FTP Testing and Hammerhead Sharks

Accurate functional threshold power (FTP) testing can be a little tricky. It's rare that you'll get to measure the real number directly -- that can only happen when riding a 1-hour TT effort in competition on a bike with a power meter (my TT bike has none). But you need an accurate number because you use it to set up all of your interval training power ranges. Therefore, you have to use other methods to test for and calculate your FTP.
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Analysis paralysis warning: If you're not really, really interested in FTP, save yourself the pain, stop reading here, and just check out my birthday present from Betty Jean instead. I think I'll call him Clayton -- Jeff seems to enjoy hammering as much as anyone I know.










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Ok, back to the numbers. In converting other testing numbers into an accurate FTP value, you have to consider the racing vs. training factor and also, if using a trainer for testing, a factor for converting your max effort on a trainer to your potential effort on the road. And finally, it's hard to do 1 hour all-out tests. I do three a year. Between those tests, I keep track of FTP by doing 20-minute efforts and using factors as described below. So you have the 20m to 60m conversion factor too.

I ran a 20-minute test last night on the Computrainer to try and establish the wattage relationship between a 20-min computrainer (CT) test and a 20-min test on the road. I started out way, way, too hard, but leveled out eventually and ended up with average 20-min wattage of 268, which is exactly what my last hour-long road FTP test calculated as my FTP. It’s also exactly 95% of my peak 20-min wattage in the Edgar Soto TT a few weeks ago. Also, it’s interesting to note that the CT gave me the exact same average wattage as did my Ergomo, so they matched perfectly.

So there are a couple of things going on here. First, I’ve become very confident that the relationship between 20-minute average wattage and 60-min (FTP) wattage is 0.95. I have multiple tests showing that my maximum 20-minute power output in races is 95% of my calculated FTP. So I’m holding fast to that relationship. I’m also pretty confident in the training-to-racing 103% relationship (adrenaline/motivation in races allows you to generate about 3% higher wattage over 1hr than in training) is accurate. What I have now is a new relationship between CT testing and road testing in training.

So here are some conversions. First, my designations are:
road = training on the road
CT = training on the Computrainer
race = data from a race

FTP has always been defined as 1 hour race average power:
FTP = 1.00 x (60m – race)

In a 1hr training road test, we increase measured power by 3% to account for adrenaline, motivation, et cetera:
FTP = 1.03 x (60m – road)

A 20-minute race TT gives you 5% higher average power than your 60-min race power, so:
FTP = 0.95 x (20m – race)

For a 20-minute non-race test on the road, we have to throw in both the 95% conversion from 60m to 20m and the training/racing adrenaline factor:
FTP = 0.95 x 1.03 x (20m – road) = 0.98 (20m – road)

Ok, here is the new stuff that I've just figured out:
For whatever reason, I’ve found that power output on the Computrainer is about 2% less than non-racing testing on the road for an extended effort (probably due to heat, lack of breeze, inability to move around, mental factors). So we need to account for that extra 2% with a third factor of 1.02, so:
FTP = 0.95 x 1.03 x 1.02 (20m – CT) = 1.00 (20m CT)

So when all is said and done and you get rid of all the numbers, you end up with a very simple relationship for testing FTP:
FTP is your average 20m power on a CT. That's without a doubt the easiest, most consistent way to test.

Cycling Peaks graphs

After seeing the power graphs I posted the other day, someone asked how much and what type of data the Ergomo collected on each ride and how it can be viewed. The answers are: more data than you would ever want to view for each ride, and I store/view it in CyclingPeaks software. Once in a while the more detailed graphs are useful. Here are some examples of ways you can view the data. All of these charts reflect Tuesday 6-26-07. As usual, click to enlarge:

Raw power charts

A few folks have inquired about seeing some raw power data, so I've thrown in some charts from the past week.

