Yes, part of the 10 minute thing is about getting the body to switch over from its shorter term anaerobic energy system to its longer term aerobic (cardio) system.
But you are right, ANY exercise is good. And a journey of a thousand miles begins with a single step, and small but regular amounts of exercise can help build your fitness and
The other thing is that it is difficult to make a universal recommendation that applies to everyone. Recommending 2 minutes may well be appropriate for some of the people you mention, but many others can and should be doing a lot more than that. A single figure is not useful for everyone, but then again not naming a figure at all doesn't provide much of a guideline.
I guess encouraging people to do what they can is about the right approach?
Fitness Minutes: (112,042)
46,222 4/3/13 5:06 P
Thanks for your suggestion--and you are absolutely right--every time we move more than what we did the day before, no matter for what time period, it all adds up. The reason we recommend 10 minutes is that is the standard for many people to begin and while I understand there are those who can't or who are unable to do longer time periods, unless we know more about the person's current ability, it is very difficult to give them specific advice.
Back when I first started SP, there was no way I could have done 10 minutes at a stretch. So I started with 2 minutes done several times per day and built up. I notice that over and over doing at least 10 minutes at once is emphasized which I assume is to get the heart rate up for effective cardio.
I do wish that there would be a mention of smaller amounts of time and encouraging to do them several times per day would be something to help very handicapped people to at least start and then build up. As it is, I have had several people just give up on exercising at all because they can't do the 10 minutes at the beginning. Please, please consider mentioning the alternative for handicapped people.