Specificity was another concept claimed to define training status, particularly task-specific activities related to maximal strength. Strength, power, and body composition distinguished elite athletes from lower competitive levels 10, 28, 60. Muscle fiber area increased significantly in the concurrent training group, whilst negligible changes were noted in the resistance training group. This study also concluded that the type and volume of endurance training impact the "interference effects" of resistance training . The optimal sequence should be determined based on the primary goal, such as maximal strength, power or endurance, allowing workouts to be adjusted for more effective results . In addition, another study reported a ~14% increase in the weight lifted during the 5RM front squat after 16 weeks of CrossFit®-based exercise in recreationally active males and females . This information is essential in determining the most effective training program for CrossFitters and give fundamental support for coaches to design an optimal training schedule (i.e., predominantly aerobic vs. anaerobic workouts). Moreover, the additional time under tension resulting from the continuous execution of two or more exercises in a circuit mode, as typical in CrossFit®, has a more pronounced effect on the HRV response . In intermittent exercises (like CrossFit®), autonomic modulation varies according to the intensity, implying that a low number of repetitions and moderate to high loads are key factors in cardiovascular stress . Concurrently, we also evaluate studies that have assessed changes in movement techniques, psychological well-being and recovery times, providing valuable insights for CrossFit® researchers, coaches, practitioners and people in general that are interested in these specific routines. CF performance was measured using the Fight Gone Bad (FGB) workout and muscle power was evaluated in a 30-second WAnT. Because betaine (BET) supplementation may improve muscular strength and endurance, it seems plausible that BET will also influence CrossFit performance (CF). For most people, the best strategy is to focus on a balanced fitness routine that includes strength training, cardio, and healthy lifestyle habits that support long-term health. However, studies in women show mixed results, with some finding little change or even slight decreases in testosterone after certain HIIT programs. Some research suggests HIIT may temporarily increase testosterone in men. There are no legal alternatives to testosterone that provide the same anabolic effects. A positive drug test for testosterone will result in a suspension or ban from CrossFit competition. What happens if a female CrossFit athlete tests positive for testosterone? Safe and effective supplements include creatine, beta-alanine, caffeine, and protein powder. What supplements can female athletes use to improve performance without risking their health? It just takes more time, dedication, and a well-structured program. What are the signs that a female athlete might be using testosterone? Given that CrossFit® exercises range from ~2 to 40 min, it becomes evident that CrossFitters rely on well-developed aerobic and anaerobic energy pathways 9,14. Effective training and adaptation in sports and exercise require monitoring, quantifying and regulating both external and internal training loads 3,21. Some CrossFit® workouts elicit substantial hormonal and metabolic disturbances, coupled with short-term heightened oxidative stress and inflammation 10,18,19. To evaluate fitness and monitor changes in work capacity, CrossFit® incorporates benchmark workouts (Table 1), with Cindy and Fran being the most extensively assessed 7,14,15,16,17. As in any sport, peak performance in CrossFit® competitive events is achieved only after years of structured training and requires continuous progression that should be carefully monitored throughout the training process 8,13. In competitions, the requirements for the workout of the day are announced to participants just a few minutes before the event, marking a key distinction from other sports, where athletes typically know in advance which discipline will be performed 8,13. A key factor influencing the adherence and continuation of practice may be psychological factors (like motivation), which encourage participants to engage consistently in exercise . This increase seems to occur at the beginning of the training and persists for up to 30 min after the session (Tibana et al., 2018). There was a consensus that lactate levels are high immediately after a CrossFit® training session. WOD, workout of the day; RFT, rounds for time; AMRAP, as many rounds/repetitions as possible; NS, not significant; KB, kettlebell; DU, double under; C&J, clean and jerk; RM, maximum repetition; GOT, glutamic oxaloacetic transaminase; GPT, glutamic pyruvic transaminase. Of the 25 studies analyzed, all had different training protocols regarding the training stimulus administered. IL-6 increased after WOD-independent training, while IL-10 increased as a function of WOD characteristics (Tibana et al., 2016). CK seemed to increase after training (Durkalec-Michalski et al., 2018; Timón et al., 2019) or to decrease within 72 h after training (Tibana et al., 2019a). Timón et al. (2019) were the only researchers to evaluate GOT and GPT responses after training, and their results showed significant increases values independent of the WOD. Blood glucose did not change between healthy and overtraining syndrome athletes in an undescribed training protocol (Cadegiani et al., 2019). Testosterone replacement therapy can be a valuable treatment option for those experiencing symptoms of low testosterone and who haven’t been able to naturally increase their testosterone. This workout will push your cardiovascular system and stimulate testosterone production with bursts of intense effort. It’s during this stage of sleep that your body does most of its muscle repair and hormone production. Six studies (Tibana et al., 2016, 2019a; Michnik et al., 2017; Durkalec-Michalski et al., 2018; Cadegiani et al., 2019; Timón et al., 2019) investigated inflammatory responses (see Table 2). Cholesterol showed no differences after training (Shaw et al., 2015), and creatinine did not change after 6 months of CrossFit® training (Cadegiani et al., 2019). Cholesterol, creatinine, GOT and GPT were each investigated in only one study. However, blood lactate responses after the protocols were similar regardless of the WOD time. Chronically, Murawska-Cialowicz et al. (2015) reported non-significant changes in lactate values after 3 months of CrossFit® training.
