Training with a power meter is a hot topic at the moment; gadget guys relish the opportunity to buy more bike bling and café racers have another topic to thrash out over coffee, but why should the club racer or serious casual rider part with their hard earned cash for another gizmo?
I’ve stopped improving! If this doesn’t apply to you, it might make you think of someone you know: a person takes to cycling and starts riding more and more. The more they ride, the fitter they get. The fitter they get, the more they want to ride. Racing ensues. Learning strategy takes some time, but this rider progresses quickly from back of the pack in a low grade to be upgraded (perhaps several grades) and be much more competitive. And then…nothing. After one to three years of rapid progress, their performance stops improving.
A fundamental truth of performance in sport is that your body adapts to the load applied and no more. When you start an aerobic sport (cycling, running, rowing etc) the body has to make lots of adaptations to this unfamiliar activity. Just the very act of participating causes dramatic improvements. Coinciding with this are technique improvements – pedalling gets smoother, gear selection becomes more intuitive, line selection through corners is refined and so on.
After a while, however, your body is on top of it all and it can stop adapting. Even riding quite a bit more is really no problem for the plateaued cyclist such that a 50% increase in riding time (and don’t we all wish we had the free time for that!) might result in a 5% increase in racing speed. This is the point at which a proper training program will continue the process of progress.
Advances in speed and fitness can be found again through a properly designed training program. Generally a program designed for an individual will challenge their weak points while not completely neglecting their strengths. Jumping into a structured training program might give the rider another couple of seasons of strong gains in performance before once again they hit a plateau.
The reasoning behind this slow (or no) progress is that each exercise might be exactly the correct drill to address that cyclist’s needs, but unless it is performed at the appropriate intensity it cannot provide just the right amount of load for the body to adapt to. The fitter a cyclist is, the more specific should be their training loads.
Before the advent of modern miniaturised electronics, riders rode to RPE (rate of perceived effort). RPE is fairly effective, but is open to a wide range of interpretation even by one rider over the course of a single week. Mood, quality of sleep, recent diet, caffeine and alcohol intake – there is a long list of things that will alter RPE from ride to ride.
Once portable heart rate monitors came on the scene they provided a much more objective measure of effort level for the athlete. Yet as good as they are, and they were a huge step forwards from the nothing that preceded them, they are still subject to variation from external influences. If, like many cyclists, you have an espresso before your ride, it will boost your heart rate. The day you don’t bother to have one all your heart rate zones will be too high for the effort level.
It is power that makes our bikes go forwards. The laws of physics dictate the relationship between power produced and velocity realised. So, while heart rate and RPE are proxy representations of power – a relationship that we know skews around – power is power; Watts are Watts. If you know that your functional threshold power (called FTP, it is the power level you can produce for one hour) is 500W, then any time you are doing a drill at 500W you are at your FTP.
Power is an even better monitor for anaerobic efforts than aerobic ones. A sprinter might sprint for ten seconds. In ten seconds the heart barely has a chance to respond, and the RPE is not at all meaningful in such a short effort.
If you use your power meter in racing then you will learn exactly what the demands of your racing are on you. Say you are not the best climber in your grade and on the long climbs you can stay with the pack for half of the hill. Later your power file might reveal that you sat on 300W for the first half of the hill, and then your power dropped to 260W and the bunch rode away from you. You know that to keep with the bunch you need to produce 300W for the entire climb. It gives you something very specific to work on and that makes achievement that much easier.
If the time trial is your thing you can be very analytical in achieving your race results. You predict you will need to ride 52 minutes over 40km to win the upcoming event. That is a hair over 46km per hour. On your TT bike at 46kmh, you are generating 275W. One way to win the race would be to train such that you can hold 275W for just under one hour (ie, raise your FTP to 275W). Another would be to improve your riding position and/or equipment selection to lower your power requirements at 46kmh to under your current FTP. If that current FTP is 260W and some new race wheels lower your power at 46kmh to 260W then you are now ready to win that title.
As a coach, all these things are fantastic tools to work with. There are, however, two more subtle uses for power that are actually my favourite uses of a meter. These are; to pull apart a training ride and to quantify fatigue. I coach cyclists who live all over Australia (and even overseas), thus I cannot ride with them. Those riders who have a power meter and send me their power files are essentially carrying me along for their training rides where I can see every little thing that they do, every time that they do it. This insight is good even if that rider was directly in front of me because I cannot see ‘power’.
Intervals are a classic training exercise. Regardless of duration (10 seconds or 10 minutes) an interval itself should be done at a constant effort. Most people start out going too hard, have to back off, pick it up again and so on (in a longer interval this can occur several times). Eventually they will learn to start off a little more gently and essentially they do the entire interval at a single cadence. But this is still not quite right as cadence ≠ power. Heart rate typically settles in the second minute during a steady effort so it is useless for sub-90 second intervals. Power can, and should, be constant across the interval. With a power file I can determine if exercises were done correctly, if they were done at the correct intensity and if they were abandoned at the right time (too many cyclists suffer from the just one more attitude).
The difference between hard training and overtraining is a very fine line. A really motivated rider can sit on that line for months before mysteriously plunging into the quagmire of overtraining, unless they can quantify their training load. With heart rate monitoring, a special HR monitor, specific software and a very dedicated athlete it is possible to monitor fatigue levels fairly accurately.
Many power meters will now report your intensity factor (IF) at the end of each ride (no computer hook-up required). IF is a way of quantifying how intense a ride was and by itself is a pretty good way of characterising how hard a cycle of training was (compare across cycles). The software that I track my riders with uses power data to calculate a score for each ride, which can be added together to quantify a week, month or year. This is often referred to as training impulse, or TRIMP. When graphed, it makes excesses of training fairly obvious.
Power measuring provides insight into how you should be training; it lets you see if you are training right, it makes that training as goal-specific as possible and it helps keep an eye on training loads (too high or too low). Using power really is a no-brainer for anyone who takes their cycling seriously. Even an expensive meter costs less than a set of race wheels and I would argue that the meter is the better investment.