Whether you’re just finishing up a cyclocross season or building up your aerobic base after a fall break, it never hurts to be reminded of the importance of aerobic training. While the methodology of winter training has evolved over the years from “keeping it in the small chainring” to more accurate and precise training plans — with the help of power meters, heart rate monitors, and the metrics we can track on TrainingPeaks like aerobic decoupling (Pw:Hr) and efficiency factor (EF) — controlling intensity and staying focused on aerobic conditioning remains important and can be challenging for many athletes.
Aerobic training takes decades to fully develop, which means that you can see continual improvement in performance, unlike in higher-intensity zones, where performance can begin to plateau in four to six weeks.
Aerobic Training Is All About Going Longer, Not Harder
Most endurance athletes love to see progression in their training and performance, which is a great motivator and a necessary quality for any successful endurance athlete. The problem many of the most motivated athletes encounter during base season is that they don’t feel like they are progressing — they are itching to race and test themselves with some all-out efforts.
One way to test yourself during the base season is to perform submaximal aerobic workouts that consist of long, steady efforts ranging from 60 to 180 minutes at .75 intensity factor (IF). Analyzing the Pw:Hr (i.e., cardiac drift) from these efforts is a good way to check in on aerobic fitness. Having a Pw:Hr of less than 5% on longer steady-state efforts will ensure that your aerobic fitness matches the power demands of the effort. Cardiac drift above 5% can be a sign that the intensity is too high or that other environmental factors, such as heat and fueling, need to be addressed.
Make sure to keep things consistent when keeping track of these workouts over time. That way, when you look back at these rides, you can use EF (i.e., normalized power divided by average heart rate) to give you a snapshot of how your aerobic fitness has improved. This approach is a way to get some positive reinforcement that all these long steady rides are working even though you’re not smashing a new 20-minute PR every weekend.
Aerobic Workouts for Cyclists
Progressive overload is central to any training plan, and without progress, there is no positive adaptive response. When focusing on training Zones 1-4 up to your lactate threshold (which occurs at Zone 5a), it’s best to progress first by lengthening the time spent in zone per workout or training cycle before increasing power. This will make sure that you are maximizing long-term performance and aerobic development. These aerobic workouts are like the foundation of your fitness. The more time you can put into them before the race season the more intensity you can handle later on.
Increase Duration, Not Power
For example, if you have a threshold of 300 W, you would complete a sweet spot workout with 4 x 10 minutes at 280 W while feeling comfortable and in control throughout. A few days later or the following week, you should progress to 3 x 15 minutes at 280 W or 4 x 12 minutes instead of bumping the power numbers up to your threshold. Progression doesn’t always have to come from increasing power — it can and should come from increasing work or time at a given intensity first.
These principles remain true at lower Zone 2 and 3 intensities as well, but there may be limitations with allowed training time that make it more feasible to increase intensity if you are already maximizing your available time. Having accurate power and heart rate data makes it easier for athletes and coaches to measure and quantify time in zones. This data helps determine whether or not thresholds need to be raised to keep working in the correct power zones.
Maximizing Aerobic Training
All effective training plans allow for some wiggle room. I always want to get the most out of myself if I’m having a good day and to “just get the work done” if it’s a mediocre day. During base season, going longer by adding 30 minutes to your endurance ride, extending a tempo interval by a few minutes, or adding another effort at the same power to expand your time in the prescribed training zone is where you should focus on making the most of a good day.
Progressing by going longer at lower intensities during aerobic training will make sure you build efficiency in sub-threshold zones and maximize your aerobic base. If you make your Zone 2 day a little longer or do one more sweet spot effort on the good days — instead of making a tempo effort into a threshold effort or finishing the workout with a five-minute VO2 effort — you will have maximized your aerobic base come race season. This will allow you to complete more time above threshold and capitalize on those max aerobic and anaerobic efforts during racing season (when it matters most).
References
Iannetta, D. et al. (2018, September 10). Metabolic and performance-related consequences of exercising at and slightly above MLSS. Retrieved from https://pubmed.ncbi.nlm.nih.gov/30120803/
Jones, A.M. & Carter, H. (2000, June). The effect of endurance training on parameters of aerobic fitness. Retrieved from https://pubmed.ncbi.nlm.nih.gov/10870864/
