#24: Uplifting

Adding weight to the muscle-centric medicine movement.

Muscle Growth

Gone are the days when bodybuilders, professional athletes, and Hollywood celebrities were the only people lifting weights.

Since the pandemic, weightlifting has:

• Become the second most popular fitness trend in 2023.

• Been the most popular type of workout class in 2022.

• Been searched nearly twice more on Google YoY from 2022 to ‘23.

And according to ClassPass data, there was a 94% YoY increase in strength training class reservations from 2021 to ‘22.

The reason behind the growing trend? Lifting weights can lift the quality (and quantity) of life.

Muscle-Mortality Link

In general, higher levels of lean muscle mass are associated with lower mortality rates, especially from chronic conditions.

Exercise—specifically muscle-strengthening—really is the “billion-dollar drug that never gets prescribed”, meaning a longer life could be found at your local gym.

• It takes less than an hour of strength training per week to reduce all-cause mortality by 10-17%.

• Resistance training is also just as effective at reducing anxiety and depression in adults as antidepressants.

Midlife Muscle Crisis

Leading the shift toward “muscle-centric medicine” is Dr. Gabrielle Lyon, an osteopathic physician trained in geriatrics, obesity, and nutritional science. It was during her training that she realized muscular atrophy to be an even greater public health threat than obesity.

“All of my sickest patients had one thing in common. They all had unhealthy muscle”.

~ Dr. Gabrielle Lyon, The Midlife Muscle Crisis (Ted Talk)

Most of us lose 3-8% of muscle mass each decade after the age of 30, and some lose even more due to a condition called sarcopenia. Decreases in skeletal muscle mass lead to lower testosterone, estrogen, growth hormone production, and increased insulin resistance.

According to Dr. Lyon, muscles are the organ of longevity, acting as sites for both amino acid storage and glucose metabolism regulation. When muscles contract during exercise, they release myokines, changing how nutrients are utilized by the body while also bolstering immune, brain, and endocrine functions.

Essential to muscle-centric medicine are proteins and amino acids, the building blocks of muscle tissue. The current dietary recommendation is 0.8g per kg of body weight, but that number is treated as a maximum. Protein guidelines set us up to do the bare minimum for our health, similar to current blood testing standards.

Pumping Up

With more people turning to dumbbells rather than treadmills for a healthier life, gyms are removing cardio equipment and making room for more strength-related activities.

Life Time Fitness locations have created new spaces for their resistance training Alpha Strength classes, while OrangeTheory Fitness recently launched a new strength training session called Strength 50.

Boutique studios such as Barry’s, F45, and Madabolic, are also increasingly taking the CrossFit approach—selling functional strength over pure cardio.

Measuring Gains

Resistance training is medicine, so it’s no surprise the body composition market is expected to reach $1.5B by 2030. Adding to medical grade DEXA scans, CTs, and MRIs are consumer smart scales and mobile apps quantifying a user's muscle mass content.

• Styku: A leading 3D body scanner used to make millions of measurements with 2mm accuracy within 35 seconds.

• Made Health: Allows users to accurately measure muscle and fat composition by taking a single photo of themselves.

• BioAdaptives: Announced Fit Your Outfit, a tracking system to detect unwanted muscle loss during obesity management.

• Spren: Offers $120/year for unlimited iPhone-based body composition assessments with comparable accuracy to DEXA, which costs up to $300 per scan.

Elsewhere, NASA recently funded the first wearable to measure muscular atrophy—an issue exacerbated by space travel. Astronauts can lose up to 20% of their muscle mass during a spaceflight lasting as little as 5 days.

Overweight Under-Muscled Epidemic

In the era of GLP-1s, we are too focused on losing weight.

Though these drugs are curbing obesity, losing muscle mass is a major side effect. So if being under-muscled is the real epidemic, as Dr. Lyon suggests, weight loss pills may be doing more harm than good in the long run. As such, doctors should prescribe these medicines along with comprehensive strength training programs and protein-rich diet regimens to minimize muscle loss.

Using GLP-1s alone, our population will certainly shed weight, but in the form of fat and muscle. In doing so, BMI will become an even worse predictor for overall health, underscoring the growing importance and acceptance of looking to skeletal muscle mass to assess long-term health.

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What I’m reading this week:

• PE-Owned Health Care Saw Bankruptcy Surge as Playbook Failed, Bloomberg

• Take This Dance Class and Call Me in the Morning, NYT

• America’s Growing Birthweight Crisis, Time

• British youth smoking ban advances, Axios

• A blood test to detect cancer? Some patients are using them already., Washington Post