Eleven-Week Preparation Involving Polarized Intensity Distribution Is Not Superior to Pyramidal Distribution in National Elite Rowers

ORIGINAL RESEARCH published: 02 August 2017 doi: 10.3389/fphys.2017.00515 Eleven-Week Preparation Involving Polarized Intensity Distribution Is Not Superior to Pyramidal Distribution in National Elite Rowers Gunnar Treff 1*, Kay Winkert 1 , Mahdi Sareban 1, 2 , Jürgen M. Steinacker 1 , Martin Becker 3 and Billy Sperlich 4 1 Division of Sports and Rehabilitation Medicine, Ulm University Hospital, Ulm, Germany, 2 Institute of Sports Medicine, Prevention and Rehabilitation, Paracelsus Medical University, Salzburg, Austria, 3 Data Mining and Information Retrieval Group, Julius-Maximilian University, Würzburg, Germany, 4 Integrative and Experimental Training Science, Institute of Sport Science, University of Würzburg, Würzburg, Germany Edited by: James (Jim) David Cotter, University of Otago, New Zealand Reviewed by: Brett Tiaki Smith, University of Waikato, New Zealand Anthony Rice, Australian Institute of Sport, Australia *Correspondence: Gunnar Treff Specialty section: This article was submitted to Exercise Physiology, a section of the journal Frontiers in Physiology Received: 27 February 2017 Accepted: 05 July 2017 Published: 02 August 2017 Citation: Treff G, Winkert K, Sareban M, Steinacker JM, Becker M and Sperlich B (2017) Eleven-Week Preparation Involving Polarized Intensity Distribution Is Not Superior to Pyramidal Distribution in National Elite Rowers. Front. Physiol. 8:515. doi: 10.3389/fphys.2017.00515 Frontiers in Physiology | www.frontiersin.org Polarized (POL) training intensity distribution (TID) emphasizes high-volume low-intensity exercise in zone (Z)1 (<first lactate threshold) with a greater proportion of high-intensity Z3 (>second lactate threshold) compared to Z2 (between first and second lactate threshold). In highly trained rowers there is a lack of prospective controlled evidence whether POL is superior to pyramidal (PYR; i.e., greater volume in Z1 vs. Z2 vs. Z3) TID. The aim of the study was to compare the effect of POL vs. PYR TID in rowers during an 11-wk preparation period. Fourteen national elite male rowers participated (age: 20 ± 2 years, maximal oxygen uptake (V̇O2max ): 66 ± 5 mL/min/kg). The sample was split into PYR and POL by varying the percentage spent in Z2 and Z3 while Z1 was clamped to ∼93% and matched for total and rowing volume. Actual TIDs were based on time within heart rate zones (Z1 and Z2) and duration of Z3-intervals. The main outcome variables were average power in 2,000 m ergometer-test (P2,000 m ), power associated with 4 mmol/L [blood lactate] (P4[BLa] ), and V̇O2max . To quantify the level of polarization, we calculated a Polarization-Index as log (%Z1 × %Z3 / %Z2). PYR and POL did not significantly differ regarding rowing or total volume, but POL had a higher percentage of Z3 intensities (6 ± 3 vs. 2 ± 1%; p < 0.005) while Z2 was lower (1 ± 1 vs. 3 ± 2%; p < 0.05) and Z1 was similar (94 ± 3 vs. 93 ± 2%, p = 0.37). Consequently, Polarization-Index was significantly higher in POL (3.0 ± 0.7 vs. 1.9 ± 0.4 a.u.; p < 0.01). P2,000 m did not significantly change with PYR (1.5 ± 1.7%, p = 0.06) nor POL (1.5 ± 2.6%, p = 0.26). V̇O2max did not change (1.7 ± 5.6%, p = 0.52 or 0.6 ± 2.6, p = 0.67) and a small increase in P4[BLa] was observed in PYR only (1.9 ± 4.8%, p = 0.37 or −0.5 ± 4.1%, p = 0.77). Changes from pre to post were not significantly different between groups in any performance measure. POL did not prove to be superior to PYR, possibly due to the high and very similar percentage of Z1 in this study. Keywords: rowing, training intensity distribution, elite athletes, interval training, high intensity, high volume, training zones 1 August 2017 | Volume 8 | Article 515 Treff et al. Polarized Training in Rowers INTRODUCTION Z2 and Z3 (Steinacker et al., 1998). Single case studies reported a TID of 85% in Z1 (Nybo et al., 2014) in an elite lightweight rower from Denmark and ∼81% in Z1 in a double Olympic champion from Norway (Seiler and Tønnessen, 2009), with both reports not specifying the percentages spent in Z2 and Z3. Most analyses so far report a pyramidal TID, i.e., decreasing amount of training spent in Z1, Z2 and Z3. German junior rowers e.g., exhibited a TID of ∼95-3-2 (i.e., percentage in Z1, Z2, Z3) during the last 9 weeks before the first competition (Guellich et al., 2009) and nine successful Olympic rowers from New Zealand featured a TID of 77-17-6 (Plews et al., 2014). A successful French rower employed a TID of 45% Z1 and 55% Z2 (Lacour et al., 2009), notably a TID emphasizing “threshold” intensity. Only one investigation so far reported a polarized (POL) TID of 932-5 in a Belgian elite sculler (Bourgois et al., 2013). POL is characterized by a relatively high amount of volume performed in Z1 and Z3, with less volume in Z2. Taking into account that rowing is a high-intensity sport and being aware of several reports from other endurance disciplines like e.g. running, cycling or cross-country skiing (Stöggl and Sperlich, 2015), the long-term stimulus of POL may improve endurance performance with potentially less autonomic and hormonal stress and boredom, which is supported by experiments in club rowers who especially emphasized Z3-training (Driller et al., 2009; Ní Chéilleachair et al., 2016). Several observational studies of national or world-class athletes from various sport disciplines like running (Billat et al., 2001) or cross-country skiing (Seiler and Kjerland, 2006; Sandbakk et al., 2011; Tønnessen et al., 2014) successfully applied a POL TID. Only one controlled study in 18 club rowers following a 28-day detraining period reported a similar increase of ergometer performance with POL (72-0-28) compared to a control group exaggerating low-intensity rowing (98-2-0; Ingham et al., 2008). Integrating the findings of rowing studies as well as findings from other endurance sports (Neal et al., 2013; Stöggl and Sperlich, 2014) strong evidence exists that POL may be applied in high performance rowing, but this notion is drawn on two serious limitations: Firstly, performance benefits of POL have been concluded based on retrospective observations, but prospective randomized-controlled data on sub-elite or elite level rowers do not exist. Secondly, POL has been compared to static TIDs which do not change over weeks or months. From a methodological point of view, experiments involving static TIDs are convenient for scientists to compare differences between groups, but a static TID does not mirror real-training scenarios in high performance sports, in which TIDs are shaped “dynamically” with increasing percentages of Z2 and Z3 before competitions. Notably, this is recommended by the current scientific literature (Bangsbo et al., 2010; Tønnessen et al., 2014). Altogether, numerous successful TIDs exist in rowing (i.e., POL and PYR), data from various disciplines and rowing are conflicting, and no prospective randomized-controlled investigation exists comparing POL to a dynamic TID in elite rowers. The (...truncated)