Sock Doc Training Part V: That Marathon May Kill You?

Sock Doc Training Part IV: The Sock Doc Training Formula

A marathon or any event for that matter can be a very stressful to the human body if not prepared for properly, and especially if an unhealthy diet, training, and lifestyle factors are too much for the body to bear. High caliber long distance athletes and sports icons have died, perhaps as a result of their running and other factors.

Jim Fixx, the author of the 1977 best-selling book, The Complete Book of Running, died of a heart attack at the age of 52. Fixx is credited with popularizing the sport of running and demonstrating the health benefits of regular jogging. His autopsy revealed that atherosclerosis had blocked three of his coronary arteries by 70% or more. This lead to the belief by many that running was not as beneficial as once thought. However, Fixx was genetically predisposed (his father died of a heart attack at age 43 and Fixx himself had a congenitally enlarged heart), and had several lifestyle issues – he had a stressful occupation, just went through a second divorce, and was overweight and a smoker before he began running.

Ryan Shay was an American professional long-distance runner who collapsed five miles into the 2007 Olympic marathon trials. He died of a heart attack due to a pre-existing cardiomegaly (enlarged heart).

Did Pheidippides die after his marathon?

This is not as uncommon as you may think in distance athletes. A good friend of my brother’s growing up died of a sudden heart attack while out on a training run one day with his fellow cross country team. He was only 24 and a national level runner. Steve Larson, the professional mountain biker, road biker, and eventually-turned triathlete who won Ironman USA in 2001, died suddenly in 2009 at age 39. Recently, (March 2012), the famous ultrarunner Micah True, aka “Caballo Blanco” died of cardiac arrest while on a training run.

A recent study (Jan 2012) in the New England Journal of Medicine looked at the incidence and outcomes of cardiac arrest. (Cardiac arrest is when the body doesn’t efficient pump blood due to poor heart contractions whereas a heart attack is lack of blood flow to the actual heart muscle.) The study found that atherosclerotic coronary disease and hypertrophic cardiomegaly accounted for the majority of cardiac arrests and the incidence rate was significantly higher during marathons, and in men over women. The atherosclerotic coronary disease does not result in the traditional plaque rupture leading to an embolism (blockage in a blood vessel), but ischemia – lack of oxygen that is unable to meet the demand the body requires.

In December of 2011 an article published in the European Heart Journal found that marathon runners and others engaging in extreme endurance exercise may temporarily damage the right ventricle of their heart. This was reversed one week later in most of the 40 athletes they studied but five of them showed lasting damage.

These cardiovascular damaging effects of long, hard training and racing are in-line with what many long distance athletes put on their bodies. Athletes are taxing their cardiovascular systems throughout a distance event much like it’s a chronic high intensity interval session over a very long period with inadequate recovery. And everybody has to sprint to the finish – even if they’re last. If you’re training aerobically and will have built a sufficient aerobic base, then you’ll be racing primarily aerobically and be able to withstand anaerobic periods during the race. The chance of any ischemic incidence is greatly lowered, perhaps eliminated, in such a conditioned athlete.

I think, based off the groups of people I associate with as well as the types of patients I see in my office, that the boom of half and full marathon racing is creating more and more unhealthy people. Too many people should not be doing these events as they’re not healthy enough even for a 10K. I say healthy, not fit – as they have the fitness to stick out the miles, but their health suffers because their lives and training are too anaerobic. Interestingly, those doing ultras and Ironman distance triathlons seem to be healthier and my thought there is it is because they are training much more aerobically since these events can last in the 10-20 hour range, if not longer. There are of course still a lot of unhealthy long distance triathletes and ultra runners, but from my experience, it’s the people who want an obtainable goal and sign up for a half or full marathon that end up injuring themselves and decreasing their overall health.

Perhaps those who put the stickers “13.1” or “26.2” on the back of their vehicles to say they went the distance should also include their heart rate, maybe their time too – but heart rate is more important. It’s much more respectful to the body for a 40 year old to run a marathon in 4:00 at a 140-150 HR than do the same race in 3:30 at a 155-165 HR. A marathon run by a Kenyan in 2 hours is often going to be much less stressful on his body than someone “running” a 4-6 hour marathon.

Extreme racing and training can take a toll on an athlete’s body; even a highly fit individual. But this doesn’t mean that aerobic conditioning is bad as discussed in Part I. Dietary and lifestyle factors play a huge roll here. Inflammation is clearly one main factor that will raise your risk of not just performing poorly, but perhaps dying from working out or racing. Inflammation of the body can be measured via a blood test to test for C-reactive protein. CRP levels increase dramatically in acute inflammation and remain high when there is chronic inflammation. Elevated CRP levels are associated with diabetes, hypertension, and cardiovascular diseases. Inflammation is often dramatically increased following a marathon. Although the inflammation may subside in many, if there are several other health factors involved then the athlete could be in a chronic state of inflammation. A healthy CRP level should be <1.0 mg/L, although “normal” is allowed up to 3.0 mg/L. I’ve raced 20 Ironman races and check my CRP at least once a year. It is always well below 1.0 mg/L , often <0.5 mg/L.

