The Claim
Acute caffeine intake at 3 mg/kg increases mean velocity and power output during muscular endurance testing at 65% 1RM in the back squat for resistance-trained males by 6–9% in both morning and evening sessions, and increases performance by 6–9% in the morning session for the bench press.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Consuming 3 mg of caffeine per kilogram of body weight before exercise increases the speed and power output during back squat endurance tests at 65% of one-rep max by 6–9% in trained men, regardless of time of day, and increases performance by the same amount in the morning during bench press tests.
See the scientific wording
Acute caffeine intake at 3 mg/kg enhances mean velocity and power output during muscular endurance testing at 65% 1RM in the back squat for resistance-trained males, improving performance by 6–9% in both morning and evening sessions, but only in the morning for the bench press.
Caffeine blocks signals that slow down nerve and muscle activity, allowing nerves to fire more strongly and muscles to contract faster and longer without getting tired as quickly. This makes the body produce more power and move weights faster during repeated lifts.
What the research says
1 studyThis study found that taking a caffeine pill before lifting helps trained men squat faster and harder at moderate weight, no matter if it’s morning or night. It also helps them bench press better—but only in the morning.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.