Friday, January 2, 2009

Endurance sports...the hidden killer??


and cigarettes are good for you...

Lately my blog has been linked to several sites that contain strange anti-exercise screeds or imply in some way that endurance training is detrimental to one's health. One site,CrossFit, seems to be holding me up as some sort of caveat against “too much” endurance training, or maybe the CrossFit guys simply think my blog is cool. Either way let me dispel some myths about my heart condition and endurance training.

As I've said before , there is no reputable science that suggests or concludes that endurance training by itself leads to dangerous arrhythmias, or other heart conditions. A cocktail of conditions may encourage arrhythmias, and there is a very small segment of the population that has a genetic predisposition towards certain heart conditions, (AVRD/C, below) and to those people endurance sports and training can be detrimental in the long term. But for the vast majority of people, endurance sports are simply not going to damage your heart in any way. And to the vast majority of people a modest routine of aerobic endurance training is beneficial for heart health. For those who happen to be crazy about a sport that pushes endurance training to the extreme, as in my sport of bicycle road racing, or marathon running or cross-country skiing, there is nothing deleterious about pushing those limits, as far as heart health is concerned.

If my past behavior had any impact on my current heart condition, it was most likely the times when I raced or trained while sick. I’ve raced in subtropical countries, eaten bad food, drunk bad water, raced through colds and flus and bronchitis. The most likely reason for the scar on my heart that caused my arrhythmia is a viral infection that I was exposed to somewhere along the way. My condition was not caused by the overall training volume of my life to date.

There is a chance (genetic tests are still pending) that I am one of a very few who have a genetic condition known as Arrythmogenic Right Ventricular Displasia / Cardiomyopathy. While, technically, I do have ARVC (Arrythmogenic Right Ventricular Cardiomyopathy), the cause of this condition in most likely not genetic, but rather idiopathic (which basically means that they don’t know for sure). Genetic ARVD/C is a gradual weakening of the walls of the heart through the degradation over time of the muscular tissue. With this condition endurance exercise accelerates the process of degradation. Doctors recommend nothing more than walking, bowling, or golf as activities. Really bad cases of ARVD/C end up as candidates for heart transplant. The disease is still quite unknown, and more is being discovered every day.

Thus far my doctors have been pretty certain that I do not have genetic ARVD/C. There is no cardiac history in my family, and I have only a few of the telltale signs of ARVD/C that show up on an EKG. Even without these indications, I am having the genetic testing done just in case, but I have confidence in my doctors and, since November ‘08, have resumed a modest training program.

Regarding CrossFit and its anti-endurance anti-Long Steady Distance philosophy, I think there is some truth in it at the most basic level. “Specialist” endurance training is not for everyone, and certainly us “specialists” have grave weaknesses in all around fitness (don’t even ask me to do a pull up). But the notion that somehow short, predominantly anaerobic training will make you competitive at anything but the most amateur level in a specialist endurance sport is misguided, nor are most people committed to a specialist sport particularly interested in the kind of fitness CrossFit results in. In the case of bicycle road racing, for example, endurance-overload training effectively recruits fast-twitch muscle for slow-twitch use, extending endurance at the end of a 4 to 6 hr event, thus many road racers limit their anaerobic strength training. Fast to slow twitch muscle recruitment only happens with an LSD program. There are many other effects of LSD endurance training that are necessary to compete at the top level of these specialist sports, but that is a rant for another day...

10 comments:

arrhythmia rules said...

Hi Craig
Just come across your blog - my son is a crossfit fan and into judo. However my reason for responding is that I have lone atrial fibrillation, not nearly as serious as yours. I still try to keep fit and am certain it helps. It certainly improves my quality of life.

However onto the meat. There are now studies which show a correlation between high level endurance exercise and atrial arrhythmias: one actually looks at former Swiss pro cyclists showing a link. However the link is not identified ie it is something that population had but what. What is I understand becoming clear is that arrythmia can link to high vagal tone brought on by training. Higher vagal tone will occur whether it is cross fit style or long and steady.
As you point out does the stress damage come from the endurance or other life style factors - in my case did I push too hard physically when I took youth groups away, worked weeks or so on end with late night discos and some early mornings. Thought I was invincible. No idea. Is it genetic - certainly a study now suggests for some.
My arrhythmia is partly vagal but also sympathetic in origin. Exercise seems to help, though overdoing things is bad. The balance is very hard to find. I keep saying I will start to blog it since it can be a hard fight.
I go kayaking, cycling 5,000k last year and generally keep fit. Times of low fitness have not shown lower rates of arrhythmia.
I will come back to your blog.

arrhythmia rules said...

