The longevity conversation has swung hard toward resistance training over the last two years. Muscle mass as a longevity marker. Strength training as the most important intervention for aging well. Zone 2 as overhyped and time-inefficient. The message across podcasts, clips, and threads has increasingly become some version of "just lift."

To be fair, the people driving this conversation aren't actually saying that. Peter Attia stresses zone 2 constantly and treats VO2 max as one of his four longevity pillars. Gabrielle Lyon has pushed CrossFit-style circuit work as a foundation. Huberman stresses his long runs once a week. None of them are telling you to skip cardio.

But somewhere in the compression from podcast to Instagram clip, the nuance disappeared. What lands in most people's feeds is the flattened version: lifting is enough, cardio is optional, longevity is a strength problem. And a real gap has opened up between what the top voices in the space actually recommend and what most of their audience is doing.

The gap has a name most people haven't heard: pulse wave velocity, or PWV. It's one of the strongest cardiovascular mortality predictors we have. And your training may or may not be protecting it, depending on how you lift.

This piece is about the specific claim that resistance training is good for CRF too (Cardio Respiratory Fitness). That claim is true, but only under specific conditions most recreational lifters aren't meeting. Here's what the research actually shows, and how to know if your training is covering the ground you think it's covering.

What Is Arterial Stiffness, And Why Does It Matter?

Your arteries are supposed to be elastic. Every time your heart beats, a pressure wave travels through them, and elastic arteries absorb some of that pressure before it hits your brain, kidneys, and other end organs. Stiffer arteries transmit that pressure wave faster and with more force. Over decades, that difference is the wear pattern behind cardiovascular disease, stroke, cognitive decline, and kidney damage.

Pulse wave velocity is how researchers measure arterial stiffness. It's the speed at which that pressure wave moves through your arteries, measured in meters per second. Higher numbers mean stiffer arteries. Lower numbers mean elastic arteries doing their job.

Here's why you should care about the number, even if you feel fine.

Each 1 m/s increase in PWV is associated with a 12 to 14 percent increased risk of cardiovascular events and a 13 to 15 percent increased risk of cardiovascular mortality. That's not a small effect. It's one of the reasons PWV has emerged as an independent predictor of cardiovascular and all-cause mortality that's more sensitive than blood pressure alone.

Nobody in the mainstream longevity space is talking about it. But the researchers studying cardiovascular aging have been talking about it for years. It's the marker your training should be moving in the right direction.

Whether it does depends on how you train.

What The Research Shows About Different Training Types And Arterial Stiffness

The evidence base here is deeper than most people realize. Let's walk through it modality by modality.

Aerobic Training

Steady-state cardio reliably reduces arterial stiffness. Zone 2 running, biking, rowing, swimming. This is the strongest and most consistent finding in the literature. A 2024 systematic review in older adults found that aerobic and combined training improved both flow-mediated dilation and pulse wave velocity.

Not controversial. If you're doing dedicated aerobic work, you're doing your arteries a favor.

HIIT

High-intensity interval training is at least as effective as steady-state for arterial stiffness, and possibly better. A 2025 meta-analysis comparing HIIT to moderate-intensity continuous training found that HIIT was superior for reducing PWV. A separate 2024 meta-analysis in people at high cardiovascular risk found HIIT significantly reduced PWV by 0.62 m/s across 16 randomized controlled trials.

Zone 4 and 5 work isn't the villain some people make it out to be. It's vascular protective.

Circuit-Style Resistance Training

Brisk-paced resistance training with short rests improves arterial stiffness. A 2025 meta-analysis of 14 randomized controlled trials covering 704 community-dwelling older adults found circuit-based resistance training significantly reduced brachial-ankle PWV (by roughly 1 m/s), dropped systolic blood pressure by 6 mmHg, and improved body composition.

This is the finding most lifters don't know about. Circuit-style training, kettlebell complexes, EMOM-style sessions, brisk-paced bodyweight work — all of it hits the vascular system in a way traditional lifting doesn't.

Traditional Heavy Resistance Training

This is where the picture gets more complicated.

A 2021 systematic review of 23 studies concluded that low-to-moderate intensity resistance training (30 to 80 percent of one-rep max) decreases arterial stiffness, while high-intensity resistance training above 80 percent 1RM has ambiguous effects on PWV. An earlier 2013 meta-analysis in the British Journal of Sports Medicine found high-intensity resistance training was associated with an 11.6 percent increase in arterial stiffness in young subjects. Moderate-intensity resistance training showed no such association.

Cross-sectional data on competitive weightlifters shows their pulse wave velocity comes out no better than sedentary controls, while endurance athletes come in well under both.

The takeaway: heavy resistance training alone, without a cardiovascular component, has a neutral to slightly negative effect on arterial elasticity in the young and healthy population where most of these studies were done.

The Counterintuitive Finding

Here's where the story got interesting.

A research group in the UK ran two acute studies comparing different resistance training protocols to see which caused more arterial stiffness in the hours after training.

The first study compared 12 reps to failure at moderate load against 4 reps at heavy load. Same effort level, same rest periods. The 12-rep protocol produced significantly greater increases in carotid-femoral PWV than the 4-rep protocol.

The second study compared 3 sets of 12 at high effort against 6 sets of 6 at low effort, matched for total volume, rest duration, and load. The high-effort 12-rep protocol again produced significantly greater increases in PWV than the low-effort 6-rep protocol.

It's not absolute load that drives the vascular response. It's how long you spend at elevated pressure. A heavy single spikes pressure for a couple seconds and it's done. A set of 12 taken close to failure keeps blood pressure elevated 

The pattern was clear for 30 to 40 seconds, then repeats on the next set, and the next.

