Whether you like to ride in a leisurely manner or power through your rides, you may have wondered, “is cycling aerobic or anaerobic?”, is it your lungs or your legs that give you the power to make it to the finish?
Cycling is both aerobic and anaerobic. To get the most out of your training and maximize your performance, you should vary your training to accommodate both. Your lungs and your legs benefit from both aerobic and anaerobic exercise.
As someone who had a desire to climb the toughest climbs, I focused heavily on longer rides. I didn’t have as much time so I started doing time trials frequently. Much to my surprise, my climbing ability was improving quickly too.
Below we’ll be looking at the science behind the aerobic/anaerobic debate and how to get the best out of your training so that you can smash your cycling goals.
Table of Contents
Some people believe that one energy system is more useful than the other and solely focus on perfecting that system. By which I mean that some people believe they are capable of short sprints but don’t excel at long road rides. That’s not quite true.
All these systems that give your body energy are connected and work together so your training needs to incorporate this.
So there is a similarity between both aerobic and anaerobic energy, though when it comes to accessing them, there are three different ways to do so:
For the first one to happen, there must be oxygen present. This is what gives it its name aerobic.
The other two don’t need oxygen so are considered to be anaerobic.
If we get more scientific for a moment, to power bodies we use adenosine triphosphate (ATP), which is a molecule. Our bodies carry around 100g of ATP.
This may sound like a lot but it will only last for roughly two seconds.
When we first start putting our body under stress, we turn to use the ATP in our system - we access this using the PCr/alactic system.
Our body will use this when we need high intense but very short efforts. I’m talking between one to 10 seconds, a sprint to the finish for example.
After those initial ten seconds, your body has to find energy somewhere else. This is where anaerobic glycolysis comes into play.
This one is more simple; your muscles will break down the glycogen stores (glucose), which releases energy.
Similar to the PCr/alactic system, there is no reliance on oxygen. Neither will it be an option for very long - we’re talking up to 4 minutes.
This type of energy burn is used by climbers and track riders. When it comes to road cyclists, the aerobic pathway is most relied upon.
Aerobic cycling will break down macronutrients in your systems, including things like carbs, fats, and proteins.
The reason this works so well for road cyclists is that it keeps your body fueled. It will keep on breaking these nutrients down, using oxygen, for as long as you want to keep going.
You may be thinking that if you’re into track cycling or a keen sprinter, that it’s best to focus your training efforts on anaerobic and ensure that the pathway is working as efficiently as it can.
Whatever you are training for, you should be aiming to increase your recovery process and how best to produce your energy.
If you want to improve your PCr/alactic system, focus on doing high-intensity interval training. In practice, this means that you should be going full gas for short stints.
You should aim to give it your all for thirty to forty seconds, and follow this up with a recovery time of around 15 to 180 seconds. This will depend on your training goals, hence the varied time.
If you want to do some anaerobic training, this will also require high-intensity movements but the stints are longer, both with recovery and work.
You’re looking at between 1 to 4 minutes of high-intensity work - achieving around 90% of your maximum effort.
Aerobic training is great for getting used to long rides like sports or club rides. These involve riding at 60 - 80% maximum effort for around 2 to 3 hours.
This may have made it sound rather simplistic but in truth, it isn’t.
You can see benefits across the board on all the exercises you do. Focusing on one set of training principles can see you improving more than one energy system at a time.
Leonard does a good job of explaining the differences in training.
Cycling is biased towards aerobic performance, which is true even on the track.
Even in a 10-second sprint, you can see that the aerobic pathway has had some impact.
We now know that if you focus on training one energy pathway, you will help other pathways. What’s worth noting is that high-intensity interval training (HIIT) is what provides the most benefits.
When you vary the kinds of stress you apply to your body, it handles them the best. So when you train that way, it helps you to develop your stamina.
Let’s say you go for a ride every week at 85% of your maximum heart rate, and do this every week. Sure, you’re going to see an improvement in certain aspects, though it won’t be as much if you had varied the power levels and changed the amount of effort required.
What you need to know is that long rides take time. So if you swap a long ride out for a HIIT session, you might achieve your goal more quickly and spend less time doing it.
With short-term anaerobic exercises, there are plenty of benefits linked to them. This includes improving your insulin sensitivity as well as increasing your metabolic rate.
One reason why it’s important to increase your insulin sensitivity is that it will help to break macronutrients down and you can use them for fuel.
A good way to do this is if you do sprint sessions for several weeks, in place of aerobic sessions. You should begin to notice a difference.
Even with all this evidence, there are still riders out there who prefer to simply put in the miles when it comes to training for an endurance race.
The fact is that a lot of riders don’t focus on anaerobic capacity. They don’t see why they should do a few HIIT sessions if it isn’t putting the miles in.
To which I have to say, I used to have the same mindset. Miles and climbing were all I was interested in until I started doing time trials when I was short on time. After a while, I started to notice that I was performing better on the hills too. Noticeably, my heart was under less strain and since then, I’ve always varied my training.
The reality is that training helps our bodies in ways that we don’t always understand or appreciate.
Some people may see a HIIT session as a waste of a training session because why would they need to do a dozen 10 seconds sprints in a sportive? However, it doesn’t mean that you won’t benefit from that type of training.
Studies have shown that over time, as we age, anaerobic power and capacity will decrease but our aerobic power won’t change all that much.
The reason for this is that our anaerobic pathways will become less efficient as the years pass. However, it does demonstrate that HIIT training can benefit your aerobic capabilities.
If you’re looking for the best type of HIIT workouts, here’s something to help you out:
Even as a sportive rider, it can be advantageous to add an interval session to your weekly training. Also, when winter hits, it can help you to keep your fitness ticking over. You won’t need to go out for long rides when the weather isn’t suitable.
Training Peaks looks at how Important is Anaerobic Energy in Cycling.
When you take all these aspects into account, long club rides and short sprints play their part. They are important to get your legs and lungs working.
If you spring to over 30 seconds then you’re going to be targeting all of your energy systems.
Whatever type of cycling you like to do, it’s best to vary your training program to get the best out of your energy systems.
What are you training for?