RoadBikeReview.com's Forum Archives - General


Archive Home >> General(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 )


Why watt's and not hr?(8 posts)

Why watt's and not hr?PODIUMBOUNDdotCA
Oct 9, 2002 11:58 AM
Out of curiousity why are watt's prefered over hr? Isn't wattage just as inaccurate depending on technique, varying max wattage, etc.

I'm not an expert on how wattage for a workout is predetermined so if someone would be willing to teach me that'd be great.

Thanks!
Nick
PodiumBound.ca
re: Why watt's and not hr?brider
Oct 9, 2002 12:17 PM
The wattage you generate is going to be less dependent on outside conditions than speed. When predetermining what wattage you'll use in a particular drill, you have to first know your baseline. HR can vary with your particular arrousal level, how fatigued you are, etc, while wattage is going to be much more constant.
two different measurementsDougSloan
Oct 9, 2002 12:41 PM
Think of them as tachometer and dynomometer. With people, though, the tach varies a lot according to fatigue, lag time, hydration, temperature, conditioning, effort, etc. The dyno will always indicate work actually being done, regardless of any other variables.

The two taken together can tell you something. If you make 500 watts at 175 bpm today, but made 500 watts at 190 bpm two months ago, you can conclude that you are in better shape now.

If you want to do short, consistent intervals, aim for 400 watts, for example, and hold it for 60 seconds, you can do so; if you tried to do short intervals by hr, it would be very irregular, and with the lag time you'd have to sprint hard to get the hr up at first, then back way off to hold it down later on, requiring a varied effort. If you tried to go by speed, then that would be affected by wind, temp, road, etc. Watts is always watts.

Doug
Doesn't this shatter the whole idea of zone training?PODIUMBOUNDdotCA
Oct 9, 2002 1:15 PM
Say an effort is at 400 watts just at anaerobic threshhold... and one day it is and you do the same workout a few days later and its way above AT. Doesn't this kill the idea of zone training?

Nick
PodiumBound.ca
no, just differentDougSloan
Oct 9, 2002 1:24 PM
Zone training takes into account your heartrate. You are training your cardio-vascular system. Typically, this is used on longer intervals, right?

For *short* intervals, the heart just does not respond fast enough so that hr is a legitimate indicator of what you are doing. In such cases, watts are probably the better indicator.

Even if doing zone training solely using hr as a reference, it might still be useful to know power output along the way. You can track progress or being over worked, tired, etc.

Doug
btwDougSloan
Oct 9, 2002 1:27 PM
By the way, a while back I questioned the usefulness of wattage information indicated by SRM's and the like. I'm reversing myself, after having used a Computrainer for a couple months. I think it's very useful to note actual power compared to heart rate while training. It's an easy reference to know if I'm really working hard or am I just tired, or what improvement I've experienced. No other measurement of output is as accurate or repeatable as wattage.

Doug
Talk to Chris CarmichaelKerry Irons
Oct 9, 2002 5:13 PM
Or any other up to date coach. For all the reasons mentioned, HR can be an unreliable predictor of what is going on. Your AT/LT does not change just because you are over trained, dehydrated, etc. If you train based on watts, you are getting the most scientific information about what your body is putting out, and that is what you work from. As noted in other posts, comparing your wattage and HR can be instructive about how your training is progressing and how you are doing on a given day. HR training was developed when wattage information was not available. You can do a good job with HR training, but you can do a better job with wattage training.
Talk to Chris CarmichaelLactate Junkie
Oct 11, 2002 10:54 AM
Power and heart rate should always be used together. If your heart rate is telling you that you are tired and overtrained, it is stupid not to listen to that information and go out and drive yourself to a specific wattage level. That the problem with watts, your power meter cannot give you any indication when you are tired and should rest!

Another problem with watts is psychological. There is a tendency for riders to become so fixated on the power that they forget everything else in an effort to hit the next level. Some coaches are have even taken to covering up the wattage readout on the units being used by their charges to avoid this problem.

The last issue with power is the lack of information. There hasn't been a lot of research done on training with power and a lot of the stuff out there simply substitutes watts for heart rate. This may or may not be the most effective use of the information. It is going to take more time and research and general use to be certain. Conversely, there is a wealth of information and data on training with heart rate, so it is going to be a while before it becomes really obsolete. That and the fact that you can buy a great hrm for $100 and a cheap power setup is about 7X that much right now.

It isn't a case of either—or. The issue is both, like having an extra bullet in your gun—if you can afford it and are going to make use of it.