Scientists measure how energy is spent in martial arts

An athlete wears a portable gas analyzer during a judo match. Credit: © Journal of Visualized Experiments

Two judo fighters face off, one in a white judogi (the traditional judo uniform) and one in blue. They reach for each other's shoulders and lock arms, in what looks like an awkward dance, before the fighter in blue throws his opponent head-over-feet onto the mat.

Judo and mixed martial arts have become increasingly popular over the past few years and scientists have taken note. The two fighters were actually filmed as part of a that demonstrates how researchers can quantify exactly how the athletes are spending their energy. The video will be published in JoVE, the Journal of Visualized Experiments.

Previously, researchers have only been able to study predictable sports that are easy to replicate in the laboratory, such as running. With this new method, scientists will be able to study the team and individual sports that have previously been neglected.

"Each sport has specific characteristics which confer different to them," said paper-author Dr. Emerson Franchini. "One of the most important aspects of the metabolic demand is the relative contribution of the energy systems."

Three energy systems are used in exercise: the aerobic metabolism, which uses oxygen to convert nutrients into energy; lactic anaerobic metabolism, which doesn't require oxygen and makes energy exclusively from carbohydrates, with lactic acid as a by-product; and alactic anaerobic metabolism, which makes energy without oxygen and doesn't produce lactic acid.

In this article, the researchers chose to study judo, a complex and unpredictable sport. To figure out the relative contributions of each , the researchers recorded the participants' resting , and used a portable gas analyzer (which looks a little bit like a mini jet-pack) to measure exercise oxygen consumption. The researchers took these measures, as well as post-exercise oxygen consumption, rest lactate concentration, and peak lactate concentration post-exercise, and used various mathematical formulas to determine how much each individual energy system contributed.

"One amazing aspect of this method is that it can provide information regarding the energy demands of specific components within a sport," said JoVE Content Director, Dr. Aaron Kolski-Andreaco. "For example, the relative contributions of the systems can be calculated for different Judo throws, and the authors elegantly demonstrate this in their article."

As the authors point out, the problems with assessing unpredictable or team sports in the laboratory has meant that less attention has been paid to those sports by scientists. They hope that this method will help change that.

More information: To watch the full video article, please follow the link: www.jove.com/video/3413/determ… tems-during-exercise

Provided by The Journal of Visualized Experiments

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Muscles burn lactic acid as well as carbos

Apr 19, 2006

Most athletes see lactic acid as their enemy, and think that training helps them eliminate the metabolic waste product from their muscles so they will function longer and harder. But UC Berkeley physiologist George Brooks ...

New data tests the exercise 'talk test'

Sep 13, 2011

New research by University of New Hampshire exercise scientists confirms that a low-tech, easy-to-administer test is an effective tool for gauging exercise intensity, but that it does not correspond as neatly as previously ...

Lactic acid found to fuel tumors

Nov 20, 2008

A team of researchers at Duke University Medical Center and the Université catholique de Louvain (UCL) has found that lactic acid is an important energy source for tumor cells. In further experiments, they discovered a new ...

Recommended for you

Gamers helping in Ebola research

19 hours ago

Months before the recent Ebola outbreak erupted in Western Africa, killing more than a thousand people, scientists at the University of Washington's Institute for Protein Design were looking for a way to stop the deadly virus.

Carcinogenic role of a protein in liver decoded

22 hours ago

The human protein EGFR controls cell growth. It has mutated in case of many cancer cells or exists in excessive numbers. For this reason it serves as a point of attack for target-oriented therapies. A study ...

A new way to diagnose malaria, using magnetic fields

Aug 31, 2014

Over the past several decades, malaria diagnosis has changed very little. After taking a blood sample from a patient, a technician smears the blood across a glass slide, stains it with a special dye, and ...

User comments