“Our recent study shows that exercise leads to expansion of the mitochondrial network and, as a result, energy is distributed to muscle in a more effective manner,” says Professor David Hood��from the School of Kinesiology & Health Science in the Faculty of Health.

David Hood

On the other hand, the research shows that mitochondria become smaller or more fragmented when the muscle is not used –��due to aging, for example��–��which leads to cellular damage and degeneration of muscle cells.

The study, “Expression of Mitochondrial Fission and Fusion Regulation Proteins in Skeletal Muscle During Chronic Use and Disuse”, assesses the effects of aging on mitochondrial morphology and has been accepted for publication by the peer-reviewed journal��Muscle and Nerve.

Led by Hood, director of the Muscle Health Research Centre at 91��ɫ, the study was conducted by his graduate students Sobia Iqbal, Olga Ostojic, Kaustabh Singh and Anna-Maria Joseph.

The findings indicate that the proteins involved in maintaining the size and shape of mitochondria are also regulated by exercise, or lack thereof. According to the researchers, this can have important implications for energy production in muscle, the benefits of exercise and the consequences of chronic inactivity on our health.

The research received support from a Natural Science & Engineering Research Council of Canada grant.

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The study by principal researcher Tara Haas of 91��ɫ’s School of Kinesiology & Health Science and Muscle Health Research Centre in the Faculty of Health in collaboration with 91��ɫ kinesiology Professor Michael Riddell was published online in the peer-reviewed journal in October.

Tara Haas

“Cortisol is a steroid hormone normally present in our body in small amounts, but a continuous increase in cortisol levels is linked with the development of obesity and Type 2 diabetes,” says Haas.�� The research by her team looked at the effects of sustained increases in the levels of the stress hormone corticosterone (the form of cortisol found in rodents) on the smallest blood vessels, capillaries, within skeletal muscles.

What they found, says Haas, “was a substantial reduction, by 30 per cent, in the number of capillaries within the muscle.” As capillaries bring oxygen and nutrients to the muscle cells, this reduction could have significant consequences for muscle function and perhaps even blood sugar disposal.

“This is important as a reduction in the number of capillaries could influence the ability of a person to be active, which could cause their condition to worsen,” says Haas. The finding may help to explain why people with Type 2 diabetes have difficulty growing new capillaries in other tissues, such as the heart.

Michael Riddell

The researchers then took a closer look at the mechanisms involved in the reduced capillary growth by using cultured endothelial cells – those cells that form capillaries – chronically treated with the stress hormone. They found that corticosterone repressed several major intracellular signal pathways involved in controlling cell proliferation and migration, which likely contributes to the lack of capillary growth.

“This research is significant because it highlights that a chronic elevation of stress hormone can have significant negative consequences to the small blood vessels within skeletal muscle that are in charge of providing much needed oxygen and nutrients,” says Haas. “It also points the way to identifying how cortisol, through its effects on blocking appropriate blood vessel growth, may contribute to cardiovascular complications of diabetes or obesity.”

Skeletal muscle endothelial cells in culture

Haas says the findings warrant further research to determine if treatment with synthetic steroid hormones carries similar risks. The capillaries in the skeletal muscles studied were affected using a low, but continuous exposure, to the stress hormone. The amount of synthetic steroid hormones, such as hydrocortisone, people are usually prescribed to block inflammation in the body, can be 25 times higher than the amount used in the study.

Haas is a member of the newly formed Angiogenesis Research Group, which investigates the adaptation of the skeletal muscle capillary network to physiological and pathological conditions.�� The research was supported by the Natural Sciences & Engineering Research Council of Canada (NSERC) Discovery Grants to Haas and Riddell, as well as awards to 91��ɫ students, including Eric A. Shikatani, who was the recipient of a Heart & Stroke Foundation of Ontario Master’s Studentship Award. In addition, student Anastassia Trifonova was the recipient of a NSERC CGSM graduate scholarship, and Anna Krylova and Andrei Szigiato were recipients of NSERC Undergraduate Student Research awards.

By Sandra McLean, YFile deputy editor

Republished courtesy of YFile– 91��ɫ’s daily e-bulletin to research stories on the research website.

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Many people overestimate the size of one serving of food as defined in Canada’s Food Guide, so they may be overeating even if they believe they are being careful, according to a study by Jennifer Kuk, a professor in the School of Kinesiology & Health Science in 91��ɫ’s Faculty of Health, and lead author Sharona Abramovitch, a former graduate student at 91��ɫ. The study was published online Tuesday in the journal .

