6. Push the Pain Barrier

No pain, no gain—right? The last workout will push the pain barrier to that final level, as you’ll do some higher aerobic intervals—all above your functional threshold power (FTP). In the opening part of the workout, you’ll run through five short 30-second bursts at 125% FTP. Then you’ll do it again. In the last part of the workout, you’ll do more efforts above FTP, but extend the duration to 2 minutes at 115%—three times.