Blood lactate recovery and respiratory responses during diagonal skiing of variable intensity

Abstract

The aims of the study were to investigate blood lactate recovery and respiratory variables during diagonal skiing of variable intensity in skiers at different performance levels. Twelve male cross-country skiers classified as elite (n06; V O 2max 07393 ml × kg (1 × min (1 ) or moderately trained (n06; V O 2max 06195 ml × kg (1 × min (1 ) performed a 48-min variable intensity protocol on a treadmill using the diagonal stride technique on roller skis, alternating between 3 min at 90% and 6 min at 70% of V O 2max . None of the moderately trained skiers were able to complete the variable intensity protocol and there was a difference in time to exhaustion between the two groups (elite: 45.097.3 min; moderately trained: 31.4910.4 min) (P B0.05). The elite skiers had lower blood lactate concentrations and higher blood base excess concentrations at all 70% workloads than the moderately trained skiers (all P B0.05). In contrast, V E /V O 2 and V E /V CO 2 at the 70% V O 2max workloads decreased independently of group (P B0.05). Partial correlations showed that V O 2max was related to blood lactate at the first and second intervals at 70% of V O 2max (r0(0.81 and r0(0.82; both P B0.01) but not to V E /V O 2 , V E /V CO 2 or the respiratory exchange ratio. Our results demonstrate that during diagonal skiing of variable intensity, (1) elite skiers have superior blood lactate recovery compared with moderately trained skiers, who did not show any lactate recovery at 70% of V O 2max , suggesting it is an important characteristic for performance; and (2) the decreases in respiratory exchange ratio, V E /V O 2 , and V E /V CO 2 do not differ between elite and moderately trained skiers.

Biomechanical determinants of oxygen extraction during cross‐country skiing

“…However, despite the correlations between O 2 extraction and cycle characteristics, EMG activity, and pole forces at a given exercise intensity, the alterations in these other variables were not paralleled by reduced O 2 extraction in the arms when the exercise intensity was reduced. Therefore, in this respect (as well as with regard to blood metabolites; see below) a preceding period of high‐intensity DP may have long‐lasting effects on subsequent periods of lower intensity shown to be adequate for recovery in the case of DIA (Björklund et al., , ).…”

“…This is consistent with the report that following combined arm and leg cranking at 90% of VO 2peak , lactate removal occurs more rapidly during recovery from leg than from arm exercise (McGrail et al., ). In addition, aerobic power is associated with the ability to reduce blood lactate levels during periods of lower exercise intensity (70% VO 2max ) following more intensive exercise (90% VO 2max ) (Björklund et al., ). The inability of skiers performing DP to remove lactate during periods of lower intensity is comparable with that of skiers with lower aerobic power utilizing DIA (Björklund et al., ).…”

“…In addition, aerobic power is associated with the ability to reduce blood lactate levels during periods of lower exercise intensity (70% VO 2max ) following more intensive exercise (90% VO 2max ) (Björklund et al., ). The inability of skiers performing DP to remove lactate during periods of lower intensity is comparable with that of skiers with lower aerobic power utilizing DIA (Björklund et al., ). Therefore, a further increase in upper body aerobic power might be beneficial for DP performance.…”

“…After a 10‐min warm‐up at 60% of VO 2peak , each subject performed DP on an incline of 1° for 3 min at 90% of VO 2peak (race speed), followed by 6 min at 70% of VO 2peak [moderate intensity shown earlier to allow recovery in well‐trained cross‐country skiers using DIA (Björklund et al., , )].…”

“…Previous investigations have focused on different strategies for recovery (Hermansen & Stensvold, ; McGrail et al., ). In the case of cross‐country skiing, much is already known concerning DIA (Björklund et al., , ), but recovery from high‐intensity DP skiing might demonstrate different responses because the propulsion cannot be redistributed between the upper and lower body muscles to the same extent.…”