Tag: Peter Weyand

Good news! You’re likely burning more calories than you thought

Post author By Margaret Allen
Post date March 14, 2016

Leading standardized equations used to predict or estimate walking energy expenditure — calories burned — count too few calories in nearly all cases on level surfaces, study finds. New method improves accuracy.

Jennifer Nollkamper and Dr. Lindsay Ludlow assist Dr. Takeshi Fujii in a treadmill test that captures volume of oxygen, volume of expired air and the levels of oxygen and carbon dioxide, all variables that help measure energy expenditure during walking. (Hillsman Jackson, SMU)

Walking is the most common exercise, and many walkers like to count how many calories are burned.

Little known, however, is that the leading standardized equations used to predict or estimate walking energy expenditure — the number of calories burned — assume that one size fits all. The equations have been in place for close to half a century and were based on data from a limited number of people.

A new study at Southern Methodist University, Dallas, found that under firm, level ground conditions, the leading standards are relatively inaccurate and have significant bias. The standards predicted too few calories burned in 97 percent of the cases researchers examined, said SMU physiologist Lindsay Ludlow.

A new standardized equation developed by SMU scientists is about four times more accurate for adults and kids together, and about two to three times more accurate for adults only, Ludlow said.

“Our new equation is formulated to apply regardless of the height, weight and speed of the walker,” said Ludlow, a researcher in the SMU Locomotor Performance Laboratory of biomechanics expert Peter Weyand. “And it’s appreciably more accurate.”

Ludlow and her colleagues report the new equation in the Journal of Applied Physiology, “Energy expenditure during level human walking: seeking a simple and accurate predictive solution.” The article is published in the March 1, 2016 issue, and available online at this link.

“The economy of level walking is a lot like shipping packages – there is an economy of scale,” said Weyand, a co-author on the paper. “Big people get better gas mileage when fuel economy is expressed on a per-pound basis.”

The SMU equation predicts the calories burned as a person walks on a firm, level surface. Ongoing research is expanding the algorithm to predict the calories burned while walking up- and downhill, and while carrying loads, Ludlow said.

SMU’s research is funded by the U.S. Department of Defense Medical Research and Materiel Command. The grant is part of a larger DOD effort to develop load-carriage decision-aid tools to assist foot soldiers.

The research comes at a time when greater accuracy combined with mobile technology, such as wearable sensors like Fitbit, is increasingly being used in real time to monitor the body’s status. The researchers note that some devices use the old standardized equations, while others use a different method to estimate the calories burned.

New equation considers different-sized people
To provide a comprehensive test of the leading standards, SMU researchers compiled a database using the extensive walking metabolism data available in the existing scientific literature to evaluate the leading equations for walking on level ground.

“The SMU approach improves upon the existing standards by including different-sized individuals and drawing on a larger database for equation formulation,” Weyand said.

The new equation achieves greater accuracy by better incorporating the influence of body size, and by specifically incorporating the influence of height on gait mechanics. Specifically:

Bigger people burn fewer calories on a per pound basis of their body weight to walk at a given speed or to cover a fixed distance;
The older standardized equations don’t account for size differences well, assuming roughly that one size fits all.

Accuracy of standardized equations had not previously undergone comprehensive evaluation
The exact dates are a bit murky, but the leading standardized equations, known by their shorthand as the “ACSM” and “Pandolf” equations, were developed about 40 years ago for the American College of Sports Medicine and for the military, Ludlow said.

The Pandolf method, for example, draws on walking metabolism data from six U.S. soldiers, she said. Both the Pandolf and ACSM equations were developed on a small number of adult males of average height.

The new more accurate equation will prove useful. Predicting energy expenditure is common in many fields, including those focused on health, weight loss, exercise, military and defense, and professional and amateur physical training.

“Burning calories is of major importance to health, fitness and the body’s physiological status,” Weyand said. “But it hasn’t been really clear just how accurate the existing standards are under level conditions because previous assessments by other researchers were more limited in scope.”

Energy expenditure estimates could assist with monitoring the body’s physiological status
Accurate estimations of the rate at which calories are burned could potentially help predict a person’s aerobic power and likelihood for executing a task, such as training for an athletic competition or carrying out a military objective.

In general, the new metabolic estimates can be combined with other physiological signals such as body heat, core temperature and heart rate to improve predictions of fatigue, overheating, dehydration, the aerobic power available, and whether a person can sustain a given intensity of exercise.