This first one is from the Savannah Georgia Cup crit last Saturday. It's obvious that it's a crit because of the consistent power spikes required to accelerate out of each corner (there were only two corners on the half-moon shaped course). To prepare for a race like this, doing about forty 10-second intervals at 600-700 watts with 200-watt, 30-second recovery would be about right. I rode at the back a lot and the yo-yo effect makes the cornering 'intervals' even more distinct than they would have been up front.

These two power charts are from yesterday's Macon ride. Keith rolled off the front (he might have just planned a short jaunt) and I went up to join him and turn it into a 35-minute suicide mission. It was a futile effort, but great training. The first chart is with no data smoothing and the second is with smoothing (30-sec running average, I think). The horizontal line is my functional threshold power (FTP) of 268 watts. My normalized power for the effort was 289 watts, so I think it's time for me to test FTP again.

How to win the flats - Savannah

The Savannah Georgia Cup courses last weekend were flat - that was no surprise. The TTT course had a few rollers and some breeze, but the crit and the circuit were open, flat, and the wind effects were present but minimal. I assumed going in that I had virtually no chance to win or place high in races on flat stages where a sprint finish was very likely. I've been thinking about why I made that assumption beforehand and about why it was an accurate assumption.

Trey and I formed a 2-man team for the TTT. On a flat course with a couple of short, small grades (2-4%) and a light breeze, we averaged 24.3 mph over about 14 miles. That corresponds to something between 280 and 300 watts average power output over half and hour. That seems reasonable, because my FTP is about 270 and Trey's is probably somewhere in that range also. That means each of us was essentially doing 1-minute intervals at 280-300 watts with a one minute 'rest' at about 240 watts or so. Our TTT experience was virtually identical to what one would expect to face in a two-man break off the front of a circuit or crit (except for the less aero road bikes vs. TT bikes).

The average speeds for the competitive division (4/5) crit and circuit were just under 26 mph, and both races had fairly consistent speeds. That means that the riders at the front of the peloton at any given time were riding at about 325 watts on the flats with no wind. That number seems reasonable. In order for any rider or pair of riders to get off the front and sustain a gap, they would need maybe 30 seconds of 400 or 450 watts to get away, then a sustained 325-350 watts just to maintain the small gap. Unless I'm mistaken, there aren't many category 4 or 5 riders who can generate that kind of sustained power. I can sustain 385 watts for a couple of minutes or so, but would probably not be able to ride at a sustained 300 watts for any length of time afterward. That's why my assumption about not being competitive in Savannah held true. As a matter of fact, both the crit and the circuit ended in a bunch sprint. Evidently there were no riders in our races that had the kind of power I described above.

And it gets even tougher in the elite and pro, 1, 2 races, where I think the average speeds were at least 27 mph and 28 mph, respectively.

Thankfully for me, all that I have said above goes out the window on courses like Dahlonega, where pure wattage takes a back seat to watts/kg and top speed pretty much disappears from the equation. It doesn't mean I'll podium in Dahlonega, it just means I'm not almost mathematically eliminated before I start.

Savannah Georgia Cup

The GA Cup races this weekend in Savannah were very flat and very fast. Racing from Macon were Trey Gavin, Jeff Clayton, Chad Madan, myself, and Richard Cook.

The Saturday morning Team Time Trial was the toughest of the three stages for me. Trey and I formed a two-man team (the minimum for Competitive division). It was a flat 14-mi course with a few small inclines and a light breeze on half of the route. We started out too fast with too much adrenaline, I think, and had to struggle to keep up the pace at the finish. But all in all we had a good TTT, passing the groups that started 1 minute and 2 minutes ahead of us, both of which were 3-man teams. Our average speed was 24.3 mph. It would have been very beneficial to have had one or two additional teammates. The draft effect would have been larger and it would have provided a critical extra few seconds for catching our breath between pulls. But it was a fun ride. We finished 11th of 20 teams and beat all the 2-man, 3-man, and 4-man teams. A GA Cup screw-up on the web site caused Jeff to miss his TTT start. Richard was paired with another single and had a good ride. I think Chad's team took 4th.

