Let’s start by acknowledging that the long run isn’t sexy, but it is a staple of every triathlete’s plan. It’s the steady dependable workhouse that will help you go the distance. But despite the importance of this staple workout, most athletes don’t know the answer to a basic question: How far or more importantly, how long should my long run be?
As part of a consistent training program, the long run helps build stamina, develop run economy, improve muscular endurance, and even increase speed. The act of running for an extended period increases the strength of primary muscles like quads, hamstrings, calves, and hip flexors.
This type of steady, aerobic activity is crucial to the development of capillaries, the small blood vessels that deliver oxygen to the muscles, and increasing mitochondria, which use oxygen to transform carbs and fat into energy.
Beyond the physiological benefits, athletes can also use their long run as an opportunity to work on form and technique, practice race day nutrition, and develop mental fortitude. Running for longer periods of time can lead to increased confidence in your ability to cover the miles during a race.
The physiology of the long run
Endurance training can increase the number of capillaries in the muscles, allowing for better delivery of blood. It also increases the concentration of red blood cells. The size and number of mitochondria increase with training, as well as the oxidative enzymes within.
Mitochondria are important for endurance athletes, because these cellular powerhouses supply energy to your muscles during aerobic activity.
Long runs can also alter your muscle structure and can increase the size and efficiency of slow-twitch muscle fibres which can result in a shift towards fat burning at sub-maximal exercise intensity. That type of muscular endurance and durability will be a huge help during the later stages of a race, especially one that can last 8-12 hours.
The confidence that comes from running long distances is just as valuable. Learning how to be process-oriented and engaged with run economy and technique, as you gradually fatigue during a long run, has tremendous mental crossover to race day as well.
Common long run mistakes
The most common mistakes include ramping up mileage too quickly and doing too much running on hard surfaces, which can put athletes at risk of overuse injuries like fractures or tendonitis.
The long run doesn’t always have to be a slow slog in zone 2. Adding a bit of intensity, elevation gain, and even switching up the running surface can add variety and has numerous benefits.
There is value to steady, sustained, aerobic rhythm, which reinforces run economy, but I will often prescribe one-half to two-thirds of the run with some intervals to engage the different energy systems before settling back into the steady sustained rate.
Another of my favourite variations is the progression run that builds in pace or power. This type of run has the two-fold benefit of teaching pacing control and running well on tired legs.
While the long run is often a place for sustained aerobic effort, it doesn’t always have to be that way by doing a progression run, where an athlete builds in effort, gradually moving into higher heart rate zones, helps simulate the feelings of race day fatigue, teaches pacing, and provides variety and mental stimulation.
How long should the long run be?
I prefer to base long runs off duration, not distance. Ultimately, the duration and intensity of your long run will be impacted by what event you’re racing; training for an Ironman will require much different preparation than a sprint distance. Ideally you will place the longest run in a training cycle between three to six weeks out from a big race.
If an athlete is planning to finish a longer event for the first time, they’re going to need to focus on simply building enough volume to tackle the distance, whereas the experienced or competitive Ironman can build to max duration a little earlier and then have a shorter, higher intensity, peaking phase.
Essentially, the less experienced triathlete will build volume in a linear fashion, with intermittent recovery weeks, gradually increasing until it’s time to taper. The more experienced triathlete, who’s looking to go faster, may do their longest run further out from race day, because he or she will be increasing intensity and reducing volume closer to the key event.
Have fun and don’t overtrain.