Effects of Individual Changes in Training Distribution on Maximal Aerobic Capacity in Well-Trained Cross-Country Skiers: A Follow-Up Study

Abstract

The purpose of this study was to evaluate individual changes in training distribution and the subsequent effects on maximal oxygen uptake (VO_2max). The participants were well-trained cross-country skiers who had performed a year with no substantial changes in training prior to this study. Six cross-country skiers, who were participants in a larger previous study, volunteered for a follow-up study. All skiers performed self-motivated changes in training distribution for a new preparation period in this follow-up, generally by more high-intensity training (HIT). All training characteristics were registered from training diaries. During the follow-up period, all skiers performed an incremental VO_2max test in February 2020 and August 2020. Training were categorized into three different training periods; (1) February 2019 to February 2020 (P ₁) representing the training performed prior to the follow-up, (2) February 2020 to July 2020 (P ₂), and (3) July 2020 to August 2020 (P ₃). On average, the skiers increased their VO_2max by 5.8 ± 5.0% (range: -1.8 to + 10.2%) during the follow-up study compared with the average VO_2max during the preceding year. Total training volume increased on average by 10.0 and 25.7% in P ₂ and P ₃, respectively, compared with P ₁. The average volume of HIT was similar between P ₁ and P ₂ but increased 62.8% in P ₃. However, large individual differences in training changes were observed. In conclusion, the present study revealed that individual changes in training distribution generated an increased VO_2max in four out of six already well-trained cross-country skiers. Reduced total training volume (three out of six) and increased (four out of six) HIT volume were the most marked changes.

Keywords: VO2max; cross country skiing; endurance; total training volume; training characteristic.