Hemoglobin/myoglobin oxygen desaturation during Alpine skiing

Area of Science:

• Sports Physiology
• Exercise Science
• Biomechanics

Background:

• Alpine ski racing, including giant slalom (GS) and slalom (SL), demands significant physiological exertion.
• Understanding muscle oxygenation and blood flow dynamics is crucial for optimizing athletic performance and preventing fatigue.

Purpose of the Study:

• To investigate changes in muscle blood volume (BV) and oxygen desaturation (OD) during simulated GS and SL Alpine ski racing.
• To compare these physiological responses between GS and SL events in junior elite skiers.

Main Methods:

• Thirty junior elite skiers (ages 9-17) participated, stratified by age and ski class.
• Near-infrared spectrophotometry (NIRS) measured vastus lateralis muscle BV and OD during simulated GS and SL trials.
• Joint angles, heart rate, and maximal OD during ischemia were also assessed.

Main Results:

• Smaller joint angles were observed during GS compared to SL for the ankle, knee, and hip.
• A significantly greater reduction in muscle blood volume (Delta BV) and oxygen desaturation (Delta OD) occurred during GS versus SL.
• Older skiers with larger quadriceps cross-sectional area (CSA) showed a correlation with greater Delta OD.

Conclusions:

• The lower posture adopted during GS, compared to SL, leads to greater muscle blood volume reduction and oxygen desaturation.
• This physiological response suggests compromised blood flow to working muscles during GS, potentially due to increased static load and muscle contraction.
• Findings highlight the distinct physiological demands of GS and SL ski racing.