Why Leg Strength Is the Best Predictor of Brain Health for Women Over 40 | Dr. Tommy Wood
·9 min
The episode begins with host Angela Foster introducing the topic of leg power and brain health, referencing Dr. Tommy Wood's book. Dr. Wood explains a study using the NHANES database that found relative leg power predicts processing speed in older adults. He clarifies that relative strength accounts for individual body size differences. The link between legs and brain involves two factors: the activity itself benefits the brain, and leg workouts release exokines. Exokines like IGF-1 are critical for white matter structure, which insulates neurons and supports fast processing. White matter changes with age predict cognitive decline and dementia. Randomized trials show resistance training improves strength, white matter, and cognitive function. Dr. Wood describes the neuromuscular stimulus from exercise. Foster shares her personal experiment measuring peak power in watts on a bike relative to her 53 kg weight. Dr. Wood details the study's isokinetic leg strength measurement using a machine that maintains constant speed. He suggests alternatives like Peloton bikes or leg presses for estimating power. A benchmark of double body weight on a leg press is recommended. The conversation shifts to general strength training, noting that achievable goals are lower than many assume. An example is being able to beat most peers in an arm wrestle. This requires only being in the top 25% compared to an average population. A practical routine involves one to two gym sessions per week, 30-45 minutes each, with five to six full-body exercises. Each exercise should include three sets of 8-12 reps. This regimen has been shown in studies to provide significant brain benefits. The episode emphasizes that this is achievable even with a busy schedule.
