This is part seven of a series of blogs from attendees at ACSM's Conference on Integrative Physiology of Exercise. The following blog is a reflection on the symposium titled "Molecular Transducers of Exercise-induced Muscle Hypertrophy" by Sarah Little. 

On the last day of the Integrative Physiology of Exercise conference in San Diego, Marcas Bamman, Ph.D., from the University of Alabama-Birmingham, chaired the symposium on Molecular Transducers of Exercise-induced Muscle Hypertrophy. Normally, I would be pretty intimated by a symposium on muscle biology and molecular pathways. However, this highly respected panel of scientists led talks that were complex yet easy to follow.

Overall, the main take away from the session was that exercise leads to the activation of multiple molecular pathways that are being unraveled by absolute geniuses in order to better understand how to grow and maintain muscle mass over the lifespan. 

Scott Trappe, Ph.D., FACSM, of Ball State University opened the symposium with a series of findings describing the transcriptome response to exercise in the aging athlete. Using a life-long exercise model, Dr. Trappe’s group looked at the differences between life-long exercisers, old healthy and young exercise subjects. As expected, the young athletes showed greater VO₂Max and muscle cross sectional area than life-long exercisers, but these life-long exercisers demonstrated exercise capacity and skeletal muscle health indices that were far superior to untrained old healthy subjects. Interestingly, this same hierarchical pattern was seen with fast fiber responsiveness to exercise, as well as transcriptome coordination and effectiveness, suggesting a preservation of a muscle metabolic phenotype with exercise through aging. Further, through analyzing the transcriptome signatures of each subject group, it was discovered that the function of the responding genes varies with age and exercise, with young exercisers primarily involving growth, life-long exercisers involving metabolism and the old healthy involving stress. Overall, Dr. Trappe’s group demonstrated, both at the molecular and functional levels, that exercise really is medicine.

Blake Rasmussen, Ph.D., of the University of Texas Medical Branch – Galveston discussed the role of protein turnover and anabolic signaling in exercise-induced muscle hypertrophy. Dr. Rasmussen did an excellent job of “unpacking” and simplifying some complicated intracellular signaling pathways to focus on a few key components: insulin, mTORC1 activation and translocation, and specific effects of exercise on the mTOR signaling pathway. Together, these led to three main points:

1. both inactivity and aging have been linked to reductions in mTORC1 signaling and anabolic resistance,
2. physical activity, capillary density and muscle perfusion may all be predictive of anabolic resistance, and
3. genetic manipulation of the nutrient sensing anabolic pathway can lead to muscle hypertrophy, but without concurrent exercise, it cannot improve muscle function.

John McCarthy, Ph.D., of the University of Kentucky focused on the role of ribosome biogenesis in skeletal muscle hypertrophy. For someone who has never heard of ribosome biogenesis, Dr. McCarthy provided a wonderfully clear explanation of the various methodologies to measure ribosomal RNA from in-vitro to in-vivo models, as well as the translational application of the resulting data. Linking back to muscle hypertrophy, several human and animal studies were described focusing on the effects of resistance exercise and rDNA transcription (to rRNA) and the translation of key ribosomal proteins. Interestingly, exercise-induced increases in ribosomal content (i.e. rRNA abundance) are highly correlated with the magnitude of muscle hypertrophy, and the inhibition of ribosome biogenesis prevents hypertrophy of myotubes in vitro.

Last but not least, Marni Boppart, Sc.D., FACSM, of the University of Illinois-Champaign-Urbana spoke on integrin regulation of muscle growth. Using knock out and transgenic mouse models, Dr. Boppart’s research has elucidated the mechanisms with which integrin, specifically the α7β1 complex, maintains cellular integrity and interacts with the mTOR signaling pathway to alter adaptation. While it does not facilitate load-induced growth via mTORC1, the α7β1 integrin complex may enhance growth via preservation of mTORC2 localization and signaling.