The Saturday afternoon 'crit' was hot. They called it a crit, but really it was a short, half-moon shaped circuit race with two open, wide turns. Trey and I both stayed with the front group in a race that was very fast by cat 4/5 standards (25.8 mph). I moved up to the front a couple of times, but didn't have enough juice to try anything. Trey raced aggressively and stayed up front a lot. He took 2nd in a time bonus prime and finished top 20 in the sprint. I was probably at about 30th. I didn't realize until after the race that they didn't give the same time to everyone finishing together in the final group, so I lost a few seconds there. Jeff raced well but finished mid-pack in his race, and I think Chad finished mid-pack after doing quite a bit of up-front work for Pacesetter earlier in the race.

The Sunday circuit race was on a wide, fast mini-Indy car track with about 7 turns. It was another very fast race (25.7 mph) with wide open turns and some breeze. It finished similarly to the crit for Trey and I, but included much more carnage. At least four crashes occurred during the race, with one guy breaking his collar bone, I think. Lots of scraping aluminum and cracking carbon (road rash makes no sound). Jeff covered all the breaks in his race, but none of them stuck. He finished mid-pack in the sprint.

I guess you can see that the theme down there was fast, open, sprinter's races. The TTT pretty much set the finishing order in the GC, and we don't have many sprinters from Macon, so we didn't bring home any hardware, but it was a fun weekend. Dahlonega in two weeks will see an entirely different list of names on the leaderboard.

BBQ Bass

Lunch stop at the BBQ Bass ride. Click to enlarge.

Rock 'n Rollman

I had a good ride at the Rock 'n Rollman 1/2 IM on Sunday -- I bettered last year's time by about 21 minutes and finished in 2:33:45. I'm glad I rode well, and I want to identify what I did right so it won't be a one time show. I have several theories, and it's probably some combination of all of them:

1. More mileage - My mileage/training time since April hasn't been drastically different than what I've done in past years, but it's a little higher (150-200 miles/wk this year compared with 100-200 miles/wk last year). The real difference was during the winter months. I averaged about 150 miles per week instead of 75. And a big chunk of that riding was in the Peach Peloton in 60-135 mile rides. Those long winter rides probably helped me build a bigger aerobic base, which allowed me to keep my heart rate steady at 155 bpm (7 bpm below FT) throughout the ride instead of having it decay steadily from 155 to 130 like it did last year.
2. Weights - I hit the weights over the winter -- mostly squats and leg extensions. I'm not sure the lifting really helped me, but it is a difference from last year.
3. Psychology - I think this was the big one. I've never argued that the mental approach to sports performance is important, but I think this ride was the first time I took full advantage of it. There was a steady brisk breeze in our face from the start to the half way point in Roberta. Instead of bitching and moaning about the headwind (like I heard lots of my competitors doing), I was begging for it not to stop because I had convinced myself (accurately, I think), that I was more aerodynamic than most riders (small body size, TT helmet, skinsuit, tri-bike w/aero wheels, shoe covers, etc.) and that the harder the wind blew the more time I was gaining on them. Also, I didn't have to run after the bike because I was on a relay team. That allowed me to leave it all on the road, mentally and physically.
4. No swim - Because of the relay team I didn't swim before the ride. This obviously gave me some advantage, but I don't know how much.
5. Tandem riding - This one was unexpected. I've done some tandem riding with Betty Jean this spring. It's made me much more aware of the effect of momentum on riding rolling hills. On a tandem, momentum is a much, much bigger factor than it is on a single. I've learned that increasing the effort in the last 1/4 of a short climb can make a big difference on your speed down the back of the hill. So I jumped out of the saddle toward the end of most small climbs to maintain momentum for the decent. I'm convinced it made a difference in my downhill speed and had the added benefit of improving the blood flow to my leg muscles, which is an issue that I almost never hear mentioned but I think is important. "Attacking" the hills also was good for the mental game.
6. Aero equipment - I picked up a LG aero helmet on eBay for $60 and a Colnago skinsuit for $40. I know they made some real difference (as much as a few minutes), but they definitely make me feel faster, and that's probably more important than their actual effect (see number 3).