Hi Craig
Just been catching up on some of your earlier posts. I have a friend who has a Medtronic ICD. One of his reasons for liking it is that now when he runs for the train and his heart goes into arrhythmia he can feel the Medtronic give his heart a defibrilating zap. Stops his arrhythmia and he can continue running.
All the best.

TT specialist said...

Craig, good to hear you're still a fan of riding the old two-wheeler! You need to charge CrossFit for the use of your name and story, just like Lance charges for his appearance at races!

RustyTainte said...

A friend introduced me to your blog. I am so glad he did.
Several months ago I suffered almost the same thing you described in “Mount Doom.”
Within a year of being a competitive cyclist, here in the U.S., I went from a bottom feeding Cat5 to a full blown Cat3 - winning my 4th Cat3 criterium with ease. I was ecstatic! I’m 38. Who would have thought that an old, married man could not only compete with the likes of these whippersnappers but make them rue the day? Ha. Well, after the race I kept a real nice high and couldn’t wait until my next – and last – race of the season.
So I went back into training mode. But something wasn’t right. I felt off. My heart rate skyrocketed with any small effort. Hmm? Maybe I overreached. Maybe I needed some more time off to recover. Nothing helped. Even coffee affected me. My sweet love coffee. My heart palpitated. I could feel it in my throat and there was a pain in my left side. Nerves? Maybe. I mean, I just came off a huge win and I wanted to ride it to the enormous going out party at the Greenville race.
Well race day came. I was nervous and excited. Nervous because I still felt off. My race-prep ride the day before was cut short because of my heart rate and a little dizziness. With everything in order and number pinned on, I set out on the bike for a warm up. There were some nicer rollers near the race course I could warm the legs on. Bam! Every effort was like I just finished a Pro/1/2 race. I was bummed.
Then it got worse. After chatting it up with some friends in the race, and having them give me kudos on my victory, I found myself dead last and struggling. Halfway through the race, I was getting dizzy. At ten laps to go, I quit. But it wasn’t like, “Screw this. I’m outta here.” It was like my body said enough and made a B-line to my car. Two guys – spectators - came and asked me why I quit. I couldn’t give a straight answer. Plus they were toking on cigarettes. I should have asked them if they wanted my spot in the race.
Anyway (let’s see if I can shorten this). Weeks later I was still suffering. Coffee intake was down to one small cup. Training was over. Bike rides were slow and methodical. My heart pounded all the time. My chest hurt. I was starting to have pain in my left shoulder and arm. My wife, a nurse, said enough was enough and scheduled me and my ego a doctor’s visit.
The visit was short: In, blood pressure checked, heart rate checked, and appointment scheduled for a cardiologist. He couldn’t tell anything but didn’t like my symptoms. Oh, and gave me a diuretic for my blood pressure. Yippee! Just what a cyclist wants.
Several weeks later I’m in the cardiologist. They hook me up to an EKG, do their thing, and come back to tell me the not-so good news. “You may have LVH (left ventricular hypertrophy) or athlete’s heart.” My Mount Doom. I’ve read a lot about it on the net after plugging in my symptoms and reading everything I could. He told me not to worry just yet. I needed to come back for a stress echo and stuff. Plus, he seemed more positive than not. He, himself, was an ex-athlete. A rower. He asked tons of training questions, told me that he was going to switch my BP meds, and told me to keep riding like I have been. I just couldn’t go too hard right now.
Fast forward a couple of weeks, and I find myself sprinting on a treadmill for over 13 minutes until my max heart rate was reached. I was like a chimp in a science lab. Several nurses were in there watching in awe as I beat all the records in the past. I guess the 80-somethings can’t hang with us 30-somethings, huh? After one minute at my max, a nurse grabbed my left arm and flung my on the table. Another nurse was there, echo thingy in hand ready to jam it into my ribs before I recovered. “Hold your breath,” I heard. “Roll this way.” “Arm over your head.” Etc. After all was said and done, they told me everything went great. The scans were perfect and I will know something within the next couple of weeks.
Within a week, I received a phone call. “You are fine,” the nurse said. “The doctor still wants to see you, however.” Fine? Fine?!? OK. But, so many questions lingered. What was all that about? The pain? The palpitations? Pulling out of the race? This? That? At the office, he couldn’t explain it. He seemed a bit concerned still. He was worried that he overlooked something. He even had several colleagues to study my results. Nothing was found. The initial EKG was wrong. The only thing he found was that my heart was on the upper limits of normal for its size. But everything else checked perfect.
And since then – and a week before the appointment – I have been great. My heart rate is getting back to normal. No pains. No palpitations. I’ve even went out for VO2 intervals without any problems. Today was one of those days. My power numbers are in the tank, but I just thank God that I’m not.
My race season starts next month. I’m not looking to dominate by any means. I’m going to have some fun and be blessed knowing everything is OK.

