dramatic increases in oxygen utilization, endurance and performance in as little as a 2 capsule dose
I dunno if weighing 225lbs (not exactly an endurance athlete) changes this, but I liked 5 caps for a noticeable effect.
ATP regeneration time should be accelerated leading to more muscular strength with longer durations until failure.
Rest times between all-out efforts decreased noticeably.
you won’t hit the wall cardiovascularly!
I found that I could maintain a minimum pace on many bodyweight movements almost indefinitely.

I found that I had an easier time holding pause squats, which makes me wonder is swimmers wouldn't benefit greatly from this supplement. The inclusion of electrolytes definitely helped me feel better at the end of a workout.

Overall, I got a mild increase in my abysmal cardio abilities and think an endurance athlete might benefit more.