“Making News” in the March 2012 IDEA Fitness Journal reminded me of something I investigated years ago, of interest to indoor cycling instructors. The article was “Endurance Exercise Linked to Heart Damage Risk.”
In 2006, prior to my first ultra-distance bicycle race, the Furnace Creek 508, my coach asked me to have a full physical, including an echocardiogram. It turned out that I had an enlarged left ventricle as a result of rigorous endurance training over 35 years, and two heart murmurs (leaky valves). I was in the best physical condition of my life. I completed the 508 and qualified for RAAM, although I decided not to pursue RAAM for several reasons. One was growing evidence that rigorous endurance training might negatively impact heart health.
A muscle enlarges (hypertrophies) with specific training. When weight lifters train for strength, muscle may hypertrophy. When body builders train, they seek hypertrophy specifically. An endurance athlete’s heart naturally hypertrophies because of the demand placed on it to supply blood and oxygen to working muscles.
My cardiologist agreed that my condition was not dangerous or abnormal, but should be watched.
“Endurance Cycling Tied to Lasting Heart Damage” by Nathan Seppa was published in Science News in 2005. It claimed that people who compete in grueling long-distance bicycle races could harm their hearts. Blood samples revealed the cyclists had over twice as much B-type natriuretic peptide (BNP), a natural compound that identifies risk for heart failure, as a control group of golfers who were healthy but hadn’t done competitive cycling.
BNP is a 32-amino-acid polypeptide secreted by the ventricles in response to excessive stretching of the heart muscle. BNP is elevated in patients with abnormal left ventricle function and correlates with congestive heart disease.
I found several studies correlating BNP with left ventricle hypertrophy in hypertensive patients. One study found that cycling athletes had significantly larger left ventricles than hypertensive patients without elevated BNP. The researchers concluded that BNP is elevated only in patients with enlarged left ventricles due to hypertension, not intense cardio exercise.
I discussed this with several indoor-cycling instructors, including my colleague Joan Kent. Almost immediately, Joan suggested that BNP might be nothing more than a marker of hypertrophy, regardless of cause — heart damage, hypertension, or high-volume, high-intensity endurance training. Since the heart can hypertrophy for more than one reason, it’s over-extrapolation to assume that the association of BNP with both good and bad factors necessarily links the factors. (Yes, she actually talks that way.)
I kept researching. Several studies confirmed elevated BNP in endurance athletes, although exercise-induced BNP increases are poorly understood. These studies correlated increased BNP with levels of cardiac troponins, another indicator of heart disease, specifically associated with muscle damage.
The studies confirmed increased BNP in a majority of healthy athletes after prolonged strenuous exercise, although BNP may increase not from myocardial damage, but as a protective or growth-regulating mechanism. They stated that exercise-induced increases in BNP are not the same as elevated BNP associated with heart disease. Joan countered that, again, it’s the same BNP, but may just be associated with hypertrophy, rather than disease.
The best study was “Competitive Exercise in Professional Road Cyclists” in Medicine & Science in Sports & Exercise (2003). The study questioned conclusions of heart damage in apparently healthy endurance athletes. It investigated myocardial stress in professional endurance athletes after strenuous, competitive physical exercise by looking at BNP, cardiac troponins, and EKGs.
None of the athletes showed pathology upon cardiac examination. BNP was elevated, but, based on troponins and EKGs, strenuous endurance exercise in professional road cyclists was not found to result in structural myocardial damage.
The study cited in IDEA Fitness Journal was published in the European Heart Journal in 2011. Investigators uncovered evidence that some athletes who participate in extreme endurance sports (alpine cycling, ultra-triathlons, marathons) might damage the right ventricle of the heart. Notice this article said right ventricle, which pumps blood to the lungs, not left ventricle, which pumps blood to the body and was examined in other studies.
What does this mean to the indoor-cycling instructor?
Perhaps nothing. Scientific findings vary with new hypotheses. The fact that the subject continues to come up, however, suggests that we should pay attention to it.
