5. Start small. Think 25s and 50s in the pool on long rest intervals, 200- and 400-meter repeats on the track and 30–90-second intervals on the bike, all with full recovery. These intervals may not sound like much but can be very challenging. Many athletes get attached to the idea that each week must contain a long run and a long ride, but combining volume and intensity is a recipe for burnout and injury. You’ll add volume back into the program later, but to focus on speed, workouts should be an hour or two at most.