That flips the assumption most people carry.

Why Rest Interval Matters More Than Load

Here's the mechanism that ties everything together.

Short rests between sets keep your heart rate elevated between working periods. Blood is still being pushed hard through your arteries when the next set starts. The cardiovascular system never fully resets. Under those conditions, your training is closer to interval work than to traditional resistance training. And interval work is one of the best modalities for arterial elasticity we have.

Long rests reverse it. Pressure spikes hard during the set, then fully normalizes over two or three minutes, then spikes hard again, then normalizes. Big pressure loads with no sustained cardiovascular demand between them. That's the pattern that shows up as neutral to negative in the chronic data.

Working sets close to failure isn't the problem by itself. Circuit-style training taken to hard effort improves arterial stiffness in the meta-analyses. Working sets close to failure with long rests between them, done for hours at a time, is where the cardiovascular gap opens.

Which brings us to a more useful way to think about your own training.

The Three Buckets: Where Does Your Training Actually Fall?

Every recreational lifter falls somewhere on a sliding scale. Here's how to identify which bucket your training is in and what it's giving you.

Bucket 1: Strength-First

Heavy loads, low reps (1 to 5), long rests (2 to 5 minutes), full recovery between sets.

Powerlifting, Olympic lifting, dedicated strength training.

What you get: maximum strength development, neural adaptations, dense muscle.

What you don't get: meaningful cardiovascular stimulus. Your heart rate returns to near baseline between sets. Your vascular system experiences repeated brief pressure spikes with recovery in between, which is neutral to slightly negative for arterial elasticity in the chronic data.

If this is your training, your lifting is not covering cardiovascular ground. That's not a criticism. Maximum strength expression requires near-full recovery between sets. But you need to bolt cardio on. Walk every day. Add a couple zone 2 sessions or a HIIT block per week. Don't skip it.

Bucket 2: Blended

Moderate loads, moderate reps (6 to 15), brisk pace, short rests (30 to 60 seconds), full-body organization.

Circuit-style training, kettlebell complexes, EMOM-style sessions, brisk-paced bodyweight work, most well-designed programs for busy adults.

What you get: strength progresses, muscle grows, cardiovascular system stays engaged, arterial stiffness stays low.

This is the sweet spot for anyone who isn't training for a strength sport specifically. Your lifting is doing double duty. You still benefit from walking and low-intensity movement, and adding some higher-intensity aerobic work when you have time is a bonus. But you're not in cardiovascular debt from the lifting itself.

This bucket is the default for BWS-style training. The framework was built around it before I knew any of this data, because it's the most efficient way to train busy adults who want to stay capable across every dimension without living in a gym.

Bucket 3: Hypertrophy-First

Moderate to high reps (8 to 20), long sets taken close to failure, long rests (90 seconds to 3 minutes), split routines, high volume per session.

Traditional bodybuilding, most Instagram-influencer lifting programs, "bro splits."

Long sets to failure keep pressure elevated for a long time. Long rests between them let your heart rate drop back to baseline. Neither pattern is doing your arteries any favors. Add cardio. Add walking. Take an honest look at whether your rest periods need to be as long as they are.

This is the group that most needs to hear it. Most people running this style of training assume the strength stimulus is covering their bases. It isn't. The heavy lifter takes a bigger pressure spike but recovers between sets. The bodybuilder takes a smaller spike but stays under pressure for longer periods, more times per session, without cardiovascular density to offset it.

If you're going to run a hypertrophy-focused program, run it with awareness. Bolt cardio on deliberately. Consider whether you actually need three minutes of rest, or whether 60 to 90 seconds would keep your session productive while adding cardiovascular stimulus.

Applying the Minimum Effective Dose To Cardiovascular Health

The BWS training philosophy centers on the MED (Minimum Effective Dose), the least amount of work required to drive the adaptation you're looking for. That principle applies to cardiovascular health too.

You don't need to add hours of cardio to what you're already doing. You need to know what your current training is and isn't giving you, then fill the gap that matters.

If your lifting is brisk-paced and full body, the gap is small. A daily walk closes most of it. Add higher-intensity work when you can.

If your lifting is strength-focused with long rests, the gap is bigger. Walk daily. Add dedicated cardio two or three times a week. Zone 2 works. HIIT works. Both work better than neither.

If your lifting is bodybuilding-style with long sets and long rests, the gap is the biggest. Walking, cardio, and a more honest look at how you're spending your training time are all worth considering. 

Two hours of long-rest hypertrophy work is unlikely to be the best use of your training budget if you're 40 or older and thinking about staying capable across decades.

The aerobic base builds either way. Your arteries need a bit more attention.

What This Means For The Longevity Conversation

The claim that resistance training is "good for CRF too" is technically correct under specific conditions. Circuit-style training at moderate loads with short rests does improve cardiorespiratory fitness and arterial elasticity. That's what the top voices in the space are recommending when they say lifting matters.

But what most people hear is "just lift, cardio is optional." And most recreational lifters, when told to just lift, default to bodybuilding-style programming with long rests and split routines. That default isn't giving them the cardiovascular protection the original claim was based on.

If you're in that group, this isn't a reason to stop lifting. It's a reason to lift differently, or to keep lifting the way you're lifting and add cardio deliberately.

Attia isn't wrong. Lyon isn't wrong. Huberman isn't wrong. But the compression from their message to your feed has dropped a piece of the picture that matters.

Pulse wave velocity is the marker that piece attaches to. Now you know it exists. Now you can train with it in mind.