Reno, AM, Green, M, Killen, LG, O'Neal, EK, Pritchett, K, and Hanson, Z. Effects of magnesium supplementation on muscle soreness and performance. J Strength Cond Res 36(8): 2198-2203, 2022-This double-blind, between-group study examined effects of magnesium (Mg) supplementation (350 mg·d -1 , 10 days) on muscle soreness and performance. College-aged male ( n = 9) and female ( n = 13) subjects completed baseline and posttreatment eccentric bench press sessions inducing fatigue/soreness followed by performance sessions (total volume and repetitions to failure [RTF] [65, 75, and 85% of 1 repetition maximum]) 48 hours later with perceptual measures. Subjects estimated soreness using a Delayed Onset of Muscle Soreness scale by striking a vertical line on a 6-cm horizontal line (at 24, 36, and 48 hours post trial) from 0-no soreness to 6-intolerable soreness. Results are presented as means ± SD (alpha ≤0.05). Mg significantly reduced (∼1-2 units lower on a 6-point scale) muscle soreness from the baseline eccentric to postintervention trial 24, 36, and 48 hours with no significant change for placebo (Pla) group. Performance approached significance for total RTF ( p = 0.06) and 65 and 75% RTF ( p = 0.08) (Mg vs. Pla). Perceptual responses for session rating of perceived exertion and acute rating of perceived exertion were significant for Mg (5.1 ± 2.4 to 4.1 ± 2.0) vs. Pla (5.0 ± 1.8 to 5.5 ± 1.6). Perceived recovery after supplementation was improved vs. baseline for Mg (5.4 ± 2.2 to 7.5 ± 2.3) but not for Pla (6.2 ± 2.4 to 7.2 ± 3.3). Results show significantly reduced muscle soreness, session rating of perceived exertion, acute rating of perceived exertion, and improved perceived recovery after Mg (vs. Pla) supplementation and some evidence for positive performance impact.