THE SCIENCE

Influence of adjuvant EMS training on body composition and cardiac risk factors in older men with metabolic syndrome (KEMMLER, W. / BIRLAUF, A. / VON STENGEL, S., Erlangen-Nürnberg University 2009).

Aim of study
Sarcopenia and (abdominal) adiposity are closely associated with mortality, multimorbidity, and frailty in older people. The aim of this study was to determine to what extent whole body electromyostimulation (WB-EMS) training can influence body composition and cardiac risk factors in older men with metabolic syndrome.

Methodology
After randomization, a total of 28 men with metabolic syndrome according to IDF (69.4±2.8 years) from the Erlangen area were assigned to a control group (CG: n = 14) or to a WB-EMS group (n = 14). The 14-week training WB-EMS regime provided a 30-minute endurance and strength program with the application of EMS every 5 days. In parallel, the control group underwent whole body vibration training focusing on “increasing flexibility and well-being.”

The abdominal and whole body fat mass as well as the appendicular skeletal muscle mass (ASMM) were selected as the primary end points. Secondary endpoints were the parameters of the metabolic syndrome according to IDF (waist circumference, glucose, triglycerides, HDL cholesterol, systolic and diastolic blood pressure).

Results
At a high effect size (ES: d`=1,33), the change in the abdominal fat mass shows significant differences (p = 0.004) between WB-EMS and CG (-252±196 g, p = 0.001 vs. -34±103 g, p = 0. 330). Parallel to this, whole body fat diminished by -1350±876 g (p = 0.001) in the WB-EMS group and -291±850 g (p = 0.307) in the CG (difference: p = 0.008, ES: d`= 1.23). The ASMM also showed significant differences (p = 0.024, ES: d`= 0.97) between the EMS group and vibration control group (249±444 g, p = 0.066 vs. -298±638 g, p=.173). With the exception of a significant inter-group difference (p = 0.023, ES: d` = 1.10) for the waist circumference (EMS: -5.2±1.8 cm, p = 0.001 vs. CG: -3.3±2.9 cm, p = 0.006), no further effects on the parameters of the metabolic syndrome (see above) were shown.

Conclusion
At a low training volume (about 45 minutes/week) and a short period of intervention (14 weeks), whole body EMS training exhibits significant effects on the body composition of older persons. Thus WB-EMS could be an appropriate alternative to conventional training programs for people with low cardiac and orthopedic capacity.

The effect of whole body electrical stimulation on the resting metabolic rate, anthropometric and muscular parameters of older people. The Training and Electromyostimulation Trial (TEST) (KEMMLER, W. / BIRLAUF, A. / VON STENGEL, S., University of Erlangen- Nuremberg 2009).

Aim of study
A substantial change in body composition, with an increase in abdominal body fat and a corresponding reduction in muscle mass, especially occurs in women after menopause. To counter this trend, whole body electromyostimulation training today stands out as an alternative to conventional muscle training featuring smaller orthopedic and cardiac loads at a comparably low training volume. The goal of this pilot study was to establish the applicability and feasibility of EMS training for older people as well as determine the effectiveness of this form of training on anthropometric, physiological and muscular parameters.

Methodology
30 post-menopausal women with long training experience were assigned randomly to a control group (CG: n=15) where they continued their training as usual, and an EMS group (n=15), which completed a 20-minute whole body EMS training session every four days, in addition to twice weekly strength and endurance training. The most important anthropometric data (weight, size, the percentage of body fat, waist circumference, etc.) were determined, along with resting metabolic rate and VO2.

Results
The resting metabolic rate showed significant reductions in the CG (-5.3%, p = 0. 038) and no changes (-0.2 %, p = 0.991) in the EMS group. Despite a medium effect size (ES: 0.62), mere tendencies without significant differences appeared between the EMS group and the CG (p= 0.065). The cumulative value for the skinfold thickness declined significantly in the EMS group (p= 0.001) by 8.6%, compared to a slight, insignificant increase in the control group (1.4%); a difference that turned out to be statistically significant (p = .0001, ES: 1.37). Waist circumference as a criterion for abdominal adiposity fell in the EMS group significantly (p > 0.001) by -2.3 % (vs. CG: +1.0 %, p= 0.106). The corresponding intermediate group difference turned out to be significant (p = 0.001, ES: 1.64).

