Great answers. Don't work the same muscle groups on consecutive days. Give them at least a 48 hour rest. Although it's a bit of a paradox, we work our quads every day because we walk. So just keep it in that context.
Just walk. Can't answer it any better than Stacia's. You're limited, but aren't we all. Walk as long as you can, as far as you can and as hard as you can. Within your limits, I know that you can do it.
Laura's answer is right on. Whether a heated room or not the most important consideration is to stay well hydrated. While the warmth may be an aid for flexibility exercises, it does add the ante for cardiovascular exercises.
Why? is my first question. What are you cycling? That's my second question to you. The research continues to support that approximately 55-60% of daily caloric intake should be carbohydrates, less than 10% as simple sugars. Glucose is the limiting substrate in ATP production in intracellular me...