4/21/2011 1:26pm, #1
If you're smarter than me,reply to this thread
Here's what I'm after, smart guys - I want to know if there's a way to calculate the relative energy output of 2 guys grappling, assuming they are both going at X% of their maximum.
2 guys weigh the same and are rolling at 65% max - I figure their energy output is quite similar, right? Now let's put a guy weighing at 175lb with a guy that's 225lb and they're also going at 65% of max.
Is there a semi-accurate way of calculating how much more energy the small guy has to expend during the session?
Let's eliminate bmi and strength as variables and say that both guys generate the same pound-for-pound output. I'm looking for approximates, nothing absolute.
In before "the thread title will get every single bully to post". Now focus on the calculations, please."Never trust a quote you read on the internet" - Abraham Lincoln
4/21/2011 1:30pm, #2
with differing skills, would they be expending different amounts of energy, relative to their size? Are you assuming, for this, that they are equally skilled?
I'm not smarter than anyone, but you're avatar says:
So I thought you were anticipating my whim...so I posted.
4/21/2011 1:50pm, #3
- Join Date
- Apr 2011
Right...It is complex as **** calculation( incredibly complex). Unless we have members of schools like Harvard, MIT, or Waterloo with enough funding, time, and full support of math, biology, and sociology departments we will never know the answer.
4/21/2011 1:58pm, #4
It wouldn't be that hard to observe if you could measure the increase in temperature in a confined space where they wrestled. Then could you calculate their individual thermal efficiencies and work backwards?
Alternatively you may be able to measure the VO2 max of the individuals then calculate oxygen use in a fixed space. That would likely only give you an estimate of the aerobic energy though.
4/21/2011 2:00pm, #5
- Join Date
- Jan 2007
Not really. Energy used is highly variable in grappling.
You could do it on a position/move basis, and actually calculate the amount of energy required to perform the work, but even tiny variations in a move (Upa: 2 feet flat, 1 flat 1 not, 1 not 1 flat, and 2 not flat) can drastically change how "difficult" it is (even though the end result is the same).
Lastly, their energy output is probably not similar. Being able to work without burning lots of energy is hugely emphasized in jiu jitsu. Anyone who's rolled with a wrestler, a judoka, and a bjj practitioner can tell you that their effort levels vary greatly.
As described, this is not a quantifiable thing.
4/21/2011 2:06pm, #6
Seems like part of the problem is that even though you're trying to do everything by the numbers, there's still the matter that telling someone to go 65% is very hard to actually establish. Maybe they're using 70%, or 60%.
4/21/2011 2:07pm, #7
- Join Date
- Jan 2007
THE FOLLOWING IS CONJECTURE: Thermal efficiency probably has at least 50 variables that affect how much heat someone generates per energy spent. Calculating that would be pretty damn hard, if not impossible.
I have no idea how this could be tested with any level of confidence.
4/21/2011 2:17pm, #8
The only way this question would make sense is if you got a bunch of grapplers (low-level, mid-level and high-level) to roll and do flow drills. Afterward the most accurate reading you could get on how DIFFICULT the activity was is... I guess by measuring their lactic acid levels???
You would need a gauge of each grappler's fitness level, weight and time training for any of your results to mean anything though. Also having them start from different positions would probably affect every results to a certain degree.
Do bigger guys get tired quicker when they have to work off their back? Depends. Do smaller guys expend more energy when they sweep bigger opponents? Depends.
This is an incredibly complicated question. It's not going to change the fact that: Drilling + conditioning + sparring = better fighter. Who cares how much energy it takes? That's what cardio, strength and technique training is for.
4/21/2011 2:20pm, #9
- Join Date
- May 2007
- Lafayette, IN
The only viable way I can think of doing this is with motion capture equipment and anatomical body weight tables. If you've got the weight of the individual sensors by working with the vectors generated you should be able to get the total energy of the system with a reasonable margin of error. The problems are that it would take a lot of sensors and you run the risk of them coming off while your guys are grappling. As mentioned above that only accounts for the kinetic energy. There's heat to consider and some of the energy is going to be lost as sound, too.
4/21/2011 2:27pm, #10
My fiance did her senior thesis research on the metabolic cost of consumption in corn snakes. She measured their metabolic cost by measuring the amount of CO2 that the snakes expelled using various types of meals. I believe that you could use the same kind of measurement to determine relative energy output. Not sure how you would manage the collection, but recording the amount of CO2 produced generally gives you a measure of the energy used as it relates to calorie expenditure... I'd have to talk to her about the math involved with determining energy output from CO2 production, there are formulas involved.