Rule No. 1: Go for maximum time efficiency.
Incorporating indoor cycling into your training presents an ideal opportunity to trim the waste that more than likely exists in your current routine. Increasing the time efficiency of your bike training starts with trading some volume for intensity, but it goes beyond that.
“The approach I’ve taken is to incorporate a modest increase in training intensity (more time at threshold across all three disciplines and more time above threshold as well) and an increased focus on specificity,” says Chris Carmichael, author of “The Time-Crunched Triathlete.” “That’s why the majority of the workouts in ‘The Time-Crunched Triathlete’ are brick workouts.”
Both Kessler and Potts do a short to mid-length run after every indoor ride to maximize the fitness bang they get for their workout buck.
“When I do clinics I tell people that if you have an hour and a half to work out, you’re better off doing a one-hour indoor ride and a 20-minute run than a 90-minute outdoor ride,” Potts says.
The amount of riding time you slash and the amount of high-intensity riding you add should depend on individual considerations. You’ll definitely want to retain one weekly endurance ride that’s long enough to give you the endurance you need to go the full race distance. Two high-intensity indoor rides per week are appropriate for most triathletes. None of these rides needs to last longer than an hour.
In 2009, inspired by the likes of Kessler, Stewart and Potts, I transitioned to a bike training regimen that consisted of three one-hour indoor rides and one long outdoor ride (up to five-and-a-half hours) per week. Two of those indoor rides were high intensity. One was some form of threshold ride (e.g. 30 minutes easy, 30 minutes at lactate threshold intensity) and the other was some form of interval ride (e.g. 12-minute warm-up, 12×1-minute sprints with 2-minute spin recoveries, 12-minute cool-down). This regimen represented a 20 percent reduction in my previous cycling volume, and yet, at age 38, it lifted my bike performance to a new lifetime high.