The fastest way to ruin an interval session is to race the first round. The second fastest is to race the person on the next bike.
Start with a number
Engine Build opens with two benchmarks: a 2,000-metre row and ten minutes on the air bike. Every interval after that is paced from your result, so the session is hard for you — not for someone else.
Repeatable beats heroic
If you can repeat Tuesday's session next Tuesday, you trained. If you cannot, you had a bad day. We would rather you finished every round slightly under your limit and came back stronger next week.