Cycling improvement is a combination of lots of small things. One at a time they may not make a noticeable difference, but together they do.

Jordan Engineering BBQ Bass Ride

BBQ Bass Ride details:

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Start - 9am Saturday, June 9th at the Jordan Engineering, Inc. parking lot @ 144 N. Warren St., Monticello, GA (across the street from the courthouse). My cell # is 706-318-6786 in case you get lost in the big city.

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Route - 75 miles on rural roads through Jasper, Morgan, and Putnam Counties with 58' per mile of climbing. Click on the map below or visit http://www.routeslip.com/routes/43759. The course will be marked.

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Pace - I expect the bunch may separate into a couple of groups -- probably a 16-17 mph group and a little faster 18-19 mph pack, but we will try to regroup a couple of times during the ride for BBQ or a Bass.

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Support - I'll have a couple of rolling rest stops driving the route with tools, food, drink, and Bass in case they're needed. If you want to hang out in truck for a few minutes then jump back into the group, feel free. We'll regroup a couple of times and will stop at Kinorhook BBQ for lunch at mile 46. BBQ and Beer are on the house.

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Route Options - If you'd like to ride, but want a shorter route, let me know and I'll hook you up.

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If you think you'll be riding, send me an e-mail at robert@jordan-eng.com. The folks at the little BBQ place need to know whether to expect 5 riders or 25 for lunch.

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Click map to enlarge.

Edgar Soto - Nashville

This weekend at the Edgar Soto race in Nashville finally got me back in the groove with racing. I've raced a few times this year, but none of them had the same feel as last year's Georgia Cup races. Albany's road race was slow and boring; in Perry I think my TT time was mixed up and I know my dirt road skills were screwed up. Gainesville was a good circuit race, but a single race doesn't have the same feel as an omnium weekend.

Nashville:
The Edgar Soto TT course was fairly hilly (100' of climbing per mile) and just technical enough that leaving my TT bike at home might have been a good call, although I don't think I would have gone slower on the Cervelo. I finished the course in 10th place at 18:28.

The 3-lap, 11-mile circuit course was constantly rolling, but only had a couple of spots that might be called climbs. It was sort of like 11 miles of Pate Road with a little longer climbing sections. The 60-rider field pretty much stayed together for the first two laps. On the first climb of the third lap, I saw a couple of riders up front seem to get a little jittery, so I took advantage of an opening near the yellow line to move up from about 20th to about 5th position. Just as I moved up a little gap started to form a few spots behind me. As we surged a little to open the gap further, somebody in the middle of the group must have touched a wheel and gone down. I ended up with 9 other riders in the front group. We formed a good pace line and stayed away for the last 10 miles. I took 7th of 10 in a long downhill sprint finish. Our group picked up about a minute and a half on the field -- that would've been helpful if it were a stage race instead of an omnium.

The crit course was a 6-turn clockwise course with just enough gradual climb on one side to give me a little help against the bigger sprinters. It played out like most of my crits: I struggled hard to stay with the front group for a few laps, then gradually slipped off the back with other large chunks of riders (10 to 20). Over the final 20 minutes, I gradually bridged my way from group to group to get back into the front 20 riders, but never got back to the front group of 10 or so riders. I finished 16th.

Jeff Clayton finished the TT 53rd in 17:55, but had a great circuit race, finishing 13th and picking up a couple of minutes on most of the field. He finished 16th with the front group in the crit, moving him to 13th in GC. If he rides well in Monday's road race, he could grab a top 10 in a large (125) cat 4 field.

Ergomo Accuracy Check

Since I deal with wattage numbers a lot, I thought I'd use some numbers from a recent ride to check my Ergomo Pro's accuracy. I have no reason to doubt the numbers it's giving me, but a good real world check now and then makes sense.

