Mastering the IM Run

By Tim Snow

Like an effective taper protocol, the Ironman marathon remains one of the greatest mysteries of our sport. “A mystery, wrapped in an enigma”, those who have it figured out make it look so easy, and we wonder how and why it is possible to run with such ease, after a 112-mile ride.  They are few and far between, but we see them at every race, running their way through fields of competitors who can only watch as they pass by.

Bike splits get the press.  Run splits define the race.  At the Ironman series events held weekly, the world over, it is not uncommon to see a strong cyclist sneak away from the field, and hold on for the win.  The fields in these races tend to be pretty thin, opening up the door for these uber cyclists to break away and not elicit an effective response.  But, at the big show, on the Big Island, the World Championship wreath has seldom been placed atop the head of an athlete that we wouldn’t easily identify as a strong runner.  Sure, it has happened.  But, rarely!

To the astute observer Ironman is exponential, with a specific pattern of events defined by the masses.  It is not uncommon for Pros, and age groupers alike, to have a decent swim, move up through the field during the bike, maintain that position during the first loop of the run, and then completely fall apart.  After the race, groups of athletes gather together, sharing stories of their day, astonished by the fate of their run’s second loop.  The litany of bewilderment may include, but will not be limited to, “my hamstrings and quads just started cramping”, “my legs simply wouldn’t turnover”, “I think I was low on sodium”, and “my stomach was completely bloated”.  These are just a sample, but you’ve heard it all before.  In fact, many of us have probably used a few of these, once or twice.

So, what are the ingredients of a good Ironman marathon?  What are the key components which, if properly executed, make the difference between trudging through the many miles, and running your way to a Kona slot?

It All Starts In Training

Preparation is key!  Durability is the number one race day limiter for 99% of Ironman athletes.  Your running legs must be prepared for the full 26 miles, after more than six hours of activity.  To this end, many fall into the trap of thinking that this is merely a function of running mileage.  Au contraire, mon ami!  Sure, your legs have to be able to handle the demands of running a full marathon.  But, doesn’t it go a long way, if the bike is not as damaging to your legs?  That seems pretty valid.

Bike volume!  Bike volume is so effective because it not only builds bike fitness, but it also builds durability.  This bike durability ensures that your running legs are fresher at the outset of the marathon.  We, at QT2 Systems, typically like to see no less than a 5:1 bike to run volume ratio, and many times higher for athletes with bike limiters.  Many struggling runners will operate at a smaller ratio, as they increase their running volume, thinking that they have to train more like a runner.  Running actually wreaks havoc on cycling strength.  Too much running volume, relative to cycling, can actually have just opposite of the desired effect.  Cycling, decimated by too much running volume, become less powerful.  Not only does this equate to slower bike times, but it also means that the bike leg becomes significantly more taxing, leaving your running legs in a more vulnerable state.  If in doubt, err on the side of increased bike volume.  Not only will you bike stronger, but you will feel and be fresher, as you set out on the marathon.

Proper Bike Pacing

How many times do we need to watch an athlete making a mockery of the bike course, trying to create their own personal sonic boom, only to be doubled over on the run course?  I have even seen them lying on the side of the road, as though sniped from afar.  Triathletes are smart people.  But, all logic seems to be forgotten, the moment that we straddle our bikes.  Whether we like it, or not, the bike and run legs of an Ironman are not mutually exclusive.  I know that your bike cost $6,000.  Mine did too.  I understand that you believe it to be the “ultimate triathlon weapon”.  Page 83, I read that ad too.  But, that doesn’t mean that you can try to ride it as haphazardly as you’d like, and still expect to run well.  If you want to try to be Aquabike World Champion, I can respect that.  But, you signed up for an Ironman, and an Ironman requires you to run!

The strong runners in an Ironman are the patient athletes.  They build into the bike leg, constantly increasing their effort, and are very easy to spot.  They are the athletes that you are huffing and puffing by at mile five of the bike.  Proper bike pacing is part and parcel to running well in the Ironman.  Over pacing places too much load on the legs, too soon, and often leads to a bike leg that gets slower and slower, throughout.  This can still equate to a decent bike split, but leaves the running legs in a very bad position.  As a result, the legs are too shelled to run effectively.

