I've been slumping on my fitness this past month.
It got cold, so I stopped my daily biking. Then I got sick, so I wasn't hitting my basement gym either. Then even when I recovered I just wasn't doing it. Best I was doing was walking outside to get some sun and fresh air.
Yesterday I got back in. Stretches, push-ups, squats, bag-punching, deadlifts, dumbbell routines, and a few treadmill sprints. I'm super sore today, and my cardio is shit at the moment, but it feels great.
If you've been slumping a bit this winter, I'm right there with you! Use today as a catalyst to get back in. You'll be glad you did.