Military seeks solutions to overburdened soldier problem
The military has a major interest in more accurate techniques to help address their problem of over-burdened soldiers.

“These soldiers carry incredible loads — up to 150 pounds, but they often need to be mobile to successfully carry out their missions,” said Weyand, a professor of Applied Physiology and Wellness in the SMU Simmons School of Education.

Accurately predicting how many calories a person expends while walking could supply information that can help soldiers avoid thermal stress and fatigue in the field, especially troops deployed to challenging environments.

“Soldiers incur a variety of physiological and musculoskeletal stresses in the field,” Weyand said. “Our metabolic modeling work is part of a broader effort to provide the Department of Defense with quantitative tools to help soldiers.” — Margaret Allen

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SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

Tags Annette Caldwell Simmons School of Education & Human Development, Lindsay Ludlow, Peter Weyand

Culture, Society & Family Health & Medicine Researcher news SMU In The News

HuffPo: Cheating in Sports — Where Do We Go From Here?

Post author By Margaret Allen
Post date September 21, 2015

Definitions and standards for what constitutes cheating vs. fairness have never been so needed or consequential. — Weyand

SMU physiologist and biomechanics researcher Peter G. Weyand contributed a piece on cheating in sports to the U.S. online news magazine and blog the Huffington Post.

The piece addresses how modern cheating controversies in sports indicate the need for a new approach to judge fairness that encompasses a broader range of possibilities.

Weyand leads the SMU Locomotor Performance Laboratory and is recognized worldwide as an expert in human running performance.

An expert in the locomotion of humans and other terrestrial animals, Weyand’s broad research interests focus on the relationships between muscle function, metabolic energy expenditure, whole body mechanics and performance.

Weyand’s Huffington Post article, “Cheating in Sports — Where Do We Go From Here?” published Sept. 14, 2015.

EXCERPT:

By Peter Weyand
in the Huffington Post
“I can’t define it, but I know it when I see it.” — U.S. Supreme Court Chief Justice Potter Stewart on pornography in Jacobellis v. Ohio, 1964

Consider some of the current controversies in organized sport: football inflation pressures, “flopping” and “diving” to deceive basketball and soccer officials, performance-enhancing drug (PEDs) cases, possible techno-doping via streamlined suits and artificial limbs, and the potential for genetic doping.

These and other contemporary issues pose unprecedented challenges to the integrity of organized sport. Accordingly, definitions and standards for what constitutes cheating vs. fairness have never been so needed or consequential.

History provides us with clear instances of cheating in sport: Chicago’s “Black Sox” conspiring to intentionally lose baseball games in the 1919 World Series, pitcher Gaylord Perry throwing spitballs in the 1970s, or sprinter Ben Johnson taking banned steroids leading into the 1988 Olympics.

However, many contemporary sport “cheating” controversies simply cannot be evaluated in an equivalently black and white framework.

Consider the ethical dilemmas the following situations pose for modern athletes and athletics: Is it cheating to take a new “designer drug” if: a) it is not banned, b) it enhances performance, and c) many of your competitors take it, and d) you are disadvantaged if you do not?

Is it cheating to fake a fall to induce a referee to call a foul on an opponent?

Is it cheating for an athlete seeking enhanced endurance to sleep in an altitude tent to boost red blood cell production when: a) the practice is not illegal, and b) other athletes do not have the means to do the same.

Is it cheating to use genetic techniques (rather than physical training) to activate dormant portions of one’s DNA to improve muscle performance?

Three of the preceding scenarios presented themselves years ago, the fourth may or may not have yet occurred, but has been a credible threat for some time. All four pose major challenges to the health and integrity of sport.

Yet, while the integrity of sport depends on fairness, the commitment needed to provide it in a viable contemporary form does not seem to be in place. Hence, what is perhaps the greatest threat to both the integrity and health of modern sport – an onslaught of sophisticated techniques to gain advantage by any means possible – is under-recognized, under-resourced and inadequately addressed.

Even a cursory look at the problem makes clear that performance enhancement techniques have raced ahead while standards and policies have not. Athletes and coaches have acknowledged and openly complained that outcomes are unfairly determined by technology rather than ability. Leagues have implemented new policies only to quickly acknowledge they fail to remedy the fairness problems they address (see the NBA’s flopping fines). Instructional videos for inducing foul calls on opponents have been published featuring leading players. “Dirty” athletes, like Lance Armstrong, pass hundreds of doping tests while “clean” athletes are implicated.

