Texas Triathlon Camp, Part II

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Aero Positioning on the Bike – John Cobb

*Note, all material taken directly from notes taken, no material is reproduced.


John’s session touched on a number of topics dealing with aero positioning and the need to be comfortable on your bike.  You should not dread getting on the bike or be relieved when you get off the bike.  Comfort is critical in distance racing.


Nutrition is an individual thing.  You have to figure out what works best for you, because like fitting a bike, every body is different.  Nutrition is the key to getting through the longer events.  You have to figure out what works best for you through experimentation and then implement it.  You have to do this during your training for a race.  The biggest difference between the performances of today’s athletes, whether professional or amateur is the nutrition available to them during an event.


In fitting yourself to a bike, one tool that can be used is a muscle temperature imbalance analysis.  Ideally, your muscles will be in balance – same temperature – throughout if the work they are doing is being done properly.  The analysis identifies temperature imbalances in a muscle; by looking at the mechanics of the athlete, adjustments may be able to be made on the bike’s set up which will bring the muscles back into proper temperature balance.  This might be an adjustment to your cleats or another adjustment on the bike itself.


Believe it or not, your seat should be level to slightly nose up.  This will keep you from sliding off the front of the seat and also from having to reposition yourself on the seat as often, something that is critical for longer distance athletes.  It will also put your butt on the biggest part of the seat, where you will get the most support and greatest comfort.  If your seat is wider on the back, this may actually be a cause of pain, rather than a source of comfort in a longer distance event.  Every time you stroke, your gluteus maximus is ‘rolling over’ that wider part of the set.  In a long distance event, this will cause extreme discomfort.  You also will probably adjust your set by turning the nose to one side or the other slightly.  You might be a person who isn’t quite properly aligned (your hips have a tendency to turn right or left as you stand facing forward) and this type of adjustment will provide better comfort.  The seat turn also helps to get your ‘anatomy’ out of the way.


Besides being comfortable, in a distance race the athlete will need to make maximum use of every bit of energy they produce.  A human being is not capable of producing horsepower (one horsepower = 746 watts) so a smaller unit of power is used to measure the power produced by humans, that unit being watts.  The average triathlete (5’9”, 165 lbs.) must produce 200 watts of energy to average 18 mph in an Ironman event.  To bring that average to 20 mph for the 112-mile course, the athlete must produce 250 watts.  Since the human body is not capable of producing and sustaining huge amounts of power, squeezing every inefficiency out of your performance is critical.  By eliminating inefficiencies, you can use the energy those drained from you to further your racing.  Following are some examples of inefficiencies and their cost in watts:


Standard Wheels                      30 watts for the front wheel

Race Wheels                            25 watts for the front wheel

Disc Wheels                             15 watts for the front wheel

Flapping Race Number 4 watts

Sloppy Gear Cables                   3 watts

Loose Jersey                            8 watts

Improper Tire Pressure 5 watts


If you are only capable of producing say 200 watts of power for a sustained distance event, by going to disc wheels and eliminating the last four items in the list above, you could not ‘waste’ 35 watts, but could instead apply that to going faster.  You can train with inefficient equipment or an inefficient set up and then make it completely efficient for race day.  This isn’t a bad way to train as it will build muscular endurance, but you will also need to do some training in the efficient set up so that your body knows how to handle the bike in the faster pace that you will be able to maintain.  Spray on adhesive is a good way to keep your race number from flapping.


Aero bars will help you in distance races immensely.  They are usually adjusted three ways, slightly up, level or slightly down.  The slightly up position is the most aerodynamic, however it can cause pain in the back/neck if the athlete stays in this position for an extended period.  In a flat or level position, while there is a slight loss of aerodynamics, the stress to the back and shoulders is eliminated increasing endurance for the bike and later, the run legs of the event.  A slightly down aero position is something being used in Europe primarily and may benefit climbing.  Aerobars which are shorter, with the elbow pads forward (so your forearms, not your elbows are in the pad) are the best position.  This can save you 30 watts.  For a shorter race, the pads can be moved even further forward, really making you more aerodynamic, but realizing that this will only be a non-factor because the race is not one of distance.


Transitions should be thought about, laid out and practiced once a week.  For short races (less than a half-iron) socks, gloves, caps, etc., are purely optional – they aren’t needed.


A cadence of 90 is good.  If you are doing Isolated Leg Training (single leg) try for a high number, but don’t be discouraged if it is less than half of what you are able to do with both legs.  The idea of a higher cadence is that your muscles will be under load for a shorter period of time.  So a slightly lower gear will allow you to turn a faster cadence which will reduce the workload on your muscles.  This will keep your liver from producing lactic acid.  In the end your endurance is increased.  It takes time to raise your cadence primarily because the diaphragm muscle takes a long time to train – not because your legs are slow.  It takes time for the diaphragm to adjust to the higher RPM requirements.


You can gain fitness up to about age 45.  From 45- 55 you can maintain fitness.  Even if you lose strength at an older age, you may not be able to get the strength back, but you can get your cadence up.


Joe Friel, Bike Technique & Training (Physiology)

When you are not rested or giving yourself enough time to recover, you will lose fitness.  You should maintain your consistency and frequency, but use different levels of intensity – you can’t do interval training everyday and expect to get better...MORE NEXT MONTH!


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date: September 3, 2004