You’re riding along in a group when some all-star at the front launches a blistering attack forcing the group to surge in response. Your buddy next to you pants in disgust, something about how dumb it is that guys are riding so hard, so early.
Your buddy goes on to explain that December should be a month dedicated to long and slow miles, nothing above zone 2, and that high-intensity riding during the winter will stunt fitness gains later in the year.
Training Periodization Theory
The idea to refrain from riding “too hard” during the off-season originates from the concept of training periodization [1]. In short, periodization theory is predicated on the belief that peak performance is obtained by working on specific fitness attributes in a “sequential hierarchy” [2].

Training can be confusing. In our free eBook, we’ll show you four ways to use your data and insights from science to ride better than ever.
Reality
This advice sounds logical but is there any evidence that following a sequential progression of cycling intensity is the best way to achieve peak fitness? The short answer seems to be no [2].
In fact, in a recent study comparing sprint interval training with more traditional “endurance training” similar endurance improvements were observed in both groups [3].
In other words, sprint training (which totaled roughly 90% less total training volume than the traditional endurance group) produced similar endurance adaptations to traditional “base” training.
Traditional Wisdom
But I thought in order to improve your “endurance” it was essential to do “endurance” level riding? That traditional wisdom doesn’t seem to be backed by science. For the majority of cyclists, riding “too hard” in December is probably the least of their concerns when it comes to optimizing their fitness throughout the season.
Here are several questions that might address whether or not you’re riding too hard before your office Christmas party.
Q & A: Should I be riding hard in December?
Q: How much time do you have to train per week?
A: 8 hours.
Advice: Ride hard
Q: What is your past history of long term training motivation?
A: I usually burn out by May.
Advice: Don’t ride hard; better yet don’t ride at all, unless you enjoy colder, wetter, and generally more miserable riding conditions.
Q: Is riding hard an important stress relief?
A: Yes, the affirmation I receive from crushing my friends is an important component of my overall mental health.
Advice: Ride hard.
Q: Is it difficult for you to enjoy riding or racing when you’re several notches below your typical peak fitness level?
A: Yes, being out of shape leads to a downward spiral of negative self-talk and depression.
Advice: Ride hard
Q: Do you prefer riding hard or complaining about others riding too hard?
A: I prefer complaining about others riding too hard.
Advice: Save “riding hard” for the window of time during the summer that allows you to maximize your motivation and overall training intensity.
The Takeaway
There is no “rule” for riding hard in December. Furthermore, it’s important to recognize that acquiring cycling specific fitness doesn’t seem to follow an organized and structured hierarchy of “ideal” training zones or blocks.
Your best “base” training might be hammering every weekend ride possible while doing all-out sprint training indoors or it might involve abstaining from consecutive high-intensity rides in order to conserve the energy needed to achieve your weekly volume target of 25 hours.

Training can be confusing. In our free eBook, we’ll show you four ways to use your data and insights from science to ride better than ever.
References
1. Matveev, L.P., Fundamentals of sports training. 1981, Moscow: Progress Publishers. 309 p.
2. Kiely, J., Periodization paradigms in the 21st century: evidence-led or tradition-driven? Int J Sports Physiol Perform, 2012. 7(3): p. 242-50.
3. Gibala, M.J., et al., Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance. The Journal of Physiology, 2006. 575(3): p. 901-911.