While both are crucial, if one must be prioritized, weight training is superior for healthy aging. It provides nearly all the same cardiovascular benefits as dedicated cardio, plus the unique and essential benefits of increasing lean muscle mass, strength, and bone density, which are critical for late-life functionality.

Instead of a risky one-rep max, Dr. Galpin proposes a safer, more functional strength test: the goblet squat hold. The goal is to hold a weight equal to half your bodyweight at the bottom of a squat for 45 seconds. This assesses not just leg strength but also core stability, mobility, and positional endurance.

A powerful benchmark for long-duration endurance is maintaining steady-state exercise for over 20 minutes using only nasal breathing. If you're forced to switch to mouth breathing, it indicates you've exceeded your comfortable aerobic capacity. This is a better measure of aerobic efficiency than simply tracking time or distance.

Dr. Andy Galpin suggests a simple, no-cost test for explosive power: the standing broad jump. As a basic benchmark, you should be able to jump a distance equal to your own height. For example, a 5'5" person should aim for a 5'5" jump. This provides a quick red-flag indicator for power deficits.

Just as you get annual blood work, Dr. Galpin recommends a yearly comprehensive fitness assessment covering all nine adaptations (strength, power, VO2 max, etc.). This "testing week" provides a clear barometer of your strengths and weaknesses, allowing you to prioritize training and avoid "severe performance anchors" that could lead to injury or plateaus.

Assessing anaerobic capacity doesn't require a lab. Dr. Galpin suggests a practical proxy: heart rate recovery. After an all-out effort that gets you near your max heart rate, rest for 60 seconds. Your heart rate should recover (drop) by at least 30 beats in that first minute. A slower recovery points to a deficit.

A key indicator of overall strength and health is grip strength. A simple, accessible test is the dead hang from a pull-up bar. Dr. Galpin suggests a minimum hold time of 30 seconds as a baseline. If you can hold for over 60 seconds, your grip strength is generally sufficient for health and performance.

Muscle size isn't just about aesthetics; it's vital for long-term health. Dr. Andy Galpin recommends using the Fat-Free Mass Index (FFMI) as a key metric. Men should aim for an FFMI above 20 and women above 18. Scores below 17 for men or 15 for women indicate a physiologically detrimental lack of muscle.

You don't need a specialist to identify basic movement issues. Record yourself performing key exercises (e.g., squat, push-up) from the front and side. Then, analyze the footage for four things: symmetry, stability, awareness of form, and full range of motion. This can reveal injury risks and areas for improvement.