Re-thinking Triathlon Death

During last triathlon season, there were a string of deaths in the water.  Fourteen deaths in races were largely from swimming (one death occurred on the bike)

These unfortunate events led a Washington Post writer to postulate that the deaths during the swim were the result of panic attacks.  I have also heard medical personell postulate that these events were the results of heart attacks and heat stroke.

Of the deaths, the mean age was 44 and 11 were men.  6 deaths were in sprint triathlon (1/4-1/2 mile swim, 12 mile bike, 3.1 mile run), 4 in Olympic distance (1.5k swim, 40k bike, 10k run) and 3 in the longer distances (half Iron distance or Iron distance 2.4mile swim, 112mile bike, 26.2mile run) 

The cause of these deaths has been ruled drowning, but no matter what the cause of death, if it occurs in the water, chances are it will lead to drowning.  Feelings of panic are commonplace in open water, mass start events, but they do not mean that they are panic attacks.

You can feel panicky from too much coffee, a rapid heart rate, feelings that you can't breathe, etc.  It is the things that cause the rapid heart rate and rapid breathing that can lead to metabolic problems which can lead to fatal problems.

Let's examine what happens when you jump into a cold lake.  Most swims are in bodies of water that are at least 10 degrees colder than body temperature.  Cold water immersion leads to a phenomenon known as the Mammalian Diving Reflex.  This reflex decreases breathing and slows the need for oxygen and is life saving for non-swimmers and children who fall into water .  

The more dangerous response is the Cold Shock Reflex. This reflex will cause you to take a deep breath, followed by uncontrolled hyperventilation.  A triathlete who jumps into cold water, or at least puts their face in cold water, will have a temporary breath-holding reflex.  If this same triathlete starts swimming quickly, they would be out of breath before even starting.  Imagine running down the block while holding your breath; you would feel out of breath very quickly.  

Hyperventilation will happen immediately following and is one of the components of feeling panicky.  A rapid rise in heart rate will also accompany the Cold Shock Reflex and can also lead to a feeling of panic.  A tight wetsuit can make breathing difficult as well.  It is these heart and lung changes, not panic, that are responsible for many open water deaths.

In a 2010 review of triathlon swim deaths, 7 of 9 patients were found to have cardiac abnormalities.  However, 6 of the 7 were found to have left ventricular hypertrophy, which is a common finding in endurance athletes and is expected in trained endurance athletes.  One of the patients had abnormal coronary arteries, which may have contributed to the death.  This is not compelling evidence that there is a cardiac cause of sudden death in the water.

Hyperventilation can have a negative impact on the lungs.  It is not uncommon for hyperventilation to have an effect on the airways and lead to coughing or even spasm of the vocal cords.  This makes it harder to breathe and leads to increased hyperventilation.  Which can in turn lead to increased anxiety.  Anxiety worsens the cold shock response.

With repeated cold water immersions (4 days apart), the amount of hyperventilation is shorter and not as much.  Less frequent immersions diminish the length but not the magnitude of the response. One way to reproduce this habituation to the cold shock reflex is taking repeated cold showers at 50 degrees fahrenheit for 3 minutes.

3 minute showers at 50 degrees may save your life

Finally, how can we screen for the ill-effects of the cold shock reflex?  One way is to perform maximum hyperventilation while monitoring lung changes.  This is a regular component of the cardiopulmonary exercise testing. If changes in measured lung volumes or coughing is present, perhaps these changes should be treated.  Standard cardiac stress tests will probably not be useful for screening for the cold shock reflex.  If we are to prevent triathlon swim death, other tests and decreasing the response to cold water are essential.

Caffeine and Cycling time trials

I'm a big fan of caffeine. A caf-fiend, some might say. It is rumored that ethiopian shepherds first noticed the effects of caffeine after observing energetic behavior in their goats who had just eaten coffee.

Athletes are looking for that same energy.

Two recent studies on caffeine are worth mentioning.  In the first, a caffeine related improvement in performance was seen, but not in everyone.  Although 7 out of 9 individuals had improved performance, the overall improvement in performance was 1.6-1.9%. 

