Block Periodization - Impressive Performance Gains in Pro-Athletes: Revolutionary Training Concept, Or Just a Good Way to Eventually Break Out of the Comfort Zone?

Block Periodization - Training revolution or simple trick? This is what we have to ask ourselves in view of these results.

With all the news and discussion about nutrition and dietary supplements, it's easy to lose sight of the significant impact even minor tweaks to your training routine may have on your results. The results of a recent study from the Lillehammer University College in Norway, for example, remind us all of the importance to periodize our training regimen.Now you could obviously randomly divide a year into cycles with different workout frequencies, intensities, volume, etc. It does yet go without saying that this is probably not the most promising approach to periodization.

What are good ways to periodize your training?

As B. R. Rønnestad, J. Hansen, S. Ellefsen point out in the introduction to their latest paper in the Scandinavian Journal of Medicine & Science in Sports, there is yet a "paucity of studies" that would allow us to decide which of the myriad of possible periodization strategies works best.
There is, for example, preliminary evidence that would suggest that block periodization is more effective than traditional periodization in improving performance (García-Pallarés. 2010), but this evidence is far from being conclusive and thus reason enough for the Norwegian scientists to conduct their own study to investigate

"the effects of a 1-week block of five HIT sessions, followed by a 3-week period of one HIT session per week and a naturally high volume of lowintensity training in trained cyclists." (Rønnestad. 2014)

And compare the results to those of a group of cyclists who employ a more traditional two HIT sessions per week organization while simultaneously performing a relatively high volume of low intensity training.

Mixed or exclusive periodization?

If you think in strength training terms you could probably say that we're comparing the nasty classic HST regimen with it's fixed strength-endurance, hypertrophy, strength blocks to a mixed mode regimen without a clear distinction between strength-endurance-, hypertrophy-, and strength-phases.
Much contrary to what we've seen in Spinetti's resistance training study from 2013 (learn more), the cyclists in the study at hand did capitalize on the strict separation of HIIT and steady state HIT and LISS training as it is depicted in Figure 1.

Figure 1: Weekly distribution of training in the different intensity zones during the intervention period for the block periodization group (BP) and the traditional group (TRAD; upper panel). The relative distribution of the training in the different intensity zones during the intervention period in the two intervention groups (lower panel; Rønnestad. 2014)

If you take into consideration that the "zones" represent the three heart rate (HR) zones: (1) 60–82%; (2) 83–87%; and (3) 88–100% of maximal HR. A brief glimpse at Figure 1 should suffice to see that the main difference between the two groups is the high intensity focus in week one in the blocked periodization (BP) group and the subsequent reduction of intensive training to an absolute minimum in weeks 2-4.

During these HIT sessions the participants in both groups alternated between 6x5 and 5x6 min in the intensity zone 3 (➲ all cyclists were instructed to perform each HIT session with the aim to produce the highest possible mean power output across intervals). The intervals were separated by 2.5- or 3-min recovery, respectively. This makes the actual mean power output of each HIT session an indicator of performance level.

Figure 2: Perceived well-being in the legs during the intervention period (Rønnestad. 2014) .

"In order to monitor the power output during HIT sessions, seven cyclists in the BP group and six cyclists in the TRAD group were equipped with a PowerTap SL 2.4 (CycleOps, Madison, WI, USA) mounted on the rear wheel. The PowerTap device is a valid and reliable power meter (Bertucci. 2005). Furthermore, in order to quantify how the training weeks affected the perceived well-being in the legs, the cyclists reported their perceived feelings on a 9-point scale, going fromvery very good to very very heavy after each training week (Fig. 2)." (Rønnestad. 2014)

Needless to say that the initial week took it's toll on the legs of the 21 trained male cyclists with 6 ± 4 years of competitive cycling experience in the cycling shorts (data from two dropouts due to illness was excluded).
Reference:

• Bertucci, William, et al. "Validity and reliability of the PowerTap mobile cycling powermeter when compared with the SRM device." International journal of sports medicine 26.10 (2005): 868-873.
• García-Pallarés, Jesús, et al. "Performance changes in world-class kayakers following two different training periodization models." European journal of applied physiology 110.1 (2010): 99-107.
• Laursen, Paul B., Michelle A. Blanchard, and David G. Jenkins. "Acute high-intensity interval training improves Tvent and peak power output in highly trained males." Canadian Journal of Applied Physiology 27.4 (2002): 336-348.
• Lindsyay, Fiona H., et al. "Improved athletic performance in highly trained cyclists after interval training." Medicine and science in sports and exercise 28.11 (1996): 1427-1434. 
• Rønnestad, B. R., J. Hansen, and S. Ellefsen. "Block periodization of high‐intensity aerobic intervals provides superior training effects in trained cyclists." Scand J Med Sci Sports 24 (2014): 34–42.
• Spinetti J, et al. Comparison Between Different Periodization Models On Muscular Strength And Thickness In A Muscle Group Increasing Sequence. Rev Bras Med Esporte. 2013; 19(4)
• Swart, Jeroen, et al. "Effects of high-intensity training by heart rate or power in well-trained cyclists." The Journal of Strength & Conditioning Research 23.2 (2009): 619-625..  
• Westgarth-Taylor, Christopher, et al. "Metabolic and performance adaptations to interval training in endurance-trained cyclists." European journal of applied physiology and occupational physiology 75.4 (1997): 298-304.