Question about Power Training and Heart Rate

Pureshot78

I have been reading a lot about training with power but do not have a PM yet. Over the last year I trained with HR zones using Friel's schema. Here is some background info. I am 27 years old, 5'11", 197 lbs (weight has fluctuated between 205 down to 181 back to 197 over the last year). I live in wisconsin and have moved my training indoors. I have a CycleOps Fluid2 trainer and have been doing a Time Trial workout from CTS. I do this workout about 2 times a week with one or two recovery rides inbetween workouts.

Here's my equipment stats. I have a LeMond Tourlamet bike with Ultegra 9 speed components (12-25 cassette). my rear wheel is a Bontrager Select with Maxxis Detonator 25c tire.

During the workout I do three "power intervals", 5 minutes on, 5 minutes off. For these intervals I do 110 rpm in the 19 gear. My heart rate watch doesn't have average capability but during the three intervals my HR builds to 188, 191, 195. Is setting an rpm as a fixed goal equivalent to setting a wattage goal? I know that I don't know what the wattage is but it seems like this would function in the same way. Also does anyone have a guesstimate of what the wattage might be?

My roommate uses my bike to do the same workout because his bike doesn't have a rear wheel pickup or cadence sensor. We have the same goal for cadence and gear. His HR maxes were 174, 181, 183. We are wondering what might cause these differences. I was thinking it might be due to heart stroke volume because i don't there is a huge difference in our training level.

I'd appreciate your comments on training with rpm and gearing as a goal or any other random comments you have

peterpen

It's pretty useless to compare your HR with anybody else's. Your roommate's maxHR might be 183, and yours 210 - looking at those one might assume he was working harder. But HR is very variable, easily affected by many factors.

As for finding out what wattage your workout represents, CycleOps might know - my Minoura trainer came with a chart that claimed to show the power curve at different speeds. But this would be somewhat irrelevant unless you have determined what your power at LT/ VO2max/ or some similar figure is. There's no sense picking X watts as your goal unless you know what X watts means to you as an individual.

Spunout

The more accurate heartrate for the interval in question would be the higher of the three observations. You might want to add a short speed session to your weekly plan.

Agree, don't compare HR to anyone else's.

frenchyge

You can view the power (vs. speed) curve for that trainer here: http://cycle-ops.com/products/fluidsquared.htm# Click "Comparison Chart" on the right, and then the grey "View Power Curve" button on the chart. There will naturally be some variance between your actual power and that chart due to temperature changes, tire pressure, contact pressure, etc. but yes, you can use a constant speed (or rpm in a given gear) as a gross approximation for a fixed power interval. You may find that you need to add a couple rpms for each subsequent interval to account for the resistance unit heating up (higher temperature means lower resistance and lower power), but that's something you'd have to experiment with.

I think using speed or rpm for short, trainer intervals is a better approach than using HR, because it gives you a nice, consistent target and pacing for the entire duration of your interval. Good idea.

RapDaddyo

Assuming the CycleOps power/speed curve is consistent (not necessarily accurate), there is a way to test the pace you are using for your 5min intervals. If you compute from the curve the speed that corresponds with PI/0.90 (where PI is the power level corresponding with your interval speed), that number should be pretty close to your 5MP (your max power for a 5min duration). You should be able to sustain your 5MP for 5mins, but barely. The last minute should be quite difficult and it is unlikely you could sustain the power for 6mins. That will confirm that you are doing your 5min intervals at approximately the right power level (even if you can't be sure what the absolute number is). BTW, that approach can be used to validate interval power at any duration.