Overview of the physiological benefits of karate.

As someone who generally demands proof, I recently dug into some of the scientifically justifiable assertions we, as karate-ka and karate teachers, can make regarding the physiological benefits of karate training. Below is an overview of some of the significant findings - enjoy. 
Please note that there is also a dire need for more academic depth and rigour in studies explicitly on the benefits of karate on physiology. As a recent study entitled: “Health benefits of hard martial arts in adults: a systematic review” (Rios; Marks; Estevan and Barnett, 2017) raises questions about the long-term benefits of “hard martial” (i.e. those with person-to-person violent contacts) arts for participants. As the authors rightly note, “Hard” martial arts seem to have the potential to improve balance and cognitive functions that decline with age, which can lead to poorer health outcomes among the elderly (e.g. cognitive decline, falls, and fractures). Benefits should be further investigated with improved intervention studies, representative samples, and longer follow-up periods to establish associations with morbidity and mortality in the long term”.
Some research has shown that karate training offers many benefits, including improvements in physical fitness, mental well-being, and self-defence skills. However, there are also potential risks associated with this type of training, such as injury or psychological stress.
One of the most well-known benefits of karate training is its ability to improve physical fitness. Studies have shown that karate training can improve cardiovascular endurance, strength, flexibility, and balance (Delextrat & Cohen, 2009). This is likely due to the combination of aerobic and anaerobic exercise that karate provides and the repetitive nature of specific movements, such as punches and kicks. Although overuse of the movements can lead to issues such as: 

• Tendinitis;
• Carpal tunnel syndrome;
• Tennis elbow;
• Trigger finger and trigger thumb;
• Osgood-Schlatter disease;
• Back strains and sprains;
• Shin splints.

There is also emergent evidence that karate training may enable the development of more robust and healthier tendons and ligaments; however, this benefit must be set alongside the genuine possibility of damage to these self-same tissues during high-intensity or ballistic-style training. A good starting study exploring this topic is Martial Arts Training Attenuates Arterial Stiffness in Middle-Aged Adults (found at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3880664/).
Other potential risks associated with karate training are due to the physical nature of karate, which poses a risk of musculoskeletal injuries, such as sprains, strains, and fractures (Kraemer et al., 2001). In addition, there is also a risk of head injuries, mainly if protective gear is not used correctly (Gardner et al., 2010). Long-term injuries to the hip, elbow and shoulder joints may also be issues, especially when understanding the biomechanics of kicking is not taught correctly. Focusing only on the limbs wildly when kicking offered increased chances of damage as kicks are a complex and whole-body event. To quote: from Kinematic Analysis of Mae-Geri Kicks in Beginner and Advanced Kyokushin Karate Athletes (M.Błaszczyszyn; A.Szczęsna;  M.Pawlyta;  M.Marszałek & D. Karczmit, 2019): “Thus, to develop appropriate movement activities, trainers must strengthen the acquisition, improvement, and stabilisation of neuromuscular movement patterns throughout the kinematic chain, not focusing only on the work of the limbs. Moreover, the development of motor creativity skills should be considered at the earliest possible training stage by contact with a moving target. Acquiring this knowledge can lead to better results, elimination of errors in teaching, especially in the initial training period, and prevention of injuries that occur during exercise or competition”.
In addition to physical benefits, karate training has also been shown to improve mental well-being. Research has found that karate training can reduce stress and anxiety, improve mood, and increase self-esteem and self-confidence (Ehrenreich & Ben-Ary, 2012). This is likely due to the emphasis on self-discipline, self-control, and mental focus required in karate.
However, this potential may differ from the well-researched psychological benefits/costs of this Japanese Budo. For example, the 2020 meta-study “The effect of martial arts training on mental health outcomes: A systematic review and meta-analysis” conducted by B.Moore, D. Dudley and Stuart Woodcock, concludes “Given the paucity of research examining the psychological effects of martial arts training, conducting systematic reviews and meta-analyses is difficult. This is complicated by methodological problems with much of the existing research. Regarding the above meta-analyses and systematic reviews, at times, it appears the homogeneity across research designs and statistics used to generate comparisons are questionable. It is often unclear where the data used for comparisons has been derived from. Finally, it appears that some selective interpretation of results likely to be favourable towards martial arts has occurred.” 
Moreover, there is also the cult-like and parochial mindset/worldview of numerous organisations and individuals in karate who often use pseudo-science, behaviour modification and elements of brainwashing to garner personal prestige and financial gain for unsuspecting or naive participants. This dark side of karate receives little to no attention even though it is a global, multi-billion-run industry with no actual governing national or international bodies - a unique case within sports but not within “art” communities. 
Despite these risks, the benefits of karate training outweigh the risks. However, individuals must take precautions to minimise the risk of injury and psychological stress. Likewise, instructors and organisations must begin ensuring that those issues with instructors’ licences (e.g. Shihan not only understands the techniques but also has a deep understanding of pedagogy, child safety and biomechanical functioning). Simply practising and performing karate at a high level does not guarantee effective, safe and appropriate teaching. This includes proper warm-up and cool-down periods, wearing appropriate protective gear, and practising.
Some Other References:
Delextrat, A., & Cohen, D. (2009). Physiological and anthropometric factors associated with martial arts performance. Sports Medicine, 39(5), 403-421.

Ehrenreich, S., & Ben-Ary, A. (2012). Psychological aspects of martial arts. International Journal of Sport and Exercise Psychology, 10(1), 1-16.

Gardner, E. C., Levy, A. S., & Karchmer, M. A. (2010). Injury patterns among martial arts participants: a review of the literature. The American Journal of Emergency Medicine, 28(5), 517-526.

Kraemer, W. J., Fry, A. C., Rubin, M. R., Triplett-McBride, N. T., Gordon, S. E., Koziris, L. P., ... & Newton, R. U. (2001). Physiological