Conclusion
In summary, improvements in functional parameters such as maximum strength and speed have been demonstrated along with health-relevant effects on body composition. In addition, a high acceptance of EMS training in this population of well-trained, post-menopausal women was established. So, aside from its effectiveness, the practicability of this type of training seems assured.

Electromyostimulation (EMS) on cardiac patients. Is EMS training becoming significant for the secondary prevention? (Fritzsche, D. / Freund, A. / Schenk, S. / Mellwig, K.-P. / Kleinöder, H. / Gummert, J. / Horstkotte, D., Bad Oeynhausen Heart Clinic, Herz 2010; 35 (1): 34–40)

Aim of study
The view that moderate endurance training as a part of secondary prevention improves the prognosis for chronic heart insufficiency has been sufficiently validated. Based on experience, however, only a few well supervised, highly motivated and mostly younger patients can be reached with a complimentary, sustained, sports therapy in clinical practice. Our own experience with whole body electromyostimulation of patients with cardiac insufficiency shows a thus far unanticipated potential for the regeneration of neurohumoral, inflammatory and skeletal muscular disease symptoms within the context of systemic CHI disease. Against this background, the effect and acceptance of whole body EMS in patients with cardiac insufficiency were investigated.

Methodology
15 patients with a confirmed diagnosis of CHI completed a 6-month training program (whole body EMS) with a miha bodytec device. The stimulation parameters were defined as 80 Hz and 300 μs at 4 s pulse and 4 s pause for a period of 20 minutes, followed by a cooldown in the 100 Hz range. The patients themselves chose the amplitude (mA), and the subjective feeling of “muscle contraction/current sensation” was set at step 8 of a ten-step scale. The specifications were 40–70 repetitions in the main section, with exercises in isometric holding positions and dynamic motion drills. Cardiac efficiency was assessed in an initial test and after three and six months of training by means of spiroergometry, electrocardiography (EKG) and echo; the metabolic status including creatine kinase (CK) and lactate dehydrogenase (LDH); in addition, weight and body fat distribution were determined (impedance scale).

Results
Up to a 96% increase in the oxygen uptake at the anaerobic threshold could be demonstrated (VO2AT 19.39 [± 5.3] ml/kg body weight [BW] before the start of training; VO2AT 24.25 [±6.34] ml/kg BW at the end of the training phase; p < 0.05). The diastolic blood pressure fell significantly (psyst < 0.05; pdiast < 0.001), muscle growth was up as high as 14% at constant weight. The training method was 100% accepted (no dropouts). The patients indicated that their subjective capacity was significantly higher.

Conclusion
For the first time, the study showed the effect of EMS training on patients with cardiac insufficiency. The improvement in the objective assessment of their capacity, as well as the optimization of muscle-physiological and metabolic parameters, by far surpassed the results of traditional types of aerobic training for primary and secondary cardiac rehabilitation in patients with CHI. The form of training selected holds great potential in the treatment of patients with cardiac insufficiency.

Short and long-term training effects on strength-related diagnostic parameters from mechanical and electrical stimulation (Speicher, U. / Nowak, S. / Schmithüsen J. / Kleinöder, H. / Mester, J., German Sport University Cologne 2008; published in “medical sports network” 04/2007, among others.)

Aim of study
The goal of the present study was to compare classic strength training methods with dynamic whole body EMS with regard to their effects on strength and speed.

Methodology
80 sports students were randomized into equal parts into classic training groups for hypertrophy, maximum strength, quickness and muscular endurance, the modern procedure for the whole body EMS and vibration, as well as the two mixed groups, whole body EMS/hypertrophy and vibration/hypertrophy. The classic training groups worked on the leg curl and leg extension musculature on (Gym80) machines in the respective groups in 3 series with various additional weights (30-90%, 3-15 repetitions). The EMS groups executed side steps and knee bends without additional weights (load/interval 6 s/4 s, pulse frequency 85 Hz, pulse width 350 μs, bipolar rectangular pulse (60% intensity). Standardization was via visual biofeedback. The training took place twice a week over a period of 4 weeks. Entry and exit tests were carried out on strength diagnostic machines before and after the training as well as after a two-week regeneration phase. The dynamics were measured by means of performance (strength x speed) with 40% and 60% additional load at various angles.

