Coach's Column with Drew Edsall: Training with Power vs. Heart Rate What's Better?
Question: Is it truly better to train by 'power' vs. heart rate
especially with a focus on stage racing and endurance races? What are the
benefits and what are the cons if any to training based on power?
Answer: Training with power has numerous benefits that can get you
faster on the bike for both long distance(4+ hour races) and shorter distance
races(<4 hour). This subject can turn into a book so I am going to keep this
article focused on these main points:
-Pros of training and racing with power over
-Pros of training and racing with a Power Meter
Comparison of Using a Power Meter vs Using a
Heart Rate Monitor:
With a great training program, you can improve
using either power or heart rate. Both methods have scientific evidence backing
them. You can get faster with both! But, heart rate has some distinct downsides
you should be aware of. Those include the following:
-Slight fluctuations in HR on a day to day
basis: temperature, fatigue, dehydration, stimulants such as caffeine, lack of
sleep, and time of day you train are a few examples of what can affect your HR.
One bpm isn’t always 1 bpm. Whereas for power, 1 watt is always 1 watt!
-Cardiac Drift: as you become more fatigued,
your HR continues to get higher throughout a workout due to multiple fatiguing
factors such as dehydration and muscular fatigue. Meaning 160 bpm at the start
of workout might yield 200 watts, but 160 bpm later in the workout might yield
190 watts. Once again, power doesn’t have this issue
-Response rate: HR takes about 90-120 seconds to
fully respond to a given effort. Power is instant. This comes into significant
play on the mountain bike for both workouts and race day "spiky” efforts.
Here’s a great example (See Fig 1.1 Above).
Power is in yellow here: notice how up and down
it is or "spiky”. HR is steady, however, as seen in Red at the top: notice how
steady it is even though the power is constantly up and down. Using Power for
post-race evaluation and also for workouts gives you "instant” look at the demands
of the course and your efforts. You can execute workouts better and analyze
Using a power meter can help in multiple ways.
Here are the biggest advantages to using a power meter in training and racing:
-Evaluation: power is like lifting weights. It
gives you a distinct workload, or total amount of work done. If you put out 200
watts for 20 minutes now, and then put out 210 watts for 20 minutes one month
later, then you have improved. You know when you are getting better and you can
use that information to make an awesome training program! Below is Fig 1.2, or a quick look at one of
the many analysis tools I can use to make sure my athletes on power are
improving throughout the year. This particular athlete is improving; we know
it, he knows it, that feels great and it
builds confidence which can really help athletes succeed!
(See figure 1.2 above) This graph is looking at a particular
athlete I coach. More specifically his improvements over the past few months in
peak 1 and 2 minute power. This is a weakness of his that we have been
improving to better meet the demands of his racing down in Florida mountain
-Power is instant whereas HR takes about 90-120
seconds to respond. Best way to see this is to glance at the graph above (Fig
1.1). Power gives the rider and coach instant access to the particular demands
of a course. This can really help in creating future workouts, looking at what
happened during a race or particular workout, and also looking at how the rider
did in a race (i.e. new personal records). In addition to this, the instant
response power has allows for better execution of workouts. Perfect example is
in Fig 1.3 below:
(See figure 1.3 above) This is an example of an athlete
executing 5 x 2 minute intervals. Notice the slow rise in HR(Red) and the
instant power response(Yellow). Power allows you to see instant power to the
pedals, and therefore improve workout execution and post workout analysis.
-Racing: power can do two very good things for
you come race day; it can help you pace yourself especially for longer 4+ hour
races, and it can provide invaluable post-race data. I find a lot of riders
like to go out way too fast for 4+ hour races. Sure, everyone can hang on for
20 minutes. When racing I actually anticipate this and will push a hard pace
early on knowing my competition is literally destroying their body for the
remainder of the race. Having a power meter and knowing your limits can help
keep you accountable for your efforts. A power meter can help hold your back
early on in a longer race so you can perform better and finish stronger.
Second part of this is race data analysis. This
is really where power can help, but, beware, this is can become very
cumbersome. This data provides me and my clients with data that is invaluable.
Race files can provide the following data:
-Improvements in fitness: see changes in power
maxes such as 1, 5, 20, 60 minute maximal power efforts
-Specific demands of different courses (see Fig
-Help establish Strengths and Weaknesses of
-Evaluate your tactics and how they played out
in the race: did you go out too fast, did you fade as the race went on, did you
burn too many "matches”? How can we use this to improve your results next time?
Ultimately power is a great way to train and an
even more so now. The market has gotten more competitive, prices are dropping
and the products continue to improve. Products such as Stages Power meters are easy to use on the mountain
bike, only way 20 grams, and cost below $1000.00. The market is available to
more and more riders especially mountain bikers.
Using a power meter can really help take your
training and racing to a new level. But make sure you know what you are getting
into. Be ready to take the time to look over the files and be ready to execute
workouts as planned. Do this and you will get faster and will start
accomplishing things you never thought were possible. If you need help with the
process, you might want to consider contacting a knowledgeable coach or ask
friends who use power for advice also.
Thanks for reading and best of luck fighting
the cold weather for all you winter climate people.
Drew Edsall is a Pro level coach
at Studio 92Fifty. He has been coaching mountain bike athletes for 8 years. In
addition to coaching, Drew is an accomplished Pro mountain bike racer
specializing in Marathon, Stage racing, 50 mile, and 100 mile mountain bike
races. He is currently racing for the Kenda/Felt Pro Mountain Bike Team. You
can find more info about him at www.coachdrewedsall.com or www.92fifty.com