Effect of sub-technique transitions on energy expenditure and physiological load in the classical-style technique among elite male cross-country skiers

Tomas Carlsson,Mikael Swarén,Magnus Carlsson,Lars Wedholm,Wilma Fjordell

doi:10.1007/s00421-021-04783-5

Abstract

PurposeTo investigate whether sub-technique transitions in the classical-style technique are associated with increased energy expenditure and/or metabolic stress among elite male cross-country skiers.MethodsFifteen elite male skiers completed three 10-min treadmill roller-skiing tests, each of which consisted of 5 min using the diagonal-stride technique (DS) and 5 min using the double-poling technique (DP), combined in three various modes all ensuring comparable mechanical workload, at an inclination of 2.5° and a speed of 13 km/h. In the first and third tests, the participants used 5 min continuous DS followed by 5 min continuous DP, or vice versa (no transition (NT) test), whereas in the second test, they made transitions between DS and DP every 6 s (repeated transition (RT) test). The last 3 min of each 5-min stage was used to calculate the mean values of oxygen uptake ({dot{text{V}}text{O}}_{{2}}), respiratory exchange ratio (RER), metabolic rate (MR), mechanical work rate (MWR), and gross efficiency (GE). In addition, the pre–post-difference in blood lactate concentration (Ladiff) was determined for each test. Paired-samples t tests were used to investigate differences between tests.ResultsThere were no significant differences between NT and RT tests regarding V̇O2, MR, MWR, or GE. Conversely, significant differences were found in RER and Ladiff, where the NT test was associated with higher RER and Ladiff values.ConclusionsRoller skiing with repeated sub-technique transitions is not associated with an additional aerobic energy contribution; instead, the anaerobic energy contribution was lower compared to that under continuous use of DS and DP.

Highlights

Competitions in cross-country skiing are performed using classical technique; free technique; or a skiathlon format, where the first and second halves of the race are conducted using classical technique and free technique, respectively
Significant differences between NT test and repeated transitions between sub-techniques (RT test) were found for respiratory exchange ratio (RER) and Ladiff (Table 1); there were no significant differences between tests for the variables V O2, metabolic rate (MR), mechanical work rate (MWR), and gross efficiency (GE) (Table 1)
The 10-min tests included in the NT test that ended with 5 min using either double-poling technique (DP) or diagonal-stride technique (DS) had Ladiff of 0.68 ± 0.67 mmol/l and 0.15 ± 0.67 mmol/l, respectively

Summary

Introduction

Competitions in cross-country skiing are performed using classical technique; free technique; or a skiathlon format, where the first and second halves of the race are conducted using classical technique and free technique, respectively. The non-propulsive tuck technique is used to minimise air resistance, thereby increasing or maintaining skiing speed or minimising its reduction. These sub-techniques are alternated depending mainly on the inclination of the actual course section (Ettema et al 2017; Løkkeborg and Ettema 2020; Pellegrini et al 2013). The use of DPK in competitions is currently relatively low (Marsland et al 2017), and elite skiers change instead ‘gear’ directly from DP to DS when entering uphill sections with moderate or steep inclines where the skiing speed decreases. The sub-technique transition between DP and DS or vice versa has recently been shown to be the most frequently used transition between sub-techniques with propulsive force production (Solli et al 2018)

Objectives

Methods

Results