In Part 1 of this series on interval training I tried to make the case that intensity, not volume, is the key to high performance. Most athletes measure their progress toward race goals by adding up their weekly hours/miles/kilometers/meters even though the relationship between volume and performance is weak. If your goal is to race fast the key is fast training. The reason most rely so heavily on volume as a marker of improvement is that it’s easy to measure and quantify. All that’s needed is an adding machine.
On the other hand, intensity is difficult to quantify. How do you easily express intensity in a single number? Try telling your buddies how last week’s training went without ever referring to volume. It’s difficult, isn’t it? It takes a lot more explaining than simply saying, “I trained 15 hours last week.”
Of course, performance is not all just intensity either. If you keep cutting your volume while continuing to train with high intensity, at some point performance will decline. Both volume and intensity contribute in some way to how well you race. But I’d point out that it’s not really volume that is the other critical component (besides intensity), but rather duration. If workout durations increase then volume obviously increases also. If you are training for a 10-hour event (Ironman triathlon, double century bike) then you simply must get some long workouts into your training. High-intensity intervals with very low volume simply isn’t going to hack it.
Here’s a key element in training: As the duration of a workout increases, the intensity of the workout decreases. So one simple way of looking at workout organization is to do both long, slow workouts and short, fast workouts. “Long,” “short,” “slow,” and “fast” are terms that are specific to the event you’re training for. These words have different meanings for a cyclist who is training for a 45-minute, bike criterium and a triathlete preparing for a 12-hour Ironman.
But when it comes to the combination of “short and fast,” intervals are the way to go. They allow you to maintain a racelike intensity as if you were in the race despite the fact that you aren’t tapered and rested. This allows you to train with race specificity—one of the key principles of training.
I first learned of training specificity back in the mid-1970s when I was doing my masters work at the University of Northern Colorado in Greeley. At the time I was coaching track and field at Berthoud High School. After learning of specificity in one of my classes it seemed that the best way to train my milers was to have them run a mile in practice every day at race pace. It took only one such session to see the error of my thinking. They simply couldn’t do a “race” several times a week. But when I broke the mile down into 400s (and other distances) they were then able to do more than a mile, in total, at race pace within a workout.
It’s the same for you. You simply can’t do the race every time you train. You would soon implode. But if you break it down into shorter segments (intervals) at some measure of racelike effort (pace, power, heart rate) then you can do the “race” in your training.
Nothing but intervals also has its downside. When I was in college I ran track. The coach knew only one type of training—unstructured intervals. Actually, they would probably be best called “low-structure” intervals. There was a little bit of structure. Every day after warming up he’d call us over to the bleachers where he was sitting with a can of Coke and a whistle. We knew what was next: 400-meter intervals. That was as far as the structure went. We didn’t know how many we were going to do, how fast they should be run, or how long the recoveries would be. We were just told to run them as fast as we could. The coach would decide how long the recoveries were to be and how many 400s we’d do. Eventually somebody would throw up. We soon learned that the sooner this happened the fewer intervals we’d do. So we came to call them “intervals ‘til you puke.” The workout was ineffective and I came to hate running because of it. It was years before I came back to serious training.
I still see athletes do “intervals ‘til you puke” even though we have learned a lot about interval training. In the coming installments I will get into the details of how to organize an interval session with concern for intensity, duration, recovery, and accumulated session interval time.