When I was a wee lad, I played soccer in high school. My
coach at the time was a conditioning freak and used to make us run intervals. A
lot. We did Indian runs or suicides or half-mile intervals, etc. We ran as hard as we could until we thought we were going to puke. Between drills
my teammates and I cursed the coach and asked ourselves, “Why are we doing
these?” We never really got a satisfactory answer, so we just kept on doing
what we were told.
Later I became interested in cycling, and when I learned
about the training for this sport, to my horror I found that many coaches
recommended intervals in cycling, as well. Again I asked myself, “Why are we
doing these?”
Most coaches prescribe intervals, and many athletes perform
intervals, but it’s often not clear why. In particular, the athlete may not be
aware of the intended objective of the interval training and may just be “doing
what I’m told.” Is the goal of performing intervals simply to make the athlete
tougher and more resilient? Are they simply being done to mimic the
high-intensity repeated efforts of racing, or are there specific physiological
adaptations sought after by using intervals in training? Is there more to
performing intervals than just being able to go “as hard as you can” for two,
five, or ten minutes? Are some intervals better than others (i.e., is there a
reason to perform two-minute intervals over ten-minute intervals)?
This may seem like a lot of questions, but they should be
addressed before a coach or an athlete embarks on a period of interval
training. By addressing the ultimate objective of the interval training
approach, the athlete may be more likely to give everything required in the efforts.
Further, consideration of the intervals being used and how they relate to
racing objectives may help eliminate potentially irrelevant training
approaches.
Exercise physiology tells us there are three primary
principles of training: specificity, overload, and reversibility. Intervals can
be used to address the first principle by mimicking the demands of a particular
event. This may be the most common reason most athletes perform intervals. For
example, if an athlete is training for the pursuit on the track and it’s
anticipated that the event will require a five-minute all-out effort, in
preparation the athlete may perform five-min intervals. In this case, though,
the training is being used for a very tangible purpose. The athlete can clearly
see that he’ll need to go as hard as he can for five minutes, so therefore he
will train as hard as he can for five minutes.
The second principle, overload, can also be addressed
through the use of intervals. If an athlete needs to perform sustainable
efforts of ten minutes within the context of her event, she can perform efforts
in a progressive overload fashion that builds from five, six, seven, and up to ten
minutes or more in duration. Using intervals, progressive overload of duration
(or even power if using power meter) can be applied in a very specific manner.
Finally, the third principle can be addressed by not
performing intervals. To paraphrase one of my graduate professors, use it or
lose it, baby!
Another less tangible way to use intervals is to not necessarily
address specific effort durations of an upcoming event, but within the larger
context of the overall training program target specific physiological
adaptations that will result in improved performance at a later date. In this,
I mean that certain intervals can be used to specifically target adaptations
resulting in improved VO2max, whereas others may be more likely to elicit
adaptations to the lactate threshold. Moreover, certain intervals are effective
at raising one’s anaerobic capacity or neuromuscular fitness. As we all should
be aware, the long-term goals of most competitive cyclists should be to raise
their VO2max, LT power, and, for some disciplines, anaerobic capacity and
neuromuscular fitness. Once these objectives have been attained, the specific
needs of a given event may be targeted.
It is not simply the duration of a given interval that
results in such adaptations, but also the manner in which the interval is
performed at a given intensity. In other words, an interval may not need to be
performed “as hard as you can” to target the desired adaptation. It may be
better to perform at a given percentage of VO2max for a given duration (neither
of which may be maximal), which induces an overload that’s not unduly
stressful. Also, depending on how an interval is performed for a given duration—say,
three minutes—the adaptation may be more anaerobic or aerobic, and vice versa; not
all three-minute intervals are created equal.
Therefore, knowledge of the physiological responses of
various interval approaches will provide coaches and athletes with information
to most effectively use intervals to target not only specific needs of a given
event, but also the physiological adaptations that will ultimately result in
improvement as a cyclist. Athletes should not be asking themselves, “Why am I
doing these?” but rather stating emphatically, “I am using these intervals to
improve my _________.”