Results
All types of strength training were able to improve maximum performance significantly. Maximum strength improved the most, 16%, within the hypertrophy group, followed by 9-10% for EMS. Only the EMS groups showed significant improvement in speed. The measured speed performance improved by about 30% – significantly more than by classic methods (16-18%). This is apparently due to EMS‘s direct control of fast-twitch muscle fibers.

Mixed training designs such as EMS and classic hypertrophy training show the typical changes that result from the two training stimuli (a maximum 7 % growth in strength and 12% improvement in performance). Combinations of classic and modern training procedures could thus open up new, promising configurations of stimuli. Long-term effects of whole body EMS must, in particular, be emphasized. The greatest boosts in performance appear after a two-week period of regeneration.

Conclusion
Compared with various types of training to boost strength and speed, dynamic whole body EMS training has been shown to be a highly effective training method. Whole body EMS was the sole form of training able to improve maximum sports performance in speed of movement. In addition, pronounced long-term effects are opening up new possibilities in training periodization. A carefully dosed amount of whole body EMS together with the dynamic execution of movement represents a promising combination for strength and speed training.

Electrical Muscle Stimulation as whole body training – Multicenter study on the use of full body EMS in fitness centers (VATTER, J., University of Bayreuth, 2003; publication AVM Verlag, Munich 2010).

Aim of study
The objective of this paper was to discover whether positive changes with regard to strength, anthropometry, body awareness, mood, general health factors, back pain and incontinence can be realized through the use of electrically stimulated whole body training in a field test.

Methodology
In four fitness centers, 134 volunteer subjects (102 women and 32 men) averaging 42.5 years of age were surveyed, tested and compared to a control group (n=10) and examined based on age and gender before and after six weeks of training. This involved a determination of maximum strength, physical endurance, body weight, body fat percentage, girth, frequency and intensity of back and incontinence complaints, as well as general complaint status, mood, vitality, body stability and body contouring.

,p>The 12 training units were carried out on a twice weekly basis with the following training parameters: pulse duration/interval 4 s/4 s, 85 Hz, rectangular pulses, pulse width 350 s. An approximately 25-minute training session with static exercise positions followed an habituation period totaling 10-15 minutes. The training session concluded with a five-minute relaxation program (pulse duration 1 s, pulse interval 1 s, 100 Hz, rectangular pulses, pulse width 150 s).
Results
82.3% reduced their back pain, 29.9% were symptom-free afterward. 40.3% complained about chronic pain beforehand and 9.3% after completion. 75.8% saw improvements in incontinence, and 33.3% were free of symptoms afterward. The number of medical conditions was sharply reduced (about 50%). Maximum strength rose 12.2%, and muscular endurance 69.3%. Women benefited to a greater degree than men did (13.6% vs. 7.3%). 18 subjects ended the training prematurely. No changes were identified in the control group.

Body weight and BMI remained virtually the same. The body fat percentage fell 1.4% in the training group; it rose 6.7% in the control group. The younger persons undergoing the training lost more weight than the older; no gender- or weight-related variations resulted. Among the women in the training, the body circumferences were reduced significantly at the chest (-0.7 cm), thigh (-0.4 cm), waist (-1.4 cm) and hips (-1.1 cm). Among men, they decreased at the waist (-1.1 cm) with simultaneous growth in the upper arm (+1.5 cm), chest (+1.2 cm) and thigh (+0.3 cm). The control group showed no improvement and expanded at the waist and hips in the same time frame.

Body feeling improved, with 83.0 % exhibiting less tension, 89.1% greater stability, and 83.8 % higher performance. 86.8 % noticed positive body contour effects. 90.0% of the participants perceived the training positively. High intensities brought more significant improvements for the patients with complaints but increased the incidence of muscle aches.

Conclusion
Whole body EMS training represents a persuasive method to reduce extremely common back and incontinence complaints. The increases in strength match the experience with conventional strength training and in some ways are even superior. The body contouring and mood aspects appeal to men and women at all age levels. Thus, whole body EMS is an effective form of training appealing to a wide spectrum of target groups.

Electro Muscle Stimulation (EMS) of the whole body musculature – An innovative method to relieve urinary incontinence (BOECKH-BEHRENS W.-U./SCHÄFFER, G., unpublished dissertation, University of Bayreuth, 2002).,/p> Aim of study

The objective of this study was to investigate the effects of EMS training on urinary incontinence.

