CrossFit Discussion Board  

Go Back   CrossFit Discussion Board > CrossFit Forum > Fitness
CrossFit Home Forum Site Rules CrossFit FAQ Search Today's Posts Mark Forums Read

Fitness Theory and Practice. CrossFit's rationale & foundations. Who is fit? What is fitness?

Reply
 
Thread Tools
Old 11-05-2006, 06:43 AM   #1
Israel Halperin
Member Israel Halperin is offline
 
Profile:
Join Date: Apr 2005
Location: tel aviv  tel aviv
Posts: 65
i just read this great kipping pull ups thread
http://www.crossfit.com/cgi-bin/disc...c=22&page=9021

and would like to understand what is the definition of power in regard to the pull ups here.

the way i understand it, i will get more pull ups per unit of time if i will kipp, compare to strict ones, but i wont recruit as much energy from the more isolated muscles, using strict pull ups.
how can one decide which measurement of pull ups uses more energy,work per unit of time ?
and why are the numbers of reps per unit of time count as the only, or main measurement for work in this case, and not, say, the recruitment of motor units, or CNS effort per unit of time?


  Reply With Quote
Old 11-05-2006, 07:01 AM   #2
Craig Van De Walker
Member Craig Van De Walker is offline
 
Profile:
Join Date: May 2005
Location: Beaverton  OR
Posts: 872
Off the top of my head.

We usually just measure reps because it levels the field so to speak ie person hauling around 25lbs extra fat is handicapped by the extra weight. Result when you lose extra weight your performance improves, but lose too much weight and you lose usefull muscle and performance goes down. We now have a feedback loop to help us decide how to manage our weight in a healthy way.

You can actually measure the physical work done if you only add weight and distance. Weight x distance / time. You can do it with a pencil and paper, or in your head. I don't know how to measure motor unit recruitment or CNS effort per unit of time.

We do perform strict pullups during some of the workouts. L-pullups, try to do a bunch of these, or deadhang/strict pullups. They are just not the default pullup.

If you read the FAQ page and some of the old posts things may make more sense.
  Reply With Quote
Old 11-05-2006, 09:34 AM   #3
Brad Davis
Member Brad Davis is offline
 
Profile:
Join Date: Oct 2006
Location: Blacksburg  VA
Posts: 608
Craig is right about the definition of power. Another way to think about it is in energy expended (or work done) per unit time.

The only confusion comes in when people don't think about what is doing the work that goes into the equation. For example, if you bounce the bar at the bottom of a deadlift, then gravity, by way of the elastic bounce at the bottom, supplied part of the work for the next rep.
  Reply With Quote
Old 11-05-2006, 12:01 PM   #4
Israel Halperin
Member Israel Halperin is offline
 
Profile:
Join Date: Apr 2005
Location: tel aviv  tel aviv
Posts: 65
how can you know that your expending more energy while kipping ? doing more repetitions per unit of time is just one parameter out of many others (cns effort,motor unit recruitment,time under tenstion,level of concentration..)


  Reply With Quote
Old 11-05-2006, 05:35 PM   #5
Brad Davis
Member Brad Davis is offline
 
Profile:
Join Date: Oct 2006
Location: Blacksburg  VA
Posts: 608
That's a good question, IMO. Around here, I think folks are typing about external work done.

Is there a way to quantify internal energy expended that doesn't result in external work?
  Reply With Quote
Old 11-05-2006, 07:18 PM   #6
Craig Van De Walker
Member Craig Van De Walker is offline
 
Profile:
Join Date: May 2005
Location: Beaverton  OR
Posts: 872
Time under tension, cns effort, motor unit recruitment and level of concentration are not measurable "work". I could be wrong or out of touch with recent research but I have never seen those things specifically quantified. Many times though I have seen foot pounds of work over time measured.

I do not remember hearing much discussion about more or less energy expended only more or less work being done (power being produced).

When you measure the horsepower and torque of an automobile engine you do not hear how many calculations per second the engine management system is completing, the dwell time of the injectors, cam overlap, or internal friction measures etc. just what the engine can do for the vehicle.

That being said, there are things we have been exposed to that are very hard to accomplish while doing no measurable work. Take for example a 3 minute L-sit very hard but does no measurable external work. Other examples that come to mind are handstand balancing or front and back levers.


(Message edited by vcraig on November 05, 2006)
  Reply With Quote
Old 11-05-2006, 09:05 PM   #7
Carrie Klumpar
Member Carrie Klumpar is offline
 
Carrie Klumpar's Avatar
 
Profile:
Join Date: Sep 2003
Location: Seattle/Redmond  WA
Posts: 461
Sounds like it's a matter of semantics here.

There are lots of parameters you could measure. If you want to measure power output (i.e., energy expenditure), the formula is F (t)/D (or, to super-simplify, reps per unit time).

If you want to talk about muscle recruitment, time under tension, grip strength, hypertrophy, callus wear and tear, or whatever, then the terms of the formula, obviously, will vary.
  Reply With Quote
Old 11-06-2006, 03:58 PM   #8
Mike Yukish
Member Mike Yukish is offline
 
Profile:
Join Date: Jan 2004
Location: State College  PA
Posts: 448
how can you know that your expending more energy while kipping ?

You're not expending more energy (on a per rep basis). You're expending energy faster (more power).

But you will end up expending more energy in a max reps set, because you are spreading the total force over more muscles and so can do more total reps.
  Reply With Quote
Old 11-06-2006, 05:04 PM   #9
Rafael Mattei
Member Rafael Mattei is offline
 
Rafael Mattei's Avatar
 
Profile:
Join Date: Jun 2005
Location: san juan  PR
Posts: 87
how can you know that your expending more energy while kipping ?

I think because i'm ussually more out of breath with the kipping kind, also you are not only using your arms but your abs and legs muscles to drive the pull up UP.

my .02 cents
  Reply With Quote
Old 11-06-2006, 06:09 PM   #10
Lincoln Brigham
Member Lincoln Brigham is offline
 
Lincoln Brigham's Avatar
 
Profile:
Join Date: May 2003
Location: Kirkland  WA
Posts: 3,987
how can you know that your expending more energy while kipping ?

An engineer will tell you that in almost any mechanical system as a general rule a higher power output results in a greater-than-linear increase in energy expenditure.

Think of cars and gas consumption as an analogy. Faster speeds will reduce fuel economy. A car burns more gas over a given distance when driven at higher speeds. A 4-cylinder, 40 miles per gallon Honda won't get 40 miles per gallon anymore when driven at 95 mph. A drag racer going 300mph gets about 4 miles per gallon. Power is costly. Peak power is very costly.

The human body is no different. Kipping can achieve a higher power output (pullups per minute) than strict pullups. As the body approaches maximum performance, small increases in power output (work over time) will result in huge increases in energy cost.
  Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Comments on "From load, distance, and time we calculate work, and work-capacity/intensity/power" Eric Cimrhanzel Fitness 17 11-19-2006 12:56 PM
Best time of day to work out Max Seid Fitness 23 10-19-2006 07:33 PM
Does power oly lifting work the support phase in the upper body? Blair Robert Lowe Exercises 5 02-08-2006 12:10 PM
'Power' Interval work right Up XFits Aley Tim Morrison Fitness 5 10-26-2005 12:55 AM
Situps for time/power - Help Michael Ledney Exercises 4 10-12-2005 11:05 AM


All times are GMT -7. The time now is 11:05 PM.


CrossFit is a registered trademark of CrossFit Inc.