Though all four presentations had varying areas of emphasis among molecular transducers, the main take away was clear: Exercise regulates multiple molecular mechanisms in skeletal muscle, which may be protective or preventative with aging. Ultimately, this symposium fit wonderfully within ACSM’s emphasis of exercise as medicine, while summarizing groundbreaking new studies that will help to further understand the biology of muscle hypertrophy.

Read part 1 of this series: "Can Exercise Fill the Reductionist Gap? Reflections on Dr. Michael Joyner's Keynote."
Read part 2 of this series: "Are Exercise 'Mimetics' a Realistic Substitute for Exercise Training? Reflections on the Debate." 
Read part 3 of this series: "Exercise and Energy Restriction to Improve Health: Recent Research." 
Read part 4 of this series: "Molecular Transducers of Physical Activity (MoTrPac) Update." 
Read part 5 of this series: "Metabolic Flexibility in Health & Disease: A Symposium Summary." 
Read part 6 of this series: "How Exercise Promotes Brain Health in Aging." 


Sarah Little is a doctoral student at Texas A&M University. She earned her Bachelor of Science degree from Virginia Tech and her Master of Science in Kinesiology with an emphasis in Exercise Physiology from Texas A&M University. 

Bottom Line Upfront:

Working with individuals with special needs can be both a rewarding and challenging opportunity.  If this is something that you feel you might be interested in, it’s important to get experience and make sure that you have the skillset to make a positive impact on the lives of these individuals.

Working with special needs individuals can be a very challenging but rewarding opportunity.  As I indicated in a previous post, it takes a special skillset to be able to do it.  I have coached for over 20 years now and for the last six I have also worked with special needs athletes.  I teach special education.  I am also the parent to a child with Down Syndrome, so I have a different perspective on this than most people do.  To me the most important thing, if you are thinking of working with individuals with special needs, is to have the skills set to make a positive impact on their lives.

It’s important to understand that sports, fitness, programs, academic programs, service, and leadership programs for individuals with special needs are about developing them as men and women.  It’s about teaching them skills that they can use in life.

Before working with individuals with special needs, you need to understand what you are getting yourself into, because this is not for everyone.  This requires you to be both cheerleader and stern taskmaster.  Many people get into this field for the wrong reason, they find special needs individuals to be cute.  This results in a terrible experience for the fitness/sports professional and it results in an experience that does not contribute positively to the growth and development of the individual with special needs.

It’s important to understand that sports, fitness, programs, academic programs, service, and leadership programs for individuals with special needs are about developing them as men and women.  It’s about teaching them skills that they can use in life.  If you are not doing that then you have wasted everyone’s time.

Get some experience.  This is best done by volunteering.  Everyone wants to jump straight into making money, but this is a mistake.  Volunteering gives you a chance to understand what working with the special needs population is like, it allows you to make contacts, and it gives you credibility.

Where do you find volunteer opportunities?
There are several places that you can find these.  The First is Special Olympics (www.specialolympics.org).  There are also national and state organizations.  At the local level there are Special Olympics teams that compete in multiple sports, usually clustered around cities or school districts.  The state organization usually has the contact information for the local levels.  Here you have the opportunity to do everything from just helping out at competitions all the way to coaching teams on a day-to-day basis.

Second are different service/not-for-profit organizations geared towards individuals with special needs.  For example, in the Dallas/Fort Worth metroplex we have the Down Syndrome Guild of Dallas (www.downsyndromedallas.org) and the Down Syndrome Partnership of North Texas (www.dspnt.org).  These are things you just have to search out and find something that offers programming that aligns with your interests and skills set, then you have to reach out and volunteer.

Third, there are always local opportunities to be on the lookout for.  For example, when I run my programs for children with Down Syndrome I advertise that I need help through my church’s weekly news bulletin.  

Now for the big question: Are there opportunities to make this a profitable niche for a fitness or sports professional? 
That’s a tough question to answer. 
Special needs individuals, as a population, may have more medical expenses than the “normal” population.  They may be receiving speech therapy services.  They may be receiving occupational and/or physical therapy services.  They may require medical devices, prescription medications, and other services (like a therapy dog).  All of these are costs that these families incur. 

