If there's anything that truly defines a triathlon it's the feeling of running off the bike. Whether you've just ridden to the shops or an Ironman bike leg your legs feel dead and heavy, and certainly not primed for running, let alone fast running. This form of running should almost have it's own definition with a similar distinction that "long distance running" has from "ultra running"...not to mention the associated sub-cultures that exist within essentially the same sport!!
How well you run off the bike also determines how well you finish, from age group sprint distance tris to ITU racing and up to Ironman. If you falter in the run leg there'll surely be someone running you down. Sometimes a "slower" runner will outrun a "faster" runner when thrown into a triathlon, which is another defining aspect of triathlons - a better **triathlete** can often beat a better **athlete**.
So, what contributes to running well off the bike, and what are the key criteria for doing so? The main components are fitness (bike & run), tactics, running form and psychology. Let's look at each of these.
Fitness is the biggest determinant of your ability to run off the bike. Obviously, if you haven't done any run training then you can't expect to run well, full stop!!
Having said that, your fitness in other sports - swimming and bike riding - can benefit you in running, but consistent with the rule of specificity, the fitness you gain through run training is what will get you through in the long run (pardon the pun).
To contrast the relative benefit of each single-sport fitness - and the relative difficulty of each sport - only a few cyclists could run much further than a kilometre without exhausting themselves. However most runners could ride quite long and hard, albeit not necessarily very well. Running is by far the more demanding sport and by extension running fitness will be more beneficial to running well off the bike than cycling (or swimming) fitness.
How you 'use' your relative cycling and running fitness - your tactics - also has a large influence in how you run off the bike. Most athletes have differing abilities between biking and running, even with similar relative fitness levels between the two sports.
Since the bike leg comes first, strong cyclists are often inclined to ride to the limits of their ability - which is usually faster than most - with small regard for the run leg ahead. Then, the longer the run leg the more they're likely to suffer from the extent of their exertion during the ride. Sometimes these kinds of triathletes can pull it off (eg, Normann Stadler in Kona '04 and '06) but more often than not they'll be passed during the run by athletes who rode more conservatively in order to run closer to their potential.
A simple example makes the point clear...if going 10 mins slower on the bike means you run 5 mins faster, then your overall time will be 5 mins faster. Basically, going a little slower on the bike will usually mean you run faster by a greater amount off the bike. The fact you might be strong bike rider doesn't change this model.
To use an analogy...countries having a nuclear weapon don't ever plan to use it.
This is a favourite topic of mine, and as Fitness is related to Tactics, so Running Form is related to Psychology of running off the bike. Running off the bike differs little from 'open' running, although in general it more closely resembles marathon running form than it does track running form. Either way, the basics of good running form still apply - I've previously written about this in "How to run".
In triathlon the efficient runner is rewarded with better running off the bike. Specifically, this includes the following:
* Limiting upper body motion - torso and arms.
* Holding your torso in an erect position which is more efficient to maintain.
* Slightly shorter steps, although this is only to ensure running cadence is around 90-95 per leg per min (generally speaking).
* Minimising vertical movement.
At ITU level it is found that the best runners run at a cadence of about 10 less than they ride at, which links back to tactics on the bike in the gears you ride. It's very difficult to increase your run cadence off the bike, so you're better off riding at a higher cadence in the first place your most recent muscle memory when you start running is at/near that cadence.
The alternative is a slow run cadence, which implies / leads to over-striding which is closely related to poor running form. Because it's a triathlon shouldn't dramatically change your running form.
When things get really tough, such as in and half or full Ironman is where running form can really go to pot, and where athletes can tend to "give in" to the circumstances and go into a survival mode of dropping their head, rounding shoulders and back, tilting hips back and basically neglecting most of the most basic aspects of running form.
Even in sprint and Olympic distance events - which are not long races by any means - there's a large number of people who "cave in". I suspect that numerous people have the mindset that "this is a triathlon and I'd doing it tough", and so their body language follows suit and they're almost waving the white flag before even giving themselves a chance to run well.
In this case a change in perspective would help. Think of a triathlon run leg as just a run with a swim and ride beforehand - it is not a world of torment and torture. Remember the fundamentals of running well, the basics of efficient running form and all the things you've done in training many times over. Concentrate, relax and don't be defeated by the scenario.
Psychology is especially important when the weather warms up. Yes, heat does mean a slower pace but it does not mean that survival mode is the only option. On these days it's the people who run positively and with confidence who stand out from the crowd, both in terms of strong running form and actual running pace.
Psychology during the run leg - as well as the whole triathlon - can make a huge difference to your performance, and how well you deal with situations that arise during a race. For running off the bike, a positive mindset is key to running well.
In summary, running off the bike will always be a little slower than 'open' running. But there are still many similarities and the fundamentals don't change. How well you can perform those fundamentals, and maintain them, is the key to running well off the bike.