{"id":42086,"title":"Cyclocross interval training","description":"Interval training is one of the keys to success in cyclocross. But what are they and how should do them? We explain how different interval sessions improve the performance of your body's energy systems to improve at cyclocross.","content":"

Published in<\/strong>: CYCLOCROSS<\/strong><\/a><\/p>

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Interval training is one of the keys to success in cyclocross. In this article, I\u2019ll explain how different interval sessions boost the performance of your body's energy systems so you can improve at cyclocross.<\/p>

\"ProfessionalEveryone who races cyclocross wants to improve their fitness so they can ride faster for longer. Intervals are, I believe, a key ingredient to success in cyclocross. But which intervals should you use to enhance your cyclocross form?<\/p>

In this article, I explain how different types of intervals can be used to target the body\u2019s energy systems that are most needed in cyclocross.<\/p>

This is not intended to be a training schedule but a practical guide to how to, and how not to use interval sessions for cyclocross.<\/p>

I've deliberately tried to simplify the language used to describe the different energy systems that power your muscles to make the article more readable and enable you to focus on the important facts.<\/p>

How do muscles get energy?<\/h2>

Before we delve into the details of interval training, it\u2019s worth having a \u201cpeek\u201d under our skin to see how muscles get their necessary energy. Understanding how the three key energy systems operate helps to understand the relevance of interval training better.<\/p>

\"ProfessionalProfessional cyclocross riders like Sanne Cant need power as well as skills. Image: Rijden<\/em><\/p>

I\u2019m using my own terms to categorise the energy systems. That might seem like a cheat but it\u2019s to avoid making this article overly complex and because people use different names for the same energy systems.<\/p>

Adenosine Triphosphate<\/h3>

Muscles use Adenosine Triphosphate (ATP) as their energy supply but only small quantities are stored in the muscles so other sources of energy such as glucose and fat need to be converted into ATP. That\u2019s what the three different energy systems do.<\/p>

The first two, which I\u2019m calling Anaerobic I and Anaerobic II don\u2019t require oxygen for the chemical reaction that creates ATP. Anaerobic means \u201cwithout oxygen\u201d. The third, the Aerobic system requires oxygen for the chemical reaction to take place.<\/p>

Anaerobic II system - the Rocket booster<\/h3>

Imagine you are close to the finish of a road race and you launch your all-out sprint for the line. How long can you sprint for and how much power do you output?<\/p>

If you are lucky enough to have a power meter you\u2019ll be able to see afterwards that you were able to sustain the power for about ten seconds and produced maybe 1,000 or more watts.<\/p>

\u201cwhy couldn\u2019t you sustain the sprint for longer?\u201d<\/strong><\/p>

But why couldn\u2019t you sustain the sprint for longer? That\u2019s because when you use the full power of your muscles you\u2019re relying upon the Anaerobic II energy system. It has various names including ATP-PCr, Anaerobic Alactic or Neuromuscular.<\/p>

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For the first couple of seconds, the muscles use their stored ATP but the immediate supplies are soon exhausted. The Anaerobic II system then kicks in to keep supplying ATP but it only lasts for about 10 to 15 seconds.<\/p>

Think of the Anaerobic II energy system as being your rocket booster. It can produce about five times the amount of power you\u2019d produce whilst on a steady ride but lasts for only a very short period. It takes minutes for it to recharge itself and longer if you are fatigued.<\/p>

Anaerobic I system - the Sports Car<\/h3>

Let\u2019s imagine now there\u2019s a small group of riders ahead of the peloton. They are moving rapidly and you know that you have to bridge across. It will take you a couple of minutes of intense effort to jump to them.<\/p>

You\u2019ll need to reach them within about two minutes because that\u2019s the maximum period of time you can maintain the required pace. Hopefully, once you get across you can take shelter on their back wheels and recover in their slipstream.<\/p>

\"CyclocrossCyclocross demands a lot of your anaerobic energy systems. Image: Rijden<\/em><\/p>

This is where your Anaerobic I energy system is at a premium. It\u2019s more commonly known as the Glycolytic, Anaerobic Lactic, Lactic Acid or Anaerobic Glycolysis system. It can\u2019t supply as much power as the Anaerobic II system (about half as much) but it can sustain output for about two to three minutes depending upon fitness and intensity.<\/p>

\u201cthe Anaerobic I system is a battery-powered sports car\u201d<\/strong><\/p>

If the Anaerobic II system is your rocket booster, the Anaerobic I system is a battery-powered sports car with a limited capacity battery. You might wonder why if it\u2019s an anaerobic chemical reaction, that you end up breathing so heavily afterwards. That\u2019s because oxygen is required for the recovery process.<\/p>

Aerobic system - the Diesel<\/h3>

Now we come to the equivalent of the diesel engine in our three energy systems. It doesn\u2019t produce anywhere near the same power as the previous two but give it enough fuel and it just keeps on going and going. That\u2019s how professional cyclists can ride seven-hour races because, for the most part, they\u2019re relying upon the aerobic system.<\/p>

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The aerobic system utilises fat or glucose to generate the critical ATP. Which one the Aerobic energy system burns through depends upon fitness and intensity of effort. It\u2019s worth understanding this a bit more as they relate to what are commonly called VO2 Max zone and Zone 2.<\/p>

VO2 Max<\/h3>

VO2 Max is the point at which your body maximises the utilisation of oxygen to sustain the intensity of effort. It's right at the upper end of your aerobic system and feels hard.<\/p>