The point to keep in mind here is that many families may already be stretched to a financial breaking point and while they’d like to take advantage of services they may be unable to do so financially.  By definition, this is a small group of people to begin with, once you start narrowing it down by people that have the ability to afford services it gets really small, all of which makes this a difficult niche to work in and find enough business to support yourself.

Author: John Cissik teaches special education at McKinney ISD in McKinney, Texas. He coaches baseball, basketball, strength and conditioning, Special Olympics, and Miracle League. John has written 14 books and over 100 print articles on strength and conditioning, fitness, and coaching.

Keys to embarking on a path toward reduced stress and improved well-being

1. Pay attention to your breath
2. Yoga is a great way to learn breath work and relaxation
3. Physical fitness promotes mental fitness

Breath.  Have you ever thought about how your breath changes when you are stressed, exercising, or relaxed?  Learning how to relax is an integral component of stress reduction that is often overlooked.  Experts have learned over the years that exercise plays a key role in the ability to relax, but as yoga has become more popular we are finding out that the breath can also help maybe even more.

Methods of stress reduction…”tend to reduce anxiety, depression, heart rate and blood pressure, and enhance a feeling of relaxation and well-being.”

Let’s start with relaxation exercises.  Spring is a great time to check in with your mind and body to see how you are feeling.  Winter is a time when more people are inside and sedentary, but once the weather begins to warm up spending time outside is mentally refreshing and relaxing.  Notice where you are holding tension in your body, and think about your breath paying attention to whether or not you tend to hold your breath or take shallow breaths.  Mental stress tends to tighten the muscles in the body, which in turn creates more tension then raises the heart rate and tightens the muscles creating even more physical stress.  Soften the jaw and watch how the shoulders and hips relax.  Breathe slowly and deeply and notice how the body relaxes.

Yoga is a perfect stress reducer and mind/body relaxer.  If practicing yoga on a regular basis is not in your daily routine just learning diaphragmatic breathing will help tremendously.  Find a comfortable place to sit, close your eyes and take slow deep breaths, expanding the diaphragm with every inhale and exhaling completely.  “Talk” to the muscles in your body and tell them to relax and melt.  Softening the jaw releases tension in the neck, shoulders and hips and leads to total body relaxation.  Deep breathing can be done any time, anywhere.

Aerobic exercise raises the heart rate while engaging in the activity, but with regular cardiovascular exercise comes a mental and physical relaxation.  When the heart rate is elevated for extended periods endorphins, or natural pain killers, are released and in time a relaxation occurs after the exercise is completed.  If regular exercise is practiced, weight begins to shed and stress about weight is reduced.  Physical fitness promotes mental fitness, and if activities are enjoyable you will make time to exercise on a regular basis.  Exercise doesn’t always have to be in the form of aerobic exercise.  Lifting weights, pilates, yoga, and any other physically demanding exercise will help to relax the body if a regular exercise routine is followed.

Many methods of stress reduction exist, including breathing, meditation, progressive relaxation, and exercise. All tend to reduce anxiety, depression, heart rate and blood pressure, and enhance a feeling of relaxation and well-being.

Author: Mindy Caplan ACSM-EP is a New Mexico-based Fitness Instructor, Personal Trainer, Wellness/Lifestyle Coach, and Yoga Instructor.

Disclaimer: Opinions expressed in the Certification Blog are the authors’ and do not necessarily reflect positions of ACSM.

This is part six of a series of blogs from attendees at ACSM's Conference on Integrative Physiology of Exercise. The following blog is a reflection on the session titled "How Exercise Promotes Brain Health in Aging" by session co-chair Dr. Jill Barnes. 

At ACSM’s Conference on Integrative Physiology of Exercise, a common theme was how regular exercise is beneficial for multiple organ systems, and how exercise may prevent or delay the onset of age-related diseases. The last session of this conference discussed how exercise may promote brain health and reviewed recent evidence from exercise-based randomized clinical trials (RCTs) in humans.

