Associations of thigh muscle thickness with cardiorespiratory fitness and ventilatory efficiency in male soccer athletes.

Thigh muscle thickness measurements showed significant correlations with peak VO2 in male soccer athletes.

• Rectus femoris (RF), vastus intermedius (VI), and overall muscle thickness of thigh (MT) were all significantly correlated with peak VO2
• Correlations were statistically significant at p < 0.01
• Measurements were obtained using muscle ultrasound (MUS)
• Population consisted of competitive male soccer athletes

Thigh muscle thickness measurements showed significant correlations with ventilatory efficiency (VE/VCO2 slope) in male soccer athletes.

• RF, VI, and MT were all significantly correlated with VE/VCO2 slope
• Correlations were statistically significant at p < 0.01
• VE/VCO2 slope was assessed via cardiorespiratory exercise testing (CPET)
• Greater muscle thickness was associated with improved ventilatory efficiency during maximal exercise testing

Rectus femoris, vastus intermedius, and overall thigh muscle thickness were independently associated with peak VO2 in regression analysis.

• Regression analysis demonstrated independent associations between RF, VI, MT and peak VO2
• Associations were statistically significant at p < 0.001
• Body composition parameters were also analyzed alongside ultrasound measurements
• The association remained independent, suggesting muscle thickness contributes beyond general body composition measures

Rectus femoris, vastus intermedius, and overall thigh muscle thickness were independently associated with VE/VCO2 slope in regression analysis.

• Regression analysis demonstrated independent associations between RF, VI, MT and VE/VCO2 slope
• Associations were statistically significant at p < 0.001
• Both individual muscle measurements (RF and VI) and combined thigh muscle thickness (MT) showed independent associations
• Physical capacity was evaluated by CPET

Muscle ultrasound is described as a reliable method for quantifying regional skeletal muscle in athletes.

• Previous research had shown a relationship between MUS evaluations and skeletal muscle strength
• The relationship between thigh muscle thickness and cardiorespiratory capacity evaluated by CPET was previously unexplored
• Rectus femoris and vastus intermedius were the specific muscles measured via ultrasound
• Skeletal muscle represents a substantial portion of whole body mass in athletes