Yeah, I also record a lot of walks as workouts (I try to go for a 45 minute walk per day, about 4-5 km, plus a few shorter walks daily) and once every few months the Watch would like to remind me that there have been changes (oh no!) in my walking speed and heart rate.
Like, I know this. It's just that the watch is pretty stupid. If I'm out for a long walk I sometimes meet people I know and I stop to talk to them. This might lower my heart rate for a while and it will also affect my time if I forget to pause the workout. Which I frequently do.
I tend to start a walk on weekdays when I take my daughter to school. She rides her bike, so I normally jog along with her for about 5 minutes or so. When we get to her school, I have to help her park her bike, bring her bag inside and then leave her at the school yard - where I will always talk to her teachers for a few minutes. I always forget to pause my workout at this point, so my time per km goes from something like 9 minutes to 16 minutes. The watch however, doesn't realise this. Sometimes it will ask me if I'd like to pause my workout, but normally it doesn't.
Then I get going again, walking to the subway station, which takes about twenty minutes. So my heart rate goes up again and the time drops to about 11 minutes per km or so.
This confuses the Health app immensely. If you're doing a workout, you're never supposed to stop until you're done, apparently. Not to mention that I'm slower in the winter months, because I'm wearing more clothes and heavier boots and sometimes walking through actual snow. Or maybe I don't want to exercise outside during November, because November is the worst month in the Northern Hemisphere? And so on.
In a perfect world, the Watch should realise that if you're doing a walk or run and you suddenly stop moving a lot or remain in roughly one place for a minute or so, it should just pause? Once you start moving from the place you're in, start up again. Give it five minutes at pause and then ask if you want to quit? This could be an option.
But Fitness and Health is something I've considered a lot while looking at Apple's presentations over the years. These are people who take their workouts pretty damn seriously and if their end users don't, well screw 'em!
There aren't even rest days or sick days in the Fitness or Health app. Which is absurd. Anyone can tell you that recovery is just as important as being active. Let me take a rest day and don't nag me about losing my streak or whatever.
:-/