Judo training induces numerous cardiovascular changes, with some peculiarities due to the intermittent nature of the sport (12). For example, studies conducted on elite judoka have shown significant increases in maximal oxygen consumption (VO₂max), indicating a measurable improvement in aerobic capacity (13). A high VO₂max is associated with a better ability to maintain high work intensities and a faster recovery between explosive actions (14). However, judo-specific training enhances the ability to tolerate and effectively use lactate as an energy source, delaying fatigue and improving performance during high-intensity efforts (7).

Another key aspect is the improvement of heart rate recovery (HRR), an indicator of the efficiency of the autonomic nervous system in restoring the physiological balance post-exertion. Well-trained judo athletes show a more rapid reduction in heart rate after intense exercise, suggesting enhanced vagal control and more efficient recovery compared to less trained judo athletes or practitioners of lower-intensity intermittent sports (15).

Heart rate variability (HRV), another key parameter for assessing cardiovascular health and recovery capacity, is improved in elite judoka compared to amateur practitioners (12). This implies a greater adaptability of the autonomic nervous system to physical efforts, reducing the risk of overtraining and improving blood pressure regulation (16).

Cardiovascular adaptations induced by judo not only improve athletic performance but also have positive effects on general health. Regular practice of high-intensity interval sports has been associated with a reduction in the risk of cardiovascular disease, thanks to improvements in endothelial function, blood pressure regulation, and insulin sensitivity (15). Furthermore, high-intensity training such as that of judo stimulates the production of vascular growth factors, improving vasodilation and the ability to transport oxygen to tissues (17). Physiological adaptations resulting from judo training contribute to athletes' overall health (18).

However, in addition to the cardiovascular benefits, it is essential to consider the weight management strategies adopted by judokas to fit into the established weight categories for competition (19). Weight management is a crucial aspect of judo training, but it can carry to significant risks if not performed in a controlled manner. Athletes often resort to rapid weight loss (RWL) methods, which include caloric restriction and dehydration (20). Athletes who undergo to RWL can lead to stress to the cardiovascular system (19, 21). In fact, RWL can temporarily reduce plasma volume and increase resting heart rate, which may have negative consequences on performance, long-term cardiovascular function (22), and metabolic health (23).

A previous study have shown that safer weight management strategies, such as evidence-based weight management programs, can reduce the risks associated with extreme weight loss (19). For this reasons, coaches and trainers should adopt safe and effective weight management strategies, minimizing negative effects on cardiovascular function and optimizing post-competition recovery (19).

Based on these knowledges, the aim of this narrative review is to examine the physiological adaptations induced by judo practice, with a focus on cardiac function, HRV, and hemodynamic responses, to understand how training and competition can influence the cardiovascular system of judo athletes, and to examine the relationship with athletic performance.

This narrative review is divided into subsections. The first section examines the cardiovascular demands and physiological responses to judo training, detailing its impact on aerobic and anaerobic capacity, cardiac function, and vascular health. The second section synthesizes existing studies that evaluate cardiovascular training strategies, assessing their effectiveness in enhancing performance and reducing fatigue in judo athletes.

Judo training leads to an increase in both aerobic and anaerobic capacity, enabling athletes to sustain intense and repeated efforts without rapid fatigue. •

Maximum oxygen consumption (VO₂max): According to Franchini et al., elite judokas have mean VO₂max values between 50 and 60 ml/kg/min, values higher than the sedentary population and comparable to those of athletes of team sports such as football or basketball. A higher VO₂max is associated with better oxygen transport and greater resistance to prolonged effort (7).

Judo training induces to morphological and physiological adaptations similar to those found in endurance and strength sports. •

Left ventricular hypertrophy: Several studies have reported that judokas exhibit an increase in left ventricular mass, a common physiological adaptation in athletes in sports with high cardiovascular demand (27, 28). This increase in ventricular mass allows for a greater stroke volume, improving the efficiency of oxygen transport during intense physical activity (29).

The balance between the sympathetic and parasympathetic nervous systems is crucial for recovery and performance in high-intensity sports. Studies indicate that well-trained judokas show a predominance of vagal tone at rest, suggesting better autonomic control. •

Heart Rate Variability (HRV): It is known that judokas present significantly higher HRV values than sedentary subjects, with a predominance of parasympathetic activity at rest. This implies a better regulation of the cardiovascular system and a greater capacity to adapt to load variations (31).

