Comparison of Physiological and Perceptual Responses to Upper-, Lower-, and Whole-Body Exercise in Elite Cross-Country Skiers

STRENGTH TRAINING METHODS FOR SKIERS

ABSTRACT Introduction: The ski jumping sequence can be divided into four steps: support, take-off, flight, and landing. Each stage has specific tasks and functions and is closely related, with the completion of each stage depending on the previous one. Objective: Explore the effectiveness of special strength training methods for ski sportsmen. Methods: Using the method of scientific literature review, expert interview, experience, and mathematical statistics to perform the special strength training for Chinese ski athletes, comparing the changes in the jump speed and take-off of the big jumps before and after 16 weeks of strength training with a specially developed protocol. Results: There were significant differences in take-off speed and air height before and after the experiment (P<0.05). The athletes in the experimental group significantly differed in takeoff speed before and after participation in the experiment (P=0.01). Conclusion: The experimental results fully evidence that by improving the rapid contraction strength of flexor and extensor muscles of the trunk and hip joints, modern abdominal center strength training methods are more effective than traditional methods. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Upper- vs. Lower-Body Exercise Performance in Female and Male Cross-Country Skiers

Purpose: To investigate the interaction between exercise modality (i.e., upper- and lower-body exercise) and sex in physiological responses and power output (PO) across the entire intensity spectrum (i.e., from low to maximal intensity).

Methods: Ten male and 10 female cross-country (XC) skiers performed a stepwise incremental test to exhaustion consisting of 5 min stages with increasing workload employing upper-body poling (UP) and running (RUN) on two separate days. Mixed measures ANOVA were performed to investigate the interactions between exercise modalities (i.e., UP and RUN) and sex in physiological responses and PO across the entire exercise intensity spectrum.

Results: The difference between UP and RUN (ΔUP−RUN), was not different in the female compared with the male XC skiers for peak oxygen uptake (18 ± 6 vs. 18 ± 6 mL·kg−1·min−1, p = 0.843) and peak PO (84 ± 18 vs. 91 ± 22 W, p = 0.207). At most given blood lactate and rating of perceived exertion values, ΔUP−RUN was larger in the male compared with the female skiers for oxygen uptake and PO, but these differences disappeared when the responses were expressed as % of the modality-specific peak.

Conclusion: Modality-differences (i.e., ΔUP−RUN) in peak physiological responses and PO did not differ between the female and male XC skiers. This indicates that increased focus on upper-body strength and endurance training in female skiers in recent years may have closed the gap between upper- and lower-body endurance capacity compared with male XC skiers. In addition, no sex-related considerations need to be made when using relative physiological responses for intensity regulation within a specific exercise modality.

The Effects of Sub-Technique and Pole Length on Classic Roller Skiing Performance and Physiological Responses at Steep Uphill Inclination

The aims of this study were to compare performance with physiological and perceptual responses on steep uphill inclines between double poling and diagonal stride and to investigate the effects of pole length when double poling. Eight male, competitive cross-country skiers (22 ± 1.1 yrs, peak oxygen uptake (VO_2peak) in the diagonal stride: 69.4 ± 5.5 ml·kg^-1·min^-1) performed four identical tests, one in the diagonal stride, and three in double poling with different pole lengths (self-selected, self-selected -5 cm and self-selected +10 cm). Each test was conducted at a fixed speed (10 km/h), with inclination rising by 1%, starting with 7%, each until voluntary exhaustion. VO_2peak, the heart rate, blood lactate concentration, and the rating of perceived exertion were determined for each pole length in each test. The peak heart rate (p < 0.001) and VO_2peak (p = 0.004) were significantly higher in the diagonal stride test compared with double poling with all pole lengths. Time to exhaustion (TTE) differed significantly between all four conditions (all p < 0.001), with the following order from the shortest to the longest TTE: short poles, normal poles and long poles in double poling, and the diagonal stride. Consequently, a significantly higher slope inclination was reached (p < 0.001) using the diagonal stride (17%) than for double poling with long poles (14%), normal (13%) and short (13%) poles. The current study showed better performance and higher VO_2peak in the diagonal stride compared to double poling in steep uphill terrain, demonstrating the superiority of the diagonal stride for uphill skiing. However, in double poling, skiers achieved improved performance due to greater skiing efficiency when using long poles, compared to normal and short poles.

