Question: Would a power meter help me maintain steady energy expenditure throughout time trials and triathlons? Could I just watch the monitor, ride at a pre-determined wattage and thus be sure that I performed at optimum intensity? What about in road races? — Barry M.
Coach Fred Matheny Replies: Power meters are often touted as great pacing aids for time trials.
Let’s say you know from training the wattage level you can sustain for the race distance. During the event, you’d simply set the monitor to display average wattage and stay within 10 watts of that figure from start to finish.
In theory, this means you’ll always be at your maximum sustainable intensity for the distance. You won’t start too hard (a common mistake) and then slow significantly near the end. And you won’t go too hard on climbs, thus risking blowing up and being unable to maintain speed on the downhills and flats.
That said, I don’t find power meters to be very useful in this way.
TTs aren’t really steady-state efforts unless the course is dead flat. Even then, there will be a turnaround and perhaps headwind sections. When the going gets tough, you have to venture above your lactate threshold for short periods, then back off slightly to recover.
So to maintain a given average wattage, you need to know how much above the average you can go on climbs or into headwinds but still recover sufficiently when conditions allow. This is why I think power meters are less effective in time trials than perceived exertion.
As for road races, forget about it. It’s fine to race with a power meter and record the data for later analysis. And it’s a great training tool to help you learn how deeply you can dig on short climbs and still have enough left to recover. But during races, you should be racing, not looking at flashing numbers on your handlebar.
Bike fitness coaching says
Hi Fred, let’s chat on this topic since as a certified power based trainer through hunter allen, I have different thoughts on power meters on TT/Tri bikes.
larry english says
power meter is no better than heart rate monitor
you still have to know thresholds and decide what to do about them
and way less expensive, can use on any bike. no installing.
Kerry Irons says
When I was doing weekly 10 mile TTs throughout the season year after year, my wife got me a heart rate monitor for Christmas. I used it religiously in my time trialing and found out that “this is what my heart rate is when I feel like this.” In other words, perceived exertion was equivalent to the HRM. I’ve not used a power meter but I think some will use the technology as a substitute for paying attention to the feedback they are getting from their body.
Coach David Ertl says
I believe the main value of power meters is at the beginning – to keep us from starting off too fast. I find it difficult to keep my power within my target at the beginning even using a power meter – it just feels too easy. But by the end, I’m glad I did. The other place it can help is on downhills or tailwinds. We tend to take it too easy and not ride at our threshold. Power meters can push us harder at these times. But once in a steady state effort, perceived exertion and heart rate monitors agree quite well with a power meter.
I find a power meter worthless during a TT. You waste a ton of mental focus on whether you’re going to hard or easy or worse, wasting physical energy trying to maintain an exact wattage. Although I do like it to analyze my performance after the race. My best races are typically when I don’t look at anything, but just maximize my effort the entire race. I sometimes like to see average speed and heart rate, if I need a little feedback.
I bet more experienced riders feel this way and are faster but less experienced riders can benefit from the power meter.
donald ostertag says
I would love to have one as a training aid to see how much power I am putting out and to find out how much I am improving (or not) over time.
Charlie J says
I’m an experienced Master’s Time Trialist. I’ve found that training and racing with a power meter has helped me significantly improve my technique and speed. Power meters are affordable enough these days. I strongly recommend using one if you want to improve as a time trialist.