“In contrast, caffeine had a suppressive effect on ratings of perceived exertion ( D = -0.8; 95% CL, -1.1 to -0.6; P < .00001; n = 147).”
“…,caffeine led … ventilation ( D = 3.36 L·min-1; 95% CL, 1.63-5.08; P = .0001; n = 73), blood lactate (D = 0.69 mmol·L-1; … < .00001; n = 208), and blood glucose (D = 0.42 mmol·L-1; 95% CL, 0.29-0.55; P < .00001; n = 129).”