APEX PWR  |  Lessons in Longevity

Strength Training in Tigard, Oregon: Why Leg Strength Predicts Brain Health

The strength of your legs today is one of the most accurate predictors of your brain health two decades from now. Not your diet. Not your genetics. Your legs.

That headline made the rounds on social media recently, and the research behind it is real. It comes from a landmark study by Steves, Mehta, Jackson, and Spector, published in Gerontology in 2016, conducted at King's College London. The study followed 324 healthy female twins, ages 43 to 73 at baseline, for over a decade. In a subset of identical twin pairs, the researchers added MRI brain imaging 12 years after baseline to see whether early differences in leg power produced visible differences in brain structure later.

They did. The twin with stronger legs at baseline showed less brain atrophy, better cognitive performance, and larger brain volume than her genetically identical sister with weaker legs. The effect held even after controlling for diet, cardiovascular health, smoking, and the lifestyle factors typically blamed for cognitive decline.

This article walks through what the study actually found, the biological mechanisms behind it, and what to do about it if you live in the Portland metro area and want to act on the science.

The King's College London Twin Study

The Steves et al. study (PMID: 26551663) is one of the cleanest pieces of evidence we have on leg strength and cognitive aging, and it earns that status because of its design.

The researchers used the TwinsUK volunteer registry to recruit 324 healthy female twins. At baseline in 1999, they measured leg power using the Nottingham Power Rig, a validated device that measures explosive lower-body force production. They also ran cognitive testing using the Cambridge Neuropsychological Test Automated Battery, then re-tested 10 years later.

For a subset of 20 identical twin pairs who differed meaningfully in baseline leg power, they added structural MRI brain imaging in 2011 to 2012. The MRI subset is where the most striking findings emerged. Because identical twins share their genetics and most of their early environment, any differences in brain structure between them have to come from something modifiable in adulthood.

The result: the twin with greater leg power at baseline had measurably better preserved brain structure and cognitive function 12 years later. The researchers defined a 25-watt difference in leg power as clinically meaningful, corresponding to roughly 10 years of age-equivalent difference in women in this cohort.

Two important caveats. The study was conducted in women only, ages 43 to 73, and the authors note that further research is needed to confirm whether the findings extend to men. For our primary audience of women in midlife and beyond, however, this is some of the most relevant longevity research published in the last decade.

Why Leg Strength, Specifically

The legs house the body's largest muscle groups: quadriceps, hamstrings, glutes, calves. When trained intensely, these muscles do something many people do not realize they do.

They function as an endocrine organ.

Skeletal muscle is no longer understood as a passive system of contractile fibers. Decades of research, most prominently from Bente Pedersen's lab in Copenhagen, has established that working muscle secretes hundreds of signaling proteins called myokines into the bloodstream. Several of these myokines, including irisin, cathepsin B, IL-6, IGF-1, and FGF-21, are known to cross the blood-brain barrier or signal across it. Once they reach the brain, they stimulate the production of brain-derived neurotrophic factor (BDNF), which supports neuroplasticity, neuron survival, and the growth of new brain cells.

The larger the muscle being trained, and the more intense the training, the larger the myokine response. This is why the legs matter. Training your quadriceps and glutes with intent produces more signaling output than training your biceps or triceps, simply because there is more muscle producing the signal.

The Three Mechanisms Behind Leg Day and Brain Health

Why This Matters Most for Women

The Steves study was conducted exclusively in women, which is rare and worth noting. Most exercise science has historically been run on male subjects, then extrapolated to women. Here, the entire dataset is female, ages 43 to 73, which maps precisely onto the period in a woman's life when the stakes for long-term health begin to compound.

Women face a particular set of physiological transitions during this window. Estrogen decline through perimenopause and menopause accelerates loss of bone density, lean muscle mass, and aspects of cognitive function. Strength training is the single most evidence-supported lifestyle intervention for slowing all three.

The combination of leg-focused strength training and an objective measurement strategy (a DEXA body composition scan and a DEXA bone density scan) gives a woman in her 30s, 40s, or 50s a complete view of her trajectory. You see exactly where lean mass is, exactly where bone density is, and you build a strength training program calibrated to defend both.

This is what we built our adult strength training program around. For women in Beaverton, Tigard, Lake Oswego, Tualatin, and across the Portland metro, this is the work.

Three Ways to Start Training at APEX

Walking into a strength training program looks different depending on what you need. We run three distinct paths so the entry point matches the person.

Most clients start with the Strength Training Foundations Trial, which gives you a low-friction way to experience the coaching and programming before committing.

Get an Objective Baseline: DEXA Body Composition and Bone Density

Strength training works. But you cannot manage what you do not measure. Before starting (or while training), an objective baseline of where you stand today gives you the data to know whether your program is actually working.

Two Gold Standard measurements anchor that picture, and both can be done in a single appointment at APEX PWR in Tigard.

• DEXA Body Composition Scan: precise measurement of fat mass, lean mass, and how each is distributed. The clearest answer to whether your strength training is actually building muscle and reducing fat.
• DEXA Bone Density Scan: the Gold Standard imaging used in clinical medicine to assess osteopenia and osteoporosis risk. Especially important for women in their 30s, 40s, and beyond.

The data from both scans informs how your strength program is structured. If bone density is trending down, lower-body resistance training and impact work get prioritized. If lean mass is below where it should be for your age and goals, programming and nutrition adjust accordingly.

Serving Tigard, Beaverton, Lake Oswego, Tualatin & the Portland Metro

APEX PWR is located at 11105 SW Greenburg Rd in Tigard, central to the Westside Portland metro.

Clients from Beaverton reach us in roughly 10 to 15 minutes via OR-217. We work with adults across professional, parent, and athlete demographics across all neighborhoods in the Beaverton area, with strength training for women a particular focus.

Clients from Lake Oswego, Tualatin, and West Linn are typically within a 10- to 15-minute drive. Our facility offers a quiet, intentional alternative to the standard commercial gym, with semi-private group sizes that protect coaching quality.

For Portland residents in the Southwest, West Hills, and downtown areas, we are accessible along I-5 or Barbur Boulevard.

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