Cardiovascular health without the cardio cult
Resistance training is, itself, a cardiovascular event. The same brutal set that builds your quads also remodels your heart. The choice between strength and heart health is a false one.
Among the deepest assumptions in modern fitness is that ‘cardio is for your heart, weights are for your body.’ It's the cleanest division of labour, and it's almost entirely wrong. A correctly-run set of slow-cadence resistance training is, in cardiovascular terms, indistinguishable from a hard interval. The heart doesn't know it's leg day.
What happens to your heart during an honest HIT set
- Heart rate climbs to 85–95% of age-predicted max within 45 seconds.
- Stroke volume rises sharply as venous return increases.
- Lactate accumulates rapidly, triggering the same clearance machinery as sprint training.
- Post-set, parasympathetic rebound improves heart-rate variability for hours.
This is not an analogy. It's the same physiological cascade you pay for in a Zone-5 interval, compressed into a 90-second window, and delivered alongside an unambiguous hypertrophy stimulus. Two adaptations, one set.
The 2023 evidence
A 2023 systematic review in the European Journal of Preventive Cardiology, pooling 41 trials, found that high-intensity resistance training produced cardiovascular adaptations. VO2 peak, arterial compliance, blood pressure reduction. Statistically indistinguishable from moderate-intensity aerobic protocols, at a fraction of the time cost. The authors' polite conclusion: ‘Resistance training should be considered a primary cardiovascular intervention, not an adjunct.’
Your heart cannot tell the difference between a slow leg press to failure and a Zone-5 interval. The metabolic demand is the same. The recovery cost is lower. The muscle gain is the bonus.
Where cardio still earns its keep
Genuine endurance athletes need genuine endurance training. There's no shortcut to running a sub-three marathon. But for the 99% of adults whose goal is ‘be healthy, stay strong, live long, feel good,’ the data is clear: brief, intense resistance work captures the cardiovascular benefit and adds a separate gift the treadmill never offered. Muscle. Bone. Posture. Insulin sensitivity. Grip strength.
The practical implication
You don't owe your heart a single minute of dedicated cardio. You owe it one or two honest strength sessions a week and a long daily walk. That is, by the modern evidence, the most cardiovascularly protective routine an adult can follow. Anyone telling you otherwise is selling you running shoes.
Read next: The cardio cult is wrong, Why twelve minutes a week is enough.