The best way to calculate wattage is using data from a climb because air resistance becomes almost negligible at low speeds. Since air resistance is the most difficult to accurately measure (using friction factors and frontal area estimates), the smaller role that it plays, the more confidence I have in the calculation.

I used a wattage calculation spreadsheet to input bike weight, body weight, climb length, climb slope, air temperature, air friction factor, tire rolling resistance, drivetrain friction, rider frontal area, and power output (I entered the average power reading from the climb as measured by my Ergomo Pro).

I was amazed to find that the spreadsheet calculation for climb time matched my actual climb time (as recorded by my Ergomo) to the exact second -- 1 minute, 5 seconds. Later I performed the same calculation for one other climb on the same ride and it matched the calculation by 1 second. That satisfies me that my power meter is giving me good data.

Pedal force & muscle fatigue

Past testing has shown me that I achieve my highest power for a constant heart rate (150 bpm) at 65 rpm. My power is significantly higher at that cadence than at 55 rpm or 75 rpm. That's a lot lower (about 20 rpm lower) than my normal cadence. I've more or less ignored the heart rate/cadence data due to two assumptions that I've held:

1. The goal is not to achieve the lowest heart rate, it's to put out the maximum wattage.
2. The higher muscle force required to hold the lower cadence at a given wattage would result in power fade on longer rides more than would a higher cadence with lower muscle force.

This past week's experiments with higher pedal force (a low-cadence hill repeat session last week and last night's group ride) revealed an interesting new wrinkle: My perceived exertion is significantly less when climbing at high power and low cadence than it has been with higher cadence. I guess that's to be expected because the higher cadence climbing is putting a larger share of the physiological load on oxygen transfer (aerobic system). The higher force, lower cadence approach is much more anaerobic. My average pedal force for the 1-minute interstate hill climb on Pate was about 600 lb-in (that's equivalent to alternating 90-lb one-leg squats). That's a lot higher than my typical pedal force of around 450 lb-in.

So the question boils down to this: Can I reduce my cadence when climbing hard and still have the same amount of gas left at the end of a 2 to 4 hour ride. If so, I think I can climb faster with less pain -- and those are both good things.

Switching back to strength

So the cycling tripod is skills, VO2, and strength.

For me, skills work is the most difficult to improve because I don't enjoy doing cornering drills and one-leg intervals and because skills improvement is difficult to quantify, so I can't easily see improvement. Also, I think skills are determined for a large part by genetics. My brother-in-law was a much better athlete in high school than I was; but 20 years later, I can easily best him in any type of speed or endurance sport. However, I never have stood, still don't stand, and never will stand a chance against him in any skills test. He's better at golf, tennis, darts, horseshoes, skeet, bowling, Frisbee, basketball.... you get the picture. I think skills are inborn and you can only do so much to improve them.

Oxygen transfer can be greatly improved with training. Lots of that improvement comes from losing body fat and some of it comes from getting more efficient at processing oxygen. But after a decade of training, increasing oxygen transfer even a little bit gets very difficult. My oxygen transfer genetics are pretty good (VO2max=67 ml/kg/min - most people who like to ride bikes, swim, and run for fun have pretty good oxygen transfer, otherwise they'd be miserable and probably would spend more time golfing and writing). This is the leg that I lean on the most by far for my current cycling ability. If I had been born with a VO2max of 45, I likely wouldn't have become a cyclist.

Strength is the one leg of the tripod where I might have room for some significant gains. The next phase of my training will include lots of pedal force work such as low cadence intervals and more sprint work. I'll see if I can make improvements in FTP through muscle strength and increase maximum power output with neuromuscular training. The key is to add this additional training while still doing enough of the stuff I've already been doing so that my oxygen transfer doesn't suffer.

As a side note: There has been enough written on strength training (particularly on off-season weight training) for cycling to fill lots of books; but I tried weight training last winter and I'm not convinced that it was helpful for me - particularly if you consider that I could have spent that time doing low cadence work on the bike. I guess if I skip the squats this winter and suffer next spring I'll be changing my tune.

