While die-hards will bunny suit up to get into the saddle, or strap on the outback skis in search of snow-crust skiing, they're also missing out on the best time of the year to train indoors. And that, my friends, is right now!
For starters, now's the time to start working on that summer body. Work begins right now on muscular development becomes apparent when you loose those last few more pounds of body fat with increased Spring and Summer cardio effort.
In fact, one of the more common mistakes I see in the gyms is incomplete range of motion exercise. People get too hung up on the volume of weights, and end up jerking and throwing the weight through a shortened range of motion. And, as a result, they do, in fact, develop shorter muscle fibers than the disciplined lifter who exercises good form by moving the resistance fluidly through it's complete range of motion.
It takes focus and some practice, but if you're looking for a long, lean and toned muscular look, focus on a complete range of motion, use smooth controlled muscle contractions, and be sure to keep good overall body posture throughout the exercise.
Then, when the weather finally does warm up, and you get get outside for extended periods of additional cardio to pull off a few more pounds, the emerging muscle tissue is beautifully developed and will emerge in good form.