Monitoring Blood Biomarkers and Training Load Throughout a Collegiate Soccer Season. Issue 11 (November 2019)

• Record Type: Journal Article
• Authors: Huggins, Robert A.; Fortunati, Andrea R.; Curtis, Ryan M.; Looney, David P.; West, Chris A.; Lee, Elaine C.; Fragala, Maren S.; Hall, Matthew L.; Casa, Douglas J.
• Is Part Of: Journal of strength and conditioning research. Volume 33:Issue 11(2019)
• Publication Date: 2019-11
• Subjects: sports physiology -- exercise stress -- hematology -- athletic performance; Physical education and training -- Periodicals; Weight training -- Physiological aspects -- Periodicals; Physical fitness -- Periodicals; 613.7
• DOI: 10.1519/JSC.0000000000002622
• Languages: English
• ISSNs: 1064-8011

Abstract

Abstract : Abstract: Huggins, RA, Fortunati, AR, Curtis, RM, Looney, DP, West, CA, Lee, EC, Fragala, MS, Hall, ML, and Casa, DJ. Monitoring blood biomarkers and training load throughout a collegiate soccer season. J Strength Cond Res 33(11): 3065–3077, 2019—This observational study aimed to characterize the responses of a comprehensive panel of biomarkers, observed ranges, training load (TL) metrics, and performance throughout the collegiate soccer season (August–November). Biomarkers ( n = 92) were collected before the start of pre-season (PS), in-season weeks (W)1, W4, W8, and W12 in NCAA Division I male soccer players ( n = 20, mean ± SD ; age = 21 ± 1 years, height = 180 ± 6 cm, body mass = 78.19 ± 6.3 kg, body fat = 12.0 ± 2.6%, VO2 max 51.5 ± 5.1 ml·kg·min −1 ). Fitness tests were measured at PS, and W12 and TL was monitored daily. Changes in biomarkers and performance were calculated via separate repeated-measures analysis of variance. Despite similar fitness ( p > 0.05), endocrine, muscle, inflammatory, and immune markers changed over time ( p < 0.05). Total and free testosterone was lower in W1 vs. PS, whereas free cortisol remained unchanged at PS, W1, and W4 (>0.94 mg·dL −1 ). Oxygen transport and iron metabolism markers remained unchanged except for HCT (W1 vs. PS) and total iron binding capacity (W8–W12 vs. W1). Hepatic markers albumin, globulin, albumin:globulin, and total protein levels were elevated ( p < 0.05) at W12 vs. W1, whereas aspartate aminotransferase and alanine aminotransferase levels were elevated at W1–W12 and W8–W12 vs. PS, respectively. Vitamin E, zinc, selenium, and calcium levels were elevated ( p < 0.05) at W12 vs. W1, whereas Vitamin D was decreased ( p < 0.05). Fatty acids and cardiovascular markers (omega-3 index, cholesterol:high-density lipoprotein [HDL], docosahexenoic acid, low-density lipoprotein [LDL], direct LDL, non-HDL, ApoB) were reduced at W1 vs. PS ( p ⩽ 0.05). Immune, lipid, and muscle damage biomarkers were frequently outside clinical reference ranges. Routine biomarker monitoring revealed subclinical and clinical changes, suggesting soccer-specific reference ranges. Biomarker monitoring may augment positive adaptation and reduce injuries from stressors incurred during soccer.