My good friends running bike and ski shops in the north woods of Wisconsin have a term called the 'brown zone.' It's that dead spot in the seasonal changes where it's just too cold and wet for a lot of us to enjoy cycling, and there isn't enough snow on the trails for good skiing. The trees are dormant and the ground is mostly brown.
In fact, now is 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. As a result, they do, in fact, develop shorter muscle fibers than the disciplined lifter who exercises good form.
It takes focus and some practice, but if you're looking for a long, lean and toned muscular look, use smooth controlled muscle contractions, and be sure to keep good overall body posture throughout the exercise.