Not familiar with the best winter cross training for runners, cyclists, and rowers? Check out this YouTube video I shot at the UNH Winter Carnival 10K Classic Race . All the top Eastern college racers were there. There are two forms of racing: classic which you see here, and skate. Racers have to master both. It's my favorite sport: great core workout, low impact, thrills and spills, and incredible aerobic base building.