The dose of caffeine used was 5mg/kg, taken 90 minutes before exercise.  Caffeine doses between 3 and 6 mg/kg have also shown improvement in performance.

The same authors also found that caffeine, caused an improvement in cycling performance in trained individuals, which might help explain why only 7 of 9 individuals did better.

Caffeine increases heart rate and decreases mood, two side effects that you might not want.

Caffeine works by increasing adrenaline which, in turn increases circulating fatty acids that can be used as fuel.  If you are using predominately slow twitch fibers, then you will have more of an effect from the caffeine than if you are using predominately fast twitch fibers.  Of course, everyone has a different muscle fiber profile, so if you don't know yours, then it will be hard to determine if caffeine ingestion will work for you.

Some other interesting caffeine facts:

• Eating green leafy vegetables will lessen breakdown and clearance of caffeine , giving an extra kick (Kale latte, anyone?)
• Taking Zantac (cimetidine) will also keep the caffeine from being broken down
• You don't need to withdraw from caffeine to have it make a difference
• Repeated small doses of caffeine (1-2g/kg) during prolonged exercise can also help

References:

Astorino TA, Cottrell T, Lozano AT, Aburto-Pratt K, Duhon J. Effect of caffeine on RPE and perceptions of pain, arousal, and pleasure/displeasure during a cycling time trial in endurance trained and active men. Physiol Behav. 2012 May 15;106(2):211-7. Epub 2012 Feb 12.

Astorino TA, Cottrell T, Lozano AT, Aburto-Pratt K, Duhon J. Increases in cycling performance in response to caffeine ingestion are repeatable. Nutr Res. 2012 Feb;32(2):78-84.

Graham TE. Caffeine and Exercise; Metabolism, Endurance and Performance. Sports Med. 2001. 31(11); 785-807

Matty Reed in the Performance Lab: Part 2

The Bike Fit

One of the most important things to remember about bike fit is that power output depends not only upon angles, but also upon the rider’s strengths and weakness and how to make a rider stronger.

After series of single leg squats, planks, and joint mobility measures, it was clear that the position of comfort and maximal power would depend upon further stabilizing Matt’s core muscles.  His aerodynamic position was already  tested in the wind tunnel, so I was more concerned with keeping his frontal area minimized while changing his core stability

Because riding position changes with different power outputs, it is important to use a point on the power curve that approximates race-pace wattage.  The point that we chose was where lactic acid starts accumulating.  By testing the bike fit at this point, we could see how the changes were affecting him.

After a few changes to his elbow pads, we did another trial at race wattage.  His exhaled carbon dioxide dropped, meaning that he was not accumulating lactic acid.  

Moving the elbow pads further forward let Matt use his aero bars as levers to pull back and activate some of his core muscles which gave him more power as he pedaled.  My big concern was that this position might lead to more acid accumulation, since he was using more muscles, but the changes resulted in less lactic acid accumulation, meaning he could pedal harder before the burn of the lactic acid would cause muscle fatigue.

Using stop motion video, I was able to measure and maintain his hip and knee angles that he was comfortably using. 

He had two weeks until his next race the Boulder, Colorado 5150, in which he got second place.

Matty Reed in the Performance Lab: Part 1

A project about making a great triathlete better.

I got an email about helping out Fuji sponsored rider Matt Reed with a bike fit.  It seems that even though he was having great results all season, including a frigid win in Boise 70.3, he felt as though he wasn’t getting the power output he wanted and it was harder on the bike than in previous years.

Matt came to the Performance Lab following a 5th place in the Philly Olympic Triathlon.  I felt a little bad knowing that he raced just the day before and was now going to be doing a maximal test.  VO2max testing would help us establish his muscle fiber profile and would also give us some good power benchmarks to use for bike fitting.  On the way to reaching VO2max we can figure out how the heart lungs and muscles work together.  By analyzing the data we are able to identify where he maxed out his slow twitch fibers, his anaerobic threshold and his VO2max.