Methodology
The presence, type and the intensity of urinary incontinence complaints were investigated in 49 individuals with back ailments with the help of initial and subsequent questionnaires (GAUDENZ 1979). A largely slight to moderate form of urinary incontinence was present in 17 individuals (15 women, 2 men) averaging 47 years of age. 10 units of EMS training, twice per week, each lasting 45 minutes, were carried out with the following training parameters: pulse duration 4 s, pulse interval 2 s, frequency 80 Hz, rise time 0 s, pulse width 350 s. In the process, a period of about 25 minutes of supervised training, during which various static exercise positions were assumed, followed a habituation period lasting 10-15 minutes in each case for the adjustment of individual pulse strengths. The training period concluded with a five-minute relaxation program (pulse duration 1 s, frequency 100 Hz, rise time 0 s, pulse width 150 s.

Results
An alleviation of urinary incontinence complaints was achieved in 64.7% of the cases. 23.5% became complaint-free. A decrease in complaints occurred in 24.4%, and 35.9% saw no change. These results corresponded somewhat to the improvements that have been reported for treatments of incontinence with special, local electromuscular therapies (cf. Eriksen 1987, Sebastio 2000, Salinas Casado 1990, Meyer 2001).

Conclusion
Whole body EMS training represents an effective training system. It achieves therapeutic goals such as relief from incontinence and back complaints and preventive goals such as muscle formation, body contouring and improvements in mood, vitality, body stability and general performance.

Whole body Electro Muscle Stimulation (EMS Training) for back ailments (BOECKH-BEHRENS, W.-U. / GRÜTZMACHER, N. / SEBELEFSKY, J., unpublished dissertation, University of Bayreuth, 2002).

Aim of study
The objective of this study was to investigate the effects of extensive EMS training on back ailments.

Methodology
49 employees of the University of Bayreuth with back ailments, 31 women and 18 men averaging 47 years of age, took part in the study voluntarily. The frequency and intensity of the back ailments as well as general complaint status, mood, vitality, body stability, and body contour were determined with the help of initial and subsequent questionnaires. 10 units of EMS training, twice a week, each lasting 45 minutes, were carried out within the following training parameters: pulse duration 4 s, pulse interval 2 s, frequency 80 Hz, rise time 0 s, pulse width 350 s. In the process, a period of about 25 minutes of training, during which various static exercise positions were assumed, followed a habituation period lasting 10-15 minutes in each case for the adjustment of individual pulse strengths. The training period concluded with a five-minute relaxation program featuring a pulse duration of 1 s, a pulse interval of 1 s, a frequency of 100 Hz, a rise time of 0 s, and a pulse width of 150 s.

Results
88.7% of the subjects saw a reduction in back ailments, with significant relief from the complaints in 38.8% of the cases. A slight improvement in the general complaint condition resulted in 41.9% of the cases. The frequency and the intensity of the complaints also declined sharply during the training time frame.

In addition, the EMS training led to the following general effects: 61.4% of the individuals reported an improvement in their general complaint condition, 75.5% saw an improvement in their mood, 69.4% registered increased vitality, 57.1% of the men and 85.7% of the women perceived improved body stability, 50% of the subjects asserted positive effects on their body contour, and 75.5% felt more relaxed after the training.

Conclusion
Whole body EMS training combats back ailments, a common condition, very effectively. The current evidently engages even deep muscles that can only be reached with conventional treatment measures with difficulty. The special whole body EMS training represents a time-saving, very effective all-round training that achieves far-reaching, positive health effects. At the same time, therapeutic as well as preventive objectives are achieved.

Karl Lorenz Konrad, Jean-Pierre Baeyens, Christof Birkenmaier, Anna Helena Ranker, Jonas Widmann, Johannes Leukert, Lisa Wenisch, Eduard Kraft, Volkmar Jansson, Bernd Wegener

Description of study

The aim of this scientific research was to compare the effects of EMS on improving nonspecific chronic back pain (back pain not attributable to a specific diagnosed problem) compared to physiotherapy, traditional exercise, psychotherapy, occupational therapy and education combined.

Result highlights

In the EMS group, the patient’s self-ratings of their pain improved significantly.

Their disability level was reduced by 19.7 points and their spine assessments improved significantly

In the active control group (receiving a multimodal treatment), only the muscular function improved slightly..

