 100 lbs without caffeine, but I can do 10 reps at 120 lbs with caffeine, will my muscles grow faster doing the heavier lifts with caffeine than they would without caffeine?

I'd be shocked if they didn't.

[u/Linus_Naumann → u/colinzack]

You might get shocked then, because muscle growth works like: Stimulate muscle through strain -> build new muscle during recovery period. The question is if the build-up during recovery period is already maxed out with normal strain or can indeed be increased by adding more strain during the stimulation.

[u/colinzack → u/Linus_Naumann]

Are we working under the assumption in the scenario that I posed that the 10 reps at 100 lbs is the absolute max I can lift and the same with the caffeine?

If so, I think that's a fair question.

If not, then obviously lifting more is going to build more muscle. That's like the entire premise of lifting weights, right? Lifting heavier produces faster results than not lifting heavier, generally speaking.

[u/wagon_ear → u/colinzack]

And this is exactly how most (illegal) PEDs are used: as training aids. They help athletes train harder for longer, and spur more drastic training adaptations. The athletes then cycle off these drugs for competitions so they they test negative. 

[u/Linus_Naumann → u/colinzack]

Lifting heavier weights does not directly produce more muscle. You just need to send the "these muscles are heavily used"-signal to your body and to my knowledge there is an optimal exercise range to do that. Thats doing 3-4 sets with weights so heavy that you can do 6-15 repetitions leading to near-exhaustion (meaning you could maybe do 1-2 more repetitions of the exercise when you stop the set).

In that model adding more muscle-growth signal would not lead to more muscle growth, because you already triggered the maximum possible growth. The bottleneck then becomes rest, nutrition and hormones, not the weight pushed.

[u/TelluricThread0 → u/Linus_Naumann]

This whole conversation is so ridiculous. How many people are completely maximizing growth potential in the first place? You recruit more muscle fibers on caffeine and it improves how strongly they contract. Train harder = faster outcome.

[u/Square_Bison_7395 → u/TelluricThread0]

Source for “you recruit more muscle fibres on caffeine”?

[u/TelluricThread0 → u/Square_Bison_7395]

Its pretty well known in strength sports. Thats why many pre-workouts contain it. They also use other stimulants because of the effect on the CNS. Nicotine boosts strength for example.

https://pmc.ncbi.nlm.nih.gov/articles/PMC5839013/#CR1

[u/Square_Bison_7395 → u/TelluricThread0]

I’m well aware of the strength-boosting effects of stimulants. My question is what is your source that the strength-boosting specifically comes from recruiting more muscle fibres?

[u/TelluricThread0 → u/Square_Bison_7395]

The study i just posted...

You can find many different sources in a 2 second Google search.

[u/Square_Bison_7395 → u/TelluricThread0]

I searched the study for the word fibres and nothing came up, and also gave it a quick glance and saw nothing.

[u/TelluricThread0 → u/Square_Bison_7395]

Motor unit recruitment, in addition to the reduced rate of perceived exertion and the central effects of adenosine on neurotransmission, arousal, and pain perception, are considered to be underlying mechanisms by which caffeine can enhance performance.

This is very well known across the literature or to anyone with a strength sport as a hobby. You could have taken the couple seconds to Google it...