Death of the nap and momma can jog

I knew the end was near but I didn't want to admit it. It's been coming for about 6 months now but I tried to ignore it. Yes, son's nap is no more. OK, so my friends tell me I am freaking lucky to have gotten almost 4.5 years of naps out of the kid, but now I have lost about an hour and a half of work that I used to get done during the day. This past week has been difficult because my workload is large and son decided that sleeping during the day is for sissys (that would be sisters). Son is one who usually needs a playmate in order to play. This is so unlike my daughter who I can forget about because she'll go hang out in her room and "read" books, play with her dollhouse or color for long periods at a time. Son prefers that I actively play with him. I do try to do this for a few set blocks of time during the day, but man, I've got to work.
I'm going to have to insist on a hour of quiet time in his room each day, but I feel so guilty about this. But I figure, I already feel guilty about everything else, so what's one more item on my list.

Before I had children I worked out religiously. It was 5 times a week and I really enjoyed being fit and I figured that maybe it was cancelling out some of my vices (wine and smokes). I gave up the vices, along with the exercise. I worked out until I was 8 months pregnant with son. Although I dropped my pg weight quickly, it took a lot longer for me to get back on the fitness track. And then after daughter was conceived, well, let's just say the only exercise I get is running after the kids or walking to the store or park. Husband is good about getting on the treadmill a few times a week but I just can't find the energy or the time. Today I had the time and I did it. Yep, I hopped on that treadmill and it felt good. I walked/ran a 5K and my time was abyssmal but that's OK... it's been almost three years since I did that. My 15 year reunion is in just a month and my goal is to be up to at least 4 days of treadmill time by then.