Conclusion

The data supports the hypothesis that WB-EMS is at least as effective as a multimodal treatment, which is often referred to as being the golden standard. Therefore WB-EMS may be an effective and, with 20 min./week training time, a very time-efficient alternative to established multimodal treatment models.

BOECKH-BEHRENS W.-U./SCHÄFFER, G., unpublished thesis, University of Bayreuth, 2002

Description of study

In this study 17 people (15 female, 2 male) were tested on the improvement on EMS training on their medium level of urinary incontinence. Trainees trained twice per week for a total of 10 consecutive sessions. Isometric EMS exercises were performed during a 25 minute long training session each time.

Result highlights

23% of participants were free of symptoms after the training period and
a further 24% noticed a marked lessening of their discomfort
36% felt no change in their condition.
Conclusion

Besides being a full body workout, EMS training can also offer effective relief for a group of people suffering from discomforts caused by incontinence. It helps build pelvic floor muscles, core muscles and body stability, which helps to treat and prevent this condition. It will improve body condition, overall mood, daily comfort and an increased quality of life.

Based on EMS research done by Andre Filipovic and Dr Heinz Kleinoeder (2013)

Description of study

A sports University in Cologne had some scientist evaluate the use of EMS training in professional athlete performance and comparing it to conventional strength training. With EMS training being extremely time efficient (up to 6 hours of weighted work out for the whole body per session), the extra hours gained by athletes to apply the increased strength performance to their sport specific motions are very valuable. Scientists tested 22 professional German soccer players for a period of 14 weeks of EMS training.

Result highlights

Maximum strength increased by 30%
Kicking speed increased on average by 16%
Sprint performance increased by 20%
Conclusion

With many more studies done in different fields of sports (amongst others swimming), Filipovic and Kleinoeder’s EMS research confirmed that EMS training is an effective and time efficient alternative to conventional strength training. The athletes showed considerable improvements in their sport specific motions when compared to the conventional training group. This advance can be explained by the compact muscle that was gained with their EMS training in their testing period.

Based on Will EMS training become important for secondary prevention? by FRITZSCHE, D. / FRUEND, A. / SCHENK, S. / MELLWIG, K.-P. / KLEINÖDER, H. / GUMMERT, J. / HORSTKOTTE, D., Cardiology Clinic Bad Oeynhausen, Herz 2010; 35 (1): 34–40

Description of study

The medical field has proven that moderate endurance training improves chronic cardiac insufficiency. Unfortunately in reality, patients suffering from a cardiac disease struggle to commit to this exercise in a safe and reliable way to make any positive improvements on heart and health. With previous EMS studies showing the training to have great potential in improving cardiac health, this study was set out to medically assess what those improvements could be. 15 patients diagnosed with CHI completed a 6 month EMS course and medical tests followed the function of their heart and overall health, including weight and body fat distribution..

Result highlights

Patients proved to take up 96% more oxygen when their cardio threshold was tested
Blood pressure lowered significantly and Muscle mass increased with 14% and internal bodyfat dropped dramatically
All patients stated they felt a profound increase in their performance capacity.
Conclusion

Results showed that EMS training has a great potential of secondary treatment in the symptoms of chronic cardiac insufficiency. Not only did all the medical tests showed a great improvement in numbers, the patients themselves reported to have an increased quality of life with their performance capacity increasing dramatically.

BODY BACK PAIN 
Kemmler & S. von Stengel (Institute of Medical Physics, Friedrich-Alexander University), 2010-2012

Description of study

It is extensively researched and advised by health providers, that the only way to fight the natural and age-related decline of muscle mass and body/joint function is by regular physical exercise. Sarcopenia is the word used to describe the age associated loss of muscle mass which is replaced by body fat. It is sometimes seen with obesity and especially abdominal fat seems to increase. Abdominal fat in particular, has been proven to be a cardiovascular risk. Sarcopenia occurs in every person after the age of 30 and consists of 1% muscle loss per year, accelerating even more after the age of 50. Kemmler and colleagues studied the effects of 14 weeks of EMS training in 30 post-menopausal women and 28 untrained males 40 years or older.

