Not sure I qualify for the "guru" label, but this is what works for me when training for endurance stuff. Aerobic (long slow) rides. 2 or 3 2-3hr rides per week. As you mentioned at 65-75% of HRmax. This is really slow and sometimes boring ... more so if you try it on an IDT. On the IDT, I alternate high and low cadence in 10 min cycles to relieve the boredom, always keeping HR in the zone. Aim here is to build your aerobic base, it's not a strength session!! Interval training 2 (no more than 2) hard interval sessions per week. These consist of 30-45min warmup, then go find a 1km hill and do 5 repeats (Suikerbossie is perfect for this). First repeat I just use to get into the groove ... HR at about 90% which means hard riding but still have legs to accelerate near the top. Next 4 repeats are progressively faster. last one should be very close to 100% HR. puke if necessary Warm down properly - 30min or so. Some folk prefer a shorter hill for this, but I find that if training for races like TK, the hills are long, so best get used to longer hills. You could do this on an IDT by cranking up the resistance, but takes more discipline than if you have a hill to climb. If you find you're feeling over trained or exhausted, rather miss an intensity session than a slow ride session. Non-bike training 2 x 1hr session per week. focus on core and upper body stuff. Long days in the saddle require more core strength than you think. Simple stuff like sit-ups, pull ups, squats, plank, yoga, push-ups, lunges, etc all work for me. Either go to the gym or do at home in your back yard. Possible to do this on the same day as a slow ride. My 'normal' cycle for all this is: Mon - morning: gym evening: 2hr slow ride on IDT Tue - morning: Hard interval session Wed - evening: 2hr slow ride on IDT Thur - morning: gym Fri - morning: Hard interval session. or take the day off if I'm feeling tired. Sat - easy (very easy) coffee ride with mates. 1.5hr. Sun - long slow ride >3hrs. Lastly, you will see that there is no allowance for training in the 75-90% HRmax zone. I'm of the opinion that training in that zone is a waste for endurance events. You are neither building the aerobic base efficiently, nor building strength properly. Others will disagree with this approach.