CSEP member contributions to the understanding of exercise physiology: a historical perspective on research in adult aging

September 13, 2017

The Canadian Society for Exercise Physiology will be celebrating its 50th anniversary in 2017. A signature initiative is a celebration of the contributions of Canadian researchers to exercise physiology over the past 50 years. The objective is to highlight significant Canadian contributors and their contributions to exercise physiology, health and fitness, nutrition and gold standard publications globally as well as provide insights on future research directions in these areas. These achievements have been organized into a series of short historical communiqués on prominent Canadian contributors and will be published on a monthly basis.

CSEP member contributions to the understanding of exercise physiology: a historical perspective on research in adult aging

Rice, C.L.1, Vandervoort, A.A.2 Hicks, A.L.3, and Paterson, D.H.4

1Professor of Kinesiology, and Anatomy & Cell Biology, and Research Director of the Canadian Centre for Activity and Aging at The University of Western Ontario, London

2Professor Emeritus, Faculty of Health Sciences, The University of Western Ontario

3Professor and Associate Chair, Department of Kinesiology, McMaster University, Hamilton, ON

4Professor Emeritus, School of Kinesiology and Canadian Centre for Activity and Aging, at The University of Western Ontario, London

Important contributions in the field of research exploring exercise and aging in Canada over the last 50 years are limited to a few locations and key groups that have maintained a sustained focus on the topic. The purpose here is not to be exclusive, and we recognize that many important researchers have contributed studies on physiology, health and aging from Canada over this time period, but we have attempted to highlight the main groups and key exercise physiologists, and those who have maintained an association with CSEP, in this brief historical perspective.

Dr. Roy Shephard was a pioneer in studies on aging in Canada and likely across the globe. He, together with Ken Sidney at the University of Toronto began in the 1970s to explore exercise training in older adults. They explored the effects of intensity and frequency of exercise training group programs and established that it was not dangerous for older adults to exercise vigorously. Their work focused mainly on the cardiorespiratory aspects of aging and exercise stemming likely from their work at that time on work with ‘cardiac’ patients. They continued with interest in aging for several decades and Shephard and Sidney published a formative review in Exercise and Sports Sciences Reviews entitled “Exercise and Aging” in 1978 and another one in 1990 in the Journal of the American Geriatric Society entitled “The Scientific Basis of Exercise Prescribing for the Very Old”. Dr. Shephard continued to explore aging with a focus on the immune system in the 1990s. He supported collaborative efforts with several publications between 2010 and 2016 related to a large study (Nakanojo study) on physical activity and health indicators in Japanese men and women aged over 65 years. His career to date in studies on aging have spanned almost 40 years.

In the mid-1970s, Dr. Alan McComas at McMaster University began to explore neuromuscular properties and the effects of aging. As an electrophysiologist and neurologist Dr. McComas found aging to be an interesting and useful model to explore important characteristics of the motoneuron and motor unit. He and his group were among the first to document the age-related decline in spinal motoneurons in humans using novel electrophysiologic techniques. The fundamental principles of these techniques are still incorporated in today’s technology in making estimates in vivo of the number of functioning motor units in health and aging. Two trainees of Dr McComas from the 1980s, Dr. Audrey Hicks and Dr. Tony Vandervoort, were influenced by Dr. McComas’ studies on aging. Building on her doctoral work with Dr. McComas examining the role of muscle excitability in influencing the process of fatigue, Dr. Hicks initiated studies in the late 1980s – early 1990s that probed the fatigue characteristics in older muscle, together with analyzing some of the sex-related differences in this fatigue process. Dr. Hicks was also a lead investigator (together with Dr. Neil McCartney) in one of the largest and longest duration resistance training studies in older adults in the early 1990s, in which both the efficacy and safety of long-term resistance training were clearly demonstrated. These studies have been cited widely and helped pave the way for more in-depth investigations into how resistance training can be optimally used to delay the processes of sarcopenia and dynapenia in older adults. Dr. Vandervoort’s work with Dr. McComas centred on a comprehensive exploration of neuromuscular properties in human aging by sampling a large group of healthy men and women ranging from 20 to 100 years.

Drs. Stuart Phillips and Mark Tarnopolsky continue the interest in studies on aging at McMaster. Their group explore the effects of exercise strength training with a particular emphasis on nutrition, mitochondrial function and protein metabolism in older adults. The McMaster Institute for Research on Aging (MIRA) was recently established as an interdisciplinary group of researches in the field of aging.

After leaving McMaster, Dr. Vandervoort undertook a post-doctoral fellowship at the The University of Western Ontario and established his career over the past three decades there with a specific focus on the interrelationships between loss of muscular capacity, benefits of resistance exercise, and implications for geriatric rehabilitation in older adults. Dr. Vandervoort was among the first to describe and explore the idea that with aging eccentric (lengthening) contractile function was better preserved with aging than either isometric or concentric contractions. Dr. Michelle Porter completed her PhD at his laboratory in 1995 and then continued with similar lines of research at the University of Manitoba. During this time, Dr. Vandervoort began an active collaboration with Dr. Charles Rice who also had interest in studies focused on the neuromuscular system in aging. Dr. Vandervoort’s interest in eccentric contractions continued through to his final doctoral trainee, Dr. Geoff Power, who maintains an interest in aging and eccentric contractions.

In the mid-1980s the group at The University of Western Ontario, including a cardiologist, Dr. Peter Rechnitzer, together with two basic scientists Dr. David Cunningham and Dr. Don Paterson, began to study aging and eventually established the Canadian Centre for Activity and Aging (CCAA) in 1989. Formation of the CCAA evolved following the “Retirement research study “. Cunningham and Rechnitzer showed the benefits of a one-year group exercise walk/jog program. This study of 100 exercisers and 100 in the control group was the first large group program study. Fitness improved in the exercise group, and of interest both attendance and compliance were outstanding.

