Durability is the power you still hold late in a long ride, after the kilojoules pile up. It decides gravel races, fondos, and anything past three hours. This plan measures and trains it.
In the first and last weeks you'll do a durability test: a fixed 20-minute effort fresh, a long loaded ride, then the identical effort deep. The gap between them, how far your heart rate drifts to hold the same power, is your fade. Eight weeks later you retest and watch that gap shrink.
In between, two key sessions a week. A threshold day holds your ceiling. A Saturday durability ride puts your hardest efforts behind a kilojoule wall that climbs week to week, because the stimulus is the fatigue, not the effort. Those same intervals fresh are just intervals. Buried deep in a loaded ride, they teach your body to hold power when the tank is low, the exact demand of hour four in a gravel race.
Then Sunday you ride again on Saturday's fatigue, and this is where durability compounds. A single long day teaches your body to resist fatigue within a ride. Stacking a second day on tired legs teaches it to resist fatigue across days, when glycogen is already down, the legs are already loaded, and the aerobic system has to work harder for the same power. That's the state a long event or a stage race actually lives in, and you can't reach it with one hard day and full recovery. The back-to-back forces the adaptations that matter: better fat oxidation, faster glycogen handling, and a heart rate that stays hitched to your power deep into a second day of work. Keep both days honest, the Saturday fueled and hard where it counts, the Sunday steady Zone 2, and the pair does more for your fade than either day alone.
Fueling is programmed: 90 grams of carb an hour on every long ride, built as a skill, because most amateur fade is a fueling problem more than a fitness problem.
The week has a simple shape. Rest Monday. Threshold Tuesday. Wednesday and Thursday, ride 60 to 90 minutes genuinely easy, conversational pace, one can stretch longer if you've got time. Friday, go short and light or take it off, so Saturday's ride gets fresh legs. If your easy days creep hard, the key sessions stop working.
Who it's for: riders targeting events over ~3 hours. You'll need a power meter, a heart rate monitor, and 6-10 hours a week. You'll need to know your FTP or Critical Power. For CP you can use the free First Wheel Critical Power calculator (firstwheelcoaching.com/resources/critical-power). Score your fade free at firstwheelcoaching.com/resources/durability.
Every workout is fully structured for ERG and head units. Built by Joe Lewis, professional cycling coach and former pro (Livestrong, Hincapie), First Wheel Coaching.
This is a general plan, not personal coaching. Talk to a physician before starting a new training program. Not medical advice.