energy expenditure

Hone Your Handling Skills

In order to hone your cycling skills it is important to practice them in a controlled environment. This means you should practice riding fast, cornering, and riding in groups. Creating a controlled environment is the hardest part of practicing these skills. To do so you need a safe place to ride and at least one experienced rider who has mastered all of the skills being practiced. Crank Cycling Coaches can help you do this.

Do you want to cruise through the field of riders and find the sweet spot in the peloton? Do you want to slide into the draft and reap the benefits of others' hard work? Would you like to glide through corners at high speeds, not hitting your brakes and not having to over-analyze the word Apex on google search for hours? Do you want to make it over, through, and around obstacles and hazards without worry?

Would you like to keep up on the local club ride without being afraid of riders coming too close to you, or the constant thought of being dropped and not able to catch up at the regroup spot?

All of these things can be accomplished and your mind can be set at ease with some classroom instruction and on-the-bike practice. Come to Crank Cycling's bike-handling and group riding skills clinic on April 16th, presented by Crank Cycling Coach Jesse Eisner. Jesse is a USA Cycling Certified coach and veteran racer with 2 decades worth of riding and racing experience.

See you out on the road, Coach Jesse

Link to sign up

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.

What it takes to ride with the Pros

We put a SRM on Elite amateur riders at Redlands Stage race, and then Daggs and I did a write up on his  power output.: How much power does it take to hang with the pros in a big American stage race? For the Redlands Bicycle Classic, we put an SRM power meter on the bike of Eric Marcotte, a 30-year-old chiropractor who races as a Cat. 1.

Marcotte's power decreased each time up the climb on stage 3. (Wattage is yellow, elevation is red.)

Marcotte lives in Arizona and races with the California-based Pista Palace squad. This year he won stage 2 of the Valley of the Sun and placed fifth in the GC. He then won stage 3 at the Tucson Bicycle Classic from a break. At Redlands, Marcotte was racing in a 190-man peloton that featured 13 pro teams. Here is what the numbers revealed.

How much power does it take to hang with the pros in a big American stage race? For the Redlands Bicycle Classic, we put an SRM power meter on the bike of Eric Marcotte, a 30-year-old chiropractor who races as a Cat. 1.

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!