Moderate Intensity Exercise Improves Immune Function While High Intensity Interval Training (HIIT) Reduces Immunity

Just when you thought the only acceptable way to exercise these days is with high intensity intervals (HIIT) we have some new data that suggests good old moderate intensity cardiovascular training is not only just as good, it may be better for your immunity.

Just when you thought the only acceptable way to exercise these days is with high intensity intervals (HIIT) we have some new data that suggests good old moderate intensity cardiovascular training is not only just as good, it may be better for your immunity.

While there is plenty of data supporting the benefits of HIIT, as you dig through the research comparing HIIT to more moderate intensity training you can find studies that support HIIT, others that favor moderate intensity and still more that show similar effects. With the publicity that HIIT training has received over the past few years (including in this blog) and the facilities that are built around it you might be left thinking that despite the limited and mixed research on the topic, you have to be banging out heart wrenching workouts at the local boutique gym in order to make any gains.

Today we have a study that suggests when you are talking about the effect of your exercise routine on immunity, you may be better off with more moderate intensity workouts.

The authors had half of their subjects run high intensity intervals for multiple rounds of 30 seconds at 100% intensity and then 30 seconds at 50% intensity. The moderate intensity group did an equivalent amount of work, but it was performed continuously at 75% intensity.

At the end of 9 weeks all the various physiological factors that were measured showed similar results with one major exception, immune biomarkers. The specific biomarkers were all white blood cells leukocytes, lymphocytes, neutrophils and monocytes. The high intensity training group saw negative changes in all four of these key immunity markers while the moderate intensity training group saw positive improvements.

These findings fall in line with previous studies that have found a suppression of immunity with high intensity training and others that have shown improvements with more moderate intensity approaches.

As I always caution, with every study there are limitations. This study only had 16 subjects and they were all fit, active young men ages 18-20. While it would seem logical that if this population saw these types of changes everyone else would, there is no data to say the same results would be found with women or with other age groups or people with different health status. There is also the question of what would be different if the study was of a different length of time, the training frequencies were different, or the training volumes were greater.

What does this study mean for you, the average exerciser or fitness professional? Well we know that many people find high intensity workouts uncomfortable and unenjoyable. This means a much great chance of their stopping exercise, something we obviously don’t want to happen. So, anytime we find some evidence suggesting that more moderate intensity training is just or good or better than the highly publicized high intensity approaches that supports ignoring the buzz and letting people skip the HIIT.

Certainly there are still times that certain fitness training objectives require higher training intensities, but for the average exerciser they can probably skip the intervals if they don’t enjoy or tolerate them. And if someone is dealing with any sort of illness or medical condition in which optimizing their immunity is a key factor, skipping the high intensity work in favor of other approaches just may be the safest and best approach.

 

Khammassi, M., Ouerghi, N., Said, M., Feki, M., Khammassi, Y., Pereira, B., Thivel, D. and Bouassida, A. (2020) Continuous Moderate-Intensity but Not High-Intensity Interval Training Improves Immune Function Biomarkers in Healthy Young Men. Journal of Strength and Conditioning Research. January, 34:1:249-256.

My Brain Hurts. Reconciling Different Training, Mobility and Rehabilitation Approaches.

The more I study exercise science, pain science, rehabilitation, the more my brain hurts. Figuratively that is, don’t get to excited pain science adherents. Let me try to explain my dilemma.

My path was not unlike many others. A skinny kid wants to get bigger. In my case I started a little earlier then most and was little more interested in reading the science behind why things work the way they do so I could optimize my results. This meant I started as most do with bodybuilding literature and training approaches. I learned a ton about muscle physiology and training approaches focused on adding strength and mass.

In college this led me to discovering the broader fields of exercise science and athletic training. My studies in exercise science expanded my understanding of physiology bringing in concepts such as biomechanics and motor control. My athletic training studies introduced me to concepts of tissue healing and rehabilitation.

Both inter-related fields fit nicely with my early influences drawing strongly upon accepted principles such as progressive resistance and adaptation to imposed demands. Everything from my early bodybuilding influenced days dovetailed nicely with my growing knowledge of rehabilitation and more advanced physiological exercise science based concepts.

As the years, and decades, went by I continued to add to my experience and education with concepts that continued to fit nicely with this paradigm. This structural, mechanical perspective continued to drive my evaluation and programming decisions. As I learned more neurological concepts, they continued to fit nicely into the framework I had developed.

When I started this journey strength coaching was something that existed almost solely in college and professional sports. Personal training was in its infancy and beyond a handful of celebrity trainers you could walk into just about any gym and not find a single trainer. Over the next two decades fitness blew up and became an everyday part of our existence. Personal training became a common profession and elite strength coaching became available to every high school athlete and amateur triathlete that could afford a few lessons.