Read the full article.

Follow SMUResearch.com on twitter at @smuresearch.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

Tags Peter Weyand, Simmons School of Education & Human Development

Culture, Society & Family Health & Medicine Researcher news SMU In The News

ESPN: How have players become so big and so fast?

Post author By Margaret Allen
Post date July 1, 2015

Blame a former pole-vaulter who in 1969 was weight training the Nebraska Cornhusker’s injured players

Boyd Epley changed the way Nebraska approached strength training, and soon after other programs followed their lead. (Courtesy Nebraska athletics)

SMU physiologist and biomechanics researcher Peter G. Weyand was quoted by ESPN reporter Josh Moyer in his Big Ten Blog for an article about the evolution of the speed and size of college football players.

Weyand leads the SMU Locomotor Performance Laboratory and is recognized worldwide as an expert in human running performance. An expert in the locomotion of humans and other terrestrial animals, Weyand’s broad research interests focus on the relationships between muscle function, metabolic energy expenditure, whole body mechanics and performance.

Moyer’s ESPN article, “How have players become so big and so fast? Blame a former pole-vaulter” published July 1, 2015.

Weyand’s research on the limits of human and animal performance has led to featured appearances on the British Broadcasting Corporation, the Canadian Broadcasting Corporation, CNN, the Discovery Channel, the History Channel, NHK Television Japan, National Public Radio and others.

Read the full article, “How have players become so big and so fast? Blame a former pole-vaulter.”

EXCERPT:

By Josh Moyer
ESPN Staff Writer

Nebraska’s Boyd Epley can still remember the weight-room phone call during a warm August afternoon in 1969. He didn’t know the brief talk would forever alter the college football landscape.

For months Epley, a no-name pole-vaulter from a no-name Arizona junior college, had trained — almost inadvertently — the Huskers’ injured football players. Epley lifted weights to strengthen his injured back — using techniques he picked up from a body-building friend in high school — and the Huskers’ football players mimicked him.

Tom Osborne, then a first-year offensive coordinator at Nebraska, noticed that those injured players returned to the gridiron even better than before, so he wondered what kind of impact strength training would have on healthy players. Why couldn’t Epley work his magic on the entire Huskers team? Why not call down to the weight room and hire him as the nation’s first full-time strength and conditioning coach?

“If you’re looking for the most impactful change, in terms of progression, Nebraska’s coaches coming onto the scene like that — that was probably the single most important event,” said Dr. Peter Weyand, an SMU professor of applied physiology and biomechanics, and one of the nation’s foremost experts on human performance.

Read the full article, “How have players become so big and so fast? Blame a former pole-vaulter.”

Follow SMUResearch.com on twitter at @smuresearch.

Tags Annette Caldwell Simmons School of Education & Human Development, Peter Weyand

Culture, Society & Family Health & Medicine Researcher news SMU In The News

Outside Magazine: Inside the Effort to Crack the Sub-Two Hour Marathon

Post author By Margaret Allen
Post date April 22, 2015

A bold, scientist-backed effort to achieve the impossible within the next five years may benefit all runners—even if the goal remains a moonshot.

The work of SMU physiologist and biomechanics researcher Peter G. Weyand was featured in an article in Outside Magazine about an international scientific collaboration’s effort to crack the sub-two hour marathon.

An associate professor of applied physiology and biomechanics in SMU’s Annette Caldwell Simmons School of Education and Human Development, Weyand is one of the world’s leading scholars on the scientific basis of human performance. His research on the importance of ground forces for running speed established a contemporary understanding that spans the scientific and athletic communities.

In particular, his finding that speed athletes are not able to reposition their legs more rapidly than non-athletes debunked a widespread, but baseless belief. Rather, Weyand and colleagues demonstrated sprinting performance is largely set by the force with which one presses against the ground and how long one applies that force.

This work provided the understanding that enabled Weyand and colleagues to investigate the influence of prosthetic limbs on sprint running performance.

The article published April 10, 2015.

Read the full story.

EXCERPT:

By Brian Alexander
Outside Magazine
Last year, when University of Brighton professor Yannis Pitsiladis announced Sub2-Hrs, an organized effort to break the two-hour marathon barrier within five years—a milestone akin to the four-minute mile or the ten-second 100 meters—a chorus of naysayers sprang to their feet in protest. Exercise physiologist Ross Tucker even called the effort “disingenuous” on his sports science blog.

