Biomechanical and Physiological Demands of CrossFit: A Systematic Review

CrossFit's popularity has increased as an effective training program for physical fitness. The volume of published literature suggests a continuous effort to understand and optimize CrossFit training protocols. Therefore, this study aimed to analyze scientific literature findings related to CrossFit's biomechanical and physiological demands via a systematic review. Systematic searches were conducted on PubMed, Web of Science, ScienceDirect, Scopus, and SciELO databases for articles reporting the effects of CrossFit training. Following the PRISMA guidelines, nineteen studies (n = 537 participants) examined the use of biomechanical and/or physiological variables in CrossFit performance. This review considered the one-repetition maximum, the countermovement jump, peak power, and movement technique as biomechanical variables most often used in literature. The physiological variables included blood lactate, maximal oxygen uptake, heart rate variability, and the rating of perceived exertion. These variables accurately measured strength, aerobic and anaerobic capacity, along with fatigue in training sessions and competitions. CrossFit training was shown to improve maximal oxygen uptake, muscle strength, hypertrophy, and muscular endurance while also inducing physiological stress. Strength and power variables correlated strongly with CrossFit performance, but movement technique and postural control also played significant roles. The combination of aerobic and anaerobic elements within CrossFit enhanced cardiovascular fitness and anaerobic capacity, reinforcing effectiveness when appropriately managed.