Rechnitzer, Cunningham and Paterson then pursued a very large study of 440 randomly selected men and women aged 55 to 85 years to establish fitness data for the age groups. This “population” study culminated in follow-up studies with contributions from PhD candidates including Devin Govindasamy and Liza Stathokostas. An 8-year follow-up demonstrated that among the host of variables measured it was aerobic fitness that was a determinant of the ability to maintain independence into older age.

At same time physiology of exercise responses in older adults were examined, particularly with respect to their relatively slowed oxygen uptake kinetics, to identify limitations in the oxygen transport and utilization chain. This work by Drs. Paterson and Dr. John Kowalchuk (who joined the CCAA in the early 1990s) included prime contributors: Drs. Mark Babcock, Marc Poulin, Phil Chilibeck, Rob Petrella, Chris Bell, Darren DeLorey, and Juan Murias. As well, a number of these studies also examined specific cardiovascular exercise training responses in older adults, culminating in a 12-week study of both young and older men and women published by Juan Murias et al. From the CCAA, Drs. Poulin, Bell, DeLorey, Chilibeck, and Murias all continued with significant work in the area of exercise and aging after moving on from Western, and Dr. Petrella has continued work in affiliation with the CCAA both in research and with medical oversight.

The CCAA mandate also included a “program” aspect of community physical activity “model” programs and an “education” aspect to train leaders for seniors’ physical activity, and perhaps most influential under the leadership of Nancy Ecclestone, notoriety including hosting the World Congress of Physical Activity and Aging, and at another congress contributing to the UN statements on exercise and aging. Following his doctoral training and service at the CCAA, Dr. Gareth Jones has continued work in the field of applied physiology of aging and often collaborates with Dr. Jennifer Jakobi (see below) in these studies at the University of British Columbia – Okanagan. The CCAA work culminated with Dr. Paterson’s reviews related to physical activity and health and functional independence of older adults. These reviews lead to the “Physical Activity Guidelines for Older Adults”, and were a significant influence on the WHO guidelines.

Dr. Charles Rice who did his PhD with the group at The University of Western Ontario in aging, returned in 1996 and re-joined the CCAA. Much of his work has centered on the study of the aging neuromuscular system and he regularly collaborated with Dr. Tony Vandervoort and Dr. Tim Doherty (doctoral training at the CCAA). Dr. Rice’s focus was at the motor unit level and with his collaborators and trainees they have produced the most comprehensive exploration of motor unit properties in various limb muscles in older adults including those as old as their 10th decade of life. These studies indicate that with a loss of motor units maximum rates of muscle excitation are much lower in aged adults, but differences vary among muscles. Habitual activity patterns may play an important role in determining the extent of these age-related changes among various muscles. Many of Dr. Rice’s studies also have a focus on neuromuscular fatigability and aging and they were among the first to highlight that unlike isometric function, dynamic muscle contractions are very fatiguing for older adults. Trainees from his lab with a focus on aging who have contributed, or who are currently contributing to the field of academic research on aging include: Drs. Denise Connelly, Jennifer Jakobi, Brian Allman, Brock Symons, Cliff Klein, Chris McNeil, Brian Dalton, Matti Allen, Tobias Morat, Kevin Gilmore and Eric Kirk. Most of these former trainees now have established laboratories of their own in Canada and elsewhere, and several (Connelly, Jakobi, McNeil, Dalton and Morat) continue to explore the theme of aging.

Drs. Rice and Doherty established a research collaboration in 2012 with Dr. Russ Hepple at McGill University to study neuromuscular function of Master’s Athletes. Dr. Hepple has maintained a long-standing interest in aging and did fundamental studies exploring mitochondrial function as an important factor in aging and sarcopenia. He developed this interest in aging as a graduate student at the University of Toronto with Dr. Mike Plyley and continued with interests in muscle function and aging at the cellular level at The University of Calgary before moving to McGill University. The study of world-class Master’s Athletes at McGill, with some participants aged more than 90 years, was the most comprehensive of its kind ranging from whole body and cognitive function to molecular markers. Dr. Hepple recently moved to the University of Florida and is a member of their world class Institute on Aging.

Outside of these longer, or larger established groups there are key individuals that are recognized experts in various other Canadian locations. In the area of body composition, Dr. Bob Ross and his colleagues at Queen’s University are well-known and have published studies, (some with large sample sizes), related to muscle mass, obesity and insulin sensitivity with a focus on the older adult. Dr. Phil Chilibeck and his group at the University of Saskatchewan have for many years explored bone and muscle health in aging and in relation to dietary supplementations and exercise training. Dr. David Hood, an expert in mitochondrial biogenesis and turnover at York University, has directed studies over the past several years to explore mitochondrial alterations in response to aging. Dr. Mike Sharratt at the University of Waterloo established the Schlegel-UW Research Institute for Aging in 2005 and much of his work focused on improving quality of life of seniors in long-term care facilities. Expanding focus on aging continues across Canada as underscored by Dr. Isabelle Dionne being awarded recently a Canada Research Chair in Health and Physical Exercise at Sherbrooke’s Research Centre on Aging.

Thus, many Canadian researchers have made and continue to make important contributions in the area of exercise and aging, enhancing not only our understanding of age-related changes in the responses to exercise and exercise training, but also aging has served as a model in understanding some basic physiology from motor units to oxygen transport. With the current increase in numbers and proportion of older adults, and of life-expectancy, continued research and application are needed to enhance health and functional and cognitive abilities into older age.