The cycling tripod

There's so much information available about how to best train your body to ride a bike faster, it can get overwhelming fast - even for someone who likes soaking up the numbers. To simplify the situation and look a the big picture, I often view training like a tripod having legs of 1. skills, 2. oxygen delivery, and 3. strength.

Skills
Skills includes the stuff you do with your brain and nervous system. Skills are the driver of the car. I use the term skills to describe a whole bunch of unrelated things like racing strategy, bike handling, bike fit, positive thinking, level of aggression, desire to win, pedaling efficiency, quick thinking, knowing when to grind in the saddle and when to stand, and knowing when to push a big gear and when to spin.

Oxygen delivery
Oxygen delivery is your carburetor. It's measured as how much oxygen (fuel) you can deliver to the motor (muscles). Your maximum oxygen delivery is measured by VO2max (which I've already covered in detail in a prior post), but other oxygen delivery benchmarks can more important than VO2max. Your aerobic threshold AeT (lower oxygen burning limit) and anaerobic threshold (AT), which is also known as lactate threshold (LT) or functional threshold (FT), your upper oxygen burning limit, together establish the effort range at which you can ride for a long time. The bigger the range between your AeT and AT, the better off you are.

Strength
After your brain has selected a cadence and riding position and has decided to attack or sit in, and your carburetor has supplied as much oxygen to your muscles as possible, it's all over but the crying. Your maximum performance then depends on how much force your legs are able to put into the pedals. Your cadence and pedal force together will dictate wattage output and speed.

Aerobic Threshold

Aerobic threshold AeT is the heart rate at which you start burning fat using oxygen as an exclusive energy source (no lactic acid is produced while burning just oxygen). The lower your AeT, the better, but it's not a crucial number when it comes to performance - AT is much more important. If your AeT rises above your endurance training heartrate, it could become a problem because you would not be burning oxygen exclusively during long easy rides. Tony, who performed my testing, told me that his goal is to have the spread between AeT and AT, expressed as %maxHR be at least 10%, which is what mine is now. My AeT is 70% of HRmax and my AT is 80% of HRmax.

My AeT has risen 11 bpm from 116 bpm to 127 bpm since December 2005. That's usually an indicator that I have cut back on base training. I was confused when I first saw this result because my mileage over the winter and into the spring has been a lot higher than in prior years. From November to February this year I did a long ride (50-130 miles) with the Peach Peloton almost every weekend and rode the trainer 3 to 5 nights a week, so I should have had plenty of base miles, right? The problem is that when riding the Peach Peloton rides, I counted it as winter base training; but considering what my FTP was at the time (probably 220 watts in November and around 245 watts by February) I was doing a lot of that riding in my mid to high tempo range (80-90% of FTP). So even though I was putting in lots of miles, they weren't purely endurance miles that would effectively target my AeT.

I don't think that doing lots of tempo riding in the winter was a big negative, though. It probably did a lot to help me increase my FTP. And if I can start next winter's training rides with a higher FTP of around 260 watts, then riding at the same NP as last year in the winter rides (200 watts) will be 75% of FTP, which will be more a appropriate base mile pace for me and will also make those rides a lot less taxing.

VO2max and body fat percentage

Yesterday I found a relationship between cycling performance, oxygen transfer, and body fat percentage that I have always missed.

We'll start with oxygen transfer. I think I have a solid understanding of VO2max: it's the maximum amount of oxygen your body can process expressed in milliliters per kilogram of body weight per minute. Below is a detailed description of VO2max. In a later post I'll describe how I plan to use my VO2max testing result (67 ml/kg/min) from yesterday to better structure my bike training.

