I usually train once a day (weights 3 times a week, running/cycling/swimming/sports otherwise). In 3 weeks time, I have a swim race 5km across a river and back and so for the past week I have added 4 x 2km swimming workouts to my training (which will gradually increase to 4 x 3km). I've never taken any supplements because I have a natural tendency to bulk. I've noticed however that I've already begun to lose a little weight (which I want to avoid in order to be more resistant to the cold water) and that I have trouble recovering. What would you recommend?