[maybeOneDay]

Do you have a source on your claim that 7k of sporadic and slow walking is categorically worse than a 5 minute walk that is fast?

I think that is a rather counter intuitive claim, 7k steps is about 5-6km whereas a 5 minute walk even at blistering pace is an order of magnitude less.

[Moru]

All doctors I talked to the last 5 years have said to concentrate on getting heart rate up. If you for some reason can't manage 30 minutes, maybe you have knee problems or whatever, 5 minutes now and then is better than nothing. But the most important thing is to get your heart rate up, not how many steps you take.

The recommendation in Sweden is to take 30 minutes fast walk. That has been converted to 10k steps here to sell step counters I guess.

Quick google: https://www.bbc.com/news/health-42864061