In the U.S., physical inactivity is the number 1 modifiable risk factor for Alzheimer’s disease (AD). Barnes & Yaffe calculated that 21 percent of AD cases in the U.S. could be attributable to physical inactivity and increasing the proportion of the U.S. population who are physically active by 25 percent may prevent more than 200,000 AD cases. As with many diseases, increasing physical activity could also have a substantial impact on the social and economic impacts of AD!

At this conference, Drs. Marcelo Wood and Carl Cotman, both from University of California-Irvine, reviewed studies in mice demonstrating hippocampal neurogenesis and enhanced learning and memory after access to a running wheel. These studies are quite convincing (see this recent review), and the work of Drs. Wood and Cotman seeks to understand the underlying mechanisms by which exercise enhances brain health. Dr. Wood discussed the role of histone deacetylase 3 (HDAC3) in inhibiting new memory formation in older mice and proposed the hypothesis that exercise stimulates epigenetic mechanisms that may include histone modifications. Dr. Cotman spoke about how increases in brain-derived neurotrophic factor (BDNF) with exercise may enhance the sensitivity of downstream signaling cascades to promote memory and learning. In addition, previous exercise training may “prime” the system so that BDNF levels are quickly restored with subsequent exercise, promoting neuronal adaptations.

Despite the evidence on the benefits of exercise on brain health, and specifically animal models demonstrating hippocampal neurogenesis, angiogenesis and enhanced cognitive function with exercise, the translation to aging humans is less convincing. In fact, recent systematic reviews state that the strength of the data showing that aerobic exercise increases hippocampal volume in humans is modest at best and that conclusions regarding exercise on the default mode network (an important brain network relevant to AD) could not be made. Additionally, a recent trial in individuals with dementia concluded that exercise training did not slow cognitive impairment.  

As an exercise physiologist, this is difficult to comprehend! Why is there a difference in effectiveness between animal studies and cross-sectional studies in humans vs. RCTs utilizing exercise interventions?

Next, Dr. Fang Yu from the  University of Minnesota and Dr. Jeffrey Burns from the University of Kansas Medical Center spoke on their recent work. Both investigators are at the forefront of this area with substantial expertise in conducting RCTs on exercise and brain health. They reviewed the evidence regarding frequency and duration of exercise and the relationship to risk of dementia. Many of the studies that do show a beneficial effect of exercise on hippocampal volume or memory also demonstrate a measurable change in fitness (such as VO₂ peak). So, for exercise to have a detectable effect on the brain, the dose should be high enough to improve fitness. It seems intuitive that a significant exercise dose is necessary for an effect on the brain, but we must consider that exercise-based RCTs, especially in adults with cognitive impairment, are difficult to conduct due to logistical and ethical issues.

This session highlighted the fascinating physiology underlying exercise-induced adaptations in the brain and brought up many unresolved questions in humans: 1) what is the appropriate dose of exercise for brain health? 2) how can adherence be enhanced in adults with cognitive impairment? and 3) what ways can exercise be optimized to increase the effectiveness of exercise? These questions require more research in humans. There are numerous ongoing clinical trials that will attempt to address these research questions and, hopefully, provide convincing evidence that regular exercise in humans plays an important role in the prevention of age-associated cognitive decline and AD.

Read part 1 of this series: "Can Exercise Fill the Reductionist Gap? Reflections on Dr. Michael Joyner's Keynote."
Read part 2 of this series: "Are Exercise 'Mimetics' a Realistic Substitute for Exercise Training? Reflections on the Debate." 
Read part 3 of this series: "Exercise and Energy Restriction to Improve Health: Recent Research." 
Read part 4 of this series: "Molecular Transducers of Physical Activity (MoTrPac) Update." 
Read part 5 of this series: "Metabolic Flexibility in Health & Disease: A Symposium Summary." 

