Study of Physiological Adaptations in Vertical Kilometer Runners: Focus on Cardiorespiratory and Local Muscle Demands

Area of Science:

• Sports Science
• Exercise Physiology
• Trail Running Performance

Background:

• Vertical kilometer (VK) races demand specific physiological adaptations, yet research on metabolic and cardiorespiratory responses in field settings is limited.
• Understanding these responses is crucial for effective training and periodization in trail running.

Purpose of the Study:

• To evaluate metabolic and cardiorespiratory responses during a VK field test.
• To identify sex- and performance-level differences in physiological responses.
• To determine key performance factors and their fatigue-related deterioration in VK races.

Main Methods:

• Fifteen trained trail runners (10 males, 5 females) completed a VK race.
• Global physiological response measured using a portable gas analyzer (Cosmed K5).
• Local physiological response assessed via near-infrared spectroscopy (NIRS).

Main Results:

• Significant sex differences observed in ventilation, heart rate, oxygen pulse, and hemoglobin.
• Performance level differences noted in velocity, oxygen consumption, CO2 production, and respiratory parameters.
• Key performance factors identified: oxygen consumption, CO2 production, expiratory time-to-inspiratory time ratio, ventilation, and quadriceps saturation index.

Conclusions:

• Physiological analysis underscores the importance of local muscular adaptations and respiratory capacity in short-duration VK races.
• Oxygen consumption, CO2 production, and respiratory efficiency are critical determinants of performance.
• Findings provide valuable data for training strategies in vertical kilometer racing.