The Claim
Acute ingestion of 3 mg/kg of caffeine improves mean velocity and power output during back squat exercises at 75% and 90% of one-repetition maximum (1RM) in resistance-trained males, increasing performance by 2.5–3.8 standard deviations, independent of time of day.
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.
When resistance-trained males consume 3 mg/kg of caffeine before performing back squats at 75% or 90% of their one-repetition maximum, their average movement speed and power output increase by 2.5 to 3.8 standard deviations, regardless of the time of day.
See the scientific wording
Acute ingestion of 3 mg/kg of caffeine improves mean velocity and power output during back squat exercises at 75% and 90% of one-repetition maximum (1RM) in resistance-trained males, increasing performance by 2.5–3.8 standard deviations, independent of time of day, suggesting caffeine enhances force production capacity under moderate-to-high load resistance conditions.
Caffeine enters muscle cells and makes the internal calcium storage system release more calcium, which causes muscle fibers to contract harder and faster. This allows the muscles to move weights more quickly and with more power, even when the nerves aren't firing more strongly.
What the research says
1 studyThis study found that when trained men took a caffeine pill (3 mg per kg of body weight) before squatting heavy weights, they lifted faster and with more power — no matter if they did it in the morning or evening.
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.