One-Hour Workout: VO2max Fartlek Run

Throw a little “speed play” into your training holding pattern with a run that makes the miles fly by.

This week’s run workout is courtesy of Olympian and coach Ryan Bolton, a former collegiate runner-turned-pro triathlete who now works with athletes who range from beginner to elite. Excerpted from The Triathlete Guide to Sprint and Olympic Triathlon Racing, out now from Velopress, this VO2max Fartlek running workout is ideal for mixing a little speed into what’s likely a “holding pattern” in terms of your season and training. This is also a great session for those who are running on a home treadmill.

As experts are warning athletes not to push themselves to their max intensity during a period where everyone needs to stay as healthy as possible, this is an excellent way to prevent your fitness from plateauing and your routine from becoming stagnant while still being smart. Be sure to heed the efforts in this workout from start to finish in order to not wear yourself out too prematurely—allowing you to increase your VO2 max without falling into too much physical debt. Remember, the goal here is to stay at a pace that you could increase two “notches” faster if you had to. Stay controlled, and you’ll not only hit the goal of the workout, but also stay in a healthy zone.

In a regular season, this workout would fall ideally midway through the first build phase, a little more than halfway through the plan. It’s also important to take a day or two of running and cycling rest after this session, and have an easier day before. When performing this VO2max fartlek, remember that the “off” intervals should still be at a fairly decent pace—not too slow.

VO2max Fartlek


5–10 min. Rate of Perceived Exertion (RPE) < 4, heart-rate zone Z1
5 min. build to RPE 5, HR zone Z3
5 min. dynamic exercises or drills 
6 × 60–75m strides at 80 percent of max speed effort, rest 90 sec. between intervals

VO2max Fartlek Main set

10 × 
(90 sec. with RPE 8 or HR zone low Z5a
90 sec. RPE 5–6, HR zone Z3)


5 min. easy jog

For more workouts like this, 16-week training plans for short-course athletes from beginner to advanced, and more in-depth run technique work, be sure to check out The Triathlete Guide to Sprint and Olympic Triathlon Racing, out now from Velopress.