Canada’s Food Guide is an important tool used by many general practitioners to help their patients eat more healthfully, says Kuk, so it made sense to study whether people would be able to tell from the food guide if they are eating enough of the four food groups: vegetables and fruit, meat and alternatives, grain products, and milk and alternatives.

Jennifer Kuk

“What we found was that the way people estimate one serving is essentially how much they would normally eat at one time,” says Kuk. “The majority of participants in the study inaccurately thought they would need to increase their food consumption by approximately 400 calories to meet recommendations in Canada’s Food Guide. This suggests we either need to change the size of a serving in the Guide – which has remained almost the same since 1977 – or educate Canadians more about how much food they should be consuming in a day.”

That eight-ounce steak you throw on the barbeque this summer, for example, alone exceeds the Canada Food Guide’s maximum daily allowance for meat and alternatives, says Abramovitch, a former graduate student in the School of Kinesiology & Health Science in 91��ɫ’s Faculty of Health. And only half a cup of cooked pasta is one of the eight grain servings allowed per day for a male between the ages of 19 and 50.

[stream provider=youtube flv=http%3A//www.youtube.com/watch%3Fv%3DZ8_ZEwHGRBA img=x:/img.youtube.com/vi/Z8_ZEwHGRBA/0.jpg embed=false share=false width=400 height=300 dock=true controlbar=over bandwidth=high autostart=false /]

Researchers analyzed food records from the 145 participants in the study, which included White, Black, South Asian and East Asian adults. They were asked to select what they thought was a serving, and researchers measured it to see whether the serving size corresponded with Canada’s Food Guide. They were also asked to estimate how much of something – for example, pasta – they would eat at one sitting, and to recall their diet over 24 hours.

All four ethnic groups inaccurately estimated the total number of servings they were eating in a day: they underestimated the number of servings of fruit and vegetables, grain products and meat, and overestimated the number of servings of milk and alternatives they were eating.

The research was funded by the Heart & Stroke Foundation.

Republished courtesy of YFile– 91��ɫ’s daily e-bulletin.

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“There is much we can do to foster a love of physical activity in recreation in youth,” says Professor Parissa Safai of 91��ɫ’s School of Kinesiology & Health Science in the Faculty of Health. She was on the research committee responsible for the main report and was the lead researcher for all the qualitative components of the report.

Safai designed and analyzed the research exercises with more than 140 youth at a youth summit. She also compiled a series of community snapshots with 91��ɫ kinesiology and health science PhD student Alana Harrington to highlight physical activity promotion success stories in Toronto and the GTA.

The report highlights seven key recommendations targeted at increasing physical activity among youth. Those recommendations, says Safai, include ways to support girls – the least physically active population group in Canada.

As Safai says, “Physical activity in youth is critical in the development of lifelong habits.”

But what the report found is “low levels of physical activity have not changed much over the last decade….only 42 per cent of Torontonians are physically activity during leisure time.”

Among the seven highlights, the report found that girls may require a different approach; there is a large knowing-doing gap among youth when it comes to physical activity; socio-cultural barriers make a difference; schools play an important role in fostering physical activity; and the environment, including walkable neighborhoods and safe recreation spaces, can make a difference.

Safai has been a part of the Get Active Toronto research team since 2008. “This year's report focuses on what we can do to help youth be more active. Together, Torontonians are in a position to reduce or eliminate many of the barriers that face our children and youth,” she says. “But we still need to be aware of the gaps in our knowledge of physical activity and encourage funders and researchers to continue to work together to help us all develop a more complete picture of physical activity in Toronto so that we can reduce all of the barriers we face.”

One of the ways to help youth is to encourage adults to display positive attitudes about physical activity and to be better role models for young people. “We need to understand that social isolation, embarrassment and peer pressure also contribute to physical inactivity in youth,” says Safai.

To view the , visit the website.

Get Active Toronto is a public-private collaborative seeking positive change in the physical activity levels of Torontonians.

Republished courtesy of YFile– 91��ɫ’s daily e-bulletin

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Using an animal model, the study’s researchers found that the motor performance and muscle endurance of mice with ALS improved when they were given higher than normal doses of vitamin D.

“We are the only group in Canada that is looking at the connection between dietary interventions and the effects on the ALS model,” says 91��ɫ kinesiology Professor Mazen Hamadeh (left)��of the University’s Muscle Health Research Centre in the Faculty of Health. Hamadeh supervised the research led by 91��ɫ master of science degree students Jesse Solomon and Alexandro Gianforcaro in the School of Kinesiology & Health Science.