If you keep it aerobic the majority of the time, running long distance can be very beneficial to your overall health and longevity.

In 2010, researchers from the University of Nevada, Las Vegas published a review of fourteen studies comparing longevity and mortality in elite athletes with that of the general population. Included in these studies were data for endurance athletes, power athletes and mixed-sport athletes. They concluded that elite endurance (aerobic) athletes and mixed-sports (aerobic and anaerobic) athletes survive longer than the general population, as indicated by lower mortality and higher longevity. The studies of power (anaerobic only) athletes were inconsistent.

Long-distance runners and cross-country skiers lived significantly longer than the general population (2.8–5.7 years longer). Soccer, ice-hockey and basketball players, track and field jumpers, short-and middle-distance runners, and hurdlers also survived longer than the general population (4.0 years longer).

Though the studies looked at elite athletes and not the average Joe running marathons or playing a hard weekend soccer game, it does provide merit that aerobic activity is very beneficial to the body – but it has to be true aerobic exercise. Anaerobic exercise combined with aerobic exercise is beneficial too, but only when a sufficient aerobic base has been built, (Part II). It’s most likely safe to say these types of elite athletes have a superior aerobic base.

Keeping inflammation at bay is highly dependent on diet. Zero partially hydrogenated oils and as few refined vegetable oils (corn, soy, safflower, sunflower, canola, peanut) as possible are important steps in keeping inflammation down. Good fats from extra virgin oil, fish oil, coconut oil/milk, eggs, and avocados are also vital, as is a diet low in refined sugars and carbohydrates. (Think Paleo Diet.) Obviously, most long distance athletes are carb-junkies. They drink sugary fluid replacement drinks and consume gel packs often, usually daily. Due to improper training (lack of an adequate aerobic base) they’re burning predominantly sugar when training rather than fat – so they must consume more and more sugar to fuel this cycle. This all provokes and sustains inflammation and makes their tissues insulin resistant, rather than insulin sensitive. Insulin resistance is very, very bad. How long can you train without food or some sugar water before having blood sugar handling problems such as cramping, lightheadedness, or even bonking? If it’s less than one hour then you’re very anaerobic. Aerobically conditioned athletes won’t break down and bonk or hit the wall as the miles add up.

Some note a general guideline for a well conditioned aerobic athlete can be seen in their race times over various distances. Generally, for example, if your one mile run is at 7:00 then your 5K race time should be around 22:30 (7:15/mile), your 10K time around 46:30 (7:30/mile), your half-marathon 1:41:30 (7:45/mile) and your marathon time around 3:30:30 (8:00/mile). Though genetics play some role here, if you’re running your 5K at 23 minutes and your marathon time is around four hours (or more), you’re not aerobically conditioned to run so far. You’re running the race too anaerobically (inefficiently), period.

As discussed in Part II, the more you develop your aerobic system the more you develop your mitochondria. The more mitochondria you have, the less lactate your body makes at a given intensity. This raises your lactate threshold, so what was once mostly anaerobic is now less (and more aerobic). The net result? You’re faster, more efficient, and much healthier.

Developing the aerobic system is important – actually it’s vital. There is no shortcut to it. It takes consistency and discipline in training. Consistency means you have to stick with it and give it time. If you’ve never developed your aerobic base then it could take several months, maybe a year. Follow the aerobic & anaerobic training guidelines to know when you should add in some anaerobic training and/or weights. The discipline is not just to stick with it, but to keep yourself from going too hard. A heart rate monitor becomes very important with aerobic training and you may not be able to train with your friends, unless they want to go your pace. Running long and hard too often, just like many people training for a  half or full marathon, can definitely kill you, but so can a life of no running or little movement activity. Slow down, and take the time to develop superior fitness and health.

You can post a comment or question here.

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  1. Stella says

    Dear Sock Doc,
    Two questions:
    1. I realise I need to develop my aerobic system, but should I not do any strength training at the same time? Don’t I need to build some muscle to stay injury free?
    2. There is so much discussion about barefoot or not around that I’m a little confused:) A lot of experts argue that yes, we’ve been running around without shoes for thousands of years but not on the hard surfaces like pavement, concrete, tiles and so on, and that we therefor need good shoes. What are your thoughts on that? Do you wear shoes when you compete?

    Hope to hear from you:)

  2. Adam says

    Could you explain a bit more about why a 5k @23 mins and 4+ hr marathon implies insufficient aerobic conditioning? Is it just because you are not able to keep the same pace in the marathon that you used in the 5K ?


    • says

      You’re not going to keep the same pace as a marathon – if you’re running 7 min miles in a 5K you’re not going to do that in a marathon (unless you are in great shape and went super easy in the 5K). Someone with a well developed aerobic system may run say a 7:30 pace in a 5K (around 23 mins) therefore they should be able to keep an 8:15 pace in the marathon = around a 3:35.

      • says

        Thanks. I agree that the Kenyans look much healthier after a Marathon. But there also some very fast amateur runners (sub 3h) who seem not healthy after the race.

        By the way, I have been following you advice since September. Well, at least those advice I can remember. I am 40 years old. I finished my first marathon in 4:03 at a 157 average HR.

