The positive effects of PEMF stimulation on bone repair may be beneficial in the prevention and treatment of stress fractures in athletes and soldiers. Stress fractures occur primarily in the lower limbs and result from the repetitive mechanical overload associated with high-volume of endurance training. Standard treatment includes rest, ice and painkillers. Some painkillers may actually impair bone healing (17). PEMF stimulation may be used as an adjunct to exercise training in people at high risk of stress fractures to prevent their development. In athletes and soldiers recovering from stress fractures, PEMF stimulation may accelerate the return to sport or duty by enhancing the healing of the damaged bone tissue (18). Furthermore, PEMF stimulation may relieve pain in people with stress fractures due to its analgesic effects.

Because pain is a significant barrier to exercise, the analgesic effects of PEMF stimulation may help people with osteoarthritis perform regular training to improve their physical function (19). A similar strategy may be applied in other situations in which musculoskeletal pain may limit the ability or willingness of people to perform exercise.

Exercise can induce significant muscle damage, especially when it includes eccentric muscle contractions (20). PEMF stimulation has many biological effects that may acutely enhance the recovery from such damage. These effects include reduced pain and inflammation, enhanced cellular repair and regeneration, stem cell activation and improved microcirculation, leading to better oxygenation and nutrient delivery to tissues (21). However, muscle damage and related inflammation have been proposed to be important stimuli for chronic muscle adaptations to resistance exercise (22). Therefore, it is important to directly investigate the net effect of PEMF stimulation on the muscle hypertrophy induced by resistance exercise.

PEMF stimulation is known to enhance peripheral blood flow. This effect may be particularly helpful as an adjunct to exercise in patients with impaired peripheral blood flow such as diabetic patients and people suffering from peripheral arterial disease. Exercise training is an important component in the management of these conditions (23, 24). PEMF stimulation may further enhance its beneficial effects in body parts particularly affected by vascular and microvascular alterations (25). Steward et al., (25) found that 12 weeks of PEMF stimulation let to improved endothelial vascular function and reduced blood pressure in hypertensive subjects showing that PEMF treatment could be a potential non-pharmacological and non-invasive strategy to manage vascular function and blood pressure in cohorts with peripheral vascular disease as well as hypertension.

Trofè et al. investigated the acute effects PEMF on muscle oxygenation during exercise. The authors found that PEMF enhanced muscle oxygenation and accelerated deoxyhemoglobin on-transition kinetics, indicating improved local oxygen extraction (7). In another study, the authors also found that PEMF stimulation increases the activity and metabolism of muscle fibers during physical exercise, therefore, PEMF has the potential to enhance muscular responses, particularly in low-intensity exercise scenarios (8).

Grote et al. aimed to assess the immediate and short-term effects of PEMF therapy on physiological parameters, particularly heart rate variability, following physical stress tests. Results showed that PEMF exposure influenced heart rate variability components related to sympathetically controlled blood flow rhythms, and accelerated recovery after physical strain. However, the application of PEMFs had no impact on participants overall well-being (26).

Viti et al. (27) investigated the effects of PEMFs stimulation using a PAP ion magnetic induction device, named PAPIMI, on autonomic nervous system activity in patients with chronic musculoskeletal pain. Results showed that PEMFs stimulation induced a significant parasympathetic response, which increased heart rate variability. Musculoskeletal pain conditions have been associated with a reduced heart rate variability [cfr (27)], thus, such acute autonomic change observed following PAPIMI intervention might be interpreted as a health status-related parasympathetic response. This study provided initial evidence on the potential physiological response induced by PEMF stimulation (PAPIMI device).

In a study by Parhampour et al., (28) PEMFs were applied with a 6-week resistance training program for patients with severe hemophilia A and osteoporosis. The aim was to enhance muscle strength, bone formation, and joint function. The authors enrolled 48 patients who were randomly assigned to one of four groups: resistance training alone, combined resistance training with PEMF, PEMF alone and control. Results showed that the absolute changes in the total score for joint function were significant for knees, ankles, and elbows in the resistance training alone and resistance training with PEMF, compared to the PEMF alone and control groups. The results indicated that combining PEMF stimulation with resistance training could be more effective than PEMF therapy alone.

Kandemir et al. (29) evaluated the effects of 3 months PEMF therapy in the treatment of subacromial impingement syndrome on 80 individuals randomly assigned to experimental (PEMF and exercise) or control (sham PEMF and exercise) groups. Both groups trained 5 days a week for a total of 20 sessions. Data were recorded before treatment (T0), after treatment (T1), and 12 weeks after the end of the intervention (T2). The results showed improvements in both groups compared with baseline. In the comparison between the two groups at T1 and T2, the PEMF group showed more improvements in most parameters.