Jill Barnes, Ph.D., FACSM, is an Assistant Professor at the University of Wisconsin-Madison in the Department of Kinesiology, and has an affiliate faculty appointment in the Division of Geriatrics and Gerontology in the School of Medicine and Public Health. She served as co-chair of the “How Exercise Promotes Brain Health in Aging” symposium at ACSM's Conference on Integrative Physiology of Exercise.

Physical inactivity has become a pandemic according to a recent report in The Lancet, one of the most respected medical and health journals in the world. The report’s authors are all members of the World Health Organization (WHO) and are experts in collecting and analyzing large-scale data. A pandemic means that the condition is prevalent all over the world. The impact of the WHO study is not limited to the USA or even to economically developed countries. It reaches both affluent and struggling economies all over the world. We have a lot of work to do.

In a recent CNN report, the lead researcher, WHO’s Dr. Regina Guthold, said "Levels of inactivity are more than twice as high in high-income countries as compared to low- income countries, with an increasing trend in high-income countries. Latin America and the Caribbean, and high-income Western countries are the two regions with the highest levels of inactivity, and with increasing trends in inactivity." Dr. Guthold went on to say that in 2016 (the last year of data collection) more than 25 percent of the world’s population (1.4 billion people) were physically inactive compared to 23 percent in 2010, putting more people at risk for cardiovascular disease, Type 2 diabetes, dementia and some forms of cancer. The WHO study was a review of 358 published surveys and included 1.9 million adults living in 168 countries between 2001 and 2016.

Despite some very well-intentioned work by many international sports medicine and exercise science organizations around the world, physical inactivity is a continuing problem. Here are some important facts revealed by the report:

• 16% of people surveyed in low-income countries get an inadequate amount of exercise
• 37% of people surveyed in high-income countries get an inadequate amount of exercise
• In east and southeast Asian countries, 26% of adults had insufficient physical activity in 2001, but just 17% in 2016 (the report credits China with leading the way to healthier lifestyles in that region)
• There is a gender difference when it comes to physical inactivity:
  • In south Asia, 43% of women are inactive compared to 24% of men
  • In the Middle East and North Africa, 40% of women are inactive compared to 26% of men
  • In upper income Western countries, 42% of women are inactive compared to 31% of men
  • In the USA, 48% of women are inactive compared to 32% of men, and the same or similar differences exist for the United Kingdom, India, the Philippines, South Africa and Turkey.

There have been many inspirational efforts to increase physical activity from Healthy People 2000 (and repeated reports in 2010, 2020 and a new one in preparation for 2030) in the USA, to Healthy China, to many other country-specific initiatives. These are all well-intentioned programs. However, the WHO 2025 goal of increasing global physical activity by 10 percent of the population is in jeopardy. As sports medicine and exercise science experts, we can make significant changes, and we need to do it now.

When I was interviewed for the CNN story, I suggested that we need to focus on lifestyle and behavior modification to overcome some sedentary behaviors. We cannot and should not be telling our chronically inactive friends, neighbors, clients, patients or students to simply go to a gym or get more exercise. For some that will work, but for most it will not. An alternative is to make small changes in behavior and small changes in lifestyle to increase physical activity. Taking the stairs instead of the elevator when going up or down one or two flights or parking the car in the last row instead of the first one at the grocery store are just a couple of examples.

Finally, we must make that critical connection between health care and fitness professionals. No longer is it acceptable for a physician to tell a patient to “get more exercise.”  Patients want more guidance. Through the ACSM Exercise is Medicine program, that connection can be made.  Doctors can find fitness professionals by using the United States Registry of Exercise Professionals or the ACSM ProFinder. Time to get moving!


Walter R. Thompson, Ph.D., FACSM, currently serves as the Immediate Past President of the American College of Sports Medicine. He is a Regents' Professor and Associate Dean in the College of Education and Human Development at Georgia State University. He also serves as the Executive Director of After-School All-Stars in Atlanta, Georgia.