12 minute walk or run is not REALLY exercise though. I mean who doesn't walk for 12 minutes? My mom walks more then 12 minutes getting from the subway and to work everyday...lol
I don't really exercise in the winter but I take walks for an hour at least, and run up and down my house stairs 20 times a day, vacuum all over the place, thats already two hours of movement for me and I haven't "exercised", then some evening yoga/stretches.
But this does not compare to me biking, running intensely when winter is not here, there is a big difference, now my muscles are in rest and slow maintenance, in the other mode I can feel my muscles developing, I also add push-ups and squats to my exercise periods to grow muscle quicker with the strength cardio (when biking up steep hills it feels like strength over cardio for the legs). You will feel the right intensity in your body.
Exercise its something that is putting noticeable strain on the muscles or on breathing, making sweat and heart beat very quick.
There is a difference between exercising purposely to improve strength and or stamina (what I usually only do in spring, summer and fall) and between maintenance moving, movement just enough so your muscles are not lost and are used until you are ready to start with your regime again.
But even in 'hibernating' season, a 12 minute walk is nothing for a healthy adult, if you are 90 years old maybe then its all you need.
Whats the point of the marathon runner vs the sprinter? They look built properly for their extremes, the skinny guy can't make as quick bursts, and the muscly guy will eventually tire out running if going long distance with the skinny guy. All marathon runners have a very very thin build (sometimes they have one big part, their legs and tiny upper body). I think anyone who starts marathon running will eventually get that body shape or similar.
I was thinking of adding one exercise to my lazy winter routine, the rowing machine...I have mostly marathoners build (thin body with legs being the largest most muscled part), this makes my upper body chilly in the winter, so I think some intense rowing may be on order to stay warmest. Coupled with an hour walk in the wintery woods, it should be good. Now I have to get myself to START on the rowing machine, the hard part, lol, and its in the bedroom beside mine too - I am such a lazy bear in the winter.