I thought of myself as someone on the front end of the curve. While I have always been slow about professionally adopting the latest fad, I considered myself far more grounded in the science of what we do then the average fitness/strength professional out there. It wasn’t uncommon for me to be one of if not the most experienced person in any facility I worked out of.

As the field grew from just a handful of trainers to nearly 300,000 individuals, I found more and more professionals whose knowledge and understanding I was downright jealous of and far more that made me lament the low barriers to entry that we allowed the field to have. Considering that much of my personal education came from the world of physical therapy and rehabilitation and much of my teaching was focused on less experienced trainers with limited academic backgrounds I found myself constantly teetering between professional awe and frustration.

Over this period where the profession grew tremendously the economic opportunities meant that all sorts of new training approaches were introduced. Each with a philosophy behind them and a robust educational path that needed to be followed. We saw the introduction of every sort of training approach from spinning to cross fit to Pilates to yoga to kettle bells to body weight training and on and on. Each competing for the consumers fitness dollar and for the trainers continuing education dollar.

Now I don’t have a problem with most of these approaches. Not every modality is right for every person but most of them have value for someone and whatever gets the public to move and exercise is generally a good thing. The problem as a professional interested in growing and learning is that every approach has its own scientific interpretation of the research and you must decide what is correct, or more likely what pieces are correct and what you want to incorporate into your approach.

Ah the research. That itself is a major issue. As more and more people were drawn into the broader exercise science fields the support for solid research in the field began to grow and today between the rehabilitative, medical and exercise science areas the amount of pure research being produced is mindboggling. And even then, because of the nature of how quality research is conducted, we have still only begun to scrape the surface of answering many questions about how our physiology works and constantly debunking long held beliefs.

So, where does all this blabbering leave me. For a long time, I found myself trying to find balance between developing my knowledge in rehabilitation and strength training. Both drawing upon the same foundational science but applied along different points in the training continuum. As time went by, I found myself more and more frustrated by the lack of progress my clients were making. Some of this was my fault, a lack of focused programming and support. Some of this was my clients fault, a lack of dedication to doing their work and a desire to just show up once or twice a week to follow directions and then forget about all of the things they really needed to do to change their bodies and improve.

While I continued to attract clients with injuries because of my background I became less interested in being a rehabilitation-based trainer and more in just developing strength. This urge was constantly pulled back by my client’s actual needs as well as my own injuries that kept me interested in learning more about treatment and rehabilitation. These days I would say most of my work is dealing with clients who have injuries. Despite my one-time desire to move beyond this population they just keep showing up and I’ve embraced that I bring something to training them that a lot of my colleagues do not. And my personal educational journey continues to be focused on how to better help these individuals get past their pain, move better and be stronger.

In 2011 I had the chance to start providing continuing education for TRX. I was asked to teach their sports medicine course. I had taught sports medicine classes at the college level and was nearly two decades into my career and jumped at the opportunity. While the class was originally conceived for more advanced rehabilitation professionals and we have a lot of these individuals turn out, a significant number of our attendees are average personal trainers who deal with injured clients on a daily basis.

My biggest take away was how little the average trainer really knew about the foundational sciences that underly our field. That became part of what is so fun to teach the class, the opportunity to share a little knowledge with my colleagues and help them grow as professionals but it has also been a source of personal debate. Just how much should someone know in order to call themselves a professional and go out and coach others on how to care for themselves. I’ve had more then one conversation in my various workplaces with other experienced trainers who call themselves experts on various things and then sat and watched them go out and do things that based on our current level of knowledge and research are contraindicated for the issues they claim to be experts on. It doesn’t take decades of study and training to teach basic exercises to relatively healthy people or even to give some good guidance to injured or more complex clients. I don’t think we need to set some unreasonably high standard for exercise professionals, but we do need some standards. And my level of respect for those less experienced trainers who spend their free time and money on attending seminars and trying to develop their craft has grown immensely.

But how are these less experienced trainers supposed to make sense of the myriad of training approaches and philosophies and competing scientific interpretations if someone with my background and education is struggling with it. And that is what brings me back to my initial reason for writing this.

About four years ago another equipment company, Rumble Roller, asked me to do a little consulting and teaching. Again, I jumped at the opportunity to collaborate with some colleagues I respected, influence the educational content that is being shared with up and coming professionals and just the simple variety of doing something different. I found myself having to be able to interpret and explain the foundations of self-myofascial release. Being the science geek that I am it immediately led me dive into the research literature on foam rolling and lead to one of the early articles on this blog https://fitnessbreakdown.com/category/foam-rollingfascia/ .

Before long I found myself going down the rabbit hole of fascia research and gaining an entirely new appreciation for tissue I had previously given very little though and concern. To the experts in this field fascia is life and vastly more important and fundamental to what we are as living creatures that have structure and move. So many more issues, problems and solutions can be found in a fascia-based explanation.

