#108 The Best Type of Exercise for Longevity

New study overturns "1 min vigorous = 2 min moderate" guideline using wearable data

A Nature Communications study using accelerometer data challenges decades of exercise guidelines that were based on calorie burn rather than hard.

"Hello, friends! Today we're diving into a fascinating discussion about exercise intensity. Most of us have long accepted the simple guideline that one minute of vigorous exercise equals two minutes of moderate exercise. It's intuitive, neat, convenient, but what if it's fundamentally inaccurate? That rule has shaped global physical activity guidelines for decades, yet it was largely based on calorie burn, not hard endpoints like Joining me to explore this important topic is endurance athlete Brady Homer, who has a master's in human performance and has collaborated with me before on the Found My Fitness comprehensive training guide. Today, we're breaking down a groundbreaking new study published in Nature Communications that used objective, device-based data to challenge decades of conventional exercise wisdom and guidelines. We break down the methods."

Journal club: device-based study reveals vigorous exercise is far more potent than moderate

Rhonda and Brady Homer break down the study methods, which used objective accelerometers instead of self-reported data to compare exercise intensity.

"And we're going to talk about whether or not that's accurate and where it came from. So today's podcast is more of a journal club type of episode where we're going to be discussing a new study that really kind of overturns that idea. So I'm joined by endurance athlete Brady Homer, who has a master's in human."

30-40 min/day of vigorous exercise yields 50%+ reduction in cardiovascular mortality

The dose-response for vigorous exercise was linear: 30-40 min daily linked to 50%+ reduction in cardiovascular and cancer death.

"But with the vigorous, I know that you could spend about 30 to 40 minutes per day doing this vigorous type of exercise. And that was associated with 50% or more greater reduction in like many of these categories for health outcomes, you know, cardiovascular related mortality, all-cause mortality. So type 2 diabetes incidence, right? 50% or more like reduction. That's pretty robust. And again, that was at the higher end of the vigorous intensity."

Vascular shear stress from HIIT is intensity-dependent, not volume-dependent

The endothelial benefits from blood flow shear stress depend on intensity, not duration.

"Sheer stress is. Shear stress is almost like a bad name for it because, like you said, it's kind of sounds bad. You don't want sheer stress, but like you do. The more sheer stress you get, the better. And it's not just a simple dose response. It's just not like an area under the curve, I guess, type of thing. It's you can't just do more low intensity because you're not getting the, it's the intensity of the sheer stress, not the amount over time that actually matters for those endothelial adaptations. So it's really important to do HIIT in that respect for sure. That's a really good point because it's kind of like thinking of a light breeze blowing across your face versus."

Vigorous exercise produces better hormonal milieu for cancer and cardiovascular risk

Higher-intensity exercise produces greater adrenaline, cortisol, and growth hormone, likely explaining stronger risk reductions.

"But you just get sort of this better hormonal milieu, I guess, during high intensity and vigorous exercise that you get during low intensity exercise, which I think explains probably the reduction in all of these different outcomes: diabetes, cancer, cardiovascular disease. But the last thing I think that is important with vigorous exercise for So, most people will be aware that muscle fibers are categorized into different types. We have type one, which are referred to as slow twitch muscle fibers. Then we have type two."

Exercise-generated lactate enters the brain and acts as a signaling molecule

Lactate from vigorous exercise crosses the blood-brain barrier and serves as a signaling molecule.

"And we didn't get into that, but I do feel like this is a good time to just mention it because we're talking about mechanisms. And I've mentioned, you know, the lactate signaling molecule. We know that lactate generated from exercise, particularly as you get into that vigorous type of exercise, that it does get into the brain. There's actually human studies showing that it gets into the brain. And we know it's a signaling molecule for brain-drive neurotrophic factor, a very important growth factor for brain."

9 min/day of VILPA yields 50% less cardiovascular death and 40% less cancer death

Brief vigorous lifestyle physical activity (VILPA) done in 1-3 minute bursts totaling ~9 min/day produces remarkably large mortality reductions.

"It's certainly not 10-minute on the Peloton, right? One to three minutes. And they're done multiple times a day, right? Because it's like just your everyday life, is what we're talking about. And so one of the most profound findings of the study I like to talk about, one of the Velpa studies, is on the upper end of that. So people that are doing like the three minutes short burst and they're doing that three times a day. So a total of almost 10 minutes a day, right? It's like nine minutes a day. They're getting this physical activity. And those individuals have a 50% reduction in cardiovascular-related mortality, 40% reduction in all-cause mortality, 40% reduction in cancer-related mortality. Pretty robust. I mean, especially if you start looking at some of these other studies where people are engaging in their structured physical activity based on their memories, their brain's ability to recall in the last week what they've done, it's even more robust than some of that."

VILPA studies changed my mind: unstructured vigorous movement matters as much as gym time

Vigorous intermittent lifestyle physical activity studies show that ~70 minutes/week of incidental vigorous movement matches or exceeds structured.

"We're rewarding people who do this unstructured exercise and we're saying, keep doing it. It matters. It adds up. And I'm totally with you on it. You know, these, these VILPA studies, these vigorous intermittent lifestyle physical activity studies have really changed my mind as well. I was probably less of a snob than you because you're an endurance athlete, but I was somewhat of a snob thinking, like, no, you have to like, you have to have structured time and like, you know, get your heart rate up and really like dedicate time to this."

Ideal lifetime regimen: CrossFit or Hyrox-style training combining strength and cardio

If picking one workout style for life, combined modalities like CrossFit or Hyrox that blend strength and cardio are optimal.

"I think those are probably the best. If I had to pick an ideal, like, this is the ideal workout regimen for life, it's probably one of those, obviously. I mean, what I'm doing is not, I'm not, I'm optimizing for one thing. I love doing endurance training and that's what I'm going to do. But if I had a, you know, pick was ideal, certainly those are the best because you're getting kind of the best of both worlds, especially with high rocks, which has a little bit more of the running component compared to CrossFit. So I think you're, you need to be really aerobically fit and strong to do high rocks. Not to say that you don't with CrossFit, but there's not."