If you don't like numbers and charts, now's your chance to hit the back button. Click charts to enlarge.
Friday, April 27, 2007
If you don't like numbers and charts, now's your chance to hit the back button. Click charts to enlarge.
Thursday, April 19, 2007
Someone recently asked my opinion about the importance of power-to-weight ratio. I've been thinking about that some lately and thought I'd throw in my two cents, which includes no great insight, just my rehash of the subject.
The power-to-weight ratio is most important in two situations: accelerating and climbing. To maintain a constant speed in a flat time trial, it makes little difference what you weigh, just how much air and rolling resistance you have and how much power you can maintain (losing weight might affect your frontal area a little, but not much).
The climbing aspect is obvious: The less energy you use to fight gravity the more you can put into getting to the finish line. As an example (put in your own numbers at this web site: http://www.kreuzotter.de/english/espeed.htm) let’s take the Georgia Cup Gainesville road race course (estimated numbers here). We did six laps around a course that had an average 9% climb that was about 0.7 mile long. I averaged about 285 watts for that climb over 6 laps and I weigh 148 lbs. It should have taken me 5 minutes 3 seconds to do the climb on each lap. If I gained 10 lbs and maintained the same power, I would finish the climb in 5 minutes 19 seconds, 16 seconds slower. It’s obvious that 16 seconds is more that enough time to get me dropped from the front group in a single lap. Five seconds might be enough to get dropped if the group accelerated at the top and I had nothing left. So in climbing, weight is very important. And the lighter you are, the more important it is to pay attention to bike weight becase it's a bigger percentage of your total climbing weight. If I weighed 200 lbs, a 2-lb reduction in bike weight would only save me a couple of seconds on that climb, but at 148 lbs, shaving 2 lbs off my bike weight would save me almost 4 seconds. So I get much more benefit from being a weight weenie than a heavier guy would.
The acceleration benefit of being lighter is less obvious except in criteriums. I'm a poor crit racer because I can’t accelerate. But my acceleration problems aren’t primarily due to weight, they are due to low neuromuscular (5 sec) power. I don’t think I could never lose enough weight to compensate for my limiters there, but I should probably race more crits to improve my acceleration ability.
But there is another area where acceleration is very important and I think most people don't consider it. Over the course of a race or a hard group ride, there are hundreds of short accelerations required to stay with a fast peloton or paceline. Those accelerations aren’t always intense, but a lighter rider wastes much less energy in the short accelerations required when riding in a group. Your legs will pay the price quickly if doing a hundred mini-intervals when the other guys in your group are riding with more constant effort or less taxing acceleration effort. So being able to ride smoothly is very important. When I pop in a pace line, it often happens all of a sudden because I get fatigued, I ride less smoothly, which causes me to need more accelerations to keep up, which speeds my fatigue. It can also annoy the other riders in the group. In a fast pace line the whole accelerate-fatigue thing can snowball very quickly. I still have lots of work to do there. One way to handle these types of short accelerations more easily is by riding at a higher cadence, which has helped me recently.
I was also asked my opinion about the role of genetics in the performance of pro and elite riders. I’m sure that their results are not just due to good genetics. Genetics plays a big role, but there are a lot of good training years in those guy’s and gal's backgrounds. I subscribe to this theory that I read once -- can't remember where:
If you could take 10 athletes of varying genetic ability and put an identical brain in each of them, they’d all be riding at about the same level in five years. If you take 10 athletes having the same genetic potential and put 10 different brains in them, you’ll have a very wide array of talents in five years. Genetics plays a big role -- I used to think it was most important variable, but I don’t think so anymore. It's important but not crucial.
The problem for us mortals with normal genetics is that there will always be Lances and Floyds out there that get the genetics and the brain. Nobody’s ever going to regularly beat them. And getting good quickly is much easier for those with genetic talent.
Saturday, April 14, 2007
As Andrew Coggan states in his introduction to power profiling, It's human nature to want to know how you compare to others in your sport. He developed a chart that relates racing category with power-to-weight ratio for 5-second, 1-minute, 5-minute, and FTP (1 hour) intervals. It's interesting to see where my numbers fall on the chart. I don't have accurate numbers for the 1-minute duration because I haven't tested for that time interval, but I will soon. I was pleased to see that my FTP and 5-minute power to weight ratios are good; however, it's clear that I need a lot of work on my sprinting (5 sec and 1 min).
The chart depicts in red my power-to-weight ratios. The upward slope to the right indicates a typical time trialist profile. (Based on the other numbers, I'm guessing my 1-minute number will be in the 7.2 or 7.3 watts/kg range.) A good all around racer would have a flatter profile. A sprinter's profile would slope downward from left to right. Some of it is dictated by genetics (fast twitch vs. slow twitch muscle fiber percentages). But I think I could flatten my curve quite a bit with proper training.
Click the chart to see it better.
First, there's a lot more to successful racing than power output. Second, there's a lot more to measuring power output than just functional threshold power (FTP), or 1-hour average power. The ability to generate a high power in sprints and breaks is crucial for successful racing. Nevertheless, I've found that FTP is a good benchmark to measure my current fitness and see how my training is progressing, and I plan to run 1-hour FTP tests in December, April, and August.
