Marathons are long. But it is exactly the mental challenge of going the distance that inspires and excites me. It requires a lot of training to build the so-called marathon endurance, but come race day it will be all about the mental struggle and perseverance.

For a regular person the intensity of a marathon shouldn’t be too high. In fact, some say most of the race has to be run at conversational pace.

Marathon endurance, then, is all about building the leg and core strength to sustain those grueling 42.195 meters.

And do it with a smile, because you paid for it.

Training marathon endurance

Running a marathon takes more than 2-3 hours to complete, which is why its intensity is not that high.

Our glycogen reserves are just not that big to keep us going fast for that long.

Despite lower intensity, the overall impact on the body and muscles is still enormous. And that is why people, especially beginners should target distance in their training and long run is the king workout.

I’ve read a good quote recently:

For most of the people marathon is not an endurance event – it’s really a test of pure strength.

I subscribe to it 100%. My theory is that marathon runners should also spend a fair amount of time in the gym building strong core and working on the lower body conditioning. It will help to withstand all the pounding that their body will take. With a smile, hopefully.

However, working on marathon endurance doesn’t mean we should only go slow and long. That’s just boring.

Adding speed to the training plan improves muscle economy which is critical in long-distance races.

Even elite marathoners are able to run a very fast 1K. It’s not the Usain Bolt 100-meter speed, but still very fast.

Why to train speed for marathon endurance

Improving running economy allows athletes to run any distance faster at the chosen effort level. Maybe not so visible in 5K races, but in marathon even slight gains in economy massively affect the end result.

Muscle economy is trained by growing more mitochondria in muscles, allowing them to produce more energy and be more efficient. Running much faster than the marathon effort utilizes more muscle fibers and triggers hormone release that results in the growth of mitochondria. Throughout the distance we use more and more muscle fibers as our legs get tired, so we need all the bang that mitochondria can produce to stay efficient – the more the better.

Training for this is a very slippery slope, though. Too much high intensity actually negatively affects performance. It causes fatigue to accumulate in muscles minimizing or even reversing all the gains we had.

You can easily get carried away with running fast during workout while chasing a personal best. Save it for the race, the PB will be much better after complete recovery.

How I balance speed and marathon endurance

During my training I almost never have all-out sessions at 100% effort. These kind of workouts leave muscles fatigued and ultimately result in loss of endurance and economy gains.

Workouts should end on a high note with lots of energy left in the tank. If you can still make jokes at the end of the session, you should be good.

When I add speed intervals, those are usually 80%-effort intervals or short bursts of up to 10-20 seconds. In running world the latter are sometimes called strides. The point of these short bursts of speed is to build and maintain mitochondria in our muscles that will help in recovery and economy.

My marathon endurance workouts

This was the hardest week of my training so far. As I have a 6K race coming up, I am making this my peaking week and working actively on speed. I had 4 runs in total this week:

  • Speed workout – 4 x 1K intervals at around 70-80% with long rest
  • Long run with sections at marathon effort
  • Build up run to a steady pace
  • Easy run with 10 x 10sec bursts at maximum speed.

As usual, I’ve mixed it up with swimming and cycling to reduce stress on legs and give the body more aerobic work. I also added one strength conditioning workout in the middle of the week where I did body weight exercises for every muscle group.

I felt really good towards the end of the week during a build up run and a long run. The interval work was perfect to improve economy and was not too taxing for the whole body to still perform well.

I could have spent more time stretching this week – probably something to improve over the next week. But generally, I feel pretty good going into a short taper for complete recovery, I deserved it.