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.