Prof. Martin Schwellnus dishes on exercise associated muscle cramping: The CJSM podcast

A panel of experts & contributors to CJSM — Profs. Martin Schwellnus, Stavros Kavouras, Tamara Hew, William Roberts (L to R). ACSM Denver 2017

Exercise Associated Muscle Cramping (EAMC) is the subject of several studies CJSM has published over the last several years.  It is a notorious problem for athletes and for their caregivers.

A world expert on the subject, Professor Martin Schwellnus MBBCh, MSc(Med), MD, FACSM has joined us on the CJSM podcast to discuss his newest contribution to the medical literature in this field.

Dr. Schwellnus is a Professor of Sport and Exercise Medicine, Faculty of Health Sciences, University of Pretoria and Director: Sport, Exercise Medicine and Lifestyle Institute (SEMLI), University of Pretoria
Director: International Olympic Committee (IOC) Research Centre, South Africa.  I count myself fortunate to consider him a good friend as well — someone I look forward to seeing at conferences such as ACSM or IOC injury prevention.

You can find our podcast conversation at the top of the growing list of CJSM podcasts on our journal website. You can also subscribe to all of the CJSM podcasts on iTunes here.

I praise Prof. Schwellnus for being such a lucid and erudite speaker in this podcast.  And it’s true!!!  You will definitely get a sense of that when you listen to the podcast.  Should you want to hear him yourself delivering a proper lecture, you can, thanks to the glories of social media:  check out this lecture on YouTube on the drug everyone should take!!!!*

*[steady there:  this is sport and EXERCISE medicine 😉  We’ll reserve a discussion about medical marijuana for an upcoming blog post]

Catching my breath


Part of the large contingent coming to #ACSM16 from South Africa. Photo courtesy of Phatho Zondi, current SASMA president.

I am just coming up for air after three days here in Boston, where I (and thousands of other sports medicine professionals) are attending the 2016 annual conference of the American College of Sports Medicine (ACSM).

Every year at this time I will make the pilgrimage to San Diego or Orlando or other spots in these big United States to attend this big, big conference.  Each year I leave with my brain chock full of new ideas and my bag chock full of business cards; as I step back to gain some perspective on the experience I am overwhelmed by the size and scope of the conference.  I am not complaining when I declare that it is simply not possible to attend every session one would want.  I am, rather, merely making a statement of fact!

So, like the proverbial dog trying to drink out of a gushing fire hydrant, I am doing targeted nipping at the flow of information rushing before me, and I want to share, in a most definitely non-comprehensive way, a few of the impressions I am left with as the conference heads into its penultimate day.

martin schwellnus

Slide photo courtesy of Martin Schwellnus

First, it’s been great to catch up with a host of South African colleagues, ranging from Martin Schwellnus, Wayne Derman and Jon Patricios, to current South African Sports Medicine Association (SASMA) president Phatho Zondi, Pierre Viviers and Christa Janse vanRensburg.  It’s tremendous to see these folks and realize the great distance they have come to contribute to the ACSM proceedings.  In terms of contribution, they most definitely ‘punch about their weight’:  one of the sessions I attended was Dr. Schwellnus’ lecture on Exercise Associated Muscle Cramping (EAMC), a subject about which we publish quite frequently at CJSM.  I learned a tremendous amount from that talk, and I am sharing one of the slides from his talk for which he gave permission to be photographed.

There are many other international attendees at ACSM.  I have seen my friend and fellow CJSM editor Hamish Osborne, who arrived from Dunedin, New Zealand (bringing to my mind the very real possibility that ACSM should start betting operation taking propositions on who will win the “Conference attendee who has travelled the furthest” award).  I have heard Chinese, Italian and French spoken. Read more of this post

LeBron and Exercise-Associated Muscle Cramping


Does this count as “Old School”? LeBron James, in his first incarnation as a Cleveland Cavalier (photo: Dave Hogg, Wikimedia)

Game 2 of the NBA finals is this weekend, and I’m sure the Miami Heat (despite their nickname) are hoping the air conditioning works.  In truth, I think most of us are hoping that we witness a straight up basketball affair determined more by athletic skill and less by Exercise-Associated Muscle Cramping (EAMC).

If you need a primer to know what I’m talking about, here’s a brief rundown of Game 1 and LeBron’s EAMC. 

‘Most of us’?  I truly have no horse in this race (speaking of that….I most definitely am rooting for California Chrome to bring home the Triple Crown later today), but outside of Texas, it seems that most of the country may be leaning toward the Heat.  At least that’s what ‘Big Data’ would suggest:  check out this great, data-driven map from the New York Times showing the breakdown of team allegiances across the United States.

Truly though, aside perhaps from a pocket deep in the heart of Texas (who may want victory, no matter what!), I think most fans of the NBA would rather see the outcome of the games determined by the players and not by a lack of AC.

As a team physician, like many of you, I have had–along with my Athletic Trainers–to deal with plenty of muscle cramping in my career.  Here in the States, I find it occurs most often in the very beginning of football season:  during August pre-season, or the early September games that may be played in temperatures approaching 90 degrees.  It seems the combination of relative deconditioning, environmental conditions, and plain foolishness (my adolescent athletes frequently forget to stay hydrated, despite constant reminders to do the same)  gives rise to any number of trips on to the field to assist a player downed with quad or abdominal cramps.  At some levels of the game, to circumvent that inability to maintain adequate oral hydration during a game, teams will turn to pre-game intravenous hydration, as has been discussed in literature published in this journal and blog.

Then again, perhaps there are other issues altogether different than these potential risk factors that give risk to EAMC. Despite the high incidence, the etiology of EAMC continues to be debated.

Yes, I am a believer in the powers of pickle juice, but EAMC remains a puzzle to me and others.  And so I turned to the CJSM website  this morning for guidance and found a great 2013 study:  Collagen genes and exercise-associated muscle cramping, from a group of South African authors.  I especially appreciated this article for its contribution to my basic science knowledge:  I learned so much about the biology behind EAMC.  I encourage you all, clinicians and non-clinicians, to check it out.

The authors begin the paper with an excellent overview of various hypotheses of EAMC, ranging from electrolyte depletion to altered neuromuscular control. They then explored the literature that points to the possibility that EAMC may be associated with a genetic predisposition to musculoskeletal soft tissue injury. Specifically, their research hypothesis was that “variants within collagen genes that code for components of the musculoskeletal system would increase susceptibility to EAMC.”  To test this, the authors conducted a ‘retrospective case-control genetic association study’. Read more of this post

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