“A lot of people do try and get to that 10,000 steps and they just physically can't. Their knees hurt, their back hurts, their ankles hurt."
Being someone who suffers from unspecified chronic pain, I can say that it hurts more to walk 4000 steps than to bike 200 km. It's pretty wild!
Various studies have examined the concept of 10,000 steps, and while there is no basis in that number...
Fun fact, the concept of 10,000 steps may have originated in Japan in 1965 where a pedometer called the "Manpo-kei" was sold. Translated to English, "Manpo-kei" means "10,000 step meter".
It was a literal marketing phrase!
But I don't like how the article is like "switch to cycling instead of walking because you'll burn more calories".
Physical fitness can be roughly broken into three groups:
cardio is really anything that gets your heart rate up
aerobic activities are those where you're breathing heavy, sweating, and your heart rate is up; oxygen is used as fuel here.
anaerobic activities are usually "short burst" activities like weightlifting, sprinting, etc.; this goes beyond oxygen as fuel and the body switches to glycogen, glucose, and when you burn through those, lactic acid is next. Produce enough lactic acid and you'll have sore muscles.
If all you do is walking, you aren't covering all three groups. And if you don't vary your cycling, you'll also not cover all three groups.
If you're serious about health, you have to do low intensity (aerobic), high intensity (cardio) and burst of anaerobic activities.
I've got some issues with my knees, I'm right there with you on walking vs cycling. I had to do a cardio stress test a few years back, and they only had a treadmill. My knees hurt for a month, and I told them in no uncertain terms that I was never doing that again and I'd find a cardiologist who offers a bike for that (and some do.)
I also agree very much on the variability of types of exercise. I bike in two very different ways - MTBing, which has your 2&3, and I have a cargo bike that I use instead of my car most of the time, and that tends to be zone 2 type steady state. I thoroughly enjoy all of it.
One thing that's fair to point out though, is that decent bikes are expensive. I'm really glad to see the rise of decent DTC companies that are making bikes (primarily e-bikes) more affordable - Lectric, Aventon, Himiway, etc. that new Lectric cargo bike for $1500 is a great deal, but it's still $1500. And of course that's in comparison to older companies like Specialized or Santa Cruz, where you're looking at significantly more.