Power Pulse Intervals

Circuit Diagram for a Power Pulse Generator

In my junior year at the U of A, I took a circuits class with Dr. Miklos Silzaki or Shilzagi or Sizzleki or something. He was born in Budapest, Hungary and spent some time in Russia studying Electrical Engineering and Physics. He had some interesting (read: somewhat crazy) political views and described himself as a "liberal conservative" -- which may have simply meant that he was confused. We always found it strange when he would launch into some sort of political rant in the middle of a discussion about how capacitors work.

A nice guy, but a horrible instructor. I learned just about nothing from him and I was not alone. In fact, I recall reading a letter written to the Arizona Daily Wildcat back in 2002 regarding Miklos that expressed the same dissatisfaction with his teaching abilities as my friends and I had. I was even able to use the amazing power of the internets to find that letter, and the correct spelling of his last name, Szilagyi (pronounced just how it's spelled).

John Parker, at the time an Industrial Engineering senior said, "I believe that his method of teaching would be considered, if in some other profession, fraudulent, because it fails in the most basic objective of teaching which is to TEACH."

I still remember this funny thing about Dr. Siljocky -- dangit I already forgot how to spell his name. He would start class every time asking in his thick Hungarian/Russian accent, "Gude uff tanune, und vutt tis yore virsht kwesh tone?" (translation: Good afternoon, and what is your first question?). Since we weren't learning anything in his class we never had any questions. So instead we just stared back at him waiting for his standard reply, which was, "Ull rite, ten vutt tis yore seckund kwesh tone?"

Ahh yes, good times. I took that course with a friend named Billy who was extremely intelligent and never combed his hair (think Einstein). He was much smarter than I and a really fun guy to hang out with. We took a Design of Machines course together and teamed up on a project to design a mechanical bull using four-bar linkages and force, height, velocity, and acceleration requirements. It of course required on-site testing of the mechanical bull installed at the Wild Wild West nightclub on Ina.

Investigative Field Testing with Billy

We received an A on the project. Fun class, and Dr. Ara Arabyan was an excellent instructor. Billy, by the way, now works as a project manager in San Luis Obispo for REC Solar. I wonder if he combs his hair.

I know, I know... You see, I did an image search for "Power Pulse Intervals" so I could have a visual to share for this workout and the circuit diagram for a power pulse generator showed up, which reminded me of my circuits class... which reminded me of Miklos... which reminded me of Billy... which reminded me of the mechanical bull design.

Obviously, there are side effects from an SUV-induced-windshield-headbutt-to-asphalt-faceplant.

Power Pulse Intervals

Type:	Muscular Endurance
Duration:	30 - 60 minutes
Complexity:	2 / 5 (easy)
Difficulty:	4 / 5 (difficult)
Computer:	3-second power, heart rate, cadence, lap time

Power Pulse intervals are a Muscular Endurance (ME) workout. These intervals will help increase your ME by riding above lactate threshold and ending the interval shortly after you go anaerobic. The intent is to train your body to increase its aerobic duration by pushing the "ceiling" of your lactate threshold. If you find yourself getting dropped on the fast group rides, or have mediocre time trial results, or difficulty climbing at a strong pace for extended periods of time -- these intervals will help.

The Short Version

Warm-up
5 intervals of
- - CP12 power until HR is 3 bpm above LTHR
- - rest for 1/4 the work interval time
Cool-down

The Long Version

Determining your Interval Power

The first step for doing power pulse intervals is to determine what power output you should be achieving for the interval. If the power is too high, you'll go anaerobic too quickly -- too low, and you'll stay aerobic too long (perhaps forever). The right power depends on the individual, and is typically 5-15% above your FTP. You can try different values to find one that results in the desired interval duration, or you can use your Critical Power (CP) for 12 minutes (i.e. the maximum power you can produce for 12 minutes).

If you don't have a power meter, get one. If you haven't done testing to determine your CP12, do it. Simply warm-up and ride as hard as you can for 12 minutes, trying to maintain steady power output for the duration. If you don't know your FTP, do the CP30 test (but not on the same day as your CP12 test).