Variables determining a person's VO2max include lots of body processes and physical characteristics. I'm not formally trained in any of this stuff, I'll probably leave some things out and my info might not be perfect, so take it with a grain of salt, but here are a few of the variables:

• Lung capacity - every time you breathe air into your lungs, air comes in contact with the interior surface of your lungs, which is flooded with 'used' oxygen-deficient blood that just came from working muscles. The concentration of oxygen is higher in the air than in the blood, so some oxygen diffuses into the blood, which is pumped back to the working muscles. So the area of contact between the air and the blood is important. The greater your lung capacity (volume of air you can inhale), the greater oxygen transfer you get with every breath. An average male can breath about 6 liters of air. Miguel Indurain's lungs can hold 8 liters.
• Health of lungs - lots of things can damage your lungs. The obvious ones are smoking or working in an asbestos factory, but others such as having pneumonia, getting lots of chest colds, living in a big city, or living downwind of a large coal-fired power plant can also have effects. Lung health deterioration is one of the primary reasons that VO2max is expected to decline by about 0.5 ml/kg/min per year after age 30.
• Blood volume - the volume of blood in your body doesn't change much with weight changes, but does increase somewhat with extended athletic training. The more blood you have the more oxygen you can move from the lungs to the muscles.
• Heart capacity - hearts come in different sizes and strengths. I think heart size is mostly genetic, but exercise can strengthen the heart's muscles and allow it to pump more blood. Indurain's heart could pump 50 liters per minute (13 gallons/minute) of blood. For comparison, flow from a typical residential shower head is 2 or 3 gallons per minute, so think of 20 shower heads flowing at once. That's a LOT of blood!
• Artery size - The bigger the 'pipes' carrying blood from your heart to your muscles, the more blood that can flow and the more oxygen that can catch a ride. I've seen pictures of artery cross sections for untrained average males compared to those of highly trained athletes. The difference is quite dramatic. Arteries in trained athletes can dilate to a much greater size (it seems like I remember that it was more than double) when higher blood flow is required.
• Capillary density - The more you exercise hard and deprive your muscles of oxygen when they need it, the more your body will respond by growing capillaries to distribute more oxygen in the right places within the muscles. This is one of the primary reasons why athletic training is so sport-specific. A world-class long distance runner might have great lung capacity, heart capacity, and arterial size; but if he hasn't developed high capillary denisty in his cycling muscles, he may be bettered by even moderately-trained cyclists due to their specific training.
• Cellular efficiency - The efficiency with which your cells convert the oxygen to sugars that your muscles can use to contract is important and can be improved through training. Changes in the number and efficiency of cell mitochondria and the efficiency with which you can buffer lactic acid are two examples.

That's what I knew about oxygen transfer before yesterday. But there is a significant factor related to body weight and body fat percentage that I have always missed or ignored. When analyzing cycling performance, I have always looked at body weight just the way I would look at the weight of the bike - just mass to be pulled up the hill in the gravity equation. I had always assumed that where accelerations and climbing were not a part of the equation (like a long, flat time trial), that body weight was not a real factor in performance except for the relatively small effect it has on body size and increased frontal area/wind friction. My friend Jeff, who won the Georgia state TT jersey for Cat5 last year, is powerful and he's not fat by any definition, but one look at him and you'd know he'd play tackle, not flanker. The fact that he won the TT jersey on a relatively flat course didn't surprise me a bit - it make perfect sense that he could excel in a discipline where I thought his power was important but his weight didn't matter much. But now I realize that there's more to look at in a flat TT than just power production.

What I know now is that blood volume is pretty constant for a given training level. So let's look at this scenario: In the spring I weigh 147 lbs and train 15 hours per week. My body fat percentage is 9.1 percent. I reach a certain fitness level by April and I can average 268 watts for a flat April TT, riding at maybe 23.5 mph. During the summer I maintain the same training regimen, but I add a pint of Chunky Monkey to my diet every other night. By September, I'm still well-trained and fit, and I have the same equipment, but I weigh 160 pounds and have a little excess fat (maybe 14% body fat). I ride the same TT course again, but this time I only produce 245 watts and my speed falls to 22.1 mph. Why did this happen?

