In mid April the cobbled classics are history and Ardennes week has arrived: Amstel Gold race Sunday, La Fleche Wallonne  Wednesday and Liege Bastogne Liege Sunday. These races feature narrow roads littered with numerous short, steep climbs, 30 seconds to 5 minutes in length. A race like the Fleche Wallonne is a completely different animal than the Tour of Flanders and as such favors a much different style of rider.

By short, steep climbs, we are talking about punchy 1-4 kilometer climbs with average grades between 5–12% and maximum gradients approaching 20%. These climbs are get-up-and-go out-of-the-saddle efforts, 100% power climbs. Whereas big powerful “roleurs” like Boonen, Sagan and Cancellera dominate on the cobbles, explosive power climbers like Dan Martin, Andrew Talansky, Valverde and Rodriguez stomp up these climbs for the finish line.

When the hammer drops up the Mur de Huy Wednesday and the Côte de Saint-Nicolas Sunday, the contenders will be producing in excess of 7 watts per kilogram in an all-out, full-gas effort while going for the “w”. Those kind of power-to-weight ratios earn them the big bucks and just aren’t attainable (for that long) by us mere mortals. However, we can mimic the physiological demands of those climbs in our training with VO2 Max Intervals. Because after all, everybody has a local climb where braggin’ rights are at stake.

The Ardenne climbs take the athletes anywhere from three to six minutes at 105–120 % of their threshold power. These durations are straight up VO2 efforts and very difficult. Here is a simple climbing workout to improve your explosive power climbing up your very own Mur de Huy or La Redoute:

VO2 Max Intervals: Zone 5 (105 – 120% of Threshold Wattage): 2 sets of 2 x 4 min ON 4 min OFF; 8 min in-between sets

  • Warm up easy for 15 – 30 minutes
  • Perform these intervals on a climb (if available)
  • Begin the each interval by modulating your wattage between 105% and 120% of your threshold power.

With an accurately set threshold wattage, 105-120% is pretty much as hard as one can go for 4 minutes


  • Hold your wattage in “zone 5” for 4 minutes.
  • After the first 4 minute interval turn around and coast back down the hill, turn around again and reposition yourself to begin the next interval from the same spot after 4 minutes of recovery.
  • A properly paced interval should feel moderately hard at first, difficult in the middle and like a maximal effort at the end
  • Tip: use your PowerMeters readout as motivation to hold the effort between your zone 5 wattages for the full four minutes. Don’t let your wattage dip below!
  • Use the real time feedback from your PowerMeter to go hard enough but not too hard. Try to maintain your power output above 105% but not above 120% (this is too hard and physiologically unrealistic)
  • After two intervals, take an 8 minute set break to spin around and recover.
  • After you complete both sets ride around in zone 2 or cool down.
  • Download your power file and see how many watts you were able to achieve for each interval!


“Make the power” any which way you can; it does not have to be pretty. Dance on the pedals out of the saddle or try spinning seated. Be aggressive, get after it! I recommend alternating between sitting and standing. Position your hands out on the hoods for maximum leverage to rock the bike back and forth as you pump up and down on the pedals. With the real time wattage feedback from your PowerMeter you’ll quickly see which climbing technique enables you to make the power.


These are difficult intervals (some of the toughest) so come into the workout motivated and ready to suffer. The payoff is that you will be a more powerful, faster bike rider. Imagine you are the one racing up the Mur de Huy with the taste of blood in your mouth and the podium is within your grasp! If you have snot coming out of your nose, or drool coming out of your mouth at the end of the last few intervals you are doing them correctly. For the goal-oriented athlete, there can be a tremendous amount of satisfaction in the successful completion of such a difficult workout within the prescribed zone 5 wattages.

Power Data Analysis:

The graph below is an athlete’s power data from the Ardennes Classic VO2 Intervals described above (Zone 5: 2 sets of 2 x 4 min ON 4 min OFF with 8 minutes in-between each set). This particular athlete is training for a road race with 3 climbs that last approximately 4 minutes each. Not only is this VO2 workout great for his fitness and power output, but it is specific to the power demands of his race course.

Notice the distinct plateau shaped power vs. time graph for each interval and the relative steady wattage output. The first three intervals were very strong with averages of 319, 315, and 311 watts, respectively. For the fourth and final interval, the athlete started out strong but faded and only achieved an average of 282 watts.



Since the athlete’s technique was good for the first three intervals, the decrease in power on the 4th interval tells me that he was fatigued and a fourth interval was one too much. Three successful intervals also provide a point of reference for how much VO2 work this athlete can handle in one workout or more importantly a race. Coincidentally this athlete’s A race has 3 four minute climbs so as it stands now, he can handle the power demands of the course. For future training we will continue to work on his endurance as well as his explosive VO2 climbing power.


Advanced VO2 workout: If 2 sets of 2 intervals for 4 total VO2 intervals is not enough for you, try 2 sets of 3 [2 sets of 3 x 4 min ON 4 min OFF]. However, remember to focus on the quality and amplitude of the power first before moving onto the quantity. Finally, if 24 minutes of VO2 work is not enough for you, try the grand-daddy VO2 workout off all time: 2 sets of 3 x 5 min ON 5 min OFF with 10 minutes in-between each set!

And if that is not enough for you (!) try racing 261 kilometers over 12 climbs that are between 1–4 kilometers long with average gradients between 6–11%! Oh yeah, and the finish line is at the top of one these climbs. Such is the course and power demands for this Sunday’s World Cup race: Liege-Bastogne-Liege. There’ll be 12 VO2 efforts at world class power to weight ratios providing more than enough evidence why the pros race their bikes for a livin’.

Frank Overton is the head coach and owner of FasCat Coaching, a cycling coaching company in Boulder, CO. Frank is an advocate of power based training for professional and amateur athletes. For more information about Frank, FasCat Coaching and their coaching services please email