Some examples:

1. Adam did a CP12 test and was able to hold 275 watts for 12 minutes, so his interval power is 275 w.
2. Bruce did a CP30 test and was able to hold 250 watts for 30 minutes. He is too scared to do a CP12 test so he decided to just add 10% to his FTP (250 * 1.1 = 275 w).
3. Chuck just got a power meter but refuses to do any testing, so he decided to just try 400 watts and see what happened. He immediately went anaerobic but didn't know to stop the interval because he had no idea what his LTHR was. After two minutes he puked and everyone made fun of him.

Don't be Chuck.

After you complete your first interval, you'll have a good idea of whether your power output is appropriate for this workout. If you find that your first interval only lasts two minutes, reduce the power slightly for the next one. If your interval lasts 10 minutes, increase your power slightly. You're looking for around a five-minute interval.

Choosing your Route

Since you will be maintaining relatively high power output for relatively long periods of time, you will be covering a lot of ground. On a flat course at 275 watts a 6-foot tall, 150-lb rider would cover almost two miles in a single interval. You want to avoid routes that would have stops in it to disrupt your intervals. You also want to avoid rollers which will complicate maintaining a steady power output. The ideal route would be a hill climb with a grade of 2-5% and length sufficient to complete five full intervals. Mt. Lemmon is a great option. With a constant 5% slope, that same rider would now cover about one mile per interval. Five intervals fit very nicely into a ride to Molino Basin*.

* Every Thursday morning at 5:30 the JKG group meets at Le Buzz to ride to Molino Basin. Great group of guys, highly recommended.

Starting the Workout

Before you start, make sure you are sufficiently warmed-up and your computer is displaying power (3-second average), heart rate, cadence, and lap time. When you begin the first interval, press the lap button.

Ending an Interval

During the interval you will want to glance at your computer every so often to check your power output, heart rate, and cadence. You'll see your heart rate increase quickly over the first half of the interval and then slowly creep to your LTHR. Once you see your HR three beats above your LTHR, press your lap button and reduce power to zone 1 recovery. When you press your lap button, it should display the previous lap time. While you are recovering in zone 1, determine how long your recovery interval should be (1/4 the time of the work interval).

Remember to wait until your heart rate is 3 beats above your LTHR. You want to dip slightly into your anaerobic range to push your ceiling. Keep your power steady and avoid the temptation to push harder to increase your heart rate so you can end the interval.

So if your interval lap time was 5:36, your recovery time should be about 1.5 minutes (1 minute, 24 seconds if you're a math nerd). It doesn't have to be exact, but you don't want your recovery to be too long. I usually do 1 minute of recovery for intervals under 5 minutes and 1.5 minutes for intervals under 7 minutes. You won't be recovered completely, and that is by design. Your first interval will likely be longer than the others, and you may find that interval duration decreases with each interval. If your interval length drops below three minutes, decrease power slightly for the next one to try to stay in that 3-7 minute range.

Example of a Power Pulse Interval

The workout is complete once you have finished five intervals and their associated recoveries. If you pressed your lap button at all the appropriate spots, you should have 11 laps (one of them being your warm-up). After uploading your data you can take a look at each interval and make note of their duration and average power. With that information you can determine what power output you should shoot for next time.

For example, if your intervals were:

1. 300 watts for 3 minutes (1-minute recovery)
2. 270 watts for 5 minutes (1-minute recovery)
3. 280 watts for 3 minutes (1-minute recovery)
4. 240 watts for 6 minutes (1.5-minute recovery)
5. 250 watts for 5 minutes (1-minute recovery)

then you probably want to aim for 260 watts the next time. Ideally you want all five intervals to be 5 minutes long with 1-minute recoveries.

You'll probably want to limit this workout to once a week. After a month or two you'll notice your intervals will last longer -- to the point where you'll need to increase your power to keep them under seven minutes. Congratulations, this indicates an increase of your FTP -- which means it's time for you to perform another FTP test. You can try estimating your new FTP via this workout, but it will be slightly skewed since you are performing the workout on a hill climb -- it's better to perform a consistent test every few months.

Since this workout is based on heart rate, some additional influences (e.g. dehydration, lack of sleep, hot weather) will be a factor. Also remember to keep track of your fatigue with the Performance Management Chart ("Fitness & Freshness" in Strava) and avoid overtraining.

Tolero Criterium Series #1

You know that feeling when you've just uploaded your ride to Strava and are hovering over that "Private" button with the thought that you should not show anyone how bad you did in a race?

No, of course not. Me either, I was just speaking hypothetically.

