The Longevity Metric Nobody Is Training For: Muscle Power

What is muscle power, exactly?

[0:00:48]

Dr. Jordan opens the conversation with the cleanest possible definition: muscle power is strength and speed combined. It’s not the heaviest weight you can lift. It’s not the fastest you can sprint. It’s the ability to express force quickly, and it’s one of the most important variables for predicting whether a person will be able to live independently across the second half of their life.

The science is unambiguous on this point. If you want to understand who lives independently into their 80s and 90s, you study the people who do, and you find that two variables consistently rise to the top: VO2 max and muscle power. Cardiovascular capacity and the ability to produce force quickly. Together, they form the spine of functional longevity.

Training for your worst day, not your best day

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One of the most powerful reframes in the entire conversation arrives early. Most people think about exercise in terms of their best day, the personal records they’re chasing, the look they’re trying to achieve, the workout they’re trying to complete. Dr. Jordan flips this on its head. You’re not training for your best day. You’re training for your worst day.

Your worst day is the moment your foot catches on an untied shoelace in a parking lot. It’s the slip on a patch of ice you didn’t see. It’s the misstep off a curb when your weight shifts and your body needs to react in a fraction of a second. The ability to recover from those moments is not a function of strength alone. It’s strength and speed together. It’s power. And the only way to have it on the day you need it is to have built it before.

“You’re not training for your best day. You’re training for your worst day. You’re not just training to have good abs and a nice chest. You’re doing this because you want to be able to meet life’s unexpected, unforeseen tasks that throw themselves at you.”
— Dr. Matt Jordan

Dynapenia: the word for what’s happening to your power right now

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Most people are familiar with osteopenia, the loss of bone density, and sarcopenia, the loss of muscle mass. Dr. Jordan introduces a third term that belongs in the same family: dynapenia, the loss of muscle power across the age span. It’s a newer term in the science and it’s the one most people have never heard of, but it may be the most clinically important of the three because power is the most direct predictor of whether you can do the things that constitute independent living.

The hardest truth in this section is the timeline. Power loss begins in your 30s and 40s, not in your 70s. And in the absence of resistance training, it accelerates year over year. The curve is heading down. The job of any serious longevity plan is to blunt the slope, to lose less, to stay higher on that curve for as long as possible.

The reframe: function over aesthetics

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Dr. Jordan is direct about the cultural distortion that has shaped most people’s relationship with the gym. The aesthetic outcomes of resistance training, looking better, leaning out, putting on visible muscle, are real. They happen. But they are, in his words, the least important benefit. Function is what we should care about. Function is what determines the quality of the next 40 years of your life. The aesthetics are a side effect.

“Resistance training is probably going to make you look better. But that’s probably the least important part. It’s really how you function that we care about.”
— Dr. Matt Jordan

The Disneyland observation: how an 8-year-old moves vs. how an adult moves

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Dr. Jordan tells a story that lands harder than any data point in the episode. At Disneyland with his family, the adults logged 16 kilometers of walking, drone-like, one foot after the other. His 8-year-old son Cohen logged the same distance, but never took two steps the same way twice. He jumped on railings. He spun. He sprinted. He skipped. He cartwheeled. His movement vocabulary was enormous.

The point Dr. Jordan draws from this is biological. As we age, our window for movement vocabulary shrinks. We stop doing the things we did as children, and the body responds the way bodies always respond to disuse: it loses the ability. Spring-like actions disappear. Range of motion narrows. Flexibility diminishes. The narrowing of movement vocabulary is not just an aesthetic loss. It’s a tendon health issue, a fall risk issue, and a longevity issue.

The four roles of muscle: gas pedals, brakes, struts, and springs

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One of the most useful mental models in the entire episode is Dr. Jordan’s four-part breakdown of what muscles actually do. Most people think of muscles as gas pedals, the engines that push, press, lift, and squat. Those are concentric actions, and they’re important. But they’re only one quarter of the story.

Muscles also act as brakes, controlling the downward and decelerating phases of movement. They act as struts, holding a position under load. And critically, they act as springs, storing and releasing energy through what’s called the stretch shortening cycle. Think of a kangaroo. The bounce isn’t just muscle contraction. It’s the elastic recoil of the muscle and tendon system loading and unloading in rapid sequence. That spring function is what makes movement efficient. It’s also what disappears first when we stop using it.

How to actually train power

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This is the section of the episode that converts theory into action. Power training is not heavy lifting to failure. It’s not endless light reps to fatigue. It sits in a Goldilocks zone that most casual gym-goers have never been taught to find.

The mechanics are specific. Take a load you can lift, ideally around 30 to 60 percent of your one rep max for a given movement. Lower it under control. Push it back up as fast as you possibly can. Repeat for four to six repetitions. When the speed of the bar starts to slow down, that set is over. You’re not lifting to muscular failure. You’re lifting until you can no longer move the weight quickly. Power is measured by movement speed, not by exhaustion.