Although I said your aerobic system keeps going for long periods, you can only maintain VO2 Max level efforts for five to 10 minutes unless you are highly trained.<\/p>

Zone 2<\/h3>

Zone 2 is the level of intensity where the body relies upon the most amount of body fat for its energy source. Ride harder and it will use more glucose and less fat. Ride more easily and it will still utilise fat but less of it.<\/p>

\u201cwhy does Zone 2 matter so much for cyclocross when the duration is an hour at most?\u201d<\/strong><\/p>

Zone 2 rides are nice and easy and typically last at least two hours, often much longer. That makes sense for road racers who will race for two, three or more hours. But why does Zone 2 matter so much for cyclocross when the duration is an hour at most?<\/p>

\"ZoneZone 2 rides are nice and easy but long. Image: Unsplash.<\/em><\/p>

To simplify my explanation and avoid talking about mitochondria and other odd-sounding terms, I\u2019m going to use an analogy.<\/p>

If training your anaerobic and aerobic energy systems can be thought of as developing a water pump then training in Zone 2 makes sure you\u2019ve got a nice clear and fat pipe to pump the water down.<\/p>

\u201ca very powerful pump attached to a very thin pipe\u201d<\/strong><\/p>

If you spend all your time training your anaerobic systems and VO2 Max and neglect Zone 2 training it's like having a very powerful pump attached to a very thin pipe. It will limit the effectiveness of the pump no matter how much pressure it generates.<\/p>

Zone 2 training is like building the foundations of a house. On their own, they are of little use but they are essential to building a viable property.<\/p>

The good thing about Zone 2 training is that it's a nice easy pace. The downside is that you need to put in lots of hours for it to be effective.<\/p>

\"MuscularEnergy systems, power and duration<\/em><\/p>

The physical demands of cyclocross<\/h2>

Now we have a better understanding of our energy systems, we need to consider how they apply to the physical demands of cyclocross to identify the best interval training to undertake.<\/p>

Overlapping energy systems<\/h3>

It\u2019s important to understand that these three energy systems overlap with one another. They don\u2019t just switch off. For example, when you start a really hard sprint the Anaerobic II system kicks in but whilst it\u2019s still supplying energy, the Anaerobic I system overlaps and the two run in parallel.<\/p>

Nowhere is this more noticeable for cyclocross riders than the boundary between the Aerobic and the Anaerobic I energy systems. Whilst at VO2 Max which is your maximum oxygen consumption the Anaerobic I system also contributes.<\/p>

Where intervals deliver the greatest benefit<\/h3>

Given the nature of cyclocross with repeated acceleration followed by rest and the occasional short but steep climb, you\u2019re constantly flipping between the VO2 Max and Anaerobic I energy system. It\u2019s this area where intervals can deliver the greatest benefit.<\/p>

There are advantages too in improving VO2 Max capability. If you\u2019re VO2 Max improves then it reduces your reliance on the Anaerobic I system, reducing your time to fatigue.<\/p>

Brute strength<\/h3>

You might think that you\u2019d want to develop your Anaerobic II energy system. After all races start with a sprint. The reality is that, unless your name is Mathieu van der Poel, you\u2019re probably not starting with an all-out sprint because if you did you\u2019d suddenly fade and go backwards through the field.<\/p>

\u201clow-cadence brute strength\u201d<\/strong><\/p>

Although you accelerate out of corners they tend to be more gradual increases in speed rather than flat-out efforts. But what about those short but very steep climbs? These rely upon low-cadence brute strength rather than the demands of a normal sprint. We\u2019ll look at these in more detail later.<\/p>

Maximum power or endurance?<\/h3>

Ask any cyclocross rider if they want to increase their maximum power or their ability to sustain a high power for longer and they\u2019ll respond with \u201cboth\u201d. Well, who wouldn\u2019t? But what you are trying to achieve will influence the structure of the intervals.<\/p>

\"cyclocross<\/u><\/a>If you think you lack high power but can keep going for ages at the same pace then you might want to focus on shorter but higher-intensity intervals. But if you can blast away at the start, ride hard for the first few laps and then fade then you should consider longer less intense intervals.<\/p>

Intervals for cyclocross<\/h2>

Let\u2019s assume that you\u2019ve been steadily packing in those long Zone 2 rides during the lovely warm summer months. Without them, as explained above, you\u2019ll find there\u2019s a limit as to how much intervals will benefit you.<\/p>

Additionally, you need to have developed a good level of fitness, otherwise, these intense sessions will quickly exhaust you. Slowly build up the frequency of sessions and the number of intervals in each. If you try to do too much too soon you\u2019ll exhaust yourself and find you spend the next week recovering.<\/p>

Don\u2019t do interval sessions if you have health concerns, particularly heart-related ones. I cannot stress enough how physically demanding they are.<\/p>

Rule of 3<\/h3>

The rule of three is easy to understand - don't do more than three interval sessions a week. A race counts as an interval session.<\/p>

\"ZoneA race counts as an interval session. Image: Rijden<\/em><\/p>

I'm sure some of the top cyclocross riders occasionally break this rule but they are in the peak of physical fitness.<\/p>

I strongly recommend that if you\u2019re not a regular interval user, you just start with one session plus a race to see how your body responds.<\/p>

Personally, I don't find interval sessions too bad on the day but often the next day I feel utterly drained.<\/p>

VO2 Max intervals<\/h3>

I suggest starting with a single VO2 Max session a week as these are of lower intensity than Anaerobic sessions. The classic format is up to four intervals each of five minutes at high intensity with an equal amount of rest time between each. Thus a session could look like this:<\/p>