Afternoon slow down

T was planning on going spinning, but the combination of mildly sore hamstrings and back and a general laziness are really wearing on my motivation. I want to go, but I got a feeling it's not going to happen. The only problem is that with the bad weather this weekend I don't know how much other exercise I will get since my weekend physical activity is generally based on the ability to go outside. How bad will I feel if I don't do it? Maybe a night off is okay? I've done vigorous exercise the last three days and if it weren't for this weather I know I would do something active over the weekend to make up for a night off. Ugh. Friday motivation is hard.