The Link Between Zone 2 Training, Fat Burning, and Performance
How do easy Zone 2 rides actually better your performance? Here’s a peek into the physiology of aerobic training and fat burning.
At face value, riding steadily at a relatively easy pace would not seem to help your racing. How does riding for hours on end in Zone 2 replicate shredding the field on the finishing climb in a road race or making the winning break in a criterium? While it may not seem like it, endurance rides are a requirement for successful training. One of the most important adaptations that you get from endurance rides is the ability to use fat more efficiently.
Why Fat Burning Matters in Cycling Races
Apart from explosive one-off events such as track racing, short time trials, and 5 ks, efficient fat burning is a major key that sets great racers apart from the rest of the pack. In professional cycling, there are lots of riders who can do a 5-minute or 20-minute power test on par with Grand Tour contenders; however, in real races, these riders are often pack-finishers and domestiques. Why? Racing tactics and skills play a large part, but another major key is the ability to burn fat.
At lower intensities, you burn mostly fat and some carbohydrates. The harder you ride, you begin burning an increasingly higher percentage of carbs and a decreasing percentage of fat. At around your lactate threshold and beyond, you burn almost entirely carbohydrates. If there are not enough carbs in your system (i.e., glycogen), you simply won’t be able to reach these intensities. You have surely felt this at the end of a long ride. It’s unlikely you would be able to do a 5-minute best after four hours of hard riding because there’s just not enough left in the legs.
Thus, it’s not just the riders with the highest FTP or VO2-max that end up winning a lot of races, but also those who can efficiently utilize fat as a fuel source and therefore better preserve their glycogen stores. Research has shown a correlation between the intensity at which the aerobic threshold occurs and performance in competitive cyclists. In other words, the riders who could burn fat the most efficiently perform better. You, too, can teach your body to burn fat more efficiently so that you can spare glycogen for when it matters most.
The Importance of Zone 2 Training
If you want to train your body’s fat-burning capabilities, you simply must train at the intensity where you burn the most fat! The commonly known “Zone 2” lies just below your aerobic threshold — an intensity at which you are burning large amounts of fat. Beyond this point, your body will begin to utilize more and more carbohydrates and then begin to decline in metabolic efficiency. Zone 2, therefore, is where you should spend a lot of your time training if you want to improve your fat-burning capability.
As a coach, one of the most common problems that I find when working with new athletes is that they are riding too hard. Completing a proper Zone 2 ride requires lots of discipline. Many riders don’t like going slow and feel that if they aren’t riding hard, they aren’t getting any benefit. They often ride hard up the hills and coast on the descents.
Maximize Fat Burning With Aerobic Training
The result is that almost all of their training is actually above their aerobic threshold. These types of riders are great at burning carbs, but not so good at using fat as a fuel source. Many of them have the raw numbers to be competitive in races, but they simply aren’t efficient enough to realize their full potential. They run out of juice before the end and cannot replicate the hard efforts when they matter the most.
If you find that you struggle to repeat hard efforts or feel as though you can’t reach peak numbers at the end of a race, it may be worth examining your training habits. How much of your training time is spent in Zone 1 and 2? Do you tend to go above these zones on endurance rides or in-between interval sets?
A proper Zone 2 ride should feel relatively easy and it should be very steady. Flatter routes that avoid steep climbs are ideal for these rides. You should try to eliminate coasting and surging. Any surges are defeating the purpose of the ride and every time you coast, you are also missing out on reps for your legs. By slowing down a bit, you will teach your body to burn fat more efficiently. You will also be able to recover faster from your rides and have more energy to properly execute intervals workouts.
“No pain, no gain” isn’t always true. Yes, you must be willing to suffer through intervals, but you must also have the discipline to train easy, too. Easy miles serve a very important purpose and are not a waste of time. For some riders, the best way to get faster is to first slow down.