Monitoring Blood Biomarkers and Training Load Throughout a Collegiate Soccer Season

Sex Differences in Physiological Responses to a National Collegiate Athletic Association Division I Soccer Season

ABSTRACT

McFadden, BA, Walker, AJ, Cintineo, HP, Bozzini, BN, Sanders, DJ, Chandler, AJ, and Arent, SM. Sex differences in physiological responses to a National Collegiate Athletic Association Division I soccer season. J Strength Cond Res 38(11): 1891-1899, 2024-Identifying physiological changes that occur in response to workload demands can help to elucidate athlete management and recovery strategies. The purpose of this study was to compare the physical and physiological demands between men and women throughout the course of a collegiate soccer season. Men ( N = 23) and women ( N = 26) soccer players participated in blood draws before preseason (T1) and every 4 weeks thereafter (T2-T4). Workload was determined at all practices and games via heart rate and global positioning satellite monitoring systems. Repeated measures multivariate analysis of variance and linear mixed models were used to assess workload and biomarker responses throughout the season ( p < 0.05). Both teams experienced the highest workloads during the first 4 weeks of the season ( p < 0.05), which was followed by several biomarker perturbations. Sex-by-Time interactions were observed for total cortisol, growth hormone, insulin-like growth factor-1, thyroxine, thyroid-stimulating hormone, vitamin D, and omega 3 fatty acid index ( p < 0.05). Additional Sex effects were observed for free and total testosterone, estrogen, prolactin, sex-hormone binding globulin, creatine kinase, and iron levels ( p < 0.05). Women soccer players experienced further Time effects for free cortisol, iron, ferritin, and percent transferrin saturation ( p < 0.05). Male soccer players experienced additional Time effects for total testosterone, estrogen, creatine kinase, interleukin-6, triiodothyronine, and ferritin ( p < 0.05). Despite similar patterns of change in workloads, differential fluctuations in physiological markers were observed between the sexes. Understanding sex differences in response to comparable workloads may enhance exercise prescriptions for better athlete management plans. Additional strategies to increase iron may be warranted in female athletes.

Short-Term Cocoa Supplementation Influences Microbiota Composition and Serum Markers of Lipid Metabolism in Elite Male Soccer Players

OBJECTIVES

Dietary strategies to improve arachidonic acid:eicosapentaenoic acid (AA:EPA) ratios are of interest due to potential reductions in inflammation and oxidative stress following exercise. The aim of this study was to investigate the impact of a novel dietary intervention, that is, the ingestion of 30 g of dark chocolate, on blood lipid profiles and gut microbiota composition in elite male soccer players.

METHODS

Professional male soccer players were randomly assigned to the experimental group (DC) provided with 30 g of dark chocolate or to the control group (WC), provided with 30 g of white chocolate, for 30 days. Before and after intervention, blood, fecal sample, and anthropometry data were collected. For each outcome, two-way repeated-measure analysis of variance was used to identify differences between baseline and endpoint (Week 4), considering treatment (dark chocolate, white chocolate) as intersubjects' factors. Metagenomic analysis was performed following the general guidelines, which relies on the bioBakery computational environment.

RESULTS

DC group showed increased plasma polyphenols (from 154.7 ± 18.6 μg gallic acid equivalents/ml to 185.11 ± 57.6 μg gallic acid equivalents/ml, Δ pre vs. post = +30.41 ± 21.50) and significant improvements in lipid profiles: total cholesterol (Δ -32.47 ± 17.18 mg/dl DC vs. Δ -2.84 ± 6.25 mg/dl WC, Time × Treatment interaction p < .001), triglycerides (Δ -6.32 ± 4.96 mg/dl DC vs. Δ -0.42 ± 6.47 mg/dl WC, Time × Treatment interaction p < .001), low-density lipoprotein (Δ -18.42 ± 17.13 mg/dl vs. Δ -2.05 ± 5.19 mg/dl WC, Time × Treatment interaction p < .001), AA/EPA ratio (Δ -5.26 ± 2.35; -54.1% DC vs. Δ -0.47 ± 0.73, -6.41% WC, Time × Treatment interaction p < .001) compared with WC group. In addition, 4 weeks of intervention showed a significant increase in high-density lipoprotein concentration in DC group (Δ + 3.26 ± 4.49 mg/dl DC vs. Δ -0.79 ± 5.12 mg/dl WC). Microbial communities in the DC group maintained a slightly higher microbial stability over time (exhibiting lower within-subject community dissimilarity).

CONCLUSION

Ingesting 30 g of dark chocolate over 4 weeks positively improved AA:EPA ratio and maintained gut microbial stability. Dark chocolate ingestion represents an effective nutritional strategy to improve blood lipid profiles in professional soccer players. What Are the Findings? Ingesting 30 g of dark chocolate for 4 weeks positively influences blood lipid AA: EPA ratio while maintaining gut microbial stability. What This Study Adds? Dietary intake of specific foods such as dark chocolate represents an alternative strategy to support the health and recovery of elite soccer players. What Impact Might This Have on Clinical Practice in the Future? From a clinical and translational perspective, dark chocolate ingestion positively modulates favorable blood lipid profiles and polyunsaturated fatty acid metabolism while maintaining gut microbial stability. Dark chocolate ingestion may be considered as an effective nutritional strategy in elite sport environments during periods of high-intensity training and congested competitions. Further research is required to determine functional outcomes associated with the observed improvements in blood lipid profiles.

