Lift heavy to go longer

For a long time, endurance athletes avoided the weight room for fear of gaining mass or getting tired legs. The research has turned that around. In a widely cited review, Bent Rønnestad and Iñigo Mujika concluded that adding heavy strength training to endurance training improves running economy and cycling economy: you use less energy at the same speed.

Better economy matters most late in a race, when you're running on tired legs. Studies in the review also found improvements in speed or power at VO2max and in time to exhaustion.

How to do it

• Heavy: loads you can lift roughly 4–10 times (4RM to 10RM).
• Volume: 2–3 sets per exercise, about 2–3 minutes of rest between sets.
• Intent: lift the weight with maximal intent to move it fast, even when it moves slowly.
• Maintenance: in race season, about one low-volume, heavy session a week keeps most of the gains.

Timing matters too. Keep heavy leg work away from the day before a key run or ride, and pair it with easy cardio rather than a hard session.