The Death of the Long Run?

What "Going Long" Really Means

The question I get asked the most when training for Ironman is ‘how long should my longest run be’?

This is understandable. For many people stepping up to the Ironman distance, the marathon is that insane part at the end. People raise thousands of pounds for charities on the basis of completing only the gruelling 26.2 miles. Famously for Ironman athletes: it’s just a ‘cool down’. People like to have the security of having done a marathon before to know they can run the distance. Does this really matter?

Ironman Marathon v Pure Marathon

Looking at common marathon running plans, the longest run typically lasts 18-22 miles. For some people this could be over 4 hours of running. For elites this could be close to 50 miles in one go!! Equally, if you consider the common reasons for injury in triathletes and runners is generally too much volume, not enough recovery, or a sudden increase in training volume (Runner's World). Do the two training plans go hand in hand? If you are doing an Ironman, do you need to follow the same running plans as those racing marathons? Should you base your training volume on just distance?

My Training is Spongey...

Not an actual 'magic' sponge... (Google Images)

This is best answered by considering what training effect is (we wrote an article explaining simply how Training Peaks (the software we use for coaching) estimates training effect here). Training effect or Training Stress Balance is: TSB is a function of the training volume, intensity and frequency. So to become a trained athlete, you would want to increase these as much as is safely possible. The other part of the equation is how much you are fatigued. Ideally training load will be applied, you will let your body absorb the training effects before reapplying the training load to improve fitness. This can best be thought of like a ‘magic’ growing sponge. (I know sponges don’t actually grow, but bare with me!). If you take a sponge and squeeze it really tight in water, the sponge will go back to it’s original shape while absorbing water. If this sponge grew with water (I know it doesn’t) then you would absorb the water and end up with a bigger sponge. If you re-squeezed the sponge when it was still absorbing water, you would squeeze the water out and the sponge would not have even reached it’s original size, thereby making it’s magical growing effect void. If this was an athlete’s body, it thus shows an athlete in a permanent state of fatigue. 

Load, Intensity and Frequency

We know that: 

Training Load = (Training Volume + Training Intensity) x (Training Frequency)

Therefore, the greater the volume of an individual session, the greater time needed to recover (assuming an athlete can run/train on certain days). By doing a long run, it is essentially forcing a longer recovery or risking the danger of fatigue. With fatigue can come the dangers of injury and illness. Neither of which will lead to a faster run split. In essence the time to do run training is being reduced in favour of more time to recover.

Train hard, race easy... ...it all seems fairly hard!

The second thing to think about is the training intensity. If training volume is not being increased then to increase the load, the intensity must be increased. Most athletes will consider doing interval training for about an hour, this includes a warm up and cool down. Well what happens if a longer interval session is completed instead? Fundamentally, the same training volume is achieved as a longer run session. There are however, further hidden benefits. When racing Ironman, the winner is generally the one who is most effective over the longer distance. By completing long, slow training runs, athletes are only practicing running slowly. Therefore, technique will suffer, if technique suffers, efficiency suffers . There can also be a greater chance of picking up injuries if by forcing slow running. it is better to hold a longer, interval session for say a couple of hours which will mean running higher intensities for a total distance than (perhaps?) a half marathon. These are hard sessions. The old adage train hard, race easy comes to mind. They build strength, muscular endurance and good form when tired, all vital Ironman run qualities.

Thirdly, consider the frequency of each session. If the athlete can do three shorter, but more intense sessions rather than two longer but less intense sessions, there is still time to recover between sessions but the intensity increases the training load. Now the athlete has more time to recover, train the other disciplines or, dare we suggest, spend some time relaxing, doing nothing to spending time with the family...?! It is in grey above because regularly athletes add another session. just for the sake of it without considering the consequences. If someone normally does 2 hour-long sessions a week, to add a third hour session would be to increase the volume by 50%, this is asking for an injury. It could begin as 3x40 minute sessions, and then slowly add volume if necessary. The frequency of running though would be more beneficial than doing one or two all out sessions. The same can be said of double run days.

Finally, looking back at the marathon training plans, it is important to consider the purpose of the long training run for marathon runners: to improve aerobic efficiency. However, as a triathlete, both swimming and cycling have already improved aerobic efficiency without inducing the same impact stresses which are created by running. This allows the athlete to focus on quality running sessions.

But I still haven't run a marathon!?

In a race, what happens for those last 13 miles? Well that is where you start overtaking anyone who has been doing slow and steady miles. Your aerobic endurance will still be there from cycling and running, but your running form will be better, your ability to endure hard long running sessions mean that the real mental struggles in those last thirteen miles will be easier to contend with. The mantra “Just keep running!” is replaced by “Just overtake the next person!”. 

Use intense speed sessions over longer durations to really do well at Ironman

In summary, if you can keep your running volume high by a higher frequency of shorter quality sessions, you will actually race faster than doing fewer longer slower sessions. In fact, your total running volume may even be the same, if not more per week. Use those extra couple of hours you may have been saving for an even longer run for doing some recovery instead – getting faster by doing nothing! After all, slow and steady training will mean a slow and steady race.