Rapid Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Total and Free Testosterone in Human Serum and Its Application to Monitoring Biomarker Response of Elite Athletes

Total testosterone (TT) and free testosterone (FT) are important biochemical markers for anabolism of the human body, and can also serve as early screening indicators for overtraining syndrome (OTS). Presently, there is no fast and reliable serum TT and FT determination method in the field of sport science that can meet the requirements of sports research. Thus, a rapid and accurate determination method for serum TT and FT to fill the gap is needed urgently in sports training. Herein, a simple and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of TT and FT in serum was developed and fully validated, followed by the application of professional athletes in training monitoring. Efficient pretreatments based on only one-step liquid-liquid extraction (LLE) for TT and one-step LLE after a 20 min ultrafiltration for FT were adopted in this study, and the isotope internal standard of testosterone-13C3 was used to ensure the reliability of the whole procedure. A linear range of four orders of magnitude with 0.02-100 ng/mL can meet the concentration range requirement between a higher limit for male TT and a lower limit for female FT. The accuracy, precision, stability, and matrix effect were all within the limits of the guidelines. The serum TT and FT levels of 200 professional athletes (98 male athletes and 102 female athletes) were investigated by this method. Serum TT, FT, and FT/TT levels of professional athletes were significantly higher than the general population, and serum TT levels were significantly higher by LC-MS/MS than by a chemiluminescence immunoassay. In conclusion, the LC-MS/MS method for TT and FT measurement developed in this study is time-saving and easy to operate, which can be used as a reliable method for the determination of serum TT and FT in sports training, offering valuable information for monitoring anabolism of athletes and screening OTS in the early stage.

Nutritional Optimization for Brain Health in Contact Sports: A Systematic Review and Meta-Analysis on Long-Chain ω-3 Fatty Acids and Neurofilament Light

Background

Accumulating evidence has highlighted the acute and chronic impact of repetitive subconcussive head impacts (rSHIs) in contact sports. Neurofilament-light (Nf-L), a brain-derived biomarker of neuroaxonal injury, elevates in concert with rSHI. Recently, long-chain ω-3 polyunsaturated fatty acids (LC ω-3 PUFAs) supplementation has been suggested to mitigate brain injury from rSHI as reflected by attenuation of Nf-L concentrations within contact sport athletes.

Objective

Using a systematic review with a meta-analysis, we aimed to determine the effect of LC ω-3 PUFA supplementation on Nf-L concentrations in athletes routinely exposed to rSHI.

Methods

Electronic databases (PubMed and CINAHL) were searched from inception through January 2024. One-stage meta-analysis of individual participant-level data was used to detect changes in Nf-L concentrations between LC ω-3 PUFA and control/placebo (PL) groups from baseline to midseason (MS) and postseason (PS). Least square means (±SE) for Nf-L change from baseline were compared by treatment group for MS/PS using contrast t tests. Significance was set a priori at adjusted P ≤ 0.05.

Results

Of 460 records identified, 3 studies in collegiate American football players (n = 179; LC ω-3 PUFA = 105, PL = 71) were included in the meta-analysis. Compared with PL, the change in Nf-L concentrations was statistically similar at MS [mean difference (MD) = -1.66 ± 0.82 pg·mL-1, adjusted P = 0.09] and significantly lower at PS (MD = -2.23 ± 0.83 pg·mL-1, adjusted P = 0.02) in athletes following LC ω-3 PUFA supplementation.

Conclusions

Our findings demonstrate preliminary support for the prophylactic administration of LC ω-3 PUFA in contact sport athletes exposed to rSHI; however, further research is required to determine the effective dosage required.This trial was registered at OSF (DOI: https://doi.org/10.17605/OSF.IO/EY5QW).

Seasonal Changes in Match Demands and Workload Distribution in Collegiate Soccer Across Two Seasons

ABSTRACT

Floersch, S, Vidden, C, Askow, AT, Jones, MT, Fields, JB, and Jagim, AR. Seasonal changes in match demands and workload distribution in collegiate soccer across two seasons. J Strength Cond Res 38(8): 1440-1446, 2024-The purpose of this study was to examine seasonal changes in match demands in a collegiate women's soccer team. Forty-eight NCAA Division III women soccer athletes (age: 19.5 ± 1.2 years; height: 1.67 ± 0.05 m; body mass: 64.8 ± 7.4 kg; fat-free mass: 50.0 ± 4.5 kg; body fat %: 22.6 ± 6.0) were equipped with wearable global positioning systems with inertial sensors and heart rate (HR) monitors during matches throughout the 2019 (n = 22) and 2021 seasons (n = 26). Players were classified by position: flank player (FP; n = 28), center midfielder (CM; n = 11), and center back fielder (CB; n = 9) and as starters (S, n = 17) or reserves (R, n = 31). Variables included HR, training load, total distance, high-speed distance, distance per minute, and weighted distance. Differences in match and practice session demands were analyzed using linear mixed-effects models with season (2 levels; 2019 and 2021) as a fixed factor, with alpha set to p = 0.05. Data across all matches and training sessions were collapsed and presented as mean ± SD for descriptive purposes and then grouped by session type (i.e., match or training) and position. Athletes traveled more distance at high speeds during match play in the 2021 season compared with 2019 (mean difference, 95% confidence intervals [CI]) (200, 95% CI: 104, 304 km; p < 0.05) but had a lower training load in 2021 compared with 2019 (-50, 95% CI: -63, -36; p < 0.05) during match play. For training sessions, mean HR (4, 95% CI: 2, 5 bpm), total distance (0.5, 95% CI: 0.4, 0.7), distance per minute (5.6, 95% CI: 4.5, 6.7 m·min-1), high-speed distance (43, 95% CI: 43, 18, 67 m), high accelerations (8.6, 95% CI: 5.4, 11.8 n), and high accelerations per minute (0.1, 95% CI: 0.1, 0.1 n·min-1) were all higher in 2021 compared with 2019 (p < 0.05). As a team, several differences in measures of external workload were found between seasons in both session types (training and matches). Variations in positional demands of match play appear to fluctuate by year.