Last year's race (dark), this year's (light)

I raced in two of the Tolero crits (the 5's and the 4/5's). The fields were small, I think seven guys in the 5's and nine in the 4/5's. My goals (in order of importance) were to not crash, work on cornering confidence, work on pack riding confidence, see how my sprint/jump was, and finish with the groups.

I am happy to report that I met almost all my goals. But I still hovered over that “private” button for a while...

The 5’s

I didn’t have a great warm-up but the first three laps were slow so it wasn’t a big deal. The forth lap was a prime and so we all upped the pace and I felt good. I decided not to go for the prime and wait for the next one with the intent of seeing how good my jump/sprint was.

The second prime came on the seventh lap. I stayed in fifth position with the intent of seeing how many guys I could pass on the sprint hill. I jumped hard out of the corner and pushed hard for what ended up being a 10-second burst. I was geared right with a good steady cadence. Surely I could pass at least one guy, right? Wrong.

And don’t call me Surely.

I had no jump, no acceleration, and no speed. I felt fresh and had zero fatigue in my legs but I just had no strength. Post-race data showed that my peak power was less than my 10-second power at last year’s Tolero crit. Ugh. I continued in the race with the sole intent of working on my cornering. I took corners at varying angles and found the good lines for staying off the brakes. I played around with tailgunning* to avoid the slowing of the other riders and was able to carry my speed through the corners and re-attach to the group with minimal effort.

* Tailgunning is when you are at the back of the group and allow a little gap between you and the rider in front of you. When you go through a corner, usually the group will slow and if you are right on the wheel of the rider in front of you braking is required (which wastes energy). By tailgunning, you can stay off the brakes and take the corner at your own speed, hopefully timing it right so that you regain contact with the group without needing to accelerate.

I felt good in the corners and loved the feel of the Noah, which is much stiffer than the Allez. The shorter wheelbase and more aggressive saddle-to-bar drop (giving me a lower center of gravity) really gave me a feeling of complete control in the turns. I’ve still got a ways to go with the cornering confidence, but I made some significant gains during these races.

I didn’t sprint for any of the other primes and instead waited for the finish. I didn’t have much hope based on my earlier “jump” and that negative mindset probably did more damage than my lack of strength. I was “lazy” on the last lap and didn’t try to move up into a good position. When we went into the final corner I was in last position, and despite all the power I could muster, that’s where I stayed.

Last.

The 4/5’s

With the discouraging results in the 5’s race I didn’t have much hope for the 4/5’s. The plan was to work on cornering some more and stay with the group. I didn’t plan on going after any of the primes and doubted that I had enough jump to follow any attacks. I had a better warm-up for this race which was good because it was fairly quick from the start.

The first prime came on the forth lap and the pace quickened in preparation for the sprint. I was near the back and unfortunately the guy in front of me let a gap develop during that lap. When it came time to close it he was able to power his way back into the group but I couldn’t hold his wheel and spent a lot of energy getting back in the group. I tried to recover but the pace was high and the accelerations out of the corners were taking their toll. After just 10 minutes I popped and watched the group slowly move away from me. Ugh.

I decided to stay above threshold and continue to work on my cornering. It sucks riding solo but after two laps I had caught another guy who had been dropped. I pulled around and told him we should work together to try to catch back on. We traded pulls for a while but I guess he was pretty toasted because any gains I made during my pull were lost when he pulled. After probably six laps I finished a pull and expected him to come around me but he was gone. I looked back and was shocked that I couldn’t see him at all. Apparently he crashed on the tight "dumpster corner" but I never heard it so I think he may have lost my wheel at some point prior to the crash. Hopefully he’s not banged up too bad.

The Dumpster Corner

I tried a few different lines through the dumpster corner. The green circle above represents the maximum-radius route, which in theory is the fastest line through the corner. When going through as a group you're limited on what line you can take, but when you're on the front or solo following this radius is likely the best option. I can recall riding over the concrete pad a couple times which is a very inefficient route.

I got back to work solo, working on cornering and staying above threshold. I started feeling very confident on the dumpster corner as well as the final corner before the sprint hill. At about the 5-laps to-go mark, I was lapped by a three-man break containing my good friend, Cody. I was bummed to get lapped but super excited for him. I looked back and couldn’t see the main group yet so I decided to work as hard as I could to stay away from them. Half a lap later and I had another dropped rider in my sight. I caught up to him and told him we should work together to stay away from the main group. We traded 1-lap pulls for the remainder of the race and on the last lap I asked him if he wanted to sprint it out. The only reason I wanted to sprint was for the practice, but he wasn’t interested. I did a half-hearted sprint to the line only semi-curious about the top number I could generate. It wasn’t much.

