Longer or Faster? Part 3

Traditionally, fat metabolism - how we use fats under exercise, has been one of the top endurance research focuses when aiming to explain performance determinants. In a nutshell, those with high fat oxidation (fat-ox) rates, have been postulated as the potential winners. 

I have a small window into the research community as my brother is an Associate Professor in Human Movement Science, Sport, Exercise and Rehabilitation Sciences at the University of Birmingham. One of their areas of research is substrate utilization.

The research community is no longer convinced that fat-ox rates explain performance, especially in the current era. The power needed to win a cycling race is getting higher and higher. Also, the speed to run a marathon or ultra has increased. What do you need to generate power? Energy. The paradigm has changed, and they are learning that new answers are needed to fully understand the metabolic determinants of endurance performance.

One thing coming out of this research is that fatigue resistance (or durability), is what sets athletes apart after a prolonged duration when all other testable variables look similar. It seems that better fatigue resistance corresponds to carbohydrate oxidation levels under fatigue. Essentially who is better at accessing carb-ox after you’ve been in fat-ox for a long period of time.

From the results of these studies we potentially understand that maintaining carb-ox is a mechanism to keep gross efficiency high and it could lead to a greater capacity to perform high-intensity efforts under fatigue.

This is why we have seen the massive increases in carb ingestion by elite endurance athletes coincide with record-breaking performances. Take David Roche who’s first place at Arizona’s Javelina Jundred just two months after his record-breaking Leadville 100 victory has made him one of the best-performing ultra runners in 2024.

Whereas Roche acknowledges that most studies look at higher intensity scenarios and that’s not purely what he is doing in ultras; at the end of Javelina his heart rate was in the 120s and 130s. But as someone who previously tested poorly for fatigue resistance, he ties his recent rise to the top of ultra racing to a few key changes in his training:

1. He stimulates carb-ox under fatigue. For example, doing harder efforts at the end of a long run, even with very short efforts like hill strides, you’re stimulating the same system variables that improve fatigue resistance even when you are not going hard. So this doesn’t just help performance when you are doing 1-minute or 10-minute power. It helps it after 2 hours, 3 hours, 10 hours even when you are going easy. His tip - at the end of an endurance workout add some small efforts to activate carb-ox without fully stimulating it, e.g.

   • 4 to 5 x 30s hill strides

   • 3 to 5 mins in zone 3

2. He focuses on speed and strength. “We want base fitness to come from speed. Unless you are a super freak you are going to get a lot slower by just doing easy runs. Aerobic development needs to be in conjunction with power, speed, and biomechanical development.”

3. He incorporates cross-training, modalities and only runs 4 or 5 times a week. “If you have the speed and running economy developed, then if you throw any amount of cross-training into that bucket, it’s incredibly productive”.

4. He trains high carb fueling (Roche took 130 to 150g per hour during Javelina).

It looks like FatMax training may have been a white elephant - or at least that the benefits of low-intensity run training were not exactly what we thought they were. The performance outcomes of your training may be better served by focusing your run training on speed, strength, power and the energy needed to fuel it - whilst adopting cross-training modalities to create and complement base aerobic run fitness.

This echoes my own experiences coming from running to triathlon and then into swimrun. The enforced cross-training of the latter two actually improved my run performance, as my limited run time forced me to focus on quality whilst getting the lion's share of the general lower-intensity aerobic stimulus from other training modalities. I no longer see the long run being a de facto mono-pace easy run. I see it as one of my key weekly runs and its format depends on where I am in the season and what specific stimulus I am targeting.

Emil Zátopek and Sifan Hassan didn’t win Olympic marathon gold medals in spite of their success at 5000m and 10000m - they won because of it. Kristian Blummenfelt hasn’t been dominant at 70.3 and 140.6 Ironman races in spite of his medals at Sprint and Olympic distance races - he wins because of it.

Over these last newsletters we have covered a broad range of topics centered around the position of the long run. So let’s be clear, I am not saying that the long run does not have its place, it certainly does. I think it was Frank Shorter that summarized training for run performance as “do 2 hard work-outs, a long-run and accumulate as much volume as you can for months and years on end.”

Weekly (easy) volume has always been a good indicator of marathon performance, noting that for an elite or sub-elite athlete training at least 12 hours a week this will give them >160 km - so adequate volume is a given - for recreational athletes, it is not.  I would therefore reverse the order of his sentence:

1. First, accumulate as much weekly volume as you can through regular easy-distance runs - make these a habit meaning months not weeks

2. Then, make two of those sessions hard workouts

3. Then, extend another of those sessions to make a long-run

The volume you can get to for point one will dictate how you approach points two and three. In addition, I would ensure enough strength training and consider if aerobic cross-training modalities need to be considered.

I’ll stress the cross-training point because we have traditionally seen mileage as the key variable for aerobic training. But this is a confounding variable, not a driving variable. The true questions are:

• Are you getting enough aerobic work to adapt (this does not need to be running).

• Are you building your peak running power output (this determines all other metabolic turn points and requires quality run workouts).

• Are you avoiding breakdown (through adequate fueling and managing the stress on the body).

In other words, build your volume to what you can safely sustain, and then qualify your workouts based on your goals, taking into account your strengths, weaknesses and your training periodization.

By all means, keep the long run, just think carefully about how to use it and don’t let it interfere with other key stimuli. 

Things change, do your views on training and the long run also need to?