Use power numbers as your first choice, otherwise, you can use heart rate or perceived exertion as a measure of effort. Percentages are based on FTP/Lactate Threshold Heart Rate, etc.
Warm-up
10 min fairly easy, building towards Zone 2
3×30 sec high cadence, 30-sec soft-pedal recovery
3 min Zone 2
2 min Zone 3
2 min easy
= 20 min total
Main Set
[Do this four times through]
3 min at 80–85% power/85–90% HR
2 min at 95–100% power/95–100% HR
3 min at 50% power/easy effort, HR should get back to Zone 2
2 min at 60% power/HR should be steady Zone 2
= 40 min total
Cooldown
Take a few extra minutes to spin easy here if/as needed