The researchers conducted three different studies looking at different amounts of vitamin D. The first looked at the effects of 10 times the adequate intake of vitamin D on the ALS animal model – the equivalent of 8,000 IU/day in humans. Results showed an improvement in both motor performance and endurance, but no change to disease outcomes, such as onset, progression or lifespan.

“We followed up with another study because we thought we didn’t give high enough amounts of vitamin D,” says Hamadeh. In the second study, the amount of vitamin D was increased to 50 times the suggested adequate intake amount or the equivalent of 40,000 IU per day in humans. Again, there was definite improvement in functional outcomes, but not in disease outcomes, confirming the findings of the first study, he says.

The researchers then thought that perhaps the recommended adequate intake amount of vitamin D was set too high and there was already an overabundance of vitamin D being administered. That led to a third study where only one fortieth of the recommended adequate intake amount was administered using the animal model, which induced a vitamin D deficiency. This study was published in PLoS ONE, an international online peer-reviewed journal, on Dec. 27.

This third study produced some interesting results, says Hamadeh. When vitamin D deficiency was induced before disease onset, disease severity was reduced, but after disease onset, it was worse. “So at very low levels there is something happening in the cell that is causing them to function better only for a little bit of time, only until disease onset, than they progress regularly,” he says.

The key now is to find out what molecular changes are occurring in the muscle, spinal cord and brain when vitamin D is administered, and that is what Hamadeh and his students are currently working on.

“ALS is the most common motor neuron disease and up until now there is no cure for it. It is also a fast-progressing disease. Between diagnosis and death, there are usually two to five years. We are trying to see whether by modulating the diet, by changing the diet, we can influence not only when the disease starts, but how fast it progresses and whether it can affect lifespan,” says Hamadeh.

“To find a dietary intervention that could influence a fast-paced disease after diagnosis of the disease, meaning after some irreversible damage has happened, means this particular nutrient has to be very powerful to either halt or slow the pace of the disease.”

The model Hamadeh works with suffers from heightened oxidative stress, a state of increased levels of free radicals or oxidants that are produced naturally inside the cell during normal functioning and metabolism. There is an association between oxidative stress and chronic, metabolic, autoimmune, neurodegenerative and neuromuscular diseases, including ALS, Type 1 and Type 2 diabetes, cardiovascular disease, obesity, hypertension, Alzheimer’s, Parkinson’s and multiple sclerosis.

Hamadeh hopes his research and that of his students will help not only ALS, but many other similar diseases that share common mechanisms with ALS.

By Sandra McLean, YFile writer

Republished courtesy of YFile– 91��ɫ’s daily e-bulletin.

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Blow by Blow: The Second Annual Donald Sanderson Memorial Symposium on Sport Concussion��is open to the public – athletes, coaches, parents,��researchers and anyone interested in the��physical and psychological impact head injuries can have on individuals and their families.

91��ɫ’s School of Kinesiology & Health Science will host the two-hour evening event, which will bring sports medicine and brain researchers together with athletes to discuss an injury that continues to impair the careers and health of both amateur and professional athletes − most recently, hockey champion Sidney Crosby.

The symposium is held in honour of Donald Sanderson, the 91��ɫ kinesiology student and promising hockey player who died Jan. 2, 2009 as a result of a head injury during a Whitby Dunlops game.��

�������� Right: Matt Dunigan

"Educating our student athletes about head injuries is critical,” says Cindy Hughes, manager of the Gorman/Shore Sport Injury Clinic in 91��ɫ’s School of Kinesiology & Health Science, who helped organize the symposium. “They need to understand the importance of reporting a possible concussion right away so they can receive the proper care."

, a game analyst with TSN since 1996, played football for 14 years on five Canadian teams and was inducted into the Canadian Football Hall of Fame in 2006. He retired from football in 1996 after suffering at least a dozen diagnosed concussions, and continues to struggle with the long-term effects of those concussions. He will speak about the post-concussive symptoms he has experienced since retirement and the effect of concussion on himself and his family, as well as the importance of reporting concussion and taking it seriously. A champion of research on sport concussion, Dunigan announced last spring that upon his death his brain will be donated to Toronto’s Krembil Neuroscience Centre.