The fascia experts gave some outstanding explanations for their interpretation of how the body works and what is important. What was so appealing to this was it fit nicely into my structural, mechanical view of the body. Of course my two decades of study and experience tempered my excitement. The human body is wonderfully complex with an interplay of so many different systems that any explanation that is to narrow and clear while often holding a tremendous amount of truth, often still lacks a full appreciation for these other systems and their contributions.

Flash forward to a few months ago. Rumble Roller asked me to participate in a lecture at a large fitness conference. The focus of the talk was on how the nervous system was involved in the development of mobility Our goal was to introduce the concept that the driving force behind many of the changes that happen with foam rolling, and mobility training in general, are really derived from the nervous system. While the target audience for our workshop were trainers who did not have a strong foundation in neurology and we didn’t go into too much detail, it made me start to think more about the role of the nervous system.

We think about the nervous system in some capacity in most of the work we do, though usually in the context of motor outputs. Our talk touched on the idea that sensory inputs were a much more important component to change then most of us have been giving them credit for. And a much more ignored element of our treatments and programming then they should be.

Teaching this workshop led to my being asked to participate as a student in a workshop on dermoneuromodulation. Besides being a mouthful so say, and write, dermoneuromodulation (DNM) is a therapy approach that focuses on the nerves, their health, movement and stimulation. It usually falls under that broad category of what we call pain science.

In preparation for this workshop I began reading a fair amount of the underlying theory of and arguments for some of the rationales behind this and other related aspects of pain science. And this is when my head began to explode.

Many of the main pain science adherents don’t completely dismiss and throw away the structural, mechanical perspective that underlies so much of how we look at the body, training and rehabilitation, but they do quite eloquently and supported by much research point out how much our current common perspectives fail to achieve the results that we think we are achieving with them. How much of the research literature shows what we think is happening really isn’t. How when we do get positive outcomes it isn’t because of how we have changed tissues. Just how often our normal approaches don’t produce positive outcomes. How often people aren’t getting better, experiencing less pain and more function.

The more I read pain science explanations, the more it seems so much of how we are looking at the body and trying make changes to it is wrong. Now this doesn’t mean that everything based on a structural, mechanical perspective is wrong. Much of it is right. You only have to watch a few minutes of sports on TV, walk through any gym or turn on Instagram for a few minutes to see that so much of what we do is correct. But what about all the people who are injured and experiencing pain and disability who are not improving as we would expect them to. Clearly there must be more that we aren’t seeing or doing.

And this is when my brain starts to hurt. How do we reconcile all the different approaches to movement, mobility, pain relief, tissue healing, growth and adaptation? There are more and more “systems” being offered as explanations and pathways every year. You could spend a fortune taking classes on every different approach to changing and improving the body. Most of them have research that is presented to support them. Many of them share lots of common concepts and principles. But each has its own take and even the most seasoned of experts who looks at these different systems and the theories behind them can be confused about which ones are correct, let alone the best (if even only for specific populations and problems). If it’s this confusing and challenging for well educated professionals to find a way to balance these competing (and sometimes complimentary) approaches, how does the average fitness or rehabilitation professional make sense of it all.

Sure, it’s easy to just embrace one philosophy. To follow one expert and base all your training and treatment on that approach. Many people do it that way and they come across as experts. Sure, they have a lot of people that seem to do amazing with that approach. If you take a large enough population, you can come up with a lot of individuals who do well with any one particular strategy. But in real life that just doesn’t work for everyone. You aren’t going to help every client or patient practicing just one way. And this makes me brain hurt.

Which approaches are best? I can offer up a half dozen different schools of though as to how to improve mobility off the top of my head. Yes, they all have similarities, but they also have differences. They all offer the promise of decreased pain, better movement and function but surely they can’t all be equal. And some of them may just be wrong and achieving results not because of the system but in spite of it because other mechanisms are still at action.

So, I sit here reading more and more. Trying to find balance between the different approaches. Not saying that anyone is wrong, but not prepared to say any of them are right either. In a few weeks I’ll be equipped with a new set of skills and a stronger foundation in a school of thought and approach towards caring for my clients. I may find a new philosophy that will underly all my future work. More likely I’ll find a way to incorporate a new set of ideas into what I already know and believe. I’ll probably have to throw away a little of what I have held to be true as I discover new research that proves what I thought and learned was wrong. I’ll probably have new approaches that work better than some of what I have been doing. For some of my people, probably not for all of them. And my brain will continue to hurt as I learn more and challenge the notions that underlie my 25 years of work.

Stay tuned. It’s going to be an interesting journey no matter what and who knows what body of literature and ideas I’ll be eager to write about and share as the weeks and months go by.