Red blood cell omega-3 fatty acid content is negatively associated with purposeful gameplay header frequencies in collegiate women soccer players: Implications for diet and brain health

Background: Frequent soccer heading negatively affects brain health. Omega-3 fatty acids are neuroprotective against head impacts. A biomarker of omega-3 tissue status, red blood cell (RBC) omega-3 content is reduced during soccer activity. However, whether these changes are associated with frequent heading impacts is unknown. Aim: Explore the association between soccer heading frequencies and RBC omega-3 status. Methods: A prospective cohort study in collegiate women soccer players (n  =  16). Players' RBC omega-3 status, Omega-3 Index, and self-reported gameplay header frequencies collected during a competitive season. Results: Mean Omega-3 Index (i.e., pre/postseason) was low (3.95  ±  0.44%). Postseason Omega-3 Index negatively correlated (r  =  -0.545, p  =  0.029) with heading frequencies. Change in Omega-3 Index negatively correlated (r  =  -0.663, p  =  0.005) with average headers per game. Conclusion: RBC omega-3 status is negatively influenced by frequent soccer heading throughout a competitive season which may have concerning implications for player brain health.

Monitoring Readiness to Train and Perform in Female Football: Current Evidence and Recommendations for Practitioners

PURPOSE

Monitoring player readiness to train and perform is an important practical concept in football. Despite an abundance of research in this area in the male game, to date, research is limited in female football. The aims of this study were, first, to summarize the current literature on the monitoring of readiness in female football; second, to summarize the current evidence regarding the monitoring of the menstrual cycle and its potential impact on physical preparation and performance in female footballers; and third, to offer practical recommendations based on the current evidence for practitioners working with female football players.

CONCLUSIONS

Practitioners should include both objective (eg, heart rate and countermovement jump) and subjective measures (eg, athlete-reported outcome measures) in their monitoring practices. This would allow them to have a better picture of female players' readiness. Practitioners should assess the reliability of their monitoring (objective and subjective) tools before adopting them with their players. The use of athlete-reported outcome measures could play a key role in contexts where technology is not available (eg, in semiprofessional and amateur clubs); however, practitioners need to be aware that many single-item athlete-reported outcome measures instruments have not been properly validated. Finally, tracking the menstrual cycle can identify menstrual dysfunction (eg, infrequent or irregular menstruation) that can indicate a state of low energy availability or an underlying gynecological issue, both of which warrant further investigation by medical practitioners.

The Association of Serum Calprotectin with Fitness Indicators and Biochemical Markers in High-Level Athletes: A Continuous Dynamic Monitoring during One Competitive Season

The objective was to determine the associations between several biochemical indicators and the dynamics of concentration change across four physical fitness phases over the period of a competitive season. Furthermore, associations between serum calprotectin and biomarkers of inflammation or muscle injury and physical indicators were examined.

SUBJECTS AND METHODS

Twenty professional male water polo players (median age: 28 (22-42)) were included in this study. Serum creatine kinase activity was determined by the automated photometric UV method. The concentrations of calprotectin, C-reactive protein, and myoglobin were measured using an automated immunoturbidimetric method, while an automated immunochemistry method was employed for interleukin-6, troponin I, and cortisol determination. Tests of repeated strength, maximal strength, and static strength were used to evaluate physical activity.

RESULTS

Serum calprotectin concentrations expressed in median and IQR were significantly different: T1: 2.92 g/mL (2.47; 3.86); T2: 2.35 g/mL (1.26; 2.87); T3: 2.27 g/mL (1.60; 3.27); and T4: 1.47 g/mL (1.04; 2.85) (p = 0.004). Cortisol concentration and CK activity showed significant changes among phases (p = 0.049 and p = 0.014, respectively). Each physical activity examined showed a significant seasonal decrease (all p values were 0.001). Calprotectin serum concentration and indicators of muscular injury, inflammation, and physical activity were found to be correlated during particular stages of the seasonal examination.

CONCLUSIONS

Calprotectin values determined throughout one competitive season decreased as training intensity among water polo players increased. Serum calprotectin concentrations and indicators were related to biochemical markers of inflammation and muscle damage.

Athlete External Load Measures Across a Competitive Season in High School Basketball

ABSTRACT

Askow, AT, Jennings, W, Jagim, AR, Fields, JB, Beaudoin, RG, Sanchez, GM, Weeks, JE, Oliver, JM, and Jones, MT. Athlete external load measures across a competitive season in high school basketball. J Strength Cond Res 37(11): 2206-2212, 2023-The purpose of this retrospective analysis was to quantify in-season external load and to determine if relationships existed between load metrics and basketball performance. Eleven male high school varsity basketball athletes (n = 11; mass 80.5 ± 9.6 kg, height 190.2 ± 9.4 cm, age 17.6 ± 0.7 years) were monitored across a season. PlayerLoad (PL), PL per minute (PL·min -1 ), total jumps, and explosive movements (EMs) were quantified using a commercially available local positioning unit. Basketball-specific performance metrics, including points scored, points allowed, point differentials, and shooting percentages for each quarter and game, were compiled. Data were analyzed using repeated-measure analysis of variance to evaluate differences in load by starting status, session type, game outcome, and game type. Pearson's correlation coefficients were used to assess relationships between load metrics and basketball performance. Statistical significance was set at p < 0.05. The mean values across 23 games for PL, PL·min -1 , total jumps, and EMs were 457 ± 104 AU, 10.9 ± 1.6 AU, 42.6 ± 9.6, and 46.7 ± 7.2, respectively. Relationships were observed ( p < 0.05) between PL and points scored ( r = 0.38) and free throw percentage ( r = 0.21). Further relationships were observed between PL·min -1 and free throw shooting percentage ( r = -0.27), and between points scored and total jumps ( r = 0.28), and EMs ( r = 0.26). Notable differences in game demands were observed for playing status. Meaningful differences in measures of external load were observed between each quarter of play, with the highest measures evident in quarters 1 and 3. Guards and forwards experienced minimal differences in external load during gameplay, and game outcome did not result in differences. Higher point totals corresponded with higher PL, total jumps, and EM.

