Best Cycling Workouts for Building Aerobic Endurance

By Chris Carmichael,
CTS Founder and Chief Endurance Officer

“What’s the best cycling workout I can do?” That’s a question I get all the time, and it’s not easy to answer. If you’ve been training for an appreciable amount of time, you realize there is no single best workout, but rather, it’s best to personalize workouts to your fitness level and goals. That said, developing aerobic endurance is one of the primary goals of cycling training, and there are a few workouts that work best for building endurance.

The cycling workouts that are effective for improving aerobic endurance have to be challenging enough that they stress your aerobic system, but not so strenuous that you are approaching lactate threshold. When you accumulate substantial time at this intensity, you develop greater mitochondrial density, improve capillarization of skeletal muscles, increase your capacity for muscle glycogen storage, and promote the adaptation of some fast-twitch muscle fibers (Type IIb) to act more like slow-twitch fibers (Type IIa). You will also be producing more lactate than during a more moderate EnduranceMiles ride, but at this intensity you can process that lactate as fast as you’re producing it. In other words, this intensity is key for creating the infrastructure that allows for improved supply, delivery, and processing of fuel and oxygen.

“Shouldn’t I Just Ride in Zone 2?”

Easy “Zone 2” rides – also known as FoundationMiles or EnduranceRides in CTS terminology – have become so popular that some cyclists think they’re the answer to everything. Don’t get me wrong, they’re great and the majority of your training time (even during Time-Crunched Cyclist programs) should be spent at this aerobic intensity well below lactate threshold. However, there’s a lot of room between recovery pace and anything approaching lactate threshold intensity.

You can ride steadily at an easy, conversational pace in Zone 2 for hours, but that doesn’t mean that’s the only way to utilize aerobic intensities below lactate threshold to improve aerobic endurance. And remember, anything that improves aerobic endurance – whether it’s Zone 2 or the workouts below that are upper Zone 2 and lower Zone 3 – also improves VO2 max and power at lactate threshold. All of these aspects of physiology and performance are connected. And before getting to the two workouts below, I’d encourage athletes not to be dogmatic about training intensities: you need to train all zones, just not all zones at all times!

Two Workouts That Improve Aerobic Endurance

In addition to longer FoundationMiles and EnduranceMiles rides, at CTS we use two fundamental interval workouts to develop aerobic endurance: Aerobic Tempo (low cadence) and Sweet Spot Tempo. We used to combine these into one Tempo intensity with a pretty wide power and heart rate range. These days we have separated Tempo into two distinct workouts for greater effectiveness.

Aerobic Tempo

Aerobic Tempo intervals are completed at the lower end of the Aerobic Tempo intensity range (76-85% of Treshold Power, 84-92% Threshold HR), and use a lower cadence range (75-80rpm) to increase the force component of power production (Power = Force X Angular Velocity (cadence)) and engage more muscle fibers. To do this, you’ll end up riding in a larger/harder gear to bring your cadence down. If you are doing these outdoors or on a simulated course on a virtual platform, you have to be careful not to let the power and heart rate intensity increase out of the Aerobic Tempo range when you hit hills.

Sweet Spot Tempo

Sweet Spot Tempo intervals are more challenging than Aerobic Tempo intervals (93-96% of Threshold Power, 84-92% of Threshold HR), but still far enough below lactate threshold intensity that you can complete long, uninterrupted efforts. The cadence for Sweet Spot Tempo is typically self-selected, and most moderately-experience and experienced athletes settle on about 85-95rpm.

Accumulating a lot of uninterrupted time-at-intensity is the key to success with both Aerobic Tempo and Sweet Spot Tempo intervals. The advantage of this intensity is that it you can sustain substantially longer efforts (20-60 minutes) than you can when training closer to or at lactate threshold (10-20 minutes).

Typical Aerobic Tempo and Sweet Spot Tempo workout structures are listed below. While we prescribe both the same way, for an individual athlete we might make the Aerobic Tempo intervals longer than the Sweet Spot Tempo intervals. You can do these interval workouts 2-3 times per week, depending on whether you are also doing short, high-intensity interval workouts or e-races. If you are mostly riding for endurance right now, 3 times per week can work well. If you are doing other interval workouts, then 1-2 times per week may fit your schedule better.

Tip: These intervals will feel “too easy” at the beginning, but stick with the prescribed intensity. Even as the power stays constant, your perceived effort will increase as you accumulate time during the workout.

Aerobic Tempo and Sweet Spot Tempo Example Workouts

The examples below are listed with structures at the top that are often used with new athletes or athletes returning to structured training. As you go down the list, the interval durations increase and the number of intervals decreases. At the advanced end of the spectrum, athletes can complete intervals exceeding 60 minutes.

3 x 15 minutes with 5 minutes easy spinning recovery between intervals.

2 x 20 minutes with 5-7 minutes recovery

4 x 15 minutes with 5 minutes recovery

2 x 30 minutes with 5-7 minutes recovery

1 x 45 minutes

December is a great time to incorporate the workouts in this article. For one thing, they are good for keeping warm on cold days. The intensity is not very high–meaning the speed isn’t very high–but it is high enough and steady enough to generate heat. They are also a time-efficient way to get a lot of productive work done in a 1- to 3-hour outdoor ride. When it’s cold out, many riders will be more likely to say yes to a moderately-challenging 2-hour ride compared to an easier 3- or 4-hour ride. You can also do these indoors, which is often a good idea for cyclists who have trouble finding long, uninterrupted stretches of road.