Run Faster Off The Bike

“How do I run faster in the last leg?”

This has been a burning question amongst my athletes at the moment. With the race season approaching athletes are starting to get more race focused and thinking about triathlon racing instead of training metrics.

The answer to this question often seems obvious to athletes. Run more! Unfortunately, it’s a little more complicated than that.

Most athletes are not running anywhere near their 5k or 10k p.b in the triathlon run. This means that before improving their run p.b most athletes would be better off closing the gap between their rested run time and their post bike split. Research has shown that elite athletes are between 1-12% less efficient after the bike phase of a triathlon and I would bet it is much worse for the average amateur. So what is likely to be responsible for this drop in run performance?

1. Poor neuromuscular co-ordination (which muscle units are used, how they are used and sensory feedback from working muscles) can limit speeds when running after the bike leg. Typically, this is the wobbly, empty or tight feeling you experience in your legs as you exit T2. Even for accomplished runners it can feel like your legs aren’t your own, lack power or muscles just aren’t working.
2. Bike economy (the oxygen/energy used to maintain a certain speed) is poor. Often even fast runners with reasonable bike splits will be inefficient when time trialling. This leads to greater muscular fatigue meaning that the post bike run becomes less efficient and ultimately slower.
3. Some athletes arrive at the bike-run transition with leg muscle glycogen severely depleted. This leads to a greater reliance on fat to fuel exercise, which in turn needs more oxygen, which reduces run economy and ultimately run speed.

Low Hanging Fruit

The last of these is the easiest to remedy. First improving an athlete’s aerobic capacity or general fitness will enhance the body’s ability to store and use glycogen efficiently. So just keep training consistently. Secondly the use of glucose based gels and drinks during the race will help mitigate the effects of glycogen depletion.

Pile of Bricks Time

Improving neuromuscular co-ordination after cycling is where the famous brick set comes into its own. For the uninitiated a brick set is a bike-run training set where the run immediately follows the bike effort. Whilst many people use this type of session to save time, the biggest performance benefit comes from the adaptations developed in post bike running. A typical session for improving post bike running might look like this:

4x(8min bike @8/10rpe followed by 3x60s run @ race pace)

This type of session has 4 key points:

The bike section must be long enough that the subsequent run phase is completed with leg muscles in a fatigue state. This emulates race conditions and encourages the body to recruit the least fatigued and most efficient combination of motor units. Athletes and coaches commonly choose bike efforts which are too short (less than about 4mins) such efforts will not elicit this effect.

The run that follows the bike needs to be at a high velocity, race pace or faster. For this reason, it is often best to use interval training with short rest between short efforts of running. Again this encourages efficient recruitment of muscles and improves run economy, even at slower speeds.

Repeating the bike-run transition within a single brick training session increases the frequency of occasions the body experiences the transition and leads to quicker and more efficient neuromuscular improvement.

Whilst this type of session will be hard and develop both bike and run economy, an athlete or coach should remember that this is not the session’s primary aim. Neuromuscular adaptations occur quickly (4-6 weeks) and once achieved last for months. So, after a 4-6 week block, triathletes would be better to switch back to focused run or bike sessions (preferably bike sessions, for reasons outlined below).

Bike Harder/Run Faster

Studies have shown that bike economy is good indicator of run time in elite athletes. The better their bike economy, the better their run split. This is perhaps unsurprising as these athletes, despite going faster on the bike, are using their muscles and oxygen more efficiently. Thus saving muscle glycogen and having less fatigued muscle units when entering the run phase.

So it makes sense for athletes who want to improve their run split to improve their bike economy. Most studies and coaches agree that the best way to do this is with high intensity interval workouts. Research by Etxebarria et al., 2013, published in The European Journal of Sport Science, showed that cycling sessions of made 6-9 x 5min at 80-90%HRM improved post bike 5km running splits by 60s! This type of session has also been shown to be the best way to improve time trial performance. So if you only have limited time, make sure you include this in your program.

So in summary if you want to run faster off the bike:

• aim to narrow the gap between your straight run split and post bike run split
• Ensure leg muscle glycogen is replenished before race day and topped up during the race using gels and energy drinks.
• Complete a short block of high intensity brick sets close to the racing season.
• Prioritise developing bike economy with high intensity interval sessions of 6- 9x5mins efforts at 80-90% HRM.

A final minor, but interesting point, French research (Actes du Premier Symposium International de L’Entrainement en Triathlon, Les Cahiers de l’INSEP, vol 20, pp 143-145, 1997) found that the majority of lost time happened in the first kilometre of the run leg after the bike. So, if you have trained and implemented the measures outlined above, give the opposition a good kick in through that first kilo and it’s unlikely they’ll come back!

For training programs to help with this or any aspect of Triathlon training check out:

https://www.trainingpeaks.com/coach/racesnake#trainingplansBack