Judo training also has positive effects on blood pressure and vascular function, contributing to the prevention of cardiovascular diseases. •

Reduction of resting blood pressure: It seems that judokas tend to present lower blood pressure values than the general population, thanks to increased arterial elasticity and reduced peripheral vascular resistance (33). This adaptation is similar to that observed in endurance athletes and represents a protective factor against hypertension.

Improved aerobic and anaerobic capacity is one of the most important adaptations for judoka, who must sustain high-intensity efforts alternating with recovery periods. Research suggests that VO₂max values between 50 and 60 ml/kg/min, such as those observed in judoka, are indicative of a high level of cardiovascular conditioning and endurance (36). Although these values are comparable to those observed in other team sports, it is important to emphasize that judo training does not focus only on endurance but also on explosive strategies, such as those needed to execute effective attacks and defenses.

The effects of HIIT on judoka, documented by a previous study, go beyond the simple improvement of aerobic capacity (37, 38). Such training also stimulates the ability to manage lactate accumulation, allowing athletes to maintain high performance despite increasing fatigue (39). The faster recovery of heart rate post-exertion suggests that judoka have a highly adapted cardiovascular response, which favors a rapid removal of metabolic waste products (36–38). However, the ability to manage metabolic acidosis and lactate management may be variable depending on the intensity and duration of training, as well as the experience of the athlete.

Physiological hypertrophy of the left ventricle, observed in judoka, is a well-known adaptation in many high-intensity and endurance sports (28). The comparability of these changes with those found in endurance sports, such as cycling and running, suggests that judo stimulates a response of the heart that improves the efficiency of blood pumping (27). However, unlike purely aerobic sports, judo also requires significant anaerobic and strength work, which could explain the increased thickness of the ventricular walls (3). This could have direct benefits for the management of explosive efforts and for improving the ability to cope with high-intensity efforts during combat. This type of cardiac hypertrophy appears to be a beneficial adaptation for athletes, but attention must be paid to the risk of cardiovascular overload in the case of excessive training without adequate recovery periods (40). Regular monitoring of cardiovascular health may, therefore, be essential to prevent risks related to hypertension or heart failure in elite judoka.

Adaptations in the autonomic regulation of the nervous system are one of the hallmarks of well-trained athletes. In the case of judoka, high parasympathetic activity at rest, indicated by HRV parameters such as RMSSD and HF, suggests a higher ability to handle stress and recover quickly from exertion. These autonomic adaptations are indicative of good cardiovascular health and a balanced response to load variations during training and competition (32, 41, 42).

The importance of autonomic regulation is particularly evident in judo, where phases of high intensity alternating with periods of active and passive recovery require a rapid transition between states of stress and recovery (41). The parasympathetic predominance observed in judoka could not only improve performance but also reduce the risk of cardiovascular disease, contributing to better stress management and the prevention of overtraining (43).

Another positive aspect of cardiovascular adaptations in judo is the improvement of vascular function, which translates into greater arterial elasticity and optimal management of blood pressure. Judokas tend to have lower blood pressure values than the general population, a protective factor that reduces the risk of hypertension and other cardiovascular diseases. However, transient variations in blood pressure and heart rate during combat are normal physiological phenomena, but it is important to monitor them to avoid long-term problems.

Various studies found that the ability to quickly return to baseline post-exercise is a sign of optimal cardiovascular health, but it is important that training is well-balanced to avoid periods of excessive stress on the cardiovascular system (44, 45).

The cardiovascular adaptations observed in judo not only improve the performance of athletes but also appear to have positive effects on overall cardiovascular health. However, it is essential to recognize that the intensity of judo training requires careful planning to ensure that the benefits are not offset by potential negative effects (46). To optimize cardiovascular health while maintaining peak performance, coaches should implement structured periodization, monitor HRV to assess autonomic balance, and ensure adequate recovery strategies. Additionally, safe weight management practices should replace RWL methods to prevent negative cardiovascular consequences (47, 48). By integrating these principles, judo training can provide long-term health benefits while reducing the risks associated with excessive training loads.

Future research could focus on evaluating the long-term effects of judo training, considering the relationship between intense sport practice and the prevention or development of cardiovascular diseases. Furthermore, it would be interesting to explore how personalized training strategies, which adequately balance aerobic and anaerobic efforts, can further optimize cardiovascular adaptations, minimizing the risks of overtraining or health problems. Furthermore, it would be optimal to try to perform post-career training to avoid adverse events once the athlete retires from competitive sports.