2017: Cool Stuff to Read, Part I

Here's some informative rehab and wellness-based content that I've been reading over the past several weeks. I'll try to post these more frequently throughout the year and hope it helps you as well whether you're a patient, clinician, fitness enthusiast or aspiring student.

 

Dr. Dave Tilley, PT, DPT of Shift Movement Science (gymnastics-focused physical therapy)

A Brain Spill on Mechanical vs Neurological Effects in Physical Therapy (Part 1)

A Brain Spill on Mechanical vs Neurological Effects in Physical Therapy (Part 2)

Biomechanics and neurophysiology are two sides of the same coin. They are not mutually exclusive and neither should be completely thrown out the window when considering treatment rationale.

 

Dr. Charlie Weingroff, PT, DPT

Why Rehabilitation and Fitness Should be Delivered in Parallel

The model by which I operate and how I see the physical therapy profession moving forward.

 

Dr. Jason Eure, PT, DPT as a Guest Blogger on Strengtheory.com

Squatting with Patellar Tendinopathy

A monster article on training considerations for those with patellar tendinopathy. Includes crash course in tendinopathy physiology.


 

Dr. Mike Reinold, PT, DPT

 Meniscus Repair Rehabilitation: Why Are We Still Stuck in the 90’s?

Who hasn't learned something from this guy at some point in their career?

 

Dr. Doug Kechijian, PT, DPT of Resilient Performance and Physical Therapy

What Evidenced-Based Practice Is Not

I stopped arguing on the internet a long time ago. I wonder why you see so much intellectual elitism and passive-aggressive trolling in the name of "science" when it comes to rehab and performance-based topics. A must-read.

 

Greater Electromyographic Responses Do Not Imply Greater Motor Unit Recruitment and Hypertrophic Potential Cannot Be Inferred

Link to Letter to the Editor in JSCR

The internet explodes whenever Andrew Vigotsky, Chris Beardsley, Bret Contreras and Stu Phillips collaborate.
Just because a muscle fiber is recruited doesn't necessarily mean it will undergo hypertrophic adaptations. Therefore increased EMG response doesn't necessarily mean getting more jacked...but you see this erroneous conclusion made frequently.

 

Effect of Injury Prevention Programs that Include the Nordic Hamstring Exercise on Hamstring Injury Rates in Soccer Players: A Systematic Review and Meta-Analysis.

Link to abstract

Work with soccer players? Have them do Nordic hamstring exercises to help safeguard them against hamstring injuries.

 

Exercise dosing to retain resistance training adaptations in young and older adults.

Post by The Strength Guys

Link to abstract

It takes a lot longer to lose your gains than you might think.

 

What You Should Know About Pain - Dr. Joe Gambino & Dr. Zak Gabor

Part I

Part II

Some bright PT minds dropping knowledge on pain science. Part III coming soon.

 

If you crossed any articles that you think should be included on this list, leave a comment and let me know!

The Physiology of Elite Dragon Boat Paddlers: A Research Review

Is it possible to identify physical attributes of dragon boat paddlers that would help predict their performance during 200m and 500m races? What are the aerobic and anaerobic energy demands for races of these distances? A study published in the Journal of Strength and Conditioning Research through the University of Sydney in 2013 sought to explore these questions which could potentially help guide training for dragon boat performance and help determine crew selection for races of various distances.

First, a quick crash course in exercise physiology. Our bodies require a molecule called ATP to use as fuel in order to do work. Depending on the nature of this work and the urgency in which the fuel is required, we can produce this ATP…

  • ...in small amounts but relatively quickly without oxygen to power high-intensity exercise. When your body performs high intensity exercise, it says “Hey, I need a LOT of energy and I need it NOW.” This characterizes anaerobic metabolism.

Example: Usain Bolt sprinting 100m.
 

Or, we can produce ATP...

  • ...in larger amounts but relatively slowly with oxygen for exercises that last longer periods of time. Since we don’t accumulate ATP as quickly, our bodies use this method for moderate intensity work and we can stretch this work out over long durations. Producing ATP with the use of oxygen characterizes aerobic metabolism.

Example: Running a marathon.

 

Now back to the study: Eleven “elite” Japanese male paddlers (defined as National Team competitors) were assessed for their 200m and 500m erg times on a K1 Ergo machine. The subjects paddled on their preferred sides and average power output was measured for these race sims. Aerobic and anaerobic capacity was also calculated by measuring VO2max as the paddlers performed the various capacity tests and race sims. Physical characteristics such as body mass, height, arm girth (both relaxed and tensed), body fat percentage and others were also measured.

Generally speaking, one might believe that a 200m dragon boat race is a predominantly anaerobic activity due to the shorter duration of the race while the longer 500m race has more aerobic demands. The results from the study indicated that for a 200m race lasting approximately 50 seconds, the aerobic energy contribution is 52.1%. For a 500m race lasting approximately 1 minute 50 seconds, the aerobic energy contribution is 67.5%.

Not surprisingly, the longer race which took more time had more aerobic demands than the shorter, faster race. Conversely, this also means that the 200m race requires more anaerobic metabolism than a 500m race. An interesting observation from this however is the relatively equal energy demands of aerobic and anaerobic metabolism for the 200m race sim.

I would have assumed the anaerobic component of a 200m race would be far greater than the aerobic component. This suggests that aerobic training is the predominant energy system utilized for dragon boating and should be a significant aspect of padders’ training regimen.

Another result from the study showed that flexed arm girth was the most powerful predictor of 200m and 500m race performance. But more on that later...

 

Shortcomings

As with any study, this one is not without its limitations. Eleven subjects is not a tremendous sample size for a study. The study only observed males which makes sense to control for gender, but I’d be curious to see if these study results apply to females as well. These tests were performed on paddling ergs as opposed to on an actual boat. Despite these limitations, in fairness, for reasons of practicality it would be more feasible to test small sample sizes of paddlers on ergs where VO2 max measurements and other testing procedures could be carried out.