“You don’t use heavy weights for power training. You use light to moderate loads. Lift it fast. And you don’t go to failure, because power is measured by when your movement speed starts to go down.”
— Dr. Matt Jordan

For those who can’t or shouldn’t lift heavy in a traditional squat rack, Dr. Jordan flags two excellent alternatives. Kaiser pneumatic machines, which use air compression instead of stacked weight, eliminate the momentum problem that comes with free weights and are ideal for power work. A 10-second all-out bike sprint is another. Both build the same neuromuscular quality without the risks that come with heavy loaded barbell training.

Why a coach is the most important person in your fitness life

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Dr. Jordan is emphatic on this point. The single most valuable investment a person can make in their long-term physical health is not a piece of equipment, a supplement, or a wearable. It’s a coach. Someone who knows how to teach movement, how to progress a person safely, and how to meet them where they actually are rather than where they think they should be.

The reasoning is practical. Power training, done wrong, is a fast way to get hurt. The technical demands of lifting fast under load are real. Most people walking into a gym for the first time have no framework for what good movement looks like, and most don’t have the experience to self-correct when something is off. A coach solves both problems and makes the entire process sustainable. Sustainability, Dr. Jordan repeats throughout the episode, is the only metric that matters in the long run.

The stretch shortening cycle and why skipping is back

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The stretch shortening cycle is the technical term for that spring-like action of the muscle and tendon system: a rapid stretch followed by a rapid shortening. It’s what makes a kangaroo hop. It’s what makes a child skip. And it’s a quality that virtually disappears in adult life because we stop using it.

Dr. Jordan credits his longtime colleague Stuart McMillan, CEO of Altis and coach to Olympic gold medalist sprinters, for putting skipping back into the public conversation. After appearances on the Huberman and Rich Roll podcasts, the idea that skipping is a foundational training activity has started to take hold. And for good reason. Track and field athletes skip in every warm-up. It maintains tendon health, preserves stretch shortening cycle function, and reintroduces movement variety that the average sedentary adult has lost.

The frailty cascade

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This is the most sobering segment of the episode. Dr. Jordan lays out, step by step, what happens when power loss is allowed to run its course unchecked. The chain begins with the accumulating loss of strength, power, movement vocabulary, and stretch shortening cycle function. Around the 60s, 70s, and 80s, the risk of falling rises sharply. A fall, especially a serious one, often creates a fear of falling. Fear of falling leads to reduced activity. Reduced activity leads to social isolation. Social isolation leads to depression. Depression accelerates physical decline. And at the bottom of the cascade is the transition into long-term care, frailty, and eventually mortality.

Dr. Jordan does not over-dramatize the chain. He doesn’t need to. Frailty is a multi-billion dollar problem. Most listeners have watched a version of it happen to a parent or grandparent. The most important point of the entire episode may be the simple observation that this cascade is preventable, and that the intervention is not new or exotic. It’s resistance training. It’s power training. It’s keeping your movement vocabulary alive.

“The best news is there is a magic pill, in the form of resistance training exercise.”
— Dr. Matt Jordan

Goal setting for longevity: casting votes for who you’re becoming

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In the closing section of the episode, Dr. Jordan offers a framework for thinking about goals that doesn’t rely on aesthetic milestones or 12-week transformations. Drawing on the Atomic Habits framework, he describes goal setting as casting little votes in favor of who you want to become. Not who you want to be in 12 weeks. Who you want to be in 10 years.

The measure of progress at this scale is not the body composition number. It’s not the personal record. It’s the lead metrics, the daily actions that quietly compound: three breakfasts this week with protein, vegetables, and whole grain. Three sessions of movement at 25 minutes each. The lag metrics, the visible body composition changes, the strength gains, the times on the stopwatch, are downstream of the lead metrics. They are the result, not the goal.

And critically: in longevity terms, success often looks like losing less, not gaining more. You will lose 3 or 4 percent of certain capacities per decade as you age. The goal is to make that 2 percent. To stay higher on the curve. That’s a different mindset than chasing a beach body, and it’s the one that compounds across decades.

“There’s no tech or blood test that’s going to transform you. Get a coach who understands you, buy into the process, measure the things that matter, but most importantly, make it sustainable.”
— Dr. Matt Jordan

It’s never too late to start

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Dr. Jordan’s final line is a clean one and worth ending on. It’s never too late to start. The research on adults in their 70s, 80s, and 90s makes this unambiguous. The body responds to training stimulus at any age. The window doesn’t close. The hardest part is the first appointment, the first session, the decision to begin. After that, the body does what it has always done. It adapts.