Q: Yesterday I scheduled an interval workout having four 5-minute efforts. But during the warmup and on the first interval I felt tired and that ruined my motivation. So I went home. Was that the right thing to do, or should I have gutted it out and completed the workout? -- Barry A.
Coach Fred Matheny Replies: It depends on why you were so blah. If you have felt overtrained and lacking motivation for some time, heading for the couch was definitely the right thing to do. Stay there until you feel good again. Then continue to rest a couple more days just to be sure.
Chronic fatigue will reverse your progress -- and the fun of riding a bike -- faster than almost anything.
But if during the first interval you were merely having trouble getting all systems fired up, it's best to do at least the second hard effort. Sometimes you feel bad on the first interval, but once your body catches up with the intensity you're demanding, you perk up.
If you do feel better after the second interval, continue with the planned workout. If not, pack it in. By having done 2 intervals, you'll already have gotten much of the benefit from the session.
Why do I say that? We know from weight-training studies that the first set or 2 provides the stimulus for most of the improvement gained during multi-set workouts.
So if you do 5 sets of bench presses, for instance, much of the benefit occurs during the first set. The second set stimulates a significant amount of the remaining improvement possible from the session. Each of the final 3 sets contributes a progressively smaller amount.
It's a pretty safe bet that something similar takes place while doing interval workouts on a bike. The first interval is the biggie. The second is well worth doing, but remaining intervals are subject to the law of diminishing returns.
Of course, cycling is an endurance sport and rewards those who can repeat hard efforts many times, whether they be sprints, hill jams or short time trial-like efforts. So there is more benefit in multiple sets for riders than for weight trainers.
If you feel fine, do all of the repeats in your scheduled workout. But if you feel puny, managing just 2 repeats garners a large percentage of the possible benefits without causing a lot more fatigue.
Source: RBR