As a fitness professional, my concern is the unbalanced view given to people we train. We have all experienced our students unlocking their potential through their indoor-cycling experience. We may need to stress adequate recovery, not turning every class into a max effort, the benefits of cross-training, and/or using cycling to enhance balance.
Case in point: The “Triple Crown” is a coveted California jersey given to amateur cyclists who complete three double-centuries in a season. In 2011, one of my students got it. I congratulated her and asked about her recovery plans. She told me she was going for the “1000-mile club” (first time I’d heard of it) and planned to do five before the year was over.
As a 58-year old endurance athlete with an enlarged left ventricle, two heart murmurs and a tendency to train too much without proper recovery, I’ll continue to stay informed and share my findings with you.
Ask my family, of the three components of fitness (Training – Nutrition – Rest) which is most important to me and without hesitation they will say Rest! Or in my case Sleep! I'm habitual in my sleep habits because a good night's sleep is paramount to my effectiveness the following day.
So when I heard that today is Sleep Apnea Day here in the USA, I though I should do my part to help inform you so that you can in turn inform your students.
Sleep apnea’s most frequent form is obstructive sleep apnea when the sleeper’s tongue and soft palate fall back against the back of the throat closing off the airway so firmly that the sleeper doesn’t fully inhale in repeated episodes that last 10 seconds or longer. In severe sleep apnea patients, the episodes can recur hundreds of time during the night, giving rise to serious impairment due to repeated oxygen deficiency.
My brother Dan has Sleep Apnea and for a long time he slept wearing the CPAP device shown in the video. Clumsy but a life saver for him and his wife 🙂
This tip maybe of value to some of your students, or maybe you…
I've never heard myself snore, but Amy, the Senior Group Fitness Instructor in our family has. I don't have Sleep Apnea but my snoring has had me evicted from my bed. We didn't realize it at the time, but my snoring was much worse in the winter = very dry air. Amy and I were on one of our working fitness vacations in Jamaica, when she commented that I don't snore there in the moist warm air. So we bought an inexpensive humidifier that now sits next to my side of the bed. As long as I remember to refill it with water, Amy has a quiet, restful night!
From http://wilsonbrothers.wordpress.com/2009/09/23/seebikesaw/
By ICG® Master Trainer Joan Kent
Some of your students may be severely limiting the amount of fat they eat — both good and bad — to lose weight. That’s likely to increase their consumption of carbohydrates — both good and bad. Because “bad carbs” can bring on some negative health consequences, it might pay to look at this.
Articles in science journals reference the “sugar/fat seesaw”, although research hasn’t really published an explanation for it. As the name implies, the sugar/fat seesaw is an inverse relation in dietary sugars and fats. I’d like to suggest a possible explanation for the phenomenon, in the interest of better nutrition balance for students.
When fat first enters the intestine, a hormone called CCK (cholecystokinin) is released. CCK is the most powerful satiety hormone in the body. Satiety is the feeling that we’ve had enough food and don’t need to keep eating. Fats activate a substantial release of CCK. CCK also curbs the desire for carbs. So, if fat is reduced too much (low-fat this, nonfat that, and so on), the desire for carbs may escalate.
Second, both sugars and fats trigger the release of beta-endorphin. That’s the brain chemical associated with the Runner’s High. As everyone who enjoys indoor cycling knows, you don’t have to run to get that high. Any solid cycling workout will do the trick, and the more intense the class, the greater the beta-endorphin effect.
There’s some evidence that the brain gets acclimated to a given level of beta-endorphin and that reducing beta-endorphin levels can cause withdrawal. It follows that strict limiting of fats might increase the desire for sugars as a sort of “beta-endorphin compensation.”
The third point involves saturated fat. Sat fats generate an insulin release, just like carbs. Cutting fats severely could decrease saturated fat severely. From a health perspective, that’s OK, but it could raise the desire for carbs, especially the ones that cause high insulin release.