Paddling style also differs from nation to nation. Specific instructions were given to these Japanese paddlers in terms of stroke rate and other aspects of paddling style, but perhaps national-level paddlers from other countries with different physiological qualities perform better under different parameters which could potentially change the aerobic:anaerobic contributions. This doesn’t necessarily invalidate the study but just speaks to a potential shortcoming in being able to generalize the findings to all paddlers.

I don’t believe the impact of the correlation findings are practically significant because correlation doesn’t imply causation. Just because a skilled paddler has big arms doesn’t necessarily make him a better paddler than someone of comparable experience with smaller arms. Maybe some high-performing paddlers’ arms are big because they do a lot of back-strengthening exercises, many of which are pulling motions in which the biceps are also used for elbow flexion. The observation of hypertrophied arms could just be a side-effect of other more effective strengthening, paddling-relevant exercises. I don’t foresee coaches taking out measuring tapes and checking arm diameters of their paddlers to predict how well they’ll do on races--that’s just silly.

 

Additional Thoughts & Takeaways

You never hang your hat on one study. This study contributes to the overall data pool of paddling sport-related research, which includes numerous studies on kayaking and rowing too. Incorporating evidence-based principles into coaching approaches and practice should take into account coaches’ individual experiences and values as well, in the same manner PTs combine patient values and clinician experience for evidence-based clinical decision making. 

To summarize,

  • Both 200m races and 500m races are aerobic and anaerobic activities, with the 200m being more anaerobic than the 500m
     
  • 200m races are almost 50:50 aerobic to anaerobic in terms of energy contribution.
     
  • Dragon boat paddlers should include both aerobic and anaerobic exercise into their training for optimal performance.


 

So How Do I Train Anaerobically?

While training at your bodys anaerobic threshold, several distinct ventilatory and blood-related phenomena occur. There are steep increases in ventilation, blood lactate concentration, carbon dioxide production and other markers which I won’t go into detail here. True testing of one’s anaerobic threshold involves measuring these numbers which requires a laboratory setting and equipment that most of us don’t have. Not to mention taking blood samples, and who does that in a non-clinical or non-research based setting? That's some Rocky IV Ivan Drago shit. Not very practical, but there’s another way to roughly estimate anaerobic threshold: Training at a target higher than 85% of your maximum heart rate.

Using the Karvonen Formula:

220 - Age = Max Heart Rate
Max Heart Rate - Resting Heart Rate = Heart Rate Reserve
(0.85 x Heart Rate Reserve) + Resting Heart Rate = Anaerobic Threshold Training Zone

So for example, a 27 year old with a resting heart rate of 65 bpm to train anaerobically, he/she must train at a heart rate greater than 174 bpm. Intermittent bouts of high intensity exercise at this heart rate can be an effective method of doing this.

In my next post, I’ll explore different methods of movements and anaerobic exercises conducive to dragon boating training. Stay tuned for more and if you have any questions or comments, please feel free to leave a comment or contact me!




 

References:

  1. Wilmore, J. H., Costill, D. L., & Kenney, W. L. (2008). Physiology of sport and exercise. Champaign, IL: Human Kinetics.
     

  2. McPartland, Darren; Pree, Adrian; Malpeli, Robert; Telford, Amanda (2010). Nelson Physical Education Studies For WA. Australia: Nelson.
     

  3. Ghosh AK. Anaerobic Threshold: Its Concept and Role in Endurance Sport. The Malaysian Journal of Medical Sciences : MJMS. 2004;11(1):24-36.
     

  4. Ho SR, Smith RM, Chapman PG, Sinclair PJ, Funato K. J Strength Cond Res. 2013 Jan;27(1):137-45.

 

Medium, Battling Clickbait & a Return to Long Form Blogging

Ev Williams, the CEO of Medium, recently announced that the popular blogging platform is going to lay off about 1/3 of it's employees in an attempt to shift away from a business model revolving around ad-driven media and clickbait. 

In a recent blog post, he wrote:

“The current system causes increasing amounts of misinformation…and pressure to put out more content more cheaply — depth, originality, or quality be damned. It’s unsustainable and unsatisfying for producers and consumers alike….We need a new model.”
— Ev Williams

He goes on to write, "Upon further reflection, it’s clear that the broken system is ad-driven media on the internet. It simply doesn’t serve people. In fact, it’s not designed to. The vast majority of articles, videos, and other “content” we all consume on a daily basis is paid for — directly or indirectly — by corporations who are funding it in order to advance their goals. And it is measured, amplified, and rewarded based on its ability to do that. Period. As a result, we get…well, what we get. And it’s getting worse."

It'll be interesting and I hope, refreshing to see a big online publishing platform break away from a model which appears to encourage click-bait articles and shallow content for the sake of page views to generate ad revenue. Williams states that Medium will refocus in a new direction and adopt a new model in which writers are incentivized and rewarded for the quality and value of their content which is aligned with their mission: To actually help people. 

I've decided to follow suit in my small way by resolving to stop complaining about poor wellness-related content I read in the news and instead to contribute more original, long-form blog posts to inform readers of what I believe are relevant topics in rehab and wellness. My motives obviously have less to do with ad-revenue and more to do with just creating helpful, informative evidence-based content as an alternative to the increasing amount of clickbaity, list-format online content that has gotten so popular. I'd like to start appraising relevant physical therapy and wellness-related research, both new and old, and to report on how their findings can help (or won't help, in some cases) us in our day-to-day lives. 

The first of such posts will come later in the week and will be related to the topic of dragon boat training and performance.

Thoracic Spine Mobilization