Many of the elite/pro half iron distance triathletes that I have tested have a similar profile, that is they are largely aerobic machines, using their slow twitch fibers to move them.  Once we were done with our testing, I knew that Matt was different--he has a lot more anaerobic fibers than most, which is where he gets his power.  The anaerobic fibers (also called fast twitch or Type II) are 5-10 times more powerful than slow twitch fibers.  The drawback is that fast twitch fibers can fatigue faster.

Once we know where Matt is getting his power, I gave him specific wattage based intervals to use which will help him target his strengths.  On review of the testing I was able to give Matt his nutrition requirements for the different muscle fibers that he is using when he races.

At the end of the test, I asked how he felt.  His answer? “If I knew I was going to be doing a VO2 max test, I might not have had the Ahi Tuna for lunch.”

Decreased Body Fat, Improved Mood

Let's face it, dieting is pretty brutal.  Calorie restriction not only leaves us feeling empty, but also makes us grumpy.  Furthermore, trying to lose weight in season leaves little energy to burn for training.  


Athletes who try to lose weight in season, especially if they are trying to "make weight," frequently resort to some extreme measures that leave them dehydrated, more susceptible to heat and lacking appropriate energy.


One strategy was recently reported for a jockey.


His resting metabolic needs were met by being broken down into six meals.  He maintained this regimen while continuing his daily exercise routine.  After 9 weeks, he had a 17.5 pound weight loss (8kg).  


Knowing and meeting basic metabolic needs prevents metabolic slowing which can actually result in weight gain and more difficulty in losing fat.  Using 6 daily meals helps prevent hunger which will lead to over-eating--especially when compared to the two daily meals the jockey was eating before this trial. Resting metabolic rates express the amount of calories that are burned at rest as grams of fat, carbohydrate and protein.


More importantly, aside from the loss of body fat, the jockey had an improved mood, which might help him keep up his diet and exercise routine.


source: Int J Sport Nutr Exerc Metab. 2012 Jun;22(3):225-31

Running adds years to your life and life to those years

Danish researches presenting the results of the Danish Central Register found that regular running as exercise live an average of 6 years longer than their non-running (non-exercising) counterparts. 

Jogging was associated with a 44% reduction in the risk of death over 35 years, which translates into an age-adjusted survival benefit of 6.2 years in men and 5.6 years in women.

Joggers reported an overall sense of well-being, which isn't just about extending life, but living better.

The benefit was found in 3 cumulative sessions a week, totaling one to 2.5 hours a week.

European Association for Cardiovascular Prevention & Rehabilitation
Source reference:
Schnohr P "Jogging -- healthy or hazard symposium: Assessing prognosis: a glimpse of the future" EuroPRevent2012.

Nutrition Notes

Here are the notes from a presentation that I recently gave on endurance nutrition.  While these are general guidelines and recommendations, specific numbers that apply to individuals can be calculated during exercise testing with calorimetry.  


Calorimetry lets us measure how many calories as fat, carbohydrate and protein one burns with any given exercise intensity.


Here are my nutrition guidelines for endurance events:

Nutrition Notes

Pre-Exercise

The closer to the start of exercise, the smaller amount of food needed

Choose rapidly digestible, low fiber foods (gels, liquids applesauce)

During Exercise

Energy intake for sustained high-level activity

Intake should match expenditure for maximum carbohydrate use or race pace

30-60g carbohydrate per hour

Recovery

Replace used up muscle glycogen

Prepare for the next training day/race

0.5g carbohydrate per pound of body weight & 0.16g protein per pound of body weight

Race Day Plan

24 Hours to Go

Carbohydrate-load: 2.5 minute threshold effort followed by 30 seconds at VO2max

10g/kg carbohydrate (5g/lb) over next 24 hours

Carbohydrate should be low glycemic and low fiber

3 hours to go

Last solid meal.  Meal should be mostly low glycemic carbohydrate

Protein should be 10% of total calories

2 hours to go

4-6% Carbohydrate solution (4-6 grams of carbohydrate per 100ml water)

30 minutes to go

High glycemic index snack (gel, applesauce)

Race Time

Fluid consumed to limit sweat loss to 1% of body weight

Carbohydrate if racing for more than 1 hour