Second to last.

Not exactly my idea of a good race day. But all things considered, I’m happy. I really enjoy crits and cornering well is a major factor in these races. Having the opportunity to work on that was definitely beneficial. I’m not surprised by my lack of jump. Since getting back on the bike I’ve been focused on restoring my aerobic endurance -- not anaerobic. I’ll be moving out of my Base period and into my first Build period of the year soon and I fully expect to regain the jump I once had (and hopefully surpass it).

Building a Solid Base

Khafre Pyramid near Cairo, Egypt

You've likely heard it discussed before: it's time to build up a good "base" for the coming season. So what is this base? Why do you need it? When do you start it? How do you get it and how do you know when you have it? I won't pretend to be an expert on training, but I'll offer what I've gleaned from others as well as my own personal experiences with the Base period.

What is Base?

"Periodization" is widely accepted and utilized for training. Periodization is simply breaking down a training year into different periods: usually Base, Build, Transition, Taper, and Peak. The Base period is the first "step" in a training year and is meant to be the aerobic fitness foundation for the rest of the training (and therefore is considered to be the most important component of training). Without a good base, one will likely not reach their full potential and may even experience injury when training at higher intensities later in the year.

When Should I Work on My Base?

Since the Base period is meant to be the beginning of a training year, when it starts depends on what you are training for. If you are training for the Colossal Cave road race in April your Base period will start earlier than if you are training for El Tour de Tucson at the end of November. If you aren't training for a specific event, your Base period will want to coincide with what you would consider your "off-season" (perhaps the winter months when you might ride indoors more often). The Base period requires the most time on the bike compared to the other periods, so ideally you would build your base over the time of year when you are able to devote the most time to training.

What Workouts Should I Do?

According to many training guides, the Base period is mainly about increasing Aerobic Endurance (AE). Simply put, AE workouts are riding for extended periods of time in heart rate zone 2. The minimum ride length is probably 30 minutes, and the maximum depends on the individual. For the first four weeks of Base (Base 1), you'll mostly be doing AE rides -- but it is a good idea to include some Speed workouts too. For weeks 5 through 12 (Base 2 and 3), adding some Force and Muscular Endurance (ME) workouts is recommended. The following general time percent breakdown can be used as a template:

	AE	Speed	Force	ME
Base 1 (weeks 1-4)	90%	10%	--	--
Base 2 (weeks 5-8)	70%	15%	10%	5%
Base 3 (weeks 9-12)	55%	15%	20%	10%

Everyone's heart rate zones are different, so you will need to determine your own zone 2. There are a few ways of doing this. My recommendation is to perform a 30 minute LTHR (lactate threshold heart rate) test. This test is difficult but well worth the time and effort. If you have a power meter the same 30 minute test will give you your LTHR and FTP (functional threshold power). Click here to learn how to perform the 30 minute test.

Once you know your LTHR, you can determine your heart rate zones. They are as follows:

Zone	Percent of LTHR
1 (Active recovery)	< 80
2 (Aerobic threshold)	81 - 89
3 (Tempo)	90 - 93
4 (Lactate threshold)	94 - 99
5a (Super-threshold)	100 - 102
5b (Aerobic capacity)	103 - 106
5c (Anaerobic capacity)	> 106

For example, if you find that your LTHR is 175 bpm, your zone 2 range would be 142 - 155 bpm. Aerobic endurance training will mainly utilize your slow-twitch muscle fibers. These muscle fibers produce most of the power in cycling, with the fast-twitch fibers only utilized during the very high intensity efforts associated with attacking and sprinting. Training in higher zones will be less effective at strengthening your slow-twitch fibers, so during Base training, the more time you can remain in zone 2 the better. With aerobic endurance training, fat is the primary fuel used for exercise (not carbohydrates). Make sure that you fuel your body appropriately.

If you are fairly new to training, the amount of time you should spend riding in zone 2 during the Base period depends on just one thing: how much time you have available. It doesn't matter if you are training for 100-mile road races or 30-minute crits -- the more aerobic endurance miles you can rack up during the Base period, the better. Realize, though, that it is possible to overtrain even when riding at this low intensity. Pay attention to your body and take recovery days to avoid building up too much fatigue. If you have a power meter you can monitor this with your Performance Management Chart (to be discussed in a future blog post).