Dahna Sanderson, who established the Donald Sanderson Memorial Trust Fund in memory of her son, will also speak during the symposium. A sports mom and fan for 20 years, she coached professional figure skating and is passionate about sports and sports safety.��

is a primary care sport medicine specialist, certified in family and sports medicine in Canada and the US. Currently practising in Burlington, he has been a junior hockey team physician for the past decade in Canada and the US. He is a research chair of the Hockey Neurotrauma and Concussion Initiative Research Committee and is primary investigator of the Hockey Concussion Education Project.��

Lauren Sergio is a professor in the School of Kinesiology & Health Science in 91��ɫ’s Faculty of Health. A neuroscientist, she studies the effects of age, sex, neurological disease, head injury and experience (élite versus non-élite athletes) on the brain’s control of complex movement. She works with a wide range of adults, from NHL draft prospects to Alzheimer’s disease patients, using behavioural and brain imaging techniques.��

Left: Lauren Sergio

Roy McMurtry, 91��ɫ chancellor and former chair and chief executive officer of the Canadian Football League, will deliver opening remarks. Award-winning CBC sports reporter Teddy Katz will MC the event.��

The symposium takes place in the Price Family Cinema, Accolade East Building, from 7 to 9pm. Admission is free, but registration is required. To register and for more information on speakers, visit the symposium website.

Republished courtesy of YFile– 91��ɫ’s daily e-bulletin.

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Published in the August issue of the��journal Applied Physiology, Nutrition and Metabolism, the study finds that obese people who are otherwise healthy, live just as long as their slim counterparts and are less likely to die of cardiovascular causes.

“Our findings challenge the idea that all obese individuals need to lose weight,” says lead author Jennifer Kuk, a professor in 91��ɫ’s School of Kinesiology & Health Science, Faculty of Health. “Moreover, it’s possible that trying – and failing – to lose weight may be more detrimental than simply staying at an elevated body weight and engaging in a healthy lifestyle that includes physical activity and a balanced diet with plenty of fruits and vegetables,” she says.

Kuk’s team looked at 6,000 obese Americans over a 16-year span, comparing their mortality risk with that of lean individuals.

They found that obese individuals who had no (or only mild) physical, psychological or physiological impairments had a higher body weight in early adulthood, were happier with this higher body weight, and had attempted to lose weight less frequently during their lives. However, these individuals were also more likely to be physically active and consume a healthy diet.

Right: Individuals should consult their physician about whether or not they need to shed the extra weight

Researchers used a newly-developed grading tool, the Edmonton Obesity Staging System (EOSS), which has been found to be more accurate than body mass index (BMI) for identifying who should attempt to lose weight. Developed by University of Alberta researchers, it is modelled on staging systems that classify the extent and severity of other diseases such as cancer, mental illness and heart disease. It offers five stages of obesity based on both traditional physical measurements such as BMI and waist-to-hip ratio, plus clinical measurements that reflect medical conditions often caused or aggravated by obesity (such as diabetes, hypertension and heart disease).

Kuk stresses that in order to determine whether or not they should lose weight, individuals should see a physician to be evaluated using the EOSS criteria.

The study, “Edmonton Obesity Staging System: Association with Weight History and Mortality Risk,” is co-authored by Chris Ardern, professor in 91��ɫ’s School of Kinesiology & Health Science, Faculty of Health; Timothy S. Church, director of the Laboratory of Preventive Medicine, Pennington Biomedical Research Center; Arya M. Sharma, professor of Medicine & Chair in Obesity Research and Management at the University of Alberta, and scientific director of the Canadian Obesity Network; Raj Padwal, professor, University of Alberta; Xuemei Sui, professor, University of South Carolina; and Steven Blair, professor, University of South Carolina.

Republished courtesy of YFile – 91��ɫ’s daily e-bulletin.

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The book, Talent Identification and Development in Sport, (Routledge, 2011) offers an overview of current scientific research along with practical information for parents and coaches looking to spot talent and nurture it.

“We’re hoping this book helps inform a better system for spotting talent early on and making the most of it,” says Joseph Baker (left), professor in 91��ɫ’s School of Kinesiology & Health Science, Faculty of Health. “We’ve tried to answer questions that have thus far been elusive, such as, ‘how do elite athletes develop, and when is the most appropriate time for talent identification and development interventions?’,” he says.

The book features an interdisciplinary group of contributors from sport psychology, motor learning and skill acquisition, exercise physiology and coaching. Leading researchers from the field of athlete development explain their research and how it informs our understanding of the process of sport skill acquisition. Topics include genetics and secondary factors such as birth date, cultural context and population size, perceptual motor skill acquisition and sports development policy.

Baker, who contributed a chapter on genetics, explains that performance-related genes are by no means a magic bullet for identifying natural ability.

