Indirect Assessment of Skeletal Muscle Glycogen Content in Professional Soccer Players before and after a Match through a Non-Invasive Ultrasound Technology

• Published in: Nutrients Vol. 12; no. 4; p. 971
• Main Authors: San-Millán, Iñigo, Hill, John C, Calleja-González, Julio
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-04-2020; MDPI
• Subjects: Athletes; Bioenergetics; Biopsy; Body fat; Brief Report; Calcium influx; Connective tissue; Glycogen; Glycogen - metabolism; Glycogen - physiology; Glycogens; Glycolysis; Humans; Male; match; Muscle contraction; Muscle Contraction - physiology; muscle glycogen; Muscle, Skeletal - diagnostic imaging; Muscle, Skeletal - metabolism; Muscles; MuscleSound; Muscular function; Musculoskeletal system; Nutrition; Nutritional Physiological Phenomena - physiology; Players; Professional soccer; Sarcoplasmic reticulum; Skeletal muscle; Soccer; Soccer - physiology; Technology; Ultrasonic imaging; Ultrasonography - methods; Ultrasound; Validation studies; Warm up (exercise); United States > US; match; soccer; muscle glycogen; MuscleSound
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu12040971

Skeletal muscle glycogen (SMG) stores in highly glycolytic activities regulate muscle contraction by controlling calcium release and uptake from sarcoplasmic reticulum, which could affect muscle contraction. Historically, the assessment of SMG was performed through invasive and non-practical muscle biopsies. In this study we have utilized a novel methodology to assess SMG through a non-invasive high-frequency ultrasound. Nine MLS professional soccer players (180.4 ± 5.9 cm; 72.4 ± 9.3 kg; 10.4% ± 0.7% body fat) participated. All followed the nutritional protocol 24 h before the official match as well as performing the same practice program the entire week leading to the match. The SMG decreased from 80 ± 8.6 to 63.9 ± 10.2;
= 0.005 on MuscleSound
score (0-100) representing a 20% ± 10.4% decrease in muscle glycogen after match. Inter-individual differences in both starting glycogen content (65-90) and in percentage decrease in glycogen after the match (between 6.2% and 44.5%). Some players may not start the match with adequate SMG while others' SMG decreased significantly throughout the game. Adequate pre-match SMG should be achieved during half-time and game-play in order to mitigate the decrease in glycogen. Further and more ample studies are needed before the application of this technology.