The Acute Effect of a Diaphragmatic Breathing Warm-Up on Maximal Deadlift Performance

Abstract Katz, NS, Rossow, LM, and Fahs, CA. The acute effect of a diaphragmatic breathing warm-up on maximal deadlift performance. J Strength Cond Res XX(X): 000–000, 2026—The purpose of this study was to investigate the effect of acute diaphragmatic breathing practice on muscular strength (deadlift 1 repetition maximum) performance. Forty resistance-trained adults (32 men, 8 women; age 24.8 ± 6.8 years) completed 2 testing sessions in a randomized crossover design. Each session involved a standardized warm-up followed by a 1-repetition maximum (1RM) deadlift assessment. In the experimental condition, subjects performed a 5-minute diaphragmatic breathing protocol in the supine position before testing. Deadlift 1RM was significantly greater in the diaphragmatic breathing condition than control (163.6 ± 47.1 vs. 160.7 ± 49.6 kg; mean difference = 2.9 kg, +2.8%; p < 0.05). The effect size was small (Cohen's d = 0.34). Twenty-four subjects (60%) demonstrated improved performance (mean +8.1 kg, +6.6%), while 16 (40%) subject showed no change or a decrease in 1RM (mean −4.8 kg, −2.8%). A brief diaphragmatic breathing warm-up produced a statistically significant but small improvement in maximal deadlift performance. Given its simplicity, minimal time requirement, and the fact it requires basic equipment (e.g., a bench or box for foot support and a foam roller placed between the knees), diaphragmatic breathing may serve as a practical warm-up strategy for athletes and lifters seeking marginal gains in maximal strength performance.