One key to strong cyclocross racing is being able to sustain a heart rate near your max. Cyclocross is full gas from the start, with your heart rate typically jumping to threshold intensity within the first minute and staying there for the duration of the race, or until you hit the wall.
I am typically not a great starter. Top end power is a weakness of mine, although I’m working to improve it, so the huge acceleration at the start can be challenging. Early in a race, especially in the first lap, I will often find myself further back in the field. Being able to sustain high intensity without blowing up allows me to pick off riders and work my way forward. It would obviously be ideal to sustain this intensity at the front though!
At Supercross Cup in November 2017, I had a really bad start. I didn’t have the big power surge needed to get ahead of the trouble that a loose gravel corner would cause near the beginning of lap one. Finding myself placed somewhere in the 20s just a quarter lap into the race, I was forced to push myself for the duration of the race in order to move forward and finish in third. My average heart rate and my max heart rate during the race were within two beats per minute of each other; there was no opportunity to recover.
If we are going to race with high heart rates and power numbers, we need to train the same way! VO2 max intervals are one of the most effective ways to acclimate your body to sustaining intensity. In keeping up with my theme of efficient and effective weekday workouts, they are also an awesome option.
Because VO2 max refers to the maximum amount of oxygen you can utilize during intense exercise, the intervals are hard! There is no way around it. One of the reasons they work is because they really push you. By the end of the interval, your heart rate will most likely end up at or near its max. Going into VO2 max training with the right mentality is essential. You know it’s going to be a hard training day, but it is short and it will work!
VO2 max efforts last between 3-6 minutes in duration, with 5 sets of 5 minutes often being referred to as a gold standard. While this is a great workout, if you have not been doing intense training, it will simply be too much to start. 3 minute intervals are a much more realistic, and plenty challenging, place to begin.
We will not receive much recovery from our efforts during a cyclocross race, so recovery time will be limited during your VO2 max intervals too. Limited recovery time may inhibit the power you can make as the efforts continue, but it will teach the body and mind to dig deep even when you are fatigued, making the last lap of a cross race far more enjoyable (or at least faster).
Completing VO2 max intervals:
Over three weeks, complete two days of VO2 max intervals, following the below progression. Ensure you are warmed up and ready to push the pace before the intervals begin.
- Workout 1: 4 sets of 3 minutes with 2 minutes recovery between sets
- Workout 2:3 sets of 4 minutes with 2.5 minutes recovery between sets
- Workout 1:5 sets of 3 minutes with 2.5 minutes recovery between sets
- Workout 2:5 sets of 3 minutes with 2 minutes recovery between sets
- Workout 1:4 sets of 4 minutes with 2.5 minutes recovery between sets
- Workout 2:3 sets of 5 minutes with 2.5 minutes recovery between sets
Intervals should be completed at 105-120% of functional threshold power (ftp). For example, if your ftp is 205 watts, aim to hold a range of 215-246 watts for each interval. Start the interval within this range, rather than sprinting the first minute and then struggling to maintain intensity during the final minute of the interval. If you are feeling strong, push the pace towards the end of the last few intervals in your training session, aiming to hold power near 120% of ftp.
No worries if you don’t have a power meter, VO2 max intervals can simply be completed as an all out effort for the duration. Heart rate can be a great training tool, but heart rate response will lag behind your effort, so you will not be targeting a specific number. Record the heart rate data and make sure you were close to your max heart rate at the end of the interval. In theory you should not be able to hold this intensity for longer than about 6 minutes, so if you feel fresh at the end of the interval, force yourself to dig a little deeper on the next effort. On the other end, if you hit the wall one minute into the interval, try to pace yourself better next time.
I like to complete one VO2 max session a week on the trainer to focus completely on building my power numbers, and then ride the second session of the week on the long, grass stretches of my local cyclocross course to learn how to transfer power to off road terrain.
After you complete your three week VO2 max training block, enjoy some recovery days, and then get out on your local cross course and rip some laps!