Percieved exertion 10 point scale and how to use it.

About 2/3 of the athletes I coach  use power meters to train, and the majority of them use heart rate monitors as well.  But even with athletes that use all of this fancy equipment, sometimes a  "Rate of Perceived  Exertion" (RPE) scale  is the best way to explain  the subjective  intensity of the workout.       This a basically  how hard  you are going on your own personal 1-10 scale.   While  the scale is 100% subjective, it winds up being quite reliable, and has been validated in multiple scientific  studies. ( you can do a Google Scholar search for GAV Borg or Gunnar Borg) The scale is typically given like this:

  • 0 - Nothing at all
  • 1 - Very light
  • 2 - Fairly light
  • 3 - Moderate
  • 4 - Some what hard
  • 5 - Hard
  • 6
  • 7 - Very hard
  • 8
  • 9
  • 10 - Very, very hard

But I also sometimes explain it like this:

  • 0 - Nothing at all
  • 1-2  Super easy, like a slow walk
  • 3-4 Moderate effort, you  aren't going easy anymore, but you can hold this for a long time
  • 5-6 Hard  holding this for an extended period is difficult,  at or just below   race pace
  • 7 -8 Very hard     race pace, as  you can only hold this for a couple of minutes
  • 9 Almost as hard as you could possibly go
  • 10 - This is as hard as you've ever gone your entire life, like someone is chasing you with a cattle prod.

This is  useful for large groups of people such as stationary  cycling classes ( such as the classes I teach at the  Navy and VA hospitals), or situations where athletes don't have have access to, or don't want to use devices such as power meters  or heart rate monitors.  It is also     frequently  use the RPE scale even with athletes that DO use these training devices.   The fact is, that an athlete needs to know  how to go off of feel,  to gauge their own physiological  responses,  just get a  handle on  what they can do,  and when they need to do it.      Don't get me wrong.  I love training, coaching, and racing with power.   But if you you don't know and  understand what  your boy is doing at the moment, and what you are capable of on a purely primal level.   You'll never really reach your maximum potential.

Coconut Water for Rehydration

Coconut  Water  for Rehydration When I was in Costa Rica this last April, one of the locals I was riding with suggested we stop and have a drink of fresh coconut water.    Coconut water is basically the juice from the inside of a young coconut, before that juice becomes coconut milk.    To have a taste of the stuff, we simply stopped by a roadside fruit stand, and the owner knocked a whole in the coconut and gave us a straw.   The coconut water had an interesting taste, very mildly sweet, and refreshing.   As we sat next to our bicycles,  the local rider started telling me how coconut water was a perfect rehydration drink.   He went on about how coconut water was isotonic, meaning it has the same electrolyte concentration as the blood, and that it was actually used   as IV fluid in place of saline during WWII.    Those that know me, know that I consider myself and “open minded skeptic” when it comes to this sort of thing.  Honestly I thought the local guys was probably full of it, but I was still intrigued and I decided I would investigate further when I returned home.

What I found out actually surprised me.  Not only was coconut water isotonic to blood, but it was really used in WWII and there were several journal articles reporting the emergency use of coconut water being successfully used for IV hydration in place of saline.  Another study suggested that coconut water was just as effective as a commercially available carbohydrate/electrolyte beverage in rehydrating subjects, and the subjects actually had an easier time drinking the coconut water.     Now I had to go find myself some coconut water. ( There are no roadside fruit stands with young coconut near my house).

They don’t have the stuff at the Vons supermarket around the corner,  but I found some at the Pancho Villa Market  just a few minutes away.

The coconut water I found was 70% percent coconut water ( juice)  by volume, with 30% added water and a little sugar.    12 oz of plain coconut water would have about  70 calories, but the added sugar brings the calorie count of  the stuff I bought to about  110 calories per can.  This is still a little bit more than calories than Gatorade, and  about  1/3 less than a can of soda   The extra sweetness is not unpleasant after a long hard ride in the heat,  but I wouldn’t be opposed to have the unsweetened stuff either.  It is actually quite easy to buy canned,  unsweetened coconut water  online, so I'll probably order some soon.

Physiologically I wouldn’t say its “perfect” as an electrolyte replacement drink,  as the sodium is a bit low (it has about half as much sodium as  the same volume of Gatorade).   But then again it is packed with potassium and  you are most likely going to get plenty of sodium  from your post exercise meal.    it is  really a little low on sodium for use during exercise, but is pretty good as a post exercise drink.  Some studies have even shown that  potassium  is  highly important for maintaining proper blood pressure and heart health, so the extra potassium  could be a bonus.

My personal verdict?   My fridge is almost always  stocked with a few cans of coconut water these days.  It has become my go to beverage when I get home from a long ride.  It tastes good , gives me a few carbohydrates, and  replaces some of those lost electrolytes.

So  now is the time where I give you my shameless plug for your chance to try FRESH coconut water.   We are going to have a Crank Cycling training camp in Costa Rica this February.  It will be a weeklong camp where you can ride every day, relax by the hot springs each night, and sip  fresh coconut water    straight from the coconut.  Stay tuned for details.

San Diego Velodrome Class Chariot Race

Here is a cool video, shot by Chris Grout during the adult developmental class, of a chariot race. A chariot race is a race where the riders are held at the start, and then all do one lap from a standing start. This is a great race for beginners, because there isn't a whole lot of jockeying for position, it also teaches "finshing skills" such as holding your line out of corner 4, and just keeping your wits about you when you are getting tired. This is also a cool race or drill for more advanced riders. It helps you with your explosiveness and speed, a requirement for just about any kind of racers, but even more for crit racers and track racers. You do 3 or 4 of these in one day, and I promise you you'll be feeling it! -Sean

Computrainer Course Previews

Check out Karl Coleman's blog on riding a computrainer course preview on the multirider computrainer system.: computrainer screen shot

Want to see the current  Computrainer schedule.  Check it out here.