Any number of theories have been floated as to why the Sub2-Hrs effort will fail, but all of them may be missing the point. The object of the exercise, according to team member Peter Weyand, a professor of applied physiology at Southern Methodist University, is to assemble a team of experts in various segments of human performance including genetics, physiology, training, nutrition, medicine, biomechanics and see what happens.

The exact details of the Sub2-Hrs project aren’t yet available. It’s unknown at this point, for example, if there will be some compound where athletes will train and live together under the supervision of clipboard-carrying scientists. Weyand said the plan is to screen runners who have dominated distance running (likely East Africans), for genetic variants that might predispose them to success, then apply the skills of other experts toward improving those elite athletes’ running efficiency, diet, avoiding injuries, and so on, so that one of them may break that two hour barrier within the next five years.

“There are a number of basic questions about why people run the way they do,” Weyand explained. “What movement patterns are best for performance? Are they the same patterns that prevent injuries? There is a sea of unanswered questions.”

Read the full story.

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Tags Annette Caldwell Simmons School of Education & Human Development, Peter Weyand

Culture, Society & Family Learning & Education Researcher news SMU In The News

Wall Street Journal: March’s True Madness — Flopping

Post author By Margaret Allen
Post date March 18, 2015

As in the NBA, the art of embellishing contact has become widespread in college basketball

As the 2015 NCAA tournament gets into gear, Wall Street Journal sports reporter Brian Costa quoted SMU locomotor expert Peter Weyand for an article on flopping among college basketball athletes.

The article, “March’s True Madness: Flopping,” quotes Weyand and other experts on the prevalence of flopping in college basketball and the ability of referees to detect it.

The article published March 17, 2015.

Read the full story.

EXCERPT:

By Brian Costa
Wall Street Journal
At some point during every NCAA tournament game, a player with the ball will bump into a defender. The defender will fall to the floor, seemingly blown backward by the overwhelming force of his opponent. And referees will be faced with a question that is becoming increasingly difficult to answer: Was it a foul or a flop?

Mimicking the NBA, where the practice has become widespread, college players are becoming ever more proficient in the art of flopping—embellishing or outright faking blows to their bodies to convince referees to call a foul.

The most flagrant histrionics have attracted widespread attention. In February, a video clip of St. John’s swingman Sir’Dominic Pointer flailing his arms in an apocalyptic tumble became a viral hit. But the savviest actors aren’t nearly as obvious about it.

“I’ve had countless games this year where you say, ‘That’s a flop,’ ” ESPN analyst Jay Bilas said. “There’s no way that amount of force caused that amount of physical reaction from the defender. You’d have to be shot in the chest with a bazooka to fall like that.”

Although the frequency of such plays is unclear—the NCAA doesn’t track offensive fouls—the powers that be in college basketball believe there is a problem. Belmont coach Rick Byrd, who chairs the NCAA men’s basketball rules committee, said flopping is becoming prevalent enough that he wants to address it at the committee’s next meeting in May. And it isn’t only happening with players trying to draw a charge. [….]

[….]Part of the issue for any league is the uncertainty surrounding an essential question: what amount of physical reaction should be expected on a given play?

“How much force does it really take in a typical basketball encounter to knock someone off balance?” said Peter Weyand, a physiologist and biomechanist at Southern Methodist University. “That information is not out there.”

With funding from Dallas Mavericks owner Mark Cuban, Weyand is leading a study to find out. Using people of various heights and weights, the study simulated typical basketball collisions and measured both the forces involved and the subjects’ natural reactions.

Read the full story.

Follow SMUResearch.com on twitter at @smuresearch.

Tags Peter Weyand, Simmons School of Education & Human Development

Leading standardized equations used to predict or estimate walking energy expenditure — calories burned — count too few calories in nearly all cases on level surfaces, study finds. New method improves accuracy.

For more information

Related links

More SMU Research news

Definitions and standards for what constitutes cheating vs. fairness have never been so needed or consequential. — Weyand

Book a live interview

Related links

More SMU Research news

Blame a former pole-vaulter who in 1969 was weight training the Nebraska Cornhusker’s injured players

Book a live interview

Related links

More SMU Research news

A bold, scientist-backed effort to achieve the impossible within the next five years may benefit all runners—even if the goal remains a moonshot.

Book a live interview

Related links

More SMU Research news

As in the NBA, the art of embellishing contact has become widespread in college basketball

Book a live interview

Related links

More SMU Research news