Muscle Makers

In mid- to late-2020, the “Zoom Boom” led to increased interest in fillers, injectables, and other aesthetic treatments for the face. But as the country began reopening and people started getting together with friends and family again, many dermatologists reported an uptick in interest in treatments for the body. This is likely due to patients wanting to lose the “Quarantine 15” and look and feel their best.

The popularity of body treatments continues to rise. According to the 2019 ASDS Survey on Dermatologic Procedures, there’s been a 62 percent increase over last year. Cryolipolysis and radiofrequency treatments continue to lead this category, with procedures increasing 214 and 133 percent, respectively, in the last eight years. In 2019, laser lipolysis rose 641 percent, microfocused ultrasound increased 202 percent, and tumescent liposuction grew 109 percent.

Technology continues to improve and expand the capabilities of these devices. Non-invasive body contouring procedures offer a safe and effective option to eliminate fat and now even strengthen and tone muscles. At this year’s AAD Virtual Meeting Experience 2021 (AADVMX 2021), Thomas E. Rohrer, MD, a dermatologic surgeon in Chestnut Hill, MA, discussed some of the latest technology, including high-intensity focused electromagnetic energy and electrical stimulation energy to build muscle and potentially reduce fat.

Building Muscle: What We Know

Electromagnetic energy devices create supramaximal contractions of the muscles—much stronger than is possible for people to get on their own. The devices create about 20,000 pulses in 30 minutes, Dr. Rohrer explains. Electrical stimulation devices supply the energy more directly to the muscle with lower energy to create contractions of the muscle. Electrodes are placed on the body to target different muscles. With both technologies, Dr. Rohrer says, you’re triggering an action potential with electrical energy.

“If we send the energy in there at 100 milliseconds, we can get the contraction of the slow twitch fibers. Those are the Type 1 aerobic fibers,” Dr. Rohrer says. “And if we use energy of about 40 to 50 milliseconds, you can actually get the fast twitch fibers. Those are the ones for the Type 2 of bulk or mass muscles—so building larger muscles versus the aerobic ones.”

These treatments alternate frequencies to try to hit both types of muscles during the same treatment. The goal, he says, is to try to get that muscle to contract as much as possible.

“For most of us, if we’re working out, we might get a 30 percent or 40 percent contraction of the muscle, which is pretty good. You feel like everything is contracted, but it’s not,” Dr. Rohrer adds. “Elite athletes can up to 80 or 90 percent, perhaps. But with these, they’re touting that they can get 100 percent contraction so just a much stronger contraction than we can on our own and, therefore, we can make much bigger changes, much more quickly.”

Clinical studies have shown these technologies to be safe and efficacious for body contouring. One study of 22 patients (avg. BMI 23.8 ) who underwent four 30-minute treatments on the abdomen with a high-intensity focused electromagnetic (HIFEM) field device found at three-month follow-up that the average waist size reduction was 4.37cm.²

Dr. Rohrer also pointed to studies led by Brian M. Kinney, MD that used MRI to evaluate results of the same protocol.^3,4 At six-month follow-up, there was an average 11 percent adipose tissue reduction and about an average 20 percent increase in rectus abdominis muscle thickness that lasted about a year.

Dr. Rohrer notes that the rectus abdominis muscle is on average only about 1cm thick. A 20 percent increase is only about 2mm, so it may not make a significant difference in appearance, especially in patients who may have a layer of fat over it, but in terms of function, it can make a significant difference.

Dr. Kinney also showed that treatments can result in a reduction in diastasis recti; Dr. Rohrer says this may improve the appearance of lateral abs definition in patients with lower BMIs.

Another recent study⁵ evaluated the safety and efficacy of electromagnetic muscle stimulation (EMMS) alone, cryolipolysis alone, and cryolipolysis with EMMS for noninvasive contouring of abdomen. The study found cryolipolysis and EMMS both work, but patients who had both saw the best results, which makes sense, says Dr. Rohrer. “By removing fat by freezing it—or you can heat it—and by increasing muscle you can really make a difference in how someone looks,” he says.

A new device on the market that combines radiofrequency (RF) heating and high-intensity focused electromagnetic waves into a single therapy simultaneously targets fat and muscle. Although still awaiting large, controlled clinical trials, the manufacturer says treatment can result in about an average 25 percent increase in muscle mass and a 30 percent decrease in fat.

Other muscles, such as the gluteal muscles, have been targeted with these treatments. The gluteal muscle is much bigger, so a 20 percent increase there will result in more significant change in the visible appearance, Dr. Rohrer says.

In a study presented at the American Society for Laser Medicine and Surgery 2019 that looked at HIFEM for the gluteus muscle, MRI analysis showed four 30-minute treatments resulted in an average 10.6 percent increase in the gluteus maximus and 9.8 percent for the gluteus medius and minimus at one month.⁶ Most of the hypertrophy occurs in the upper buttocks, Dr. Rohrer explains, so not only do patients gain mass, it shapes and lifts the buttocks.

What We’re Still Learning

Some questions remain about the type of muscle these treatments are creating. Is the muscle as functional as what would result from working out or is it creating bulk muscle that is visible but not as functional? Sarcoplasmic hypertrophy increases collagen, glycogen, and other non-contractile elements of the muscle and builds bulk muscle. Myofibrillar hypertrophy increases actin and myofibril size, which is actual muscle that leads to strength. Dr. Rohrer says he thinks the treatments are working to primarily build muscle for strength and balance based on recent data and personal experience.

In his office, Leah Spring, DO, led a prospective, single center, randomized, open-label, controlled study looking at the effects of treatment with a neuromuscular electrical stimulation device on muscle strength. Treatment led to a modest decrease in waist circumference, a slight increase in thigh circumference in the treated areas, and a statistically significant increase in the duration of time a treated individual could hold a single-leg wall sit, ranging from +55.7 percent to +119.3 percent, compared to baseline testing.

“The patients in the treatment group were really seeing a big difference in their functional muscles, whereas the control group really showed no improvement and were even a little worse off in the end,” Dr. Rohrer explains.

Results were similar for abdominal muscle strength. Treated individuals saw an average 43 percent improvement in endurance holding a plank compared to baseline versus the control group, who lost about 20 percent endurance.

1. https://www.asds.net/medical-professionals/practice-resources/asds-survey-on-dermatologic-procedures

2. Jacob CI, Paskova K. Safety and efficacy of a novel high-intensity focused electromagnetic technology device for noninvasive abdominal body shaping. J Cosmet Dermatol 2018;17:783–7.

3. Kinney BM, Lozanova P. High intensity focused electromagnetic therapy evaluated by magnetic resonance imaging: safety and efficacy study of a dual tissue effect based non-invasive abdominal body shaping. Lasers Surg Med 2019;51:40–6.

4. Kinney BM, Kent DE. MRI and CT Assessment of Abdominal Tissue Composition in Patients After High-Intensity Focused Electromagnetic Therapy Treatments: One-Year Follow-Up. Aesthetic Surgery Journal, 2020;40(12): NP686–NP693.

5. Kilmer SL, Cox SE, Zelickson BD, et al. Feasibility Study of Electromagnetic Muscle Stimulation and Cryolipolysis for Abdominal Contouring. Dermatol Surg. 2020;46 Suppl 1(1):S14-S21.

6. Palm M, Lozanova P. ASLMS Meeting 2019.