Hey, I had keyhole round about 6 months ago. You can find my post under the sticky thread somewhere.
My surgeon expressly forbid any and all physical activity (excluding walking, which was encouraged) for at least six weeks. No jogging, no lifting, nothing at all that'd get my heartrate up for that time. This is a little more strict than most people's instructions from what I've seen, but I stuck with the recommendations even so (and did end up healing fantastically.)
At the end of those 6 weeks, though I was allowed to resume physical activity I still had some tenderness and tightness in the area (it felt like something was pulling if I stretched my chest too much, like the scar tissue was stuck), which meant that I was leery of exercise such as pullups and chest presses and continued to avoid those for a while longer, up until about 3-4 months. I can't really say how much muscle mass I lost as I never really had much, but I didn't suffer weight gain.
Recovery wise I'd say that I was back to normal and pretty much fully 'healed' by about 1 month, and had virtually no pain or discomfort after the first week or two (and very minimally before that), minus the restriction in movement I enforced on myself. Keyhole recovery really was easy for me, but I was in excellent health and suffered no complications to cause delay.