Last August, my FTP was 220 watts. My December test improved the number to 238 watts. But today's April test showed that my FTP is now 268 watts, a 13% improvement over the past 4 months, or 7.5 watts per month.
I knew that my fitness had improved because my hill repeat interval times have plummeted of late, and I've been getting IF numbers greater than 1.00 on hard training rides, which should not happen except maybe for very short intense interval sessions. But I didn't expect my FTP to be that high. It's nice to know that hard training works sometimes.
In calculating my FTP, I looked at three numbers. First, my unadjusted average power for 60 minutes was 263 watts. Based on my experience and research, I multiply the raw average by 1.02 to 'convert' training to racing power and account for the racing motivation factor. 263 x 1.02 = 268 watts. The second way I estimate FTP is by looking at unadjusted normalized power, which was 267 watts. Lastly, I take 95% of my maximum average power for a 20-minute time trial. My highest recent 20-minute average is 283 watts. 283 x 0.95= 269 watts. The three methods only differ by 3 watts, which is amazing considering my Ergomo power meter's advertised accuracy is only about 2-3%, I think, which would be 5-10 watts.
Friday, April 06, 2007
In the past month I have noticed a significant change in my average cadence for hard group rides and races. Until recently, my typical cadence in a race was 85 to 90 rpm. For a TT, it would hover around 88-92 rpm.
Last weekend I averaged 99rpm for a 1-hour circuit race, and on Tuesday I averaged 96 rpm for a 1.5-hour hard group ride. I think the increase in cadence is a good change, but I want to be careful not to lose the ability to push a slightly larger gear if I want to (although force is one of my limiters).
I don't know if it's related to the cadence increase, but the hard 90-minute group ride on Tuesday resulted in an intensity factor (IF) of 1.04, which indicates that my functional threshold power (FTP) might have increased. For a 30- or 45-minute hard effort I would consider the IF over 1.00 to be an outlier introduced by the normalized power algorithm. But IF=1.04 for a 90-minute ride probably means my FTP has increased by at least 2-4%, which would put it around 250 watts (3.8 watts/kg).
I had already planned three 1-hour 'gold standard' FTP tests per year in December, April, and August, so I guess I'll run a test next week and find out for sure.
Tuesday, April 03, 2007
Since I've paid attention to normalized power (equivalent constant power output), I've been a little skeptical that it is a really accurate way to equate a very inconsistent power output (out of the saddle accelerations followed by back of the pack coasting then a 10-minute paceline chase) to a constant power output during that same period.
But the last two times I've been dropped (on Pate Road a couple of weeks ago on a Tuesday Macon ride, then Saturday on the dirt road in the Perry RR), I had been riding for more than an hour at an intensity factor (IF)of about 0.97-0.98. That means both efforts were equivalent to 97 or 98% of my functional threshold power (FTP) for over an hour. FTP is the maximum average wattage one can hold for a one hour flat TT.
That tells me that I have calculated my FTP accurately (about 245 watts) and that the normalized power routine, which uses a long algorithem with powers of 4 in it, does a good job of measuring riding intensity.
I'd like to keep improving so that I rarely get dropped, but at least if I do pop off the back I can look at my IF to see if I gave it 100% or if I just gave up.
The TT ride was uneventful for me, but the scoring was much more interesting. I had a decent ride, but screwed up resetting my bike computer, so I wasn’t sure of my time. When results were posted, it showed me 1 minute faster than Keith and 2 minutes faster than Todd. I was sort of shocked, but pleased nevertheless – I was in 7th for cat4 GC (or so I thought).
Several people punched off the front in the circuit race. Andrew Elisan-Visperas from the Bike Store tried his third attack on about the 3rd lap so I jumped on his wheel. He (we) didn't get far before he was about to drop me and the pack caught us anyway. I finished the circuit race in the main pack in 21st place out of about 40 starters and picked up a spot to what I thought at the time was 6th in GC.
When I got home and ran the numbers on my TT speed, I realized that 21:40 meant I’d ridden at 26.3 mph and that somebody had made a mistake with my time (you don't go from riding in the 23 mphs directly to riding in the 26 mphs without pharmaceutical assistance). I told my teammates about it the next morning and reported it to the scorers. They said they'd check it out but that the chips made timing errors improbable. Maybe improbable, but not impossible it seems.
As it turned out, the timing problems made no difference because I was shelled on the dirt road part of the 2nd lap of the RR. I was dropped along with 5 or 10 other riders on the 1st lap, but with a very hard 10-minute effort, we were able to chase back on and reach the main field at about the interstate crossing. But the chase took everything I had, so after the second dirt road section I was stranded in the back with about 10 riders - probably the same group as the 1st lap. We tried to chase back on again, but could not. At the feed zone my chase partners decided to call it a day, but I wanted to finish and get in some good training miles, so I rode the final 3 laps solo, which sucked. Thanks to Jake for the feed. But at least at the end of my 5th lap I got to see Christian breaking away for his RR win. Congratulations Mr. Parrett.
A few other items from Perry:
Todd won 3rd in cat5 GC.
Trey won 3rd in the RR with a good finishing sprint in a pack of 6 or 8.
Keith had the best MAX finish in the TT.
Christian won the cat 3 TT.
Andrew (Bike Store) won the cat 4 TT and GC.