The stress of any given training is due to the intensity and duration of the types of running that occurs. The idea of periodization of training is that during some periods you may train at a low intensity for a long duration and during other periods at a high intensity for a short duration – or any combination in between. Coaches will create different “periods” or cycles of training that focus on specific intensity/duration combinations. For instance, at the beginning of the season athletes may enter a base phase focused on slow speeds and high volume/duration. As the season progresses a shift to lower volume and faster running occurs to “sharpen” the athlete. Other coaches may structure periodization in a way such that you perform most of the running at “goal” intensity at the time closest to the race. For ultrarunners that might mean more longer, slightly faster work closer to race day. So, which periodization method if any should you use for your next race?
While a number of periodization studies of cyclist and cross-country skiers exist, there have been few studies comparing periodization studies in runners and pretty much none in ultrarunners. Still, the existing studies can shed some light on periodization usefulness. Several studies1, 2 have compared training plans which either consist of A) five high intensity interval sessions one week (so called block plan), followed by multiple weeks with only one high intensity interval session, with B) a training plan that has two high intensity interval session each and every week (the so-called traditional plan).
In general, the athletes with the block plan have better physiological adaptations and performance. Note that these performances last under an hour and the training programs only lasted four to five weeks and thus are likely not directly applicable to ultrarunners. In conclusion, there is limited evidence that a blocked approach maybe more effective than a mixed approach with regards to interval training, but the relevance for ultrarunners remains unknown.
Researchers have also tested whether starting with longer slower interval training (4 x 16 minute intervals) and moving to faster shorter intervals (4 x 4 minutes) was more advantageous than the opposite order3. The long-to-short and short-to-long groups were also compared to a third group that just did 4 x 8 minute intervals the entire time. All three groups showed a similar increase in performance after 12 weeks of training, which the authors interpreted as no added effect of the timing of the short or long intervals as long as the exercise load is the same.
Lastly, in a study4 looking at just three elite marathoners the author found that overall training stress (volume x intensity) would be high for several weeks in a row followed by a lower stress week to allow adaptation to the training stress. In addition to periodization in running stress the athletes had nutritional periodization as well. Early in the training cycle they performed more runs in glycogen depleted states to enhance their ability to use fat as energy. Later in the training cycle they practiced carbohydrate consumption while training more frequently. Race day was good to these elite marathoners with two PRs and a solid debut. While limited in the strength of evidence, periodization of overall stress to allow periods of adaptation may have beneficial effects.
The lack of science on periodization was frankly a bit of a shock to me as I’ve always assumed the dominant coaching approach was backed up by lots of evidence. However, what is not in doubt is that variation in training stress is necessary. As you plan your training on your own or with a coach the combination of both high intensity shorter intervals and low intensity long duration should be included, but the timing of each seems less important and the absolute amount will likely vary from person to person and require individualization. Build in rest weeks that follow blocks of high stress weeks (or days) to allow the body to adapt. Often unstudied and not discussed is that life stress contributes to training stress as well and needs to be accounted for since studies have shown athletes with high life stress are more likely to get injured.
Best of luck to all of you racing in 2018 and remember that the failure to have a training plan is a plan to fail.
- Rønnestad BR, Hansen J, Ellefsen S. Block periodization of high-intensity aerobic intervals provides superior training effects in trained cyclists. Scand J Med Sci Sports 24: 34–42, 2014.
- Rønnestad BR, Hansen J, Thyli V, Bakken TA, Sandbakk Ø. 5-week block periodization increases aerobic power in elite cross-country skiers. Scand J Med Sci Sports 26: 140–146, 2016.
- Sylta Ø, Tønnessen E, Hammarström D, Danielsen J, Skovereng K, Ravn T, Rønnestad Br, Sandbakk Ø, Seiler S. The Effect of Different High-Intensity Periodization Models on Endurance Adaptations. Med Sci Sport Exerc 48: 2165–2174, 2016.
- Stellingwerff T. Case Study: Nutrition and Training Periodization in Three Elite Marathon Runners. Int J Sport Nutr Exerc Metab 22: 392–400, 2012.