It is known that about 70% of the performance of long distance runners comes down to three key physiological factors: maximal oxygen uptake, lactate threshold and running economy. These factors are mostly determined by the genetic background and the physical training. Without the ability to alter our genes (unless using genetic doping), training would be our only modifiable factor.
For a long time most of the long distance athletes training methods were based in coaches advices and workloads that had previously worked on other runners, with no much use of any scientific approach.
Training can be defined as the stimulus leading to an enhanced functional capacity. Training frequency, duration and intensity configure the training load, with a threshold to surpass before getting any physical improvement. Most of the long distance training methods consider mainly the volume intensity (miles per week, for example), although the intensity has been suggested as the most important variable in the exercise. There have been many studies regarding the contribution of each of these factors and trying to determine volume/intensity zones (distinguishing between light, medium and hard sessions), but the percentage of training that should be prescribed in any of these zones is still under discussion.
This entry will show some of the approaches trying to improve the physiological determinants of physical performance.
1/Enhancing maximal oxygen uptake (VO2max)
VO2max is defined as the amount of oxygen used in a minute per kilogram of body weight.
Long distance training at a slow pace, typically favoured by trainers and athletes, has not shown any significant improvement of VO2max, even when increasing considerably training volumes.
As for training intensity, were found many variations among studies. It was usually reported an improvement in VO2max when training at near maximal (90-100%) or even higher levels of VO2max in athletes, proving the importance of high intensity interval training. Nevertheless there are also studies in long distance runners showing VO2max improvements at submaximal training intensities.
Exercising aerobically at high altitude has proved to increase VO2max, as well as generate many other physiological adaptations. As a relatively affordable alternative to these stays at high altitude there are in the market some new hypoxia inducing masks, although its effectivity is doubtful in trained athletes, although it could be more useful in sedentary subjects.
2/Enhancing lactate threshold
It is generally accepted than an increase in the lactate threshold corresponds with an improved physical performance. Some studies found an increase in the threshold with 4 months of training in women, although there was no further improvement if training continued for another 8 months. It looks as there is a plateau level, that once reached doesn´t go further, and that could explain why most of the studies involving athletes didn´t find any significant improvement, and the effects were seen only in untrained individuals. Going to higher intensities, around or over the lactate threshold in long distance runners has not clearly proved to get any improvement.
3/Enhancing running economy
With time every athlete adequate his running style to what is understood as the most economical (in energy levels) style. In other words, every runner has a style that suits him best. The most important factor seems to be the cumulative distance run over the years, and not only the training volume, although there is a negative association with age, which could be due to a reduction in the ability to store and release elastic energy. Again high intensity interval training has been shown to be also useful in improving running economy. Regarding force training, it could be better to run on hills or sand, over traditional strength sessions, as using weights could correlate with an enhanced body mass (because a muscle mass increase) that could negatively affect the running economy.
As a conclusion, there is no clear scientific evidence of what is the best approach to improve any of these variables. Additionally most of the studies have been done comparing the effect of different training loads on previously untrained individuals, and not so many in trained long distance runners. No less important is the fact that EVERY athlete have a different beneficial training load and going above it could only get detrimental effects.
What works for somebody doesn´t necessarily works for you: nobody knows you better than yourself.
Effects of Simulated Altitude on Maximal Oxygen Uptake and Inspiratory Fitness.
Int J Exerc Sci. 2017 Jan 1; 10(1):127-136.
Training to enhance the physiological determinants of long-distance running performance: can valid recommendations be given to runners and coaches based on current scientific knowledge?
Sports Med. 2007; 37(10):857-80.