Electric current + weight training = Even bigger, stronger muscles, scientists find

Man training with electrical muscle stimulation. (Photo by InnerVisionPRO on Shutterstock)

EL PASO, Texas — New research suggests that adding electrical muscle stimulation to your weight training routine could lead to greater improvements in strength and muscle growth. The study found that combining traditional resistance training with electrical stimulation produced better results than weight training alone.

Neuromuscular electrical stimulation (NMES) might sound complex, but the concept is straightforward: small electrical pulses are delivered through pads placed on the skin, causing muscles to contract. If you’ve ever seen someone using a muscle stimulator at a physical therapy clinic or gym, that’s NMES in action. Users typically describe the sensation as a strong tingling or pulsing feeling that causes their muscles to tighten rhythmically.

“Under normal conditions, the brain activates muscles by sending signals through the nervous system,” explains Sudip Bajpeyi, Ph.D., a professor in the Department of Kinesiology at The University of Texas at El Paso, in a statement. “NMES mimics this process by delivering external electrical currents to the nerves, causing the muscles to contract, without input from the brain. Think of it as though your muscles are contracting involuntarily.”

Bajpeyi and his research team at the Metabolic Nutrition and Exercise Research (MiNER) lab analyzed data from 13 different studies involving 374 participants. These studies compared people doing regular weight training exercises — like squats, leg extensions, and bench presses — against those doing the same exercises while receiving electrical stimulation through NMES devices.

What makes this approach potentially more effective than traditional weight training alone? During normal exercise, your body typically activates smaller muscle fibers first before recruiting larger ones as needed. NMES works differently. It can activate both small and large muscle fibers right from the start, even at lower intensities. Imagine having access to your muscle’s full strength potential from the very first repetition, rather than gradually building up to it.

The results, published in the European Journal of Applied Physiology, showed meaningful improvements in both muscle strength and size when NMES was added to regular weight training programs. The sweet spot appeared to be programs lasting at least eight weeks, with participants exercising multiple times per week. The research included a diverse group of participants, from teenagers to elderly adults, both men and women, and people ranging from sedentary to athletic.

Just like adjusting the volume on your headphones, the frequency of electrical stimulation could be tuned for better results. Studies using higher frequencies (85 Hz or greater) typically showed better outcomes. This may be due to the force-frequency relationship, where higher frequencies can generate stronger muscle contractions. However, the researchers note that proper placement of the stimulation pads is crucial for comfort and effectiveness.

This research opens up interesting possibilities for both fitness enthusiasts and medical applications. Bajpeyi’s team is currently investigating whether this approach might help people with Type 2 diabetes, since increased muscle mass can help the body process blood sugar more effectively.

“Exercise is medicine, but not everyone is able or willing to engage in traditional exercise,” notes Bajpeyi. “NMES has great potential for improving metabolic health by building muscle mass, which can help the body process blood glucose more effectively.”

While the findings are promising, they come with important context. Most studies focused on leg muscles, using professional-grade NMES devices under supervised conditions. The researchers emphasize that proper technique, consistent training, and adequate recovery time remain essential components of any strength training program, with or without electrical stimulation.