Reminds me of zone 2 training [1]
My target (aka zone 2) is around 140 bpm which I can achieve by walking fairly briskly -- I can still hold a telephone conversation and breath through my nose.
I have tried running in the past but I kept injuring this or the other (not at all athletic). Doing "slow" 10k+ steps per day total did not help with my weight either. But just doing these 1-hr zone-2 sessions (3-4x per week) made all the difference. Ofc ymmv!
[1] https://www.artofmanliness.com/health-fitness/fitness/zone-2...