Blood-Based Biomarkers for Managing Workload in Athletes: Considerations and Recommendations for Evidence-Based Use of Established Biomarkers

Blood-based biomarkers can provide an objective individualized measure of training load, recovery, and health status in order to reduce injury risk and maximize performance. Despite enormous potentials, especially owing to currently evolving technology, such as point-of-care testing, and advantages, in terms of objectivity and non-interference with the training process, there are several pitfalls in the use and interpretation of biomarkers. Confounding variables such as preanalytical conditions, inter-individual differences, or an individual chronic workload can lead to variance in resting levels. In addition, statistical considerations such as the detection of meaningful minimal changes are often neglected. The lack of generally applicable and individual reference levels further complicates the interpretation of level changes and thus load management via biomarkers. Here, the potentials and pitfalls of blood-based biomarkers are described, followed by an overview of established biomarkers currently used to support workload management. Creatine kinase is discussed in terms of its evidence for workload management to illustrate the limited applicability of established markers for workload management to date. We conclude with recommendations for best practices in the use and interpretation of biomarkers in a sport-specific context.

Accumulated Workload Differences in Collegiate Women's Soccer: Starters versus Substitutes

The purpose of this study was to estimate the workloads accumulated by collegiate female soccer players during a competitive season and to compare the workloads of starters and substitutes. Data from 19 college soccer players (height: 1.58 ± 0.06 m; body mass: 61.57 ± 6.88 kg) were extracted from global positioning system (GPS)/heart rate (HR) monitoring sensors to quantify workload throughout the 2019 competitive season. Total distance, distance covered in four speed zones, accelerations, and time spent in five HR zones were examined as accumulated values for training sessions, matches, and the entire season. Repeated-measures ANOVA and Student's t tests were used to determine the level of differences between starter and substitute workloads. Seasonal accumulated total distance (p < 0.001), sprints (≥19.00 km/h; p < 0.001), and high-speed distance (≥15.00 km/h; p = 0.005) were significantly greater for starters than substitutes. Accumulated training load (p = 0.08) and training load per minute played in matches (p = 0.08) did not differ between starters and substitutes. Substitutes had similar accumulated workload profiles during training sessions but differed in matches from starters. Coaches and practitioners should pursue strategies to monitor the differences in workload between starters and substitutes.

Difference in Levels of Vitamin D between Indoor and Outdoor Athletes: A Systematic Review and Meta-Analysis

Vitamin D, its importance in different processes taking place in the human body, the effects of abnormal levels of this hormone, either too low or too high, and the need for supplementation have been extensively researched thus far. Variances in exposure to sunlight can cause vitamin D levels to fluctuate. Indoor activity can be a factor for these fluctuations and can lead to a decrease in vitamin D levels. We conducted a systematic review and meta-analysis aiming to identify whether indoor compared to outdoor training has a significant influence on vitamin D levels; we also performed subgroup analyses and multivariate meta-regression. The type of training has an impact on vitamin D levels that is influenced by multiple cofounders. In a subgroup analysis not considering cofounders, the mean serum vitamin D was 3.73 ng/mL higher in outdoor athletes, a difference which barely fails to achieve significance (p = 0.052, a total sample size of 5150). The indoor-outdoor difference is only significant (clinically and statistically) when considering studies performed exclusively on Asian athletes (a mean difference of 9.85 ng/mL, p < 0.01, and a total sample size of 303). When performing the analyses within each season, no significant differences are observed between indoor and outdoor athletes. To control for multiple cofounders (the season, latitude, and Asian/Caucasian race) simultaneously, we constructed a multivariate meta-regression model, which estimated a serum vitamin D concentration lower by 4.446 ng/mL in indoor athletes. While a multivariate model suggests that outdoor training is associated with slightly higher vitamin D concentrations when controlling for the season, latitude, and Asian/Caucasian race, the type of training has a numerically and clinically small impact. This suggests that vitamin D levels and the need for supplementation should not be decided based on training type alone.

Assessing Omega-3 Intake in Sport: the Brief Food Frequency Questionnaire and the Omega-3 Index in Collegiate Women Soccer Players

CONTEXT

Omega-3 fatty acids modulate inflammatory processes and are considered beneficial for sport populations, highlighting a need to assess omega-3 intake in a practical manner. Food frequency questionnaires (FFQs) are inexpensive, noninvasive tools aimed at evaluating nutrient intakes such as omega-3 fatty acids. In healthy adults, a tailored, brief FFQ for estimating omega-3 intake was associated with the erythrocyte omega-3 fatty acid level, a biomarker for omega-3 tissue status and indicative of intake. However, the association between a brief omega-3 FFQ and erythrocyte levels, particularly the Omega-3 Index (eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA], and EPA + DHA), has yet to be explored in a sport population.

OBJECTIVE

To examine the association between omega-3 intake using a brief FFQ and the Omega-3 Index in collegiate women soccer players.

DESIGN

Cross-sectional study.

SETTING

University sport team.

PATIENTS OR OTHER PARTICIPANTS

Thirty-one National Collegiate Athletic Association Division I collegiate women soccer players.

MAIN OUTCOME MEASURE(S)

The brief omega-3 FFQ assessed dietary omega-3 intake: DHA and EPA. The OmegaQuant blood test measured erythrocyte omega-3 fatty acid (EPA, DHA) and Omega-3 Index (EPA + DHA) levels.

