|
When we think of cyclists and runners, we often think of endurance—20,000 miles a year
for pro riders, 100-mile weeks for top marathoners. But many athletes perform at elite levels
with far fewer miles. Take British cyclist Ian Hallam, for instance. A winner of 25 British
national championships, he trained very intensely only about 30 minutes a day because of
his studies. Retired from racing for ten years, he returned in his 40’s to win several
World Masters championships—on similar abbreviated training. Roger Bannister, the first
man to run a mile in less than four minutes, also did short, but very intense workouts.
Intensity Matters
In fact, a number of studies have shown that training intensity is a much better producer
of fitness than training volume. We tend to equate distance with fitness, but that’s
not the case. Because of the training principle of specificity (your body adapts to what
you ask it to do), traversing long distances at a slow pace accustoms your body to going
slowly. Of course, long rides or runs are great for burning fat, teaching your joints to
tolerate lengthy efforts, and giving you some time to think.
Still, if you want to improve your racing or boost your general fitness, there’s no
substitute for old-fashioned, hard speedwork. And that’s a plus for time-challenged
athletes because fast, intense workouts take much less time than leisurely, long ones.
In next week’s column we’ll explore how notching up the intensity of your training can work
for you. But first you need to know how to measure that intensity:
Heart Rate: Modern heart rate monitors are accurate and fairly inexpensive. They’re
a boon to coaches because they provide a window into athletes’ bodies, revealing how hard
their cardiovascular systems are working. But as indicators of intensity, they aren’t
perfect. Heart rate can vary widely for a given amount of power output due to factors like
hydration status and muscle fatigue.
To give only one example, if we put a subject on a treadmill for an hour at a steady,
moderate effort, his heart rate tends to rise during the run even though his pace stays
the same. This phenomenon, called “cardiac drift,” is caused by overheating and
dehydration. As a measure of intensity, heart rate is useful but not foolproof.
|
Gear Watch |
The Tune PowerTap Prologue
The Prologue measures crucial parameters including wattage and speed (simultaneously),
along with your choice of time, distance, heart rate, cadence and energy
expenditure. It includes a rear hub and cyclocomputer. The PowerTap Link, so you
can download information into a PC, costs an additional $200.
It’s easy to toggle back and forth between average and max speed and wattage.
Crucial to the design is an interval function. By holding down the right button
for two seconds, the unit will record up to nine intervals so you can play back
max and average power, speed, cadence and heart rate for each effort. Another great
feature—the PowerTap converts any indoor trainer into an accurate cycling
ergometer. Simply mount your PowerTap-equipped bike on the trainer and carry out
precise training indoors. http://www.power-tap.com
Performance Axiom HR400 Heart Monitor ($150)
Here’s a multi-feature monitor that not only displays your current heart rate
in beats-per-minute but as a percentage of your maximum heart rate as well, making
it easy to exercise in the correct heart rate zones. A memory function allows you
to recall the amount of time spent in your target zone as well as above and below
it. Other features include stopwatch, time of day, date, average heart rate, alarm,
and out-of-zone alarm. The display is back-lit for use in low light conditions.
http://www.performancebike.com |
|
Speed: There’s a relatively good correlation between speed and effort when running
on a track, but not when running on hilly roads or rough trails. This is because climbing,
descending, and sketchy footing require varying amounts of effort to maintain the same pace.
On a bike, the correlation is quite low due to rolling resistance, climbing and wind. For
instance, it takes virtually no effort to go 20 miles per hour with a raging tailwind, but
it’s a huge energy drain to ride back into the gale at that pace, so it’s impossible to
judge your intensity by the speed you’re traveling.
Wattage: The best way to determine how much power you’re putting out is to measure
it directly. That’s problematic for runners but can easily be done on a bike simply by
mounting strain gauges in the crankarms or rear hub. Pressure applied to the pedals is
measured in watts. The exercise bike at your favorite health club probably has a wattage
readout but due to the necessity of light-weight and weather sealing, good systems for
outdoor use have been long in coming. One system is the German-made SRM, but it’s pricey
($2,500 to $4,000) and hard to get. A new product is the American-made
PowerTap. For little more than the cost of a top-end heart rate
monitor, it brings power measuring to the serious cyclist. Unfortunately it can’t be
used for running.
Rating of Perceived Exertion (RPE): The Borg Scale of Perceived Exertion, with a
scale of 1 to 20 has been used for years. The idea was that you could simply add a zero to
the number and it would correlate with heart rate. So an RPE of 18 (“very hard”)
equaled a heart rate of 180. Unfortunately, this system didn’t work well for older
athletes whose max heart rates had fallen. Also, 20 gradations were too many for simple use.
As a result, many RPE systems now use a scale of 1 to 10.
Here’s how to gauge your intensity level using RPE. One is no activity at all (you’re
slouched on the couch) while ten is flat-out, as hard as you can go. Five is moderate
activity like a fast walk or easy spinning on the bike. Six is experienced as light effort.
At seven, you begin to breathe steadily and rhythmically. At eight your breathing
intensifies but you’re not panting. When you begin gasping and are unable to carry on a
conversation, you’ve reached nine.
With a little practice, you’ll be able to stay in a given RPE zone as you ride or run. The
key transitions are from seven to eight (when you become aware of your breathing and
conversation becomes difficult) and eight to nine, tipped off when your breathing goes
from steady and measured to panting and gasping and all conversation ceases. This is
almost always accompanied by burning in the quads, especially on the bike or running
uphill.
An RPE of approximately eight corresponds to your lactate threshold, when your body is
producing more lactate (a by-product of energy production) than it can use. Practice
treading on the edge of this threshold, increasing your pace until you start to lose
control of your breathing, then backing off slightly until your breathing settles down.
Playing on this “red line” of performance is the best way to learn about
RPE—and get an intense workout.
|