Basically, it’s linear: the more insulin we release, the more serotonin the brain makes. Serotonin is a brain chemical best known for its antidepressant effect, but it also has other functions. High levels of serotonin have been shown to reduce carb consumption. The very, very low-carb Atkins Diet makes use of this fact to keep people away from carbs. Much of the fat they push is saturated. Between the CCK and the insulin/serotonin, the desire for carbs drops.
So what does all of this have to do with the diets of indoor cycling students?
“Good” fats, typically unsaturated ones like omega-3s and omega-9s, have health benefits in the body. These include anti-inflammatory effects and reductions in heart disease, joint pain, diabetic complications, and lots more. We don’t want our students to eliminate those benefits along with the fats they cut.
When someone tries to lose weight on a very low-fat diet — and I do see clients who are still avoiding fats big-time — major changes happen. CCK, beta-endorphin, and serotonin go down. The desire for carbs goes up, and — as suggested above — the most appealing carbs are the ones that set off the highest insulin secretion. Unfortunately, those are usually “bad” carbs, such as sugar and white flour. High levels of insulin are directly linked to serious health conditions (more on this in a future post).
The best solution — along with regular workouts! — is a good balance that includes some healthful fat with each meal or snack. The fats might be avocado, olive oil, fish or fish oil, seeds, raw walnuts, almonds or other raw nuts. Adding a small amount of good fat to each meal or snack will increase CCK and beta-endorphin, making sugars and junky carbs less appealing.
Another plus is that a little more fat in a student’s diet can increase endurance. Studies on runners have shown this, but, once again, runners aren’t the only ones who benefit.
So the holidays are behind us, and hopefully the overabundant goodies. Some of our students may be back on a familiar January weight-loss track. I thought I’d address the topic of alcohol because it’s often consumed throughout the year and can definitely interfere with weight loss. There are several sabotaging factors in alcohol consumption.
– High calorie density. Alcohol has 7 calories per gram, while protein and carbs are 4 calories per gram. Only fats have greater density at 9 calories per gram.
– High insulin impact. Alcohol is a short-chain molecule that triggers high levels of insulin secretion. Insulin inhibits fat oxidation, lowering the 24-hour fat oxidation rate — an important factor in weight management — and promoting storage of dietary fat.
– Effect on appetite. Alcohol induces the release of beta-endorphin, which inhibits the satiety center of the brain. This may lead to a stronger and more frequent desire for food and a tendency to eat more at a given meal.
– Effect on food preferences. Alcohol’s beta-endorphin release may shift food preferences and cravings in the direction of sugars and fats. Eating more of those foods can lead to higher calorie intake, weight gain, even insulin resistance. Insulin resistance isn’t just the result of overweight, as is commonly believed; it can also be a cause.
– Effect on mood. Neurochemical alterations due to alcohol may result in such negative moods as depression or anxiety, as well as insomnia or disturbed sleep. These can cause a variety of issues that may affect weight:
a) Any negative mood may cause cravings, particularly for sugars or other refined carbs, and increase food consumption.
b) Serotonin is typically reduced with chronic alcohol use, and that can worsen mood and increase impulsivity. The combination may make it more likely that the student will get cravings and have difficulty resisting them.
c) Increased intake of sugars and refined carbs may lead to greater calorie intake and weight gain, further negative moods, or insomnia.
d) Alcohol disturbs sleep by interfering with the deep stages (theta- and delta-wave) that are most restorative.
e) Because of its high impact on insulin secretion, alcohol may trigger reactive hypoglycemia in susceptible individuals, which can disturb sleep by waking someone in the middle of the night and making it difficult to get back to sleep. Hypoglycemia may also result in undesirable moods, cravings and increased appetite.
f) Lack of sleep is known to raise ghrelin levels. Ghrelin has been shown to increase appetite and food intake while slowing metabolism.
g) Lack of sleep may make it difficult to train well or show up for early morning classes, and can lead to depression or other negative moods.
h) Negative moods may decrease motivation with respect to exercise altogether.