RESULTS

Brief FFQ intakes of EPA, DHA, and EPA + DHA were positively correlated with the erythrocyte EPA (r = 0.48, P = .007), DHA (r = 0.73, P < .001), and Omega-3 Index (r = 0.73, P < .001).

CONCLUSIONS

In a sample of collegiate women soccer players, the brief omega-3 FFQ was correlated with erythrocyte omega-3 fatty acid levels and may offer health practitioners a practical tool for assessing omega-3 intake in this collegiate sport population.

Total Iron Concentrations in Different Biological Matrices-Influence of Physical Training

Iron (Fe) is one of the most widely studied trace mineral elements. Fe metabolism and homeostasis could be altered by physical training. The aim of this study was to analyze the influence of long-term physical training on serum, plasma, urine (extracellular), erythrocyte and platelet (intracellular) Fe concentrations. Forty men from the same geographical area divided into a training group (TG; n = 20; 18.15 ± 0.27 years) and a control group (CG; n = 20; 19.25 ± 0.39 years) participated in this study. The TG was composed of soccer players of the highest youth category. The CG consisted of young people who did not follow any training routine and had not practiced any sport for at least the previous six months. The TG showed higher plasma and serum Fe concentrations (p < 0.05), but lower concentrations in erythrocytes and platelets compared to the CG (p < 0.01). Due to the differences observed in the extracellular and intracellular compartments, it seems necessary to perform a global Fe analysis to assess Fe status.

Relationships between Fitness Status and Blood Biomarkers in Professional Soccer Players

Background

Physical conditions are recognized to be optimal after the pre-season (PS) phase in professional sports. Given that blood measures may also reveal variations, which in turn, may present associations with fitness changes.

Objective

The aim of this study is to test the changes of blood markers and physical fitness outcomes at the beginning and following the PS phase. Additionally, we aimed also to analyze the associations of training adaptations between blood markers and the physical fitness measures. Methodology. 25 professional male soccer players (28.1 ± 4.6 years old, 2.0 ± 7.8 kg, and 176.7 ± 4.9 cm) were assessed for hematological and biochemical parameters, and physical fitness measures in the baseline and after the phase of PS.

Results

Increases in platelets were observed after the PS phase (p = 0.001, η2 = 0.39). Regarding the biochemical parameters, significant increases between PS were found for creatinine (Cre) (p = 0.001, η2 = 0.66), alkaline phosphatase (ALP) (p = 0.001, η2 = 0.79), C-Reactive Protein (CRP) (p = 0.001, η2 = 0.74), cortisol (C) (p = 0.001, η2 = 0.63), and testosterone (T) (p = 0.001, η2 = 0.76), whereas significant decreases were found for albumin (Alb) (p = 0.004, η2 = 0.29), and calcium corrected (Ca Corr.) (p = 0.002, η2 = 0.32). Moderate correlations were found between albumin and the 5-meter linear sprint split (r = -0.44 (95%CI: -0.71; -0.05)) and CRP (r = -0.48 (95%CI: -0.74; -0.10)). Moderate correlations were found between VAMEVAL and hemoglobin (r = 0.44 (95%CI: 0.05; 0.71)).

Conclusions

The overall physical fitness measures improved after the PS phase. Also, significant variations (decreases/increases) were observed for the case of biomchemical and hematological outcomes. Coaches should carefully consider the adaptative changes observed in blood parameters as the changes in whole organism and metabolism after specific critical phases as the PS in professional players. Thus, optimal management of stimulus/recovery can be warranted to minimize illness and injury rate and to follow the direction and dynamics of adaptative changes.

The Effect of Intensity Soccer Training Sessions on Marked Biochemical Indicators of Blood Acidity of Saudi Young Soccer Players

Purpose

Methods

Results

Conclusion

Seasonal Accumulated Workloads in Collegiate Women's Soccer: A Comparison of Starters and Reserves

Research quantifying the unique workload demands of starters and reserves in training and match settings throughout a season in collegiate soccer is limited. Purpose: The purpose of the current study is to compare accumulated workloads between starters and reserves in collegiate soccer. Methods: Twenty-two NCAA Division III female soccer athletes (height: 1.67 ± 0.05 m; body mass: 65.42 ± 6.33 kg; fat-free mass: 48.99 ± 3.81 kg; body fat %: 25.22 ± 4.78%) were equipped with wearable global positioning systems with on-board inertial sensors, which assessed a proprietary training load metric and distance covered for each practice and 22 matches throughout an entire season. Nine players were classified as starters (S), defined as those playing >50% of playing time throughout the entire season. The remaining 17 were reserves (R). Goalkeepers were excluded. A one-way ANOVA was used to determine the extent of differences in accumulated training load throughout the season by player status. Results: Accumulated training load and total distance covered for starters were greater than reserves ((S: 9431 ± 1471 vs. R: 6310 ± 2263 AU; p < 0.001) and (S: 401.7 ± 31.9 vs. R: 272.9 ± 51.4 km; p < 0.001), respectively) throughout the season. Conclusions: Starters covered a much greater distance throughout the season, resulting in almost double the training load compared to reserves. It is unknown if the high workloads experienced by starters or the low workloads of the reserves is more problematic. Managing player workloads in soccer may require attention to address potential imbalances that emerge between starters and reserves throughout a season.

