Many cyclists adhere to the myth of “no pain, no gain.” After all, we know that a hill is only as hard as how fast you climb it. Pain and grit is often a badge of honor for cyclists, so it may be ironic that incorporating low-intensity cardio holds a lot of promise in boosting performance.
The list of advocates for low-intensity training for endurance sports includes many endurance coaches like Phil Maffetone, Alan Couzens, Stephen Seiler and Joe Friel. If you look up common mistakes for cyclists or research polarized training, then you’ll learn that training easy to go fast is a well-accepted practice.
Doing these disciplined, easy rides takes focus because group rides, races and hills conspire to push you each and every time you hop on your bike. Cyclists tend to think about training solely from a practical or ‘functional’ perspective by understandably concluding races and group rides are hard, so training should be hard, too. This aggressive approach discounts the psychological and physiological influences on performance. If you try to train hard every day, your body and mind are going to show signs of poor recovery involving issues around poor sleep, mood, energy, soreness and motivation — which all increase your risk for injury and illness.
You can describe intensity in a variety of ways: heart rate, power and feeling are the most common for cyclists. In most training systems, low-intensity zones are set up to keep you under the ‘aerobic threshold,’ where low-intensity becomes ‘moderate’ intensity. Note: This is not anaerobic, which is where moderate-intensity becomes high-intensity.
Breathing is a great way to note both thresholds. If you train in the low-intensity range you can generally talk in full sentences. As training becomes moderate your breath deepens and you find yourself having to pause more during the conversation. As you enter high intensities, your breathing restricts you to only a few words at a time. Your goal is to be able to talk in long sentences, so get a chatty training partner for your long rides.
If you’re measuring by heart rate, aim for 75% of your maximum heart rate to define the limit of high intensity by heart rate. Friel suggests starting around 30 beats under your functional threshold power heart rate (~30-minute peak heart rate).
The important thing with this idea of going slow to get fast is you will need to start pushing yourself with high-intensity days and/or by increasing volume. In a polarized style of training you find the 10–20% of your rides that are intense push you to go much faster than the moderate efforts you might see in a group ride or longer event. It is this 10–20% of training most cyclists miss by trying to work too hard every day to make up for their limited training time.
When you start cycling or come back after extended time off, your main challenge is to get going and keep most of your training at a comfortable, or at least enjoyable, level that doesn’t leave you so sore or tired that you can’t come back to train again soon. Frequency and consistency are the main concern for new riders, or riders starting off gaining fitness
If you consider yourself intermediate or advanced and you train consistently, then it’s important to consider the amount of low-intensity riding you do. If your fitness level is plateauing, you just finished a race block or you’re struggling with motivation and consistency, then incorporate some lower intensity riding to boost your performance.