I want to introduce you to a word you’ve probably never heard before: powerpenia.

Don’t have time to read it all? Skimmable highlights below in yellow. Or skim for the golden nugget.

You’ve likely heard of "sarcopenia" - the age-related loss of muscle mass. Maybe even "dynapenia" - the loss of maximal strength. But here’s the thing that quietly ruins people’s function, independence, and longevity faster than either of those: the loss of muscle power. And it finally has a name.

What is powerpenia?

Muscle power = force x velocity. It’s not just how much you can lift, it’s how quickly you can produce force. Think about the movements that actually matter in real life: catching yourself when you trip, getting up from a chair without using your arms, sprinting across a crosswalk before the light changes, or absorbing a sudden load when your kid jumps on you. All of those require power - the ability to generate force fast.

A team of researchers formally coined the term “powerpenia” in a 2024 paper in Sports Medicine to address a massive blind spot: out of 220 published studies on age-related strength loss (dynapenia) between 2008 and 2023, only 2 actually measured muscle power. The rest measured maximal strength and called it a day. That’s a problem, because power and strength aren’t the same thing - and power declines earlier and steeper with age.

Why should you care?

Here’s the stat that stopped me in my tracks: a 2025 study published in Mayo Clinic Proceedings followed nearly 4,000 people aged 46-75 for over a decade. They measured both muscle power and muscle strength, then tracked who lived and who didn’t.

Muscle power predicted death risk 3-4x more strongly than muscle strength.

In men, low relative power carried a hazard ratio of 5.88 versus just 1.62 for low relative strength. In women, it was even more dramatic: 6.90 versus 1.71. That’s not a small difference - that’s a completely different conversation about what we should be training.

[A hazard ratio of 5.88 means those with low muscle power were nearly 6 times more likely to die during the study than those with normal power - way higher than the 1.6x risk seen with low strength alone]

The accompanying editorial in Mayo Clinic Proceedings nailed it: instead of just asking “How much can you lift?”, we should be asking “How fast can you lift it?”

​[Here's the full paper]​

What does this mean for your training?

If you’re only doing slow, heavy strength training, you’re building one piece of the puzzle. A critical piece, absolutely - but you’re leaving the most functionally important quality on the table. Here’s how to start addressing it:

1. Add intentional speed to movements you already do. Pick 2-3 exercises per session and consciously move the concentric phase (the “lifting” part) as fast as you can while staying controlled. Squats, step-ups, push-ups, rows - the exercise doesn’t change, the intent does. Your nervous system adapts to the speed at which you regularly move. If you always lift slowly, you lose the ability to recruit muscle fibers quickly.

2. Use lighter loads, moved fast. Research suggests that performing high-speed movements at 20-40% of your max may have more functional benefit than grinding out reps at 70-90%. This is also way easier on aging joints - great news if you’ve got cranky knees or shoulders.

3. Include some ballistic or plyometric work. Medicine ball throws, box step-ups with a quick drive, kettlebell swings, even rapid bodyweight sit-to-stands. These don’t have to be intense - they just have to be fast. Start simple.

4. Test it. This is where we geek out at Vital. If you’ve done force plate or dynamometer testing with us, you already have power data (rate of force development, peak power output). If your strength benchmark tests looked fine but something still feels “off” when you move - your power output might be the missing link. If you haven’t tested, we can help. I'd start with an assessment with a certified exercise physiologist (reach out if you're in Calgary by replying below!)

Golden Nugget: Here’s a free at-home test you can try right now. Time yourself doing 5 sit-to-stands from a standard-height chair, arms crossed over your chest. If you’re under 60 and it takes more than ~10 seconds, or you’re over 60 and it takes more than ~12-13 seconds, your lower body power likely needs work. This test correlates well with fall risk and functional independence in the research. Now do it again, but try to go as fast as possible - is there a big difference between your comfortable pace and your max-effort pace? If yes, you have untapped power you’re not regularly training.

Next newsletter, I’m diving into Norwegian double-threshold training - the endurance training method that’s been shaking up the running and cycling worlds. If you’re curious about why training at threshold twice a day might actually work better than what you’re currently doing, stay tuned.

And if you want your power tested, whether you’re local to Calgary or want to discuss a remote assessment plan - reply to this email. I reply 100% of the time.

Yours in physiology,

Carla