How Long Should Base Last?

There are a few methods to determining how long your Base period should last. Some training programs simply set it at 8 or 12 weeks. Some individuals I've talked to simply go by weight loss (they have a set racing weight that they shoot for). The methods I'll describe here are not meant to be the rules for ending your Base period -- I provide it because I believe the more information you have about your fitness the better you'll train. So if you want to stick to the 8-week program that is great -- you can still monitor the other techniques described here.

Efficiency Factor

Efficiency Factor (EF) is defined as the average power you produce divided by your average heart rate over the time you spend in zone 2. EF does not apply to time spent outside zone 2, so it is important to maintain a somewhat steady heart rate within your appropriate range. Typical rides require some time to warm-up, so when calculating EF you'll want to make sure you exclude that warm-up time.

EF =	Average Power (watts)
	Average Heart Rate (bpm)

Since EF is dependent on your personal LTHR, comparing your EF with other athletes is of little use. Comparing your own EF from one ride to another, though, is very useful for assessing your aerobic endurance (or generally speaking, fitness). An increase in EF from one ride to another signifies an increase in aerobic endurance. A decrease suggests you have built up significant fatigue and should utilize some recovery. A plateau suggests you have increased your Aerobic Endurance as far as you can with your current training and it may be time for you to move into a Build period.

You will find that your EF for indoor rides will be different from outdoor rides. Typically, due to insufficient body heat management, indoor rides will have lower EF values than outdoor. Additionally, if your indoor rides utilize both rollers and a trainer you will likely find that roller rides have higher EF values than trainer rides. This is because trainers provide constant resistance throughout the pedal stroke while rollers have slightly better "road feel" characteristics.

In the above example, you can see that significant gains in aerobic endurance were achived in the first three weeks. The forth week should have been more of a recovery week to eliminate some of the fatigue that had been built up. By not resting, this example shows a decrease in EF that needed another two weeks to re-gain. With very little change to EF in weeks six through eight, little aerobic endurance was gained during that time and it may have been better to move into the Build period. By monitoring your EF, you can analyze your training to ensure your time is spent wisely.

Decoupling

Another method of determining one's aerobic endurance is by taking a look at Decoupling. When you lack sufficient aerobic endurance, on longer AE rides with steady power output your heart rate will increase over time. Or alternatively, with a steady heart rate your power output will decrease over time. This is referred to as being decoupled, meaning your heart rate is not tracking with your power output. Below are examples of a decoupled ride and a coupled ride.

You can see how the heart rate in the Decoupled ride on the left steadily increases over time even though the power output is held constant. This indicates low aerobic endurance, suggesting additional Base period training in heart rate zone 2 will be beneficial. The Coupled ride on the right indicates good aerobic endurance.

Speed-based Efficiency Factor

If you do not have a power meter, get one. For $700, Stages Cycling has Shimano, SRAM, and FSA offerings. Go order one from Chris at ProBike and tell him Buzz sent you. He'll give you a great deal and reward me with a free valve stem cap for the referral.

If you still don't want to buy a power meter, you can employ an alternative equation for EF to use for your aerobic endurance training. Instead of average power, you can look at asverage speed (and then multiply by 10).

EF =	Average Speed (mph)	* 10
	Average Heart Rate (bpm)

In order to use this method, though, you will need to ensure the following:

• Identical route each time with no stops
• Identical hand position (e.g. on the hoods)
• No wind
• No drafting

Keep in mind that there are still factors that will affect speed-based EF like temperature, tire pressure, position on the bike, clothing, weight, etc. For accurate values you want everything to be as identical as possible. It is almost not worth the trouble and there are so many benefits to training with a power meter I hate to suggest this as an alternative. Seriously, just cancel your cable for six months and go buy a power meter.

A Quick Review

1. The Base period is mainly about increasing your Aerobic Endurance (AE).
2. A generic AE training ride consists of 1-2 hours of steady riding in heart rate zone 2.
3. Determine your personal heart rate zone 2 via the 30-minute LTHR test.
4. Calculate EF for each AE ride to get a feel for your aerobic endurance.
5. If you don't have a power meter, get one.