Scientists measure how energy is spent in martial arts

March 20, 2012, The Journal of Visualized Experiments
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.

Explore further: It's all in the mind - how an athlete wins head-to-head competition

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

Related Stories

It's all in the mind - how an athlete wins head-to-head competition

October 7, 2011
We've all seen the moment an athlete pushes themselves at the last second to try and win a head-to-head race, and now a sports scientist has discovered how they do that.

New data tests the exercise 'talk test'

September 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 ...

Recommended for you

Researchers illustrate how muscle growth inhibitor is activated, could aid in treating ALS

January 19, 2018
Researchers at the University of Cincinnati (UC) College of Medicine are part of an international team that has identified how the inactive or latent form of GDF8, a signaling protein also known as myostatin responsible for ...

Bioengineered soft microfibers improve T-cell production

January 18, 2018
T cells play a key role in the body's immune response against pathogens. As a new class of therapeutic approaches, T cells are being harnessed to fight cancer, promising more precise, longer-lasting mitigation than traditional, ...

Weight flux alters molecular profile, study finds

January 17, 2018
The human body undergoes dramatic changes during even short periods of weight gain and loss, according to a study led by researchers at the Stanford University School of Medicine.

Secrets of longevity protein revealed in new study

January 17, 2018
Named after the Greek goddess who spun the thread of life, Klotho proteins play an important role in the regulation of longevity and metabolism. In a recent Yale-led study, researchers revealed the three-dimensional structure ...

The HLF gene protects blood stem cells by maintaining them in a resting state

January 17, 2018
The HLF gene is necessary for maintaining blood stem cells in a resting state, which is crucial for ensuring normal blood production. This has been shown by a new research study from Lund University in Sweden published in ...

Magnetically applied MicroRNAs could one day help relieve constipation

January 17, 2018
Constipation is an underestimated and debilitating medical issue related to the opioid epidemic. As a growing concern, researchers look to new tools to help patients with this side effect of opioid use and aging.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.