As high school coaches, we struggle enough as it is to get our players to move properly. When the cold hits, it makes it even harder. You can't really blame the kids, people move more slowly in the cold. In case you need hard facts - which I respect - here is a brief article from some folks who did little bit of research: How Cold Weather Impacts Your Running.
While getting kids to move in the cold isn't easy, it will be necessary at some point. Here are some adjustments I made in our cold weather practice that had a positive effect:
1. A thorough warm-up. While a good warm-up should be a part of every practice, it is even more important in the cold. I normally have the kids just go through a typical pre-match warm-up (groundstrokes, volleys, overheads, serves, returns). In the cold, however, I added in some sprints, side shuffling, backpedaling, and quick footwork drills.
2. Mid-practice workout. If you sense your kids are slowing down, or you've just finished a drill that was a little less movement-oriented, I think it's a good idea to stop the tennis for a moment and move your body. About halfway through practice I'd reached this point, I had my guys put the rackets down and do a brief about 400m run and then did a couple sets of lunges and squats. It was very effective to get the blood pumping again.
3. Cardio-focused drills. This is often the focus of my drills anyway - keeping the kids moving, but again, it's extra important on a cold day. Singles drills: start them in one corner and feed it to the other so that they start out in a sprint. King-of-the-court type drills: feed the ball as soon as they are going to switch sides so they have to spring to get over there. A lot of it is common sense, you just have to be thinking twice about moving extra during the drills.
These three things, among others I'm sure, help drastically to keep your kids motivated and moving in a cold-weather practice.
