Can you run a solid marathon on aerobic running alone?

Pretentiousness Detective wrote:

bs in ex phys wrote:

How do you know that IIa fibers are recruited after a certain distance or time? O have heard/read this but where is the evidence that is actually happening?

Good question. Don't expect a reliable answer.

moist wrote:

Pretentiousness Detective wrote:

Good question. Don't expect a reliable answer.

It's a studied and proven outcome of endurance training. a paper that discusses current research on the subject as well as limitations of our understanding. Section 4 is of particular interest. You can dig into the references if you want:

Link:pmc.ncbi.nlm.nih.gov/articles/PMC84730...

Endurance training generally induces a fiber type shift toward a more oxidative phenotype. This is logical from the specificity of the training standpoint, considering the increased consumption of oxygen during endurance exercise. The rate of fiber type shifting appears to be less pronounced as endurance athletes progress deeper into event-specific preparation and if they begin an endurance training intervention with a higher abundance of type I fibers [19]. Luden et al. investigated the effects of 13 weeks of marathon training, followed by a 3-week taper on fiber type shifts in novice runners [20]. The investigators biopsied the vastus lateralis and soleus muscles and employed single fiber isolation techniques paired with SDS-PAGE for fiber typing. Vastus lateralis type I fiber composition increased (42.6% to 48.6%), I/IIa increased (5.1% to 8.2%), IIa decreased (40.1% to 35.8%), IIa/IIx decreased (11.9% to 6.4%), and IIx increased (0% to 1%). The soleus, a muscle comprised of predominantly type I fibers [21,22], experienced a similar but less pronounced shift, potentially indicating that certain muscles have a higher propensity for fiber type shifting than others. Importantly, biopsies were obtained after a taper, so it can be speculated that results would have been even more in favor of slower twitch abundance if measured directly post-training. Nevertheless, a shift toward type I fibers was apparent with higher volume endurance training. Other investigations have found similar patterns, indicating a shift toward type I fibers or a more oxidative phenotype after endurance training [23,24,25].
Multiple cross-sectional investigations have used one of the aforementioned techniques to demonstrate that well-trained endurance athletes possess a significantly higher proportion of type I fibers relative to sedentary or resistance-trained counterparts [26,27,28]. However, there is a dearth of long-term longitudinal evidence on fiber shifts in endurance athletes, precluding strong assertions on type I retention or shifts in elite athletics. However, one twin study has highlighted the potential for dramatic fiber type shifts over long periods of time. Bathgate et al. (Bathgate et al. 2018) carried out a case study in twins where one twin was largely sedentary throughout most of his adult life, while the other recreationally participated in endurance exercise for decades. Single fiber type analysis showed the trained twin had a vastus lateralis composition that was mostly slow-twitch (95% MHC I), amounting to 55% more MHC I fibers than the untrained twin. Moreover, the untrained twin possessed many more IIa and hybrid fibers than the trained twin. This study suggests that human muscle may dramatically shift toward one fiber type when training occurs over a lengthy period of time. Although further research is warranted to draw strong conclusions, it is possible that certain individuals have a greater plasticity/propensity toward fiber type shifts in one direction or the other and, perhaps, in general. While difficult to execute, studies examining multiple twin groups or appropriate cohorts could give insights into individual responses and the extent of fiber type shifts over a longer timeframe.

moist wrote:

Charlesvdw wrote:

It is my humble opinion that speed work is not that important for non-elite marathon runners.

That's a completely different conclusion than "I would've run no more than 2 minutes faster with speedwork."

What is your definition of what's important for non-elite marathon runners? Is it simply completing the distance? Or does time matter? Because a lot of us non-elites want to cover the distance as quickly as possible, and speedwork is an important part of that.

Just understanding the fundamentals of training shows that your statement is wrong. Aerobic and lactate thresholds are major factors in an athlete's marathon pace. And running economy and VO2max are major factors to both of those. It's a simple truth of training that developing both will result in a faster marathon pace. Running easy to MP will improve both to some degree, but an athlete is missing out on key development by not training at paces faster than MP.

In fact, it's such a dramatic difference that I'd bet that an athlete like yourself could drop from 2:55 to 2:45 just by incorporating the right speedwork at the right times. Assuming no injuries, of course.

moist wrote:

Charlesvdw wrote:

It is my humble opinion that speed work is not that important for non-elite marathon runners.

That's a completely different conclusion than "I would've run no more than 2 minutes faster with speedwork."

What is your definition of what's important for non-elite marathon runners? Is it simply completing the distance? Or does time matter? Because a lot of us non-elites want to cover the distance as quickly as possible, and speedwork is an important part of that.

Just understanding the fundamentals of training shows that your statement is wrong. Aerobic and lactate thresholds are major factors in an athlete's marathon pace. And running economy and VO2max are major factors to both of those. It's a simple truth of training that developing both will result in a faster marathon pace. Running easy to MP will improve both to some degree, but an athlete is missing out on key development by not training at paces faster than MP.

In fact, it's such a dramatic difference that I'd bet that an athlete like yourself could drop from 2:55 to 2:45 just by incorporating the right speedwork at the right times. Assuming no injuries, of course.

Charlesvdw wrote:

moist wrote:

That's a completely different conclusion than "I would've run no more than 2 minutes faster with speedwork."

What is your definition of what's important for non-elite marathon runners? Is it simply completing the distance? Or does time matter? Because a lot of us non-elites want to cover the distance as quickly as possible, and speedwork is an important part of that.

Just understanding the fundamentals of training shows that your statement is wrong. Aerobic and lactate thresholds are major factors in an athlete's marathon pace. And running economy and VO2max are major factors to both of those. It's a simple truth of training that developing both will result in a faster marathon pace. Running easy to MP will improve both to some degree, but an athlete is missing out on key development by not training at paces faster than MP.

In fact, it's such a dramatic difference that I'd bet that an athlete like yourself could drop from 2:55 to 2:45 just by incorporating the right speedwork at the right times. Assuming no injuries, of course.

Mileage is king for marathon runners. I think we can agree on that.

Marathon pace practice is important to become efficient at MP. Long runs are important to prepare the legs for the pounding of the marathon.

VO2-max is important but it is not the key determinant of marathon performance. Aerobic base and running economy are far more important. Look at the NSM thread where a lot of people prove you don't need VO2max training for improvement. And not only for the marathon but also for much shorter distances.