Intensity Control During Block-Periodized High-Intensity Training: Heart Rate and Lactate Concentration During Three Annual Seasons in World-Class Cross-Country Skiers

Purpose: To describe heart rate (HR) and blood lactate (Bla⁻) responses during high-intensity interval training (HIT) in a long-term block-periodized HIT regimen in world-class cross-country (XC) skiers.

Methods: Data were collected in 14 world-class female XC skiers (aged 25 ± 5 years; body mass, 60.4 ± 6.5 kg; and maximal HR, 194 ± 8 beats · min⁻¹) throughout three entire seasons. The HR and Bla⁻ values were determined at the end of 572 intervals performed during 63 sessions and 17 HIT blocks utilizing different exercise modes: running, running with poles, and skiing (on-snow and roller ski) with classic and skating techniques.

Results: The mean HR was 91 ± 3% of HR_max with a corresponding Bla⁻ of 7.3 ± 2.1 mmol · L⁻¹. The average HR and Bla⁻ values were relatively similar across the different exercise modes, except for a lower HR (~90 vs. 92% of HR_max) for on-snow and roller ski classical skiing and lower Bla⁻ values (5.9 vs. 7.0–7.8 mmol · L⁻¹) for on-snow classical skiing compared to the other modes, both P < 0.05. An increase in HR and Bla⁻ was observed from interval working periods 1 to 3 (90–92% of HR_max and 6.5–7.7 mmol · L⁻¹) and further from 3 to 5 (92–93% of HR_max and 7.7–9.0 mmol · L⁻¹), all P < 0.05.

Conclusions: We describe long-term use of HIT-block periodization among world-class XC skiers who achieved target HR and Bla⁻ levels in all six exercise modes employed. According to athletes and coaches, the key to successful blocks was intensity control to allow for high-quality HIT sessions throughout the entire HIT block.

Determinants of the Cardiovascular Capacity of Amateur Long-Distance Skiers during the Transition Period

The aim of this study was to identify determinants of the cardiovascular capacity of 16 male amateur long-distance skiers during the transition period. These factors can vary from amateur marathon skiers, who represent a sort of midpoint between inactive people and professional athletes. Cardiovascular capacity depends mainly on the volume and intensity of the training, which are different between these groups. Finding the factors affecting heart condition of amateur athletes can be an important element in their health care and can help the athletes to achieve their full performance potential. Therefore, ergospirometric and hematological tests were performed. As a result, predictors for volume oxygen uptake were determined using a regression model, which included the following variables: the percentage of monocytes (p = 0.031), the concentration of sodium (p = 0.004), and total calcium (p = 0.03). All these parameters negatively affected VO2 max. Biochemical and physiological monitoring of amateur athletes can help to protect their health and prepare them properly for their training. The growing popularity of long-distance competitions among middle-aged amateur athletes and the lack of guidance on how to assess their health indicate the need for further research.

Cardiovascular Adaptations to Four Months Training in Middle-Aged Amateur Long-Distance Skiers

Cross-country skiing has a positive effect on health. However, without an individual, thoughtful, and professional plan, it can cause irreversible health problems from overload and injury. The impact of exercise on results is well understood within the group of professional athletes. However, this remains unknown within the group of amateur cross-country skiers and marathon runners—in particular, the impact of the summer preparation period in which training loads performed in the oxygen zone combined with resistance training dominate. The aim of this study was to assess changes in the cardiovascular capacity and body mass composition of male cross-country skiers in the preparation period of their macrocycle. Variables were analyzed using basic descriptive statistics: mean and standard deviation (SD). To compare the results from both measurements (initial and final) the paired Wilcoxon test was used. A statistically significant increase was noted in maximum oxygen uptake and maximum minute ventilation, and a decrease in body fat content, maximum lactate concentration and lactate threshold, and heart rate on anaerobic threshold. Research indicated that in the amateur group increases similar to those in top competitors were achieved in the parameters tested, but the initial level was often significantly lower.