As for you, I will be praying for you. It’s a scary feeling having that uncertainty. But, you’re in good hands. And you are doing a wonderful thing by keeping this blog. I wish the best for you and look forward to more posts. You have a great talent in writing. Again, thank you.

c2 said...

Arrhythmia rules and Substructure- Thanks for sharing. Substructure, my advice would be to definitely keep an eye on things. What you describe sound like PVCs, I'd be curious to know what a Holter monitor would tell you. PVCs are harmless alone but they can indicate other things. Arrhythmia rules (and another commenter some time ago) mentioned an interesting study about vagal tone and PVCs. My experience is that there is definitely a link. It seems when I've been sedentary and not doing any exercise for more than a week or so I have more and stronger PVCs, when I exercise consistently but not too intensely or long (say 3-7 days a week) the PVC's decrease. Since I've been fixed I haven't done a huge amount of training so I don't yet know what a real block of training will do, but from my experience before all this happened heavy training weeks did give me more palpitations from time to time.

Anonymous said...

hello Craig,
wow, that is definetly is a bummer, but it is very...whats the word..inspriational. My dad is a cardiologist and he deals with this stuff all the time. I have a question, even though you have this heart problem, you still can live normally, right? I am doing a paper about AVRD and I could really use some real person experiances with someone who has a heart problem. Thankyou!

c2 said...

Hi Anonymous June 4,
Apologies for responding so late, I don't check this blog so often these days. I'd be happy to answer any questions you may have concerning my heart problems. I do live completely normally, and I am in the diagnostic grey zone as far as ARVD is concerned. Write me back with your questions at ccpbackoffice@gmail.com
best,
craig

Anonymous said...

Hi
Happy to help as well. johnatpickenstoporgstopuk
there are now a range of studies showing links between endurance exercise and AF. I suspect sub structure had full blown AF, perhaps because he had pushed things to the limit. So yes should watch and take care. For me that would include warm up, warm down, relax between, ensure full recovery, do everything to assist recovery, enough rest etc. Wonder how his season went?
Arrhythmia rules

Anonymous said...

Hi Craig, I found many similarities with your story. I too have idiopathic vtach. Mine is (normally) excercised induced and predictably kicks in when I get my heart rate above 170 bpm. Over the past four years, I've had 5 EP studies in attempt an ablation. During the first four attempts, they were unable to induce the VT with the various proarrhythmia drugs they give you. On the fifth attempt, I took diuretics in the days prior to the study to dehydrate, had them crank up the heat in the EP lab to 90 degrees and pedaled while on the table. We did induce the VT for about 30 seconds and my EP doctors performed some ablations in the outflow trac area. We were very excited that we had finally at the end of this ordeal. About a month after this, I told my Dr. that I wanted to do a stress test just to confirm that the ablation had been successful.Well, right on cue, about 12 minutes into the test, I went into vtach. Very disappointing.I have an ICD and have been shocked on a few occasions.I need to be careful not to let my heart rate get above 130-135 bpm. I do play golf competively and I feel like I have to careful on hot days on hilly courses. I can't get angry like I used to because the adreneline causes my heart rate to spike. Anyhow, I haven't run into many people with idiopathic vtach (know lots of people with afib), so I read your story with interest. My doctors told me the same thing as for a possible cause for the small scar...probably viral infection years ago. I'm taking a break from the EP lab for now, but I'm still hopeful that one day I'll have a successful ablation. Good luck.

Anonymous said...

I'm being investigated for possible ARVC at the moment and I'm really worried about it. I'm just a keen amateur rather than elite but I play ice hockey, run up to half marathon distance, cycle, and do long distance skate marathons. Reading about ARVC all the specialists say I'd have to stop all that. I don't know what I'd do with my life.