A couple of recent studies have looked into Block Periodization (BP) vs Traditional Periodization (TRAD) when it comes to endurance training in well trained endurance athletes (Ronnestad et al., 2014 & 2015). The major physiological determinants of endurance performance are work economy, lactate threshold and VO2max. To improve these 3 qualities, a mixture of low and high intensity training should be performed (e.g. extensive endurance training: 40-120mins @50-60% maximal aerobic speed or 65-75% HRmax; and high intensity training: 4mins @100% MAS). However, it still remains unclear how to organise low intensity training and HIT to achieve optimal performance improvements.
Block periodization (championed by Vladimir Issurin) has been theorised as an effective way to organise endurance training. Block periodization refers to focusing on a few select abilities over a short training block (1-4 weeks) while maintaining other abilities. An example of this would be heavily developing the aerobic system (cardio endurance) while maintaining the alactic system (used for short bursts up to around 10sec). In contrast, traditional periodization looks to develop multiple abilities at once which according to Issurin, leads to suboptimal adaptations in well trained athletes.
In this post, I will just look at Ronnestad et al., (2014) where the authors look to compare a BP model with TRAD periodization in regards to endurance training and leave the 2015 for a separate post. Both papers show similar findings in 2 different endurance athlete populations.
Who were the subjects and how were they grouped?
19 well trained male cyclists were assigned to either the BP or TRAD based on their VO2max. BP cyclists had 6 ± 4 years of competitive experience and had a self-reported 9 ± 3h per week of low intensity training with no HIT in the 2 months lead up prior to this study. TRAD cyclists had 6 ± 4 years of competitive experience and had a self-reported 10 ± 3 per week of low intensity training with no HIT in the 2 months lead up prior to the study.
How was the intervention organised and how long was it?
Both groups performed the same volume of both HIT and low intensity training over the 4 week intervention. Endurance training was divided into 3 HR zones: 1) 60-82%; 2) 83-87%; 3) 88-100% of HRmax. HIT sessions alternated between 6x5 and 5x6mins in the zone 3 intensity with 2.5-3mins rest between intervals. Riders were instructed to perform each HIT session with the aim to produce the highest possible mean power output across the intervals which was used as an indicator of performance. BP group performed a 1 week block of 5 HIT sessions followed by 3 weeks of 1 HIT session with a naturally high volume of low intensity training. TRAD group performed 2 HIT sessions per week throughout the intervention period, interspersed with a relatively high volume of low intensity training.
Illustration of time and volume spent in each zone
What was measured pre, post and during the intervention?
Cyclists reported their perceived well-being in the legs on a 9-point scale, going from very very good to very very heavy after each training week. Pre and post intervention, cyclists performed submaximal and maximal incremental cycling tests to gain; VO2max, Wmax (mean power output during last 2mins of maximal incremental test) and power output at 2mmol/L. There were no significant differences between the groups before the intervention in regards to these variables. I have left a few measures out just to keep this short and less complicated.
What it's like performing the incremental tests
What were the findings?
The BP group significantly increased their VO2max, Wmax and power output at 2mmol/L of blood lactate while no changes occurred in the TRAD group. Wmax increased 2.1 ± 2.8% (P< 0.05) and VO2max by 4.6 ± 3.7% (P< 0.05) with moderate to large effect sizes (ES = 0.85 & 1.34 respectively). Power output at 2mmol/L improved 10 ± 12% (P< 0.05) with a moderate effect size (ES = 0.71). Perceived well-being in the legs was significantly lower in the BP group during the 1st week of intervention compared with TRAD. However, BP reported improved well-being in the legs during the following 3 weeks (P< 0.05).
Performing 1 week of 5 HIT sessions followed by 3 weeks of 1 HIT session a week with a general focus on low intensity training resulted in superior adaptations compared with 4 weeks of 2 weekly HIT sessions interspersed with low intensity training. A BP approach could potentially be a better way of preparing for an endurance event than the TRAD approach, especially if preparation time is short.
In the next installment, I will discuss these results a little further and run through some practical applications for sports that are not pure endurance sports such as team and combat sports.