Is Electronic Muscle Stimulation Safe?Exploring the Benefits and Safety Precautions

EMS is generally safe when used as directed. However, as with any exercise or therapy program, it’s essential to consult with your doctor before starting an EMS program, especially if you have any underlying medical conditions. It’s also important to follow the manufacturer’s instructions for use and any guidelines provided by your therapist or trainer.


In recent years, Electronic Muscle Stimulation (EMS) has emerged as a popular method for enhancing muscle strength and aiding in fitness goals. However, concerns about its safety have also arisen. This article aims to shed light on the topic and address the question: Is electronic muscle stimulation safe? We will explore the benefits of EMS and provide essential safety precautions to help you make an informed decision.

Understanding Electronic Muscle Stimulation (EMS):

Electronic Muscle Stimulation, also known as neuromuscular electrical stimulation (NMES), involves the application of electrical impulses to muscles, causing them to contract and relax. This technology is often used as a complementary training technique, physical therapy tool, or muscle recovery aid.

How to safely use Electronic Muscle Stimulation:

  1. Proper equipment usage: Ensuring the use of high-quality EMS devices, with required certification (CE certificate for Europe, FDA for US, etc.) by reputable organizations is crucial. Using well-maintained equipment, following manufacturer instructions, and consulting with a healthcare professional can help mitigate any safety concerns. For example, when training with Pepper, you are guided through personalized EMS workouts developed by EMS experts. Moreover, through an extensive onboarding process, we ensure that all questions are answered before usage. This way, the users’ training experience is optimized and safety is guaranteed. 
  1. Proper exercise form: As with any exercise, your form is the key to success. When doing EMS training, an incorrect execution of an exercise can lead to some form of injury. Hence, it is important to have a professional guide you through the training, to insure injury prevention. 

Pro-tip: Pepper’s training app gives you access to EMS workouts that are developed by experts. The trainers take you through each exercise as a means to prevent users from exercise-related injuries.

  1. Personalized intensity settings: It is essential to set EMS devices at appropriate intensity levels, customized to an individual’s fitness level and tolerance. Gradual progression in intensity and duration is recommended to avoid muscle soreness or discomfort. It is vital to start with lower intensity levels and gradually increase as your body becomes accustomed to the stimulation. Overdoing the intensity can lead to muscle soreness or discomfort.
  1. Follow the safety guidelines: If any of the contraindications apply to you, you should not train with EMS:
  • Pacemaker, defibrillator, severe heart conditions
  • Acute bacterial or viral infect
  • Pregnancy

We also recommend you to follow precautions and consult with your physician if the following health situations apply to you:

  • Severe muscle strain, trauma, fractures, atrophy
  • Severe joint problems
  • Cardiovascular, heart diseases
  • Severe neurological diseases (epilepsy, multiple sclerosis, sensitivity disorders)
  • Severe metabolic diseases (diabetes type I or II, thyroid, liver, kidney)
  • Severe Blood supply or circulation disorders (ischaemia, arteriosclerosis)
  • Abdominal or groin hernia
  • Electrical equipment (e.g. cardiac monitors, ECG devices)
  • Cancer, tumour disease
  • Severe orthopaedic illnesses (arthrosis, osteoporosis, rheumatism)
  • Severe respiratory diseases (asthma, COPD, allergies)
  1. Follow the safety guidelines: It is essential to follow certain usage restrictions depending on the impulse intensity of the suit program. You should not be completing more than 50 minutes of EMS strength training per week, with each session consisting of no more than 25 minutes with a minimum of two rest days in between sessions. You can execute EMS cardio and relax units more often, as the impulse intensity is lower. In general, it is recommended to start slowly and increase the duration and frequency over time to give your body time to adjust to your new routine. As with all exercise, it is important to take rest days when needed, this is also relevant to avoid kidney damage, which we will delve into in the next passage.

The Role of Creatine Kinase (CK):

When exploring the safety of EMS training, it is essential to look into its effects on CK levels. Creatine kinase is an enzyme found in various tissues, including skeletal muscle, heart, and brain. It plays a vital role in energy metabolism, facilitating the conversion of creatine to phosphorating to provide a readily available energy source for muscle contraction.

EMS and Creatine Kinase Levels:

  1. Temporary Elevation: Research suggests that EMS may cause a temporary increase in creatine kinase levels immediately after a session. The increased CK levels are more often than not a result of HIIT training and do not indicate an injury. This elevation is typically mild and transient, with levels returning to baseline within a short period.
  2. Muscle Damage Indicators: Elevated creatine kinase levels can indicate muscle damage. However, it’s important to note that the temporary increase resulting from EMS is often a post-exercise effect, differentiating from the sustained elevation seen in conditions associated with a muscle injury.
  3. Adaptation and Recovery: With regular EMS training, the body can adapt to the stimulation, leading to decreased muscle damage indicators over time. Adequate rest periods between EMS sessions can help promote muscle recovery and minimize the potential impact on creatine kinase levels.


Electronic Muscle Stimulation is generally considered safe when used properly and under appropriate conditions. By following expert routines, utilizing high-quality equipment, and personalizing settings, individuals can minimize potential risks. While EMS may cause a temporary increase in creatine kinase levels, this is often distinct from the sustained elevation seen in muscle injury. With proper rest and adaptation, EMS can be a valuable tool for enhancing muscle strength and promoting fitness. However, it is always advisable to consult with a healthcare professional before initiating any new training regimen, particularly for individuals with underlying health conditions.


1Institute of Medical Physics, Friedrich-Alexander University Erlangen-Nürnberg, Germany; 2Department of Sports Science, University of Kaiserslautern, Germany; 3Faculty for Medical and Life Science, University Furtwangen, Germany

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