Our  January 23rd computrainer course preview of the Oceanside 70.3 course is  already sold out, so we will be adding another course preview soon.  Stay tuned for details!

Aire Urban Passport

We are running  a holiday special through the end of the month.   It is a special package we are doing with the  other member of the Aire Co-Op.    For $49 bucks you get 2 cycling classes, 2 rowing classes, 2 TRX classes, and 2 personal training sessions.    This is an amazing bargain, and costs less than start up fees for a gym membership.  If you've got a friend who has been thinking about trying one of these classes, or starting a new fitness program, make sure and pass this on. Added on 12/22/09   Here is a link where you can purchase the Urban Passport. 

Aire Urban Passport

Measuring Energy Expenditure On The Bike Continued.

This is a long overdue follow up to: Measuring Energy Expenditure on the Bike So last time we talked about how  indirect calorimetry is the gold standard, and  why equipment such as heart rate monitors and GPS units are inaccurate.    The next topic to examine is typical gym equipment such as stair climbers,  and treadmills.    These machines suffer from the same inadequacies as the heart rate monitors, in that they rely on equations and guesstimations to measure your energy expenditure.    Just hop on any gym treadmill, and it will ask you your body weight so that it can calculate your energy expenditure as your exercise.   The problem here is that there are many assumptions, and that the work you are doing is being calculated rather than truly measured.    Something else you should know about the calories as given by these machines, is that they include your energy expenditure due to your basal metabolic rate.  Most people burn  between 50 and  80 calories an hour even if they are just sitting on the couch watching TV.   So the calorie count given by these machines is inaccurate to start with, and then  you add  an additional  50+ calories that doesn't really count towards your energy expenditure from exercise, because you would be burning those calories even if you were sitting on your butt!

So the most accurate method of measuring energy expenditure  is definitely indirect calorimetry (measurement of  expired O2 and Co2), but it isn't practical because of these expense involved, and because you have to breath into a mouthpiece containing Oxygen and CO2 sensors.   The next best way of measuring energy expenditure is going to be through the use of power meters.  Power meters such as Power Tap and SRM, use strain gauges to measure force. The strain guages are little strips of metal at  hub or crank, and the amount of deflection is measured.   Power is force X distance/time.  If you measure force with the strain gauges, you can  measure distance with the rotation of the hub or cranks, and then time is measured with a simple clock.    So power meters accurately measure power.  From power  and time you can easily calculate work, and work is measured in Joules.   It's an easy calculation, 1 watt for 1 second = 1 Joule.    Think of it  like this:   If watts were miles per hour, Joules would be total miles.   So if you measure power, you can quite readily get Joules.  At the end of the workout, you can look at your powermeter and and it will give the total joules.  One joules is actually a tiny amount of work, so this measurement is typically expressed as Kilojoules, or thousands of Joules, also known as KJ.

Now we can calculate how many calories you burned during your workout.  We know how many KJ you did, as it was calculated from watts and time.   For demonstration purposes,  let's just say it was 1000KJ.  Calories and Kilojoules are both measurements of energy.    There are 4.18 KJ in every Kilojoule , so you actually did only 239 Calories worth of work.   However, the human body  about 24% efficient at turning food energy into mechanical energy and pedal power, while the other 76% is lost as heat.   So it actually took you about 4.16  times as many Calories to produce that 239 Calories of work.   239 times 4.16 = 996...basically  the number of Kiojoules you did.  This is why we typically tell riders that the number of KJ they do during their workout  is the same as the number of calories burned.   Riders frequently ask me if their body weight makes a difference, and the answer is no.    A larger rider can typically put out more watts, and therefore  do more kilojoules in a given amount of time.    But is still takes a 100lb rider just as many calories to do 150 watts for an hour,as it takes a 200lb rider to do 150 watts for an hour.  The only difference is that the larger rider will burn more calories as part of his basal metabolic rate, but he would burn those even if he were sitting at his desk typing on his keyboard, so that doesn't really count towards his energy expenditure from exercise.

So.... indirect calorimetry is still the most accurate way to measure energy expenditure on the bike, but power meters are definitely the next best thing, and are much more practical for every day use.

All of our bikes at Crank Indoor Cycling are equipped with powertap power meters.  At the end of every ride, you can use your console to examine your data and a d find out your energy expenditure.  This has obvious implications for weight management, but it  is also one of many indicators of fitness.  If you are able to do more KJ of work, and  burn more calories in a similar workout, you know that your fitness level has increased.

Have any more questions about power measurement or measuring energy expenditure?  Feel free to ask questions in the comment section or come to class and ask me afterward!

Ironman AZ

I just wanted to give a shout out to Matt Buster and Karl Coleman.   Both of these are class regulars who  competed in Ironman Arizona last weekend. Karl Came in under  just under11 hours and Matt Came in around 11:20.  A good bike leg contributed to the success of  both of  them.   They each took 25 minutes off of their PRs for their bike legs, and are convinced that their indoor training  at the studio helped them achieve that goal.   Good Job guys, we know we'll see you back in class after you've indulged in a little post event R&R!

Saturday Classes

You've asked for it, and here it is....Saturday classes.   Jeanine will be doing her Cy-Core Class on Saturdays starting at 10AM.  Come on in for 30 minutes of cycling, followed immediately by 30 minutes of core centered yoga.  We will also be having Cy-Core classes on Tues & Thurs at 7.  Jeanine is spin  and yoga certified, and will get you through   great workout that will get your cardio system working, and  and make your body lean and strong.   Those of you that already attend 6 AM cycling class on Tues and Thurs are welcome to stick around and get another 30 minutes of cycling at no charge .