As you can tell, alcohol can get in the way of a student’s attempts to lose weight, and the sabotage goes far beyond the so-called “simple arithmetic” of calories in/calories out. What’s even worse is that, with the exception of calorie density, most of the factors above hold true for sugar, as well.
What we eat before cycling classes is very important, but what we eat afterward is even more important. The main value of eating right after a class is that we recover well and can train well the next day. ACSM guidelines are clear that, while three days a week of exercise can postpone the inevitable age-related fitness decline, more frequent workouts are necessary for fitness improvement. So refueling is key.
If your students are anything like mine, though, the refueling meal — and “meal” is a generous term — might range from a banana to nothing but a latte. Neither of these offers the best post-workout fuel. Below are a few points on post-cycling consumption to encourage your students to eat the right stuff.
According to Maughan’s Nutrition in Sport and other research, the best post-workout fuel is a combination of starch and protein, in a ratio of about 3:1. The original study by Zawadki et al. used a 2:1 ratio, and I've seen 4:1 used in others, but the generally recognized guideline these days is 3:1.
It’s best to eat within 30 minutes after the class ends. For many students, that will mean eating in the locker room, so convenience is a factor, but we’ll get to that in a moment. First let’s look at three reasons that this 30-minute refueling window is critical:
Glycogen replacement (repletion) is most effective within 30 minutes because the enzyme (glycogen synthetase) that facilitates it is in its most active form.
Missing the 30-minute window can trigger transient insulin resistance that may persist for hours. If that occurs, later meals won’t replace glycogen as effectively as if refueling starts within 30 minutes.
The carb/protein mix stops the cortisol response, which otherwise tears down muscle tissue.
Actually, the above three reasons have refueling windows of slightly different durations, but it makes the most sense to eat within the smallest window to cover all bases.
For convenience, I recommend a slice or two (maybe three after a tough class) of a bread that’s easy to find and store in a locker. It's Alvarado St. Essential Flaxseed bread. Here are a few points that make the bread a good choice:
Alvarado flaxseed bread is whole grain (a good thing, of course) but has fairly large air spaces, raising its glycemic index. Carbs with a high GI provide faster glycogen repletion.
The flaxseeds in it are whole, thus used by the body as fiber, rather than as fat. It's better to avoid fat in the refueling window because fat slows absorption of carbs. Fast absorption is key following a class.
It's lower in calories than most bread — 50 calories per slice vs. 80-100 in other breads.
Other foods can substitute for Alvarado flaxseed bread, but the combination of starch and protein is preferable to sugary recovery drinks, fruit (the wrong post-workout fuel altogether), or the recently touted chocolate milk, which contains mostly sugars.
Getting your students to eat starch and protein 30 minutes or less after class may help many of them recover faster and perform better in the next class.
I came up from the “Man Cave” (my office) and heard cheers of approval and encouragement coming from our TV. I had been preparing for an interview with a nationally known Nutritionist who has some interesting ideas on how we should be communicating to our students. “What are you watching Abby?” I asked my elder daughter. “Man vs. Food” she replied. “It's a show where this guy is challenged to eat these impossibly large meals in a race against the clock.”
Maybe it's just me, but I started to getting really angry watching this very over weight show host stuff his face with a mountain of food. It took me a minute to understand where my anger was coming from, and it wasn't caused by the host.
What I was reacting to was the crowd behind him and how they cheered his destructive behavior. I couldn't help but think of similar self-destructive people like John Belushi or Quasimodo from The Hunchback of Notre-Dame who resort to self-deprecating humor as a way to seek approval of others. How pathetic.
Please watch this and tell me if I'm alone here.
Listen for the money quote;and then like an idiot, I dig in.
Which calls to mind a line from John Belushi's biggest movie Animal House (but he doesn't say it and it's directed at the Bluto – the stereotypical dumb fat guy) Have you no self respect, man?
