A number of studies show that having caffeine 30 to 90 minutes before a workout does indeed benefit you in several ways.
It decreases
perceived effort (makes exercise feel easier), makes you more resistant
to fatigue, and especially with high-intensity stuff like sprinting and
cycling, increases power output and the number of reps you can perform before failing, and last but not least, boosts strength and muscle endurance.
In
short, caffeine makes for better workouts in just about every way, but
you have to take enough. Some studies have shown performance benefits
with dosages as low as 3 mg per kg of body weight, but 5 to 6 mg per kg
is more common and generally accepted as the “optimal” dose for maximizing benefits while also mitigating unwanted side effects.
To
put those numbers in perspective, 6 mg per kg would be about 300 mg for
a 120-pound woman (~3 cups of coffee) and 500 mg (~5 cups) for a
180-pound man. That’s much more than most people ingest before training,
which is usually closer to 100 to 200 mg.