Fueling on the Bike

The bike leg of an Ironman is an opportunity to fuel the upcoming run.  This is the portion of the race when the bulk of the day’s calories and fluids are consumed.  Proper pacing allows the athlete to ride intensely, but to also focus on fueling the race.  Heart rates are relatively low, allowing for the absorption of these fuels.  If at any point during an Ironman your intensity is not allowing you to consume your fuels, then you are going much too hard!  Slow down!  Back off!  Ironman requires you to think beyond the moment, and a strong run is going to have to be adequately fueled.  Translate feeling good on the bike into opportunities to eat and drink more.  While every one else is leaving T1 with a full head of steam, storming their way towards the front of the race, the runner is front-loading their fluid intake, to ensure adequate hydration.  I don’t mean to give the impression that the bike should be ridden nice and easily.  That is certainly not my intent!  But, the bike leg is so much more involved than simply riding for speed at one given moment.  It is a time to multi-task, and carbohydrate/fluid consumption is one of those tasks very high on the list.  Any level of intensity that stands in the way of multi-tasking should be eliminated, immediately.

Proper Bike Cadence

Strong runners know that their cycling cadence is going to play a key role in defining their running cadence.  Ideally, an Ironman running cadence will fall between 90 and 105 steps per minute, depending upon height.  This minimizes the braking and impact forces of each step.  Bike cadences that vary to much start to adversely affect running cadence.  For this reason, the goal of any Ironman athlete should be to choose gearing that is going to allow for cycling cadences that are as close to 80-95rpm as possible, regardless of the terrain, and be able to do that throughout.  Gone are the days of powering up hills, or through flats, with gearing that grinds the legs down.  This is the equivalent of doing 112 miles worth of leg presses, and then heading out for a marathon.  Not a good plan!  When it comes to cadence, ride how you want to run.

Proper Run Pacing

It’s not all about the bike!  The run matters too.  Proper run pacing is often defined within the very first mile.  Some believe that the Ironman marathon can be negative split, so they start off very slowly, building into their intended pace.  This is actually one of the very few times when I would disagree with this kind of a pacing strategy.  The Ironman is just too long of an event, and the body is not going to be able to remain stimulated throughout its entirety, without significant peripheral fatigue.  The strong runners in an Ironman will actually take the pace out at about 20-30 seconds per mile faster than what they expect to average on the day.  Knowing that a fade is inevitable, they try to log as many miles as possible, before it sets in.  Once the inevitable occurs, durability and sensible bike/run pacing allow for the athlete to weather the effect, within a relatively small pacing window.  While many Ironman athletes may see the difference between their fastest and slowest mile paces differ by more than two or three minutes, the properly paced runners will realize no more than a minute’s difference in pace.

Naturally, the key to properly pacing the run lies in the application of everything mentioned above.  But, knowing what you are and are not capable of is half of the battle.  Athletes who are limited by durability should feel no shame incorporating planned walk breaks into their run pacing strategy.  At some point, those lacking durability are going to become peripherally limited, and forced to walk.  Better to do so under your own volition, in a controlled and voluntary manner.  Why not spread your walk breaks over the course of the marathon course, perhaps through every aid station?  I’m not referring to a slow pedestrian pace, but rather a solid power walk with run like cadence.  This will allow you to take down your nutrition, such that it can be effectively absorbed, all while aggressively moving forward and giving your legs a bit of a break, and reset.  We have all been out on a run and stopped to tie our shoes or allow traffic to pass by.  Once we resume running our legs feel slightly fresher than they did before.  This is the goal of this particular strategy.  In fact, I know of a certain female who currently owns the second all-time fastest marathon split in Kona, and is still not afraid to pull this out of her bag of tricks.

In Ironman, consistently strong runners don’t just happen.  Their run splits require a great deal of preparation, patience, and premeditation.  Unfortunately, it is not as simple as just training more like a runner.  The bike plays a significantly greater role in the run than it is credited with.  Strong run splits come at a sacrifice, primarily of the ego.  The runner knows that it is not sexy to hold back on the bike, and consider the race as a whole, rather than three independent events.  As an entity greater than the sum of its parts.  The runner knows that he or she will always have to endure the inevitable – “You know, if your bike was stronger…”  Runners also know that you can never count them out, that they always have the final say in a race.  And, that most triathletes are just a few changes away from being just like them.

About the author ...

Tim Snow is a USAT Level II Coach and Training Services Director of QT2 Systems.  Tim as been in the sport of triathlon since 1998, completing over 250 multisport events.  As a coach, Tim specializes in identifying, and addressing, specific athlete limiters, both physical and mental. 



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