Jeon et al. explored the impact of PEMF therapy on recovery from delayed-onset muscle soreness (DOMS) after isometric exercise. A 10-min PEMF on the brachii biceps post-training improved DOMS symptoms in the following days, improving overall recovery quality. Additionally, PEMF treatment increased muscle activation frequency and reduced electromechanical delay, implying a shortened recovery time. However, no significant effect was observed on the peak of isometric force generation, warranting further studies to validate PEMF's positive influence on enhancing and expediting the recovery phase (30).

Galace de Freitas et al. aimed to assess the impact of PEMFs and exercises on pain reduction, function improvement, and muscle strength in patients with shoulder impingement syndrome. They reported that the combination of PEMF and shoulder exercises effectively enhanced function, muscle strength, and reduced pain in SIS patients. However, the results should be interpreted carefully due to the lack of significant differences between the groups (31).

Interestingly, the positive effects of PEMF therapy have been mostly reported in extreme situations, while outcomes for healthy adults remain yet to be elucidated (33). Athletes are frequently involved in preseason training camps where they undergo intensified training to optimize adaptations for the competition seasons (34). The initiation of such a training regimen after a period of inactivity poses a substantial physical challenge to athletes. Given the existing research and the widespread application of these devices in real-world scenarios, PEMF holds the potential to enhance athletic performance as athletes transition back to regular training seasons. This could be achieved by boosting recovery and reducing fatigue during training camps.

PEMF stimulation should thus gain attention in the athletic and therapeutic exercise communities for its potential benefits in enhancing performance, accelerating recovery, and promoting overall musculoskeletal health. PEMF application helps in reducing muscle soreness and stiffness after intense workouts, enabling athletes to recover faster and perform consistently at high levels (30). PEMF therapy is useful in managing both acute and chronic pain conditions enabling individuals undergoing rehabilitation to continue their therapeutic exercises without discomfort. The regular use of PEMF stimulation can improve muscle performance by enhancing cellular function and energy production leading to improved strength, endurance, and overall athletic performance (7, 8, 18, 29, 31). Athletes may experience better training outcomes and improved results in their competitive activities. Further, PEMF therapy is also effective in reducing inflammation and promoting the healing of joint and ligament injuries being a valuable tool for both injury prevention and recovery (18). Lastly, PEMF stimulation is a non-invasive, drug-free treatment option, which can be particularly important for athletes who wish to avoid the side effects of medications or the risks associated with invasive procedures.

PEMF stimulation offers a range of potential benefits for athletes and those involved in therapeutic exercise. From enhanced recovery and pain reduction to improved performance, PEMF therapy presents a promising adjunctive treatment to support physical health and optimize athletic outcomes.

Although PEMF stimulation has been used for decades, there are currently no guidelines for categorizing PEMF. The main issue concerns the stimulation protocols, including time of exposure and frequency. However, those parameters are difficult to standardize. A discussion on the electromagnetic characteristics of PEMF stimulation can be found in the review by Flatscher et al. (21). Briefly, electromagnetic fields are composed of magnetic and electric fields that influence each other. PEMF applies intermittent, current pulse-generated magnetic field pulses over a short period of time. Tissues are affected by the applied PEMF field in two ways: firstly, the magnetic field creates a force on tissue-resided molecules which depend on their magnetic reactive properties, and secondly, the induced electrical field, which exerts a force on the ions present in the tissue (21); both result in a forced movement of ions or charged particles, such as proteins (35, 36). Mansourian and Shanei (37) performed a meta-analysis on PEMF in vitro studies showing that the effect of PEMF differs between cell type (stem cells) and origin (human/animal).

Almost every article discusses the heterogeneity of PEMF parameters used and positive effects are repeatedly reported A summary of results and characteristics of the reviewed research articles is shown in Table 1. Even though reliable research on such parameters has not been performed yet, PEMF is safe, non-invasive, relatively inexpensive and has been shown to positively contribute to many different conditions.

The data shown in this brief review demonstrate that PEMF application in physical activity and sport is a burgeoning field with considerable potential. Future research should focus on understanding how PEMF influences muscle metabolism, ATP production, and neuromuscular function. Detailed mechanistic studies are needed to elucidate how PEMF can be used to improve strength, endurance, and recovery at systemic level. Further studies should explore optimal frequencies, intensities, durations, and application timings relative to training sessions. Customizing protocols based on sport-specific demands and individual athlete profiles can enhance the practical utility of PEMF.

It is important to underline that, to date, the long-term effects of regular PEMF use on athletic performance and injury rates are underexplored. Longitudinal studies should track athletes over extended periods to assess how sustained PEMF use influences performance metrics, injury incidence, and career longevity providing insights into the viability of PEMF as a long-term tool in sports. Further, athletes of different ages and genders may respond differently to PEMF therapy. Future studies should investigate how factors such as age, sex, and hormonal variations influence the efficacy of PEMF enhancing personalized approaches to athlete care.

In conclusion, while the current literature on PEMF in physical activity and sport is promising, extensive research is necessary to fully harness its potential.