It happened because in the fall I have to distribute my blood volume over more body tissue. I have 13 pounds of fat in my body in the fall that wasn't there in the spring (13 pounds is equivalent to 52 sticks of butter). Fat is blood dense, so there is a lot of my blood hanging out in that 13 pounds of fat that can't be used to carry oxygen to my cycling muscles, so I can't generate as much power and I go slower.

The end result is that body weight and body fat percentage has more of an effect on cycling performance than I had previously thought.

Metabolic Testing Results

Cycling is a great sport. It's healthy, it's social, and it can be extremely competitive. It gives me a free pass to eat good food and drink great wine. And if group rides are any indication, I can hope to maintain fitness and strength in cycling for several decades to come. But that's enough waxing poetic, now for the numbers.

A lot of the enjoyment I get from cycling is from being a lab rat in the science experiment of training. About 17 months ago, when I was first considering switching from triathlon to full-time cycling, I decided I'd get tested for some basic metabolic benchmarks. It was December 2005, I'd been training with some sort of structure for about 5 years, and the numbers looked something like this:

December 2005
Predicted max heartrate: 182 bpm
Lactate threshold (LT): 135 bpm (heartrate where sugar burning takes over as energy)
Aerobic threshold (AeT): 116 bpm (heartrate where I first start burning fat)
VO2max: 64 ml/kg/min (ability to uptake and use oxygen)
Body fat percentage: 10.4%

Yesterday I had the numbers run again to find out how they've changed after a year and a half of more intense cycling-specific training.

May 2007
Predicted max heartrate: 182 bpm
LT: 145 bpm
AeT: 127 bpm
VO2max: 67, but hit 70+ for short period in test
Body fat percentage: 9.1%

Over the next few posts, I'll take a look at each of the results and their implications to my training and racing (and eating). Also, I learned a few new things about exercise physiology from Tony Myers at ATS that I found interesting, so I'll elaborate on those as well.

Lots of Charts

If you don't like numbers and charts, now's your chance to hit the back button. Click charts to enlarge.

It's obvious that the use of power measurement for training is relatively new to all except pro and olympic athletes. Lots of folks are looking for the most useful ways to analyze at their data in Cycling Peaks. Specifically, I've had several folks have ask about my recent Performance Manager and mean maximal power data. I'm still learning how to use the data and to find the best ways to benefit from it in training and racing, but I've pasted some charts below with rough descriptions.

This is my Performance Manager data from May 1, 2006 through May 1, 2007. One of the most significant things I can draw from this chart is to see that I was virtually untrained (chronic trainin load = 24 TSS/d) this same time last year. My current CTL, 75 TSS/d, is higher now than my peak TSS for all of last year, which occurred in early August. That's either great news or it means I'm in for a really stale summer.

This is my performance manager chart for this season (since November). It's just a blow-up of the 1st chart, but has my 5 best power outputs for various time intervals superimposed onto it. It's worth noting that I've set most of my 1-min, 5-min, 20-min, bests in April and had a big spring up-tick in the 1-hr (I only test that every 4 months).

These are my weekly bests for each time interval for the season. I obviously had an easy week in early February. All the lines are pretty flat until late February. That's when I started doing more intensity work. I've made good progress in the 25-second to 5-minute range, but the sprint power seems stuck in neutral - an indicator that I either need to modify my training or get new parents.

This is a mean maximal power plot comparing November through February with March and April. The yellow line is March-April. As indicated in some of the other charts, the change is minimal up through about 15 seconds, but significant progress shows up in longer time intervals. From 30sec to 1hr, I've gained 30 to 50 watts.

Lastly, this is my mean maximal normalized power comparing the same periods as the previous chart. Normalized power isn't calculated for efforts under 5 minutes. Good progress across the board here except I'm not doing 2-3 hour harder rides now like I was this winter in the Peach Peloton.

Thoughts on weight, genetics

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.

Power profiling

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.

April FTP Test results

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.