Strength Training Is The Most Underused Medicine Of The Last Fifty Years

Most people meet strength training the wrong way. They meet it in a fluorescent-lit corner of a gym, surrounded by people who already lift, wondering if they look stupid. Or they meet it in a fitness magazine where the goal is visibly to sell supplements. Or, worse, they meet it as a footnote in a weight-loss program — squeezed in between cardio and macros — as if it were optional.

It isn’t optional. The strength of your skeletal muscle is one of the single most predictive markers of how well you will age. It outranks blood pressure. It outranks BMI. In several recent cohort studies it outranks resting heart rate.

I spent twenty years in the lab asking what skeletal muscle actually does for the rest of the body. The answer is: more than anyone realized in the 1990s, when strength training was still a sport-specific tool rather than a clinical one.

What changed

The shift started around 2009 with the American College of Sports Medicine position stand on progression models in resistance training (Ratamess et al., 2009, Medicine and Science in Sports and Exercise). That paper organized two decades of disorganized research into a clinical protocol. Suddenly resistance training had a dose, a frequency, an intensity, and a measurable adaptation — the same way drugs do.

Then the epidemiological studies started arriving. Liu et al. (2019) in the British Journal of Sports Medicine combined data from over 370,000 adults across 11 cohort studies. People who performed any amount of strength training had a 21% lower all-cause mortality and a 17% lower risk of cardiovascular disease compared to people who did none. The benefit peaked at around 30 to 60 minutes per week. After that, adding more strength training stopped adding more benefit, but the floor — doing any strength work at all — was where the biggest gain was.

Figure reference: Liu Y et al., “Associations of resistance exercise with cardiovascular disease morbidity and mortality.” Med Sci Sports Exerc. 2019;51(3):499–508. PMID: 30376511. Reference Figure 2: dose-response curve of strength training minutes per week vs. all-cause mortality reduction.

This is the part that didn’t make the front page: thirty minutes a week. Two short sessions. That’s the dose that moves a mortality curve. Not three hours, not five. Thirty minutes.

What it does at the cellular level

When you contract a muscle under load, a few things happen that your nervous system, endocrine system, and metabolism all care about.

The first is mechanical. The muscle fibres experience tension and micro-damage, and the satellite cells around them activate to repair and build. That repair process is mTOR-dependent — the same mTOR pathway that’s targeted by some longevity drugs. Resistance training is a non-pharmacological way to activate it episodically, which is what the body seems to want.

The second is metabolic. Active muscle is the largest organ system in the body that responds to insulin. Every kilogram of trained muscle is metabolically active tissue — it burns calories, takes up glucose, and offers a buffer for postprandial sugar spikes. In a 2016 paper I led as first author (Botezelli et al., Scientific Reports, 2016), we showed that strength training in fructose-fed animals prevented hyperinsulinemia and inflammation even when body weight didn’t change. Muscle quality was doing the work. Body weight was a lagging indicator.

The third is hormonal. Resistance training upregulates androgen receptor density, improves growth hormone pulsatility, and improves the testosterone-to-cortisol ratio. None of these effects come from cardio alone.

Why most people skip it anyway

Two reasons, in roughly equal measure. The first is intimidation — gyms are designed for people who already know what they’re doing, which makes them hostile to people who don’t. The second is the persistent myth that strength training is “for getting big.” It isn’t. Hypertrophy is a goal you can choose to chase; strength as health is what happens by default when you load a muscle two or three times a week for any duration.

If you’re a woman reading this and thinking “I don’t want to get bulky” — the math doesn’t support that fear. Women have roughly one-tenth the circulating testosterone of men, and “bulky” requires very high training volume plus surplus calories plus years. What women lifting produces is denser muscle, denser bone, and an insulin-sensitivity profile that protects against the metabolic decline that accompanies menopause.

The minimum effective dose

If you’re starting from zero, here’s the protocol that produces results inside eight weeks:

Two full-body sessions per week, 40 to 50 minutes each, separated by at least 48 hours. Each session has five movement categories: a squat (any variation), a hinge (Romanian deadlift, hip thrust), an upper push (bench press, push-up, overhead press), an upper pull (row, lat pulldown, pull-up regression), and a carry or core piece (farmer carry, plank).

Two to three sets per movement. Six to twelve reps per set. The last set should leave you with 1 to 3 reps in the tank — not failure, but effortful. Progress the load when you hit the top of the rep range with good form across all working sets.

That’s it. That’s the protocol that turns most clients from “I don’t really lift” to “I lift” inside two months.

Where this lives in the BTZ system

The Lean & Strong and Elite programs are built around this dose-response curve. Weight Well clients are programmed two strength sessions per week as a non-negotiable baseline — even when their stated goal is fat loss — because muscle is the metabolic asset that holds the result.