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How to build and keep strength as you age
Learn how muscle, resistance training, and everyday strength support performance, resilience, and independence across adulthood.
Explore StrengthSystem guides
The six systems that decide how well you hold up.
Each guide covers one capacity system: what it does for you, what actually improves it, how to tell whether it is working, and when a symptom belongs with a clinician rather than a training plan.
Free to read · No account needed · Review dates on every guide
Start with the system you are least sure about.
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Cardiovascular capacity
Understand aerobic fitness, walking, heart-rate zones, intervals, and the role cardiovascular capacity plays in long-term health.
Explore Cardio - 03
Mobility and balance
Build the range, control, and stability needed to move confidently through work, training, travel, and daily life.
Explore Mobility - 04
Recovery and readiness
Use sleep, stress, training load, soreness, and wearable data as useful signals without letting a score control your day.
Explore Recovery - 05
Nutrition for performance
Make sense of protein, hydration, creatine, micronutrients, and food habits that support an active body.
Explore Nutrition - 06
Which health measurements are worth tracking
Learn which measurements are useful, which are limited, and how to follow trends without overreacting to a single number.
Explore Biomarkers