        Reading this today
        “It’s much more respectful to the body for a 40 year old to run a marathon in 4:00 at a 140-150 HR than do the same race in 3:30 at a 155-165 HR.”
        I feel that maybe I went too fast for my current condition.

        • says

          That is a bit high of a HR for a marathon, even though many hit averages in the 160s. No big deal if it’s just one or two races and you’re not constantly putting your body under such stress, but you’ve only been doing this for a few months. Plenty of room for improvement which I’m sure you’ll continue to see.

  3. mcannon says

    It is very easy to adopt a Steve Prefontaine outlook and just go hard all the time, you figure-the harder I push the stronger I will get…apparently not. Pushing hard then might make you head strong, but not very smart of healthy then..? Great article, very interesting. When using a HR monitor, how could you tell if you were overtraining/training past your aerobic capacity? Is it simply a case of your HR being unusually high for the pace and distance you’re running?

  4. Sol Lederman says

    Great series. Thank you. I’m a fellow MovNat alum who discovered this great blog through the Facebook Movnat alum group.

    I’m curious to know what you think about mouth breathing vs. nose breathing. Is it true that mouth breathing puts the body in panic mode? I enjoy aerobic conditioning on my Concept2 rower (yeah, not very “natural” movement but I enjoy the meditative aspect of it; I can get into a nice groove and keep my heart range in an aerobic zone easily.) And, I can row in any weather. Anyway, I like the idea of keeping my mouth closed for the entire workout. It works well to keep me in the aerobic zone.

    Your thoughts?

    • says

      Thanks Sol.

      I don’t think that’s the case with mouth breathing, as long as it’s controlled. Obviously if someone is panicking then they’re going to breathe through the mouth rather than nose and if they calm down then they can breathe nasally again, but I don’t see a problem with breathing through the mouth while exercising.

      And although rowing is not “natural”, that and cross country skiing may be two of the best “total body” exercises you can do.

  5. Daren says

    As a fairly new participant in road biking, I think I started all wrong. I would go out on 10 mile rides and push as hard as I could. I would come back exhausted and it would take hours for my heart rate to drop. This led to multiple trips to the doctor who said to “keep doing what you’re doing”.

    It didn’t make sense to keep doing that, so I have changed my workouts to, I think, one that is almost exclusively aerobic. I’m 36 y/o male, overweight (5’10” 210lbs @ 20% bodyfat). I have changed to sitting on a trainer in my living room and getting my pulse in the 135-144 range for an hour. I mix up the cadence just to give me some variety. I stand when I feel I need to stand (to rest my butt). Then, on the weekend, take one long ride – hills, flats, fast, slow, anaerobic and aerobic…just having fun. All I do is make sure that between every hard pace (HR 160+), I mix in a period where I let my heart rate come back down to that 135-144 mark for a few minutes.

    My times are still slow (14-15mph), but when I get off the bike I feel good. I started this at 238lbs and I’m trying to get down to 180lbs. Is what I’m doing in line with what you’re teaching here? I’m not trying to be a world-class cyclist, but I’d love to be able to do 7-10 days of 100+ miles without feeling like I’ve hurt myself. Right now, I can do 50-60 road miles comfortably (in my chosen HR range).

    Any advice would be appreciated.

  6. npmb13 says

    Wow doc… I trained for almost 6 months building my base – I did skip close to 3 weeks due to family in the hospital and then I got ill. My marathon Avg HR was 162 bpm & Max HR 177 bpm. I’m a 35 female :-/

    Gotta hit the anaerobic base again.

  7. Nathan says

    Hi, I’ve only just seen this site (and its awesome) as I’ve been doing some research on health and fitness. I’ve just signed up to my first half marathon here is Australia, and I would really appreciate your thoughts.

    I’m 37yo male, 180cm tall and currently 84kg (185 pounds) – This time last year I was 112kg (246 pounds). In the last year I’ve taken up amateur boxing, changed my diet and exercise regime completely, and have seen a huge increase in fitness (general wellbeing).

    My current traing program is:
    Mon – 2h boxing training (skills and fitness & conditioning – pushups etc)
    Tues – 5km run
    Wed – 2h boxing – (skills and fitnesss – sparring sessions & conditioning – pushups etc)
    Thurs – Rest
    Fri – 7-8 km run
    Sat – 1h boxing

    Now on Sundays I’m doing a long run between 18km and 22km.

    I take daily vitamins (multi, iron, calcium and Vit D) I also use BCaa tablets and ensure Im properly hydrated.

    Last Sunday I did 19km in 1h 48min and I generally do 7km around the 38 min.

    I think I have a pretty balanced regime for a half marathon, but I’m concerned I might be setting myself up for some health issues with taking this on, (given my efforts over the last year) although I currently feel great when working out.

    I feel confident to do the half marathon in a reasonable time without pushing myself to extremes, but I’ve started to see some changes/things e.g. sore eyes, mood changes/impaitence, food cravings late of evening (health of course), some sleeplessness.

    Are these signs I’m overdoing it? Am I vitimin deficinet ? What do you think, I’d really appreciate your thoughts.

    Thanks, Nate in Australia !

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