Heavy Lifting for Women Over 40: Why 3-5 Reps Beats 8-12 for Strength, Brain, and Longevity

Stacy Sims emphasizes that power—the ability to produce force quickly—is a premier predictor of healthspan and longevity. When women enter perimenopause, the typical advice is to do hypertrophy work to offset lean mass loss, but this ignores the quality of the muscle. By using loads near the 3-5 rep max, the body receives a clear signal to recruit high-threshold motor units and force myosin to ‘grab on tightly’ to actin. This adaptation maintains explosive strength that prevents the functional decline seen with aging. She notes that the journey to lifting heavy takes time, requiring an understanding of reps in reserve (RIR) and rating of perceived exertion (RPE) to push hard without failure. The protocol is not just about adding weight; it’s about intentional, quality-driven power output that doubles as a bone-density builder.

Stacy introduces French contrast as a high-level solution for women who already have strength but are losing the quick, explosive quality of movement. She describes it as ‘really hard, but so powerful in function.’ The protocol leverages the immediate neural after-effects of a near-maximal contraction to supercharge plyometrics, then uses rapid, submaximal reps to groove speed. This method directly counters the age-related decline in power without sacrificing strength, making it especially potent for women in menopause who want to maintain athleticism and daily function. It’s not an everyday protocol but a strategic tool for those ready to push beyond conventional heavy lifting.

Sims explains that myosin, one of the contractile proteins in muscle, is driven by estradiol. When estrogen declines, myosin’s ability to grab onto actin and produce a strong contraction weakens, causing a loss of power. The typical 8-12 rep range creates a metabolic cost and can build some lean mass, but it doesn’t provide the strong central nervous system stimulus needed to force myosin to adapt. In contrast, heavier loads in the 3-5 rep range with 1-2 reps in reserve send a potent signal that says ‘you have to grab on tightly’ to actin, preserving muscle power. She references Brad Schoenfeld’s recent work debunking strict rep ranges for hypertrophy, supporting the idea that low-rep training can also build lean mass, tackling both muscle quantity and quality in one go. This shift is critical for women navigating perimenopause and beyond, as it directly protects the power output that predicts how well we’ll live as we age.

Sims connects the hormonal profile of amenorrhea to the same myosin impairment seen in perimenopause. By advocating power training across these two populations, she reinforces that the loss of estrogen—not age—is the primary driver of muscle quality decline. This suggests that the heavy, low-rep protocol is a universal intervention for low-estrogen states, not just a menopause strategy.

Sims uses this research to dismantle the ‘hypertrophy vs. strength’ dichotomy. She has been advocating that power training is both strength and muscle-building, and the Schoenfeld data gives her argument backing. This means women can confidently pursue low-rep heavy lifting without worrying they’re missing out on muscle gains, making the protocol more accessible and evidence-based.