Should the primary focus of your training be on volume or intensity?
We get some help answering that question from a study by Gaskill and associates done in 1999. It’s now getting somewhat old, but still has good lessons for us. It’s also a long-term study that is rare in sport science.
Most studies of endurance athletes last a few weeks at most, and for good reasons. It’s difficult to get athletes to agree to drastically change their training (or whatever is being studied) for an extended period of time. Research also costs money, so the longer the study, the more money that is spent. And scientists, like all of us, like to see things happen quickly. So waiting for more than a few weeks to gather data for study and analysis is not common. But this study took two years.
The sport scientists from the University of Montana manipulated the training of 14 amateur, cross-country skiers for those two years. In year 1 the athletes trained similarly with about 600 accumulated annual hours (that’s about 12 hours per week). Of the 600, about 17% was at or above lactate threshold. That’s roughly two hours per week on average. In fact, the “polarized training” studies I’ve recently written about report that to be a fairly good target range for high-intensity training.
At the end of year 1 the 14 skiers pre-tests, post-tests, and race results were compared. The seven athletes who improved the most were assigned to a High-Responders group. The others, who showed little improvement in year 1, were assigned to a Low-Responders group.
Then, in year 2, the High Responders continued with the same training as in year 1 while the Low Responders reduced their volume by 22% doing about 470 annual hours (around 9.5 hours per week). The Low Responders also doubled their total training time above lactate threshold to about 35% (roughly 3 hours per week).
The High Responders, who kept their training the same as in year 1, had no significant changes in test or race results by the end of year 2. The Low Responders following year 2 had significant improvements in their VO2max, lactate thresholds, and race results compared with year 1. They rose to the performance level of the High Responders.
So what are the lessons we can learn from this study? The first is that the response to any training program varies considerably between individuals. In sport science this is referred to as the “principle of individuality.” In this example, some of the athletes responded well to high volume, others to high intensity.
Another lesson is that training the same way year after year produces about the same results. Something needs to change to improve. Should the change be in volume or high intensity? That’s a hard question to answer without knowing more about the individual. But, in general, the newer you are to your sport, the more likely you are to respond better to volume increases. Experienced athletes, those who have been in their sport for several years (perhaps more than 3 years), will usually respond better to increases in the volume of intensity done at or above lactate threshold.
Determining how to train is often a matter of trial and error. If you aren’t responding well to your workout program, it may be that you need more total training volume or more high-intensity efforts. Of course, there could be other issues, such as making your easy days too hard, inconsistent training, significant psychological stress in your life, poor nutrition, inadequate recovery, and so on. But if you can eliminate such training detractors as these, then the biggest remaining variable is the periodization of your volume and intensity. The only way to find out for sure is to try something different from what you’ve done in previous years and see what happens.