Blood Biomarkers Variations across the Pre-Season and Interactions with Training Load: A Study in Professional Soccer Players

Background: Pre-season training in soccer can induce changes in biological markers in the circulation. However, relationships between chosen hematological and biochemical blood parameters and training load have not been measured. Objective: Analyze the blood measures changes and their relationships with training loads changes after pre-season training. Methodology: Twenty-five professional soccer players were assessed by training load measures (derived from rate of perceived exertion- known as RPE) during the pre-season period. Additionally, blood samples were collected for hematological and biochemical analyses. Results: For hematological parameters, significant increases were found for platelets (PLT) (dif: 6.42; p = 0.006; d = -0.36), while significant decreases were found for absolute neutrophils count (ANC) (dif: -3.98; p = 0.006; d = 0.11), and absolute monocytes count (AMC) (dif: -16.98; p = 0.001; d = 0.78) after the pre-season period. For biochemical parameters, there were significant increases in creatinine (dif: 5.15; p = 0.001; d = -0.46), alkaline phosphatase (ALP) (dif: 12.55; p = 0.001; d = -0.84), C-reactive protein (CRP) (dif: 15.15; p = 0.001; d = -0.67), cortisol (dif: 2.85; p = 0.001; d = -0.28), and testosterone (dif: 5.38; p = 0.001; d = -0.52), whereas there were significant decreases in calcium (dif: -1.31; p = 0.007; d =0.49) and calcium corrected (dif: -2.18; p = 0.015; d = 0.82) after the pre-season period. Moreover, the Hooper Index (dif: 13.22; p = 0.01; d = 0.78), and all derived RPE measures increased after pre-season period. Moderate-to-very large positive and negative correlations (r range: 0.50-0.73) were found between the training load and hematological measures percentage of changes. Moderate-to-large positive and negative correlations (r range: 0.50-0.60) were found between training load and biochemical measures percentage of changes. Conclusions: The results indicated heavy physical loads during the pre-season, leading to a decrease in immune functions. Given the significant relationships between blood and training load measures, monitoring hematological and biochemical measures allow coaches to minimize injury risk, overreaching, and overtraining.

Lower Extremity Movement Quality and the Internal Training Load Response of Male Collegiate Soccer Athletes

CONTEXT

Training load and movement quality are associated with injury risk in athletes. Given these associations, it is important to understand how movement quality may moderate the training load so that appropriate injury-prevention strategies can be used.

OBJECTIVE

To determine how absolute and relative internal training loads change during a men's National Collegiate Athletic Association (NCAA) soccer season and how movement quality, assessed using the Landing Error Scoring System (LESS), moderates the relative internal training load.

DESIGN

Prospective cohort study.

SETTING

Division I athletics.

PATIENTS OR OTHER PARTICIPANTS

One NCAA Division I male collegiate soccer team was recruited and followed over 2 consecutive seasons. Fifty-two athletes (age = 19.71 ± 1.30 years, height = 1.81 ± 0.06 m, mass = 75.74 ± 6.64 kg) consented to participate, and 46 met the criteria to be included in the final statistical analysis.

MAIN OUTCOME MEASURE(S)

Daily absolute internal training load was tracked over 2 seasons using a rated perceived exertion scale and time, which were subsequently used to calculate the absolute and relative internal training loads. Movement quality was assessed using the LESS and participants were categorized as poor movers (LESS score ≥5) or good movers (LESS score ≤4).

RESULTS

The 46 athletes consisted of 29 poor movers and 17 good movers. Absolute (P < .001) and relative (P < .001) internal training loads differed across the weeks of the season. However, movement quality did not moderate the relative internal training load (P = .264).

CONCLUSIONS

Absolute and relative training loads changed across weeks of a male collegiate soccer season. Movement quality did not affect the relative training load, but future researchers need to conduct studies with larger sample sizes to confirm this result.

Muscle Damage Biomarkers in Congestion Weeks in English Premier League Soccer Players: A Prospective Study for Two Consecutive Seasons

The current study was conducted to compare muscle damage biomarkers in single- vs. multi-match weeks in elite soccer players for two consecutive seasons. A secondary objective was to analyze the influence of playing position and exposure time on muscle damage in single- vs. multi-match weeks. This is a prospective cohort study performed in a professional elite soccer club in the English Premier League during the 2018-2019 and 2019-2020 seasons up until the lockdown due to the COVID-19 pandemic. Data were collected in the Medical Department Room of an English Premier League Club before and after the soccer game from a total of 29 elite soccer players (mean ± S.D.; age = 27.59 ± 3.83 years; height = 1.83 ± 0.05 m; body mass = 80.16 ± 7.45 kg) who were enrolled in the club during both seasons. The main outcome measurements were creatine kinase (CK), weight, lean mass, % fat DEXA, high speed running, total distance, density of total distance and high-speed running and wellbeing questionnaires. Significance was set at p < 0.05. Players who completed more than 60 min in the previous game had significantly increased pregame CK levels and fatigue in multi-match weeks. Midfielders had both significantly increased pregame CK and muscle soreness in multi-match weeks. Midfielders and players with an exposure time of at least 60 min showed higher pregame CK values that should play a key role for deciding substitutions.

Acute Effects of Training Loads on Muscle Damage Markers and Performance in Semi-elite and Elite Athletes: A Systematic Review and Meta-analysis

BACKGROUND

The relationship between exercise-induced muscle damage (EIMD) indicators and acute training loads (TL) is yet to be reviewed extensively in semi-elite and elite athlete populations.

OBJECTIVES

The objectives of this systematic review and meta-analysis were threefold: (1) to evaluate studies of EIMD following the initial period of the preseason in semi-elite and elite athletes: (2) to examine acute physiological and performance responses across two periods of the season with similar TL; and (3) to examine acute physiological and performance responses to acute changes in TL during the season.

METHODS

The CINAHL, PubMed, Scopus, SPORTDiscus and Web of Science databases were systematically searched for studies that investigated: (1) semi-elite or elite athletes in team or individual sports following a periodised training programme; and (2) measured acute responses to training. Studies were excluded if: (1) conducted in animals; (2) non-English language; or (3) a conference abstract, review or case report. The Kmet Quality Scoring of Quantitative Studies tool was used for study appraisal.

SYNTHESIS METHODS

Data were quantitatively analysed by generating forest plots to report test statistics for statistical significance and inter-trial heterogeneity.