Result highlights

Increase in walking speed greater than any other exercise method and Significant decrease in abdominal fat and waist circumference
Power and strength increased and Increase in muscle mass
Increase aerobic capacity.
Conclusion

The study results show EMS training can be used by most age groups and can help people improve their body composition as well as their physical capacity. In conclusion of their findings, the scientists stated the following: “… to our best knowledge, we are not aware of conventional exercise studies that reported comparably favourable changes of body fat and free fat mass. The results are remarkable especially considering the short duration…”

W.-U. Boeckh-Behrens, N. Grützmacher and J. Sebelefsky, unpublished thesis, University of Bayreuth, 2002.

Description of study

EMS training started in the medical field and was initially used to help patients in their rehabilitation from injuries and reduce symptoms of chronic back pain. Besides activating te major back muscle groups, EMS also activated the deeper muscle groups that are hard to reach with conventional training methods. With strength training being the most effective long lasting therapy for back pain, EMS provides a low impact solution for pain relief. Boeckh-Behrens and colleagues from the University of Bayreuth in Germany, started a study to map out how big the effects of EMS training can be for people struggling with lower back pain. The scientist assessed 49 people that scored high on an index of chronic lower back pain before, during and after 5 weeks of EMS training.

Result highlights

After 6 weekly sessions 88.7% of the participants that used to suffer from chronic lower back pain reported a significant decrease in pain (in frequency and intensity)
After 2 sessions 25% of participants were completely pain free and After 6 sessions 50% of participants were completely pain free
75% of participants noticed an overall improvement of mood and vitality.
Conclusion

The findings of this study showed that EMS training is a highly effective method of treatment for chronic lower back pain. Not only did the participants find relief in back pain frequency and intensity, they reported a major positive effect on mental wellbeing and physical vitality.

EFFECTS OF WHOLE-BODY ELECTROMYOSTIMULATION ON LOW BACK PAIN IN PEOPLE WITH CHRONIC UNSPECIFIC DORSAL PAIN: A META-ANALYSIS OF INDIVIDUAL PATIENT DATA FROM RANDOMIZED CONTROLLED WB-EMS TRIALS Kemmler and colleagues, Evid Based Complement Alternat Med. 2017; 2017:8480429

Description of study

With lower back pain being the leading cause of functional disabilities worldwide, scientist set out to research the effect of EMS training in people suffering from unspecified lower back pain in people aged 60+. While recognised in all medical fields that physical exercise is the preferred option of treatment, it is found kinesiophobia (the fancy word for fear of moving while in pain) is restricting this treatment option. Their theory was to test if EMS was a time efficient, safe and joint friendly option of treatment for this group of 310 patients.

Result highlights

When compared to TENS, stabilisation exercises and electrical acupuncture, EMS training showed to be significantly and dramatically more effective.
All groups training with EMS reported significant reduction of lower back pain compared to the control groups.
75% of participants noticed an overall improvement of mood and vitality.
Conclusion

The researchers found EMS to be highly effective as a method of pain management in senior individuals debilitated with this injury, much more so then the pain relief experienced by TENS treatment. They explained the possible short term effect of pain management is caused by reduced transmission of pain by the nerves due to electrical stimulation. The long term effect is by build-up of spinal muscle causing support and stabilisation..

VATTER, J, Universität Bayreuth, 2003; Publication AVM-Verlag München 2010.2003, a study by the University of Bayreuth (“Electrical Muscle Stimulation as a Whole-Body Workout – Multicentre Study on the Use of Whole-Body EMS Training in Studios”)

Description of study

During 6 weeks 134 volunteers with an average age of 42 years completed 2 EMS training sessions per week. After this period the results in various body parameters were compared with a control group.

Result highlights

82% noticed a relief in back pain, 30% of those were free of pain. The maximum body strength of participants increased by 12%, and their endurance by 69%
Body fat percentage decreased by 1.4%. Female trainees lost 1.5 cm at the waistline and 1.1 cm at the hips
Male trainees gained 1.5 cm in the upper arms and reduced their waistline by 1.1 cm. 83% of participants noticed positive changes and had an increased feeling of wellness.
Conclusion

When compared to the control group doing regular exercise, EMS trainees showed better results in increase in body strength, desired body shape and treatment of back pain. The overall mood and wellness was scored higher than in conventional strength training. The study supports EMS training as extremely effective and efficient, which can benefit a broad range of target groups; from coach potatoes to professional athletes.