“There are now companies that scan for performance-related genes in newborn babies. Theoretically such criteria should be able to predict an individual’s potential to become an elite athlete – or anything for that matter. The problem is that scientists aren’t sure exactly what criteria they’re looking for quite yet,” he says.

“Alongside biological realities, we must look at factors like where and when an individual grew up, cultural norms, and the sport programs and polices in place at that time. These variables can all have an enormous impact,” says Baker.

The volume’s latter half offers case studies examining international success stories from the “trenches” of talent identification and development, from individual sports like track & field and gymnastics, to team sports including soccer and rugby.

“Athletic prowess is commonly thought of as a combination of nurture and nature, but the interplay of these factors is quite complex,” says Baker. “Our aim was to give a state-of-the-science overview that would be accessible for parents, coaches, athletes and anyone interested in talent development.”

The book is co-edited by Steve Cobley, senior lecturer in skill acquisition and sport psychology within the Carnegie Faculty at Leeds Metropolitan University, UK, and Jörg Schorer, research associate at the Institute of Sport Science at the Westfälische Wilhelms-University Münster, Germany. Baker is part of 91��ɫ’s Lifespan Health��& Performance Laboratory and is a visiting research fellow at Leeds Metropolitan University, UK.

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"Food addicts" are also more likely to have impulsive personality traits, attention deficit disorder and to use food to "self-soothe" in times of stress, according to the study.

Contributing author Professor Caroline Davis, of 91��ɫ in Toronto [School of Kinesiology & Health Science, Faculty of Health], said: "These results strongly reinforce the view that food addiction is an identifiable condition with clinical symptoms, and is characterized by a psycho-behavioural profile that is similar to conventional drug abuse disorders."

Davis added: "This type of information will help us develop personalized treatment approaches for those who struggle with overeating and escalating weight gain."

Posted by Arielle Zomer, research communications officer,��with files��courtesy of YFile– 91��ɫ’s daily e-bulletin.

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Right: As part of their involvement with the Ontario Health Study, researchers will take physical measures such as blood pressure during a series of mini clinics that will be held this fall

One of the most ambitious community-based medical surveys ever conducted, the��study will track the��health of Ontario residents over the course of their lifetimes.��A community health project, the is aimed at establishing��the largest population-based��longitudinal cohort study ever attempted in North America, and will be the first major epidemiological survey��to be conducted online.��

The study will focus on identifying gene-environmental��determinants of different chronic diseases, including cancer, asthma, heart disease, diabetes, Alzheimer's, mental health disorders and more.

As part of 91��ɫ’s involvement, researchers from the School of Kinesiology & Health Science and the psychology program will be holding mini clinics this fall to collect physical measures from volunteers from 91��ɫ and its neighbouring communities. The mini-clinics will also provide a venue for the distribution of health information and health promotion materials. The 91��ɫ researchers involved in the study are: ��

• Professor Chris Ardern (Kinesiology & Health Science),��whose research is��focused on the epidemiology of physical activity, obesity and cardio metabolic risk.��
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• Professor Sherry Grace��(Kinesiology & Health Science), a researcher��specializing in cardiac psychology and the utilization of health services.
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• Professor Jennifer Kuk (Kinesiology & Health Science), whose research looks at��obesity and related health risks (cardiovascular disease and Type 2 diabetes) and��the influence of physical activity using both exercise interventions and epidemiological approaches. |
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• Professor Jane Irvine (Psychology), a researcher whose work focuses on stress and cardiovascular disease, and modifying cardiovascular behaviour and psychosocial risk factors.
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• Professor Paul Ritvo (Kinesiology & Health Science), head of the Ritvo Lab and a researcher specializing in health behaviour change.

The questionnaire, which is completely voluntary, takes about 30 minutes to complete and will ask participants about��their general health, genetic history and lifestyle.��The study��will then follow participants over their lifespan to��determine how a variety of factors influence participants' health over a long period of time. The data��collected will in turn help��researchers��develop strategies for the prevention and treatment of diseases, as well as to inform health-policy changes.

Irvine��chairs the��social health component of the��survey and will work with Ritvo and Grace. Ardern and Kuk��are leading the obesity and physical activity component of the survey.��As part of their involvement with the study, the��researchers will have access to��the data��collected.

More information on the clinics will be forthcoming. In the meantime, 91��ɫ community members interested in learning more about the��study should visit the website.

Republished courtesy of YFile– 91��ɫ’s daily e-bulletin.

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