RESULTS

Of the included studies (n = 32), athletes experienced greater creatine kinase (CK) concentrations (Z = 4.99, p < 0.00001, I² = 74%), inflammatory factors and other indirect measures of muscle damage in the initial phase of the preseason period compared to the off-season; there were no changes in CK (Z = 1.43, p = 0.15, I² = 74%) across two time points of similar TL; and there were concurrent increases in CK with increases in TL (Z = 4.26, p < 0.0001, I² = 36%) and vice versa (Z = 4.33, p < 0.0001, I² = 79%).The qualitative analysis identified that the response of inflammatory factors and other indirect measures of muscle damage to changes in load were inconclusive.

LIMITATIONS

This review included varying age, sex, sports and competition levels. The group level meta-analysis failed to identify within-athlete or position-specific differences across time.

CONCLUSION

Blood biomarkers of EIMD may not differ across periods of similar TL, however can be considered a sensitive monitoring tool for assessing responses following acute TL changes in semi-elite and elite athletes.

Effects of 14-weeks betaine supplementation on pro-inflammatory cytokines and hematology status in professional youth soccer players during a competition season: a double blind, randomized, placebo-controlled trial

Objective

Systemic elevations in pro-inflammatory cytokines are a marker of non-functional over reaching, and betaine has been shown to reduce the secretion of pro-inflammatory cytokines in vitro. The aim of this study was to investigate the effects of betaine supplementation on tumor necrosis factor alpha (TNF-α), interleukins-1 beta (IL-1β), − 6 (IL-6) and the complete blood cell (CBC) count in professional youth soccer players during a competitive season.

Methods

Twenty-nine soccer players (age, 15.5 ± 0.3 years) were randomly divided into two groups based on playing position: betaine group (BG, n = 14, 2 g/day) or placebo group (PG, n = 15). During the 14-week period, training load was matched and well-being indicators were monitored daily. The aforementioned cytokines and CBC were assessed at pre- (P1), mid- (P2), and post- (P3) season.

Results

Significant (p < 0.05) group x time interactions were found for TNF-α, IL-1β, and IL-6. These variables were lower in the BG at P2 and P3 compared to P1, while IL-1β was greater in the PG at P3 compared to P1 (p = 0.033). The CBC count analysis showed there was significant group by time interactions for white blood cells (WBC), red blood cells (RBC), hemoglobin (Hb), and mean corpuscular hemoglobin concentration (MCHC). WBC demonstrated increases at P3 compared to P2 in PG (p = 0.034); RBC was less at P3 compared to P1 in BG (p = 0.020); Hb was greater at P2 compared to P1, whilst it was less at P3 compared to P3 for both groups. MCHC was greater at P3 and P2 compared to P1 in BG, whereas MCHC was significantly lower at P3 compared to P2 in the PG (p = 0.003).

Conclusion

The results confirmed that 14 weeks of betaine supplementation prevented an increase in pro-inflammatory cytokines and WBC counts. It seems that betaine supplementation may be a useful nutritional strategy to regulate the immune response during a fatiguing soccer season.

Psychometric Properties of the RESTQ-Sport-36 in a Collegiate Student-Athlete Population

The purpose of the current study was to examine the reliability and validity of the RESTQ-Sport-36 for use in the collegiate student-athlete population. A total of 494 collegiate student-athletes competing in National Collegiate Athletic Association Division I, II, or III sanctioned sport completed the RESTQ-Sport-36 and Brief Profile of Mood States (POMS). Structural equation modeling (SEM) procedures were used to compare first order to hierarchical model structures. Results of a confirmatory factor analysis (χ²[528] = 1129.941, p < 0.001; SRMR = 0.050; CFI = 0.929) and exploratory structural equation modeling analysis (χ²[264] = 575.424, p < 0.001; SRMR = 0.013; CFI = 0.963) indicated that the first order 12-factor structure demonstrated the best fit of all models tested. Support was not observed for the fit of any hierarchical model. Moderate to strong correlations were observed between stress and recovery subscales and mood states, thus supporting the construct validity of the abbreviated RESTQ measurement model. The current findings provide support for the measure's use in this population and give pause as it relates to the scoring and interpretation of hierarchical factors such as Total Stress and Total Recovery. Overall, the current results indicate that the RESTQ-Sport-36 may be a useful tool for collegiate student-athlete training load and competition monitoring.

Evaluating the effects of oral contraceptive use on biomarkers and body composition during a competitive season in collegiate female soccer players

High training demands throughout the competitive season in female collegiate soccer players have been shown to induce changes in biomarkers indicative of stress, inflammation, and reproduction, which may be exacerbated in athletes using oral contraceptives (OCs). This study aimed to compare biomarkers and body composition between OC-using and nonusing (CON) female soccer players throughout a competitive season. Female collegiate soccer players were stratified into two groups based on their reported OC use at the start of preseason (OC: n = 6; CON: n = 17). Before the start of preseason and immediately postseason, athletes underwent a battery of performance tests. Blood draws and body composition assessments were performed before preseason, on wks 2, 4, 8, and 12 of the season, and postseason. Area-under-the-curve ratios (OC_AUC:CON_AUC) indicated the OC group were exposed to substantially higher levels of sex hormone-binding globulin (AUC_ratio = 1.4, probability = P > 0.999), total cortisol (1.7; P > 0.999), C-reactive protein (5.2; P > 0.999), leptin (1.4; P = 0.990), growth hormone (1.5; P = 0.97), but substantively lower amounts of estradiol (0.36; P < 0.001), progesterone (0.48; P = 0.008), free testosterone (0.58; P < 0.001), follicle-stimulating hormone (0.67; P < 0.001), and creatine kinase (0.33, P < 0.001) compared with the CON across the season. Both groups increased fat free mass over the season, but CON experienced a greater magnitude of increase along with decreased body fat percentage. Although similar training loads were observed between groups over the season, the elevated exposure to stress, inflammatory, and metabolic biomarkers over the competitive season in OC users may have implications on body composition, training adaptations, and recovery in female athletes.NEW & NOTEWORTHY This study highlights the influence of OC use on physiological changes that occur over a 4-mo intense, competitive season and the differential systemic exposure to biomarkers, specifically those of inflammation, stress, anabolism, and energy balance, between OC-using and nonusing soccer players. Additionally, this study provides insight into changes in body composition with prolonged training between female athletes with and without OC use.

Effects of eight weeks exercise training on serum levels of adropin in male volleyball players

OBJECTIVES

To evaluate the effects of an eight week exercise program on the lipid profile in serum, serum levels of adropin, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in male volleyball players.

METHODS

Sixteen healthy male volleyball players participated in this study. Subjects performed eight weeks of aerobic and resistance training, and body mass index (BMI), body fat ratio, total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), adropin, SBP, and DBP values were measured at the start (untrained) and end (trained) of training. Non-HDL-C was calculated by subtracting HDL-C from TC.

RESULTS

Body fat percentage and BMI values decreased significantly after eight weeks of exercise training. There was a statistically significant decrease in the post-test values of LDL-C, TG, non-HDL-C, and DBP compared to pre-test measurements. There was a significant increase in the trained levels of adropin and HDL-C compared to untrained levels. Pearson's correlation analyses revealed a negative and significant relationship between changes in DBP and adropin levels before and after exercise.

CONCLUSIONS

Eight weeks of exercise training decreased LDL-C, TG, non-HDL-C, and DBP and an increased serum levels of adropin in male volleyball players.

Effects of regular exercise on inflammatory biomarkers and lipid parameters in soccer players

Since chronic dyslipidemia and inflammation play a major role in the etiopathogenesis of atherosclerotic plaque, we investigated the effects of a 7-week exercise on the serum lipid profile, plasma atherogenic index (PAI), and inflammatory biomarkers interleukin (IL), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein (MCP)-1 in male soccer players. Methods: The participants in this study were 22 healthy male soccer players aged 19-25 years. IL-1β, IL-6, IL-10, TNF-a, MCP-1, and lipid profile were recorded before and after the program. PAI was calculated as log (TG/HDL-C), where TG is triglyceride and HDL-C is high-density lipoprotein cholesterol. Results: There were significant decreases in post-exercise IL-6, TNF-α, and MCP-1 (for all, p< .05). Compared to the pretest values, there were significant decreases in posttest total cholesterol (TC), TGs, low-density lipoprotein (LDL), non- high-density lipoprotein cholesterol (non-HDL-C), and PAI (for all, p< .05). In contrast, HDL-C values increased after exercise (p< .001). After exercise training TC, TGs, LDL-C, non-HDL-C, and PAI decreased and HDL-C increased, indicating improvement in parameters of dyslipidemia. The decreases in IL-6, TNF-α, and MCP-1 suggest a decrease in systemic inflammation.

The effects of 14-week betaine supplementation on endocrine markers, body composition and anthropometrics in professional youth soccer players: a double blind, randomized, placebo-controlled trial

Objective

Betaine supplementation may enhance body composition outcomes when supplemented chronically during an exercise program. The purpose of this study was to evaluate the effect of betaine supplementation on development-related hormones, body composition, and anthropometrics in professional youth soccer players during a competitive season.

Methods

Twenty-nine players (age, 15.45 ± 0.25 years) were matched based upon position and then randomly assigned to a betaine group (2 g/day; n = 14, BG) or placebo group (PG, n = 15). All subjects participated in team practices, conditioning, and games. If a subject did not participate in a game, a conditioning protocol was used to ensure workload was standardized throughout the 14-week season. Growth hormone (GH), insulin-like growth factor-1 (IGF-1), testosterone, cortisol, height, weight, and body composition were assessed at pre-season (P1), mid-season (P2) and post-season (P3). Anthropometric variables were also measured following a one-year follow-up (F).

Results

Significant (p < 0.05) group x time interactions were found for testosterone and testosterone to cortisol ratio (T/C). Both variables were greater in BG at P2 and P3 compared to P1, however, the testosterone was less in the PG at P3 compared to P2. There was no significant group by time interactions for GH, IGF-1, lean body mass, or body fat. There was a significant (p < 0.05) group x time interaction in height and weight at F, with the greater increases in BG compared to PG.

Conclusion

Betaine supplementation increased testosterone levels and T/C ratio in youth professional soccer players during a competitive season. Betaine supplementation had no negative effects on growth (height and weight) and may attenuate reductions in testosterone due to intense training during puberty.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12970-021-00417-5.

Biomarkers Correlate With Body Composition and Performance Changes Throughout the Season in Women's Division I Collegiate Soccer Players

The purpose of this study was to evaluate the effects of a competitive soccer season on biomarkers and performance metrics in order to determine the correlation between changes in biomarkers, body composition, and performance outcomes. Twenty-one Division 1 female collegiate soccer players were monitored throughout the 16-week season. Player workload was measured using heart rate and Global Position Satellite systems at all practices and games. Performance testing, including vertical jump, VO_2max, and 3-repetition maximum testing for bench press, squat and deadlift, occurred prior to pre-season and immediately post-season. Blood draws occurred prior to preseason and every 4-weeks thereafter, following a game. Body composition was assessed prior to the start of season (week 0) and weeks 6, 10, 14, and 17 (post-season). Delta area under the curve was calculated for biomarkers and body composition variables to account for seasonal changes adjusted for baseline. Pearson-product moment correlations were used to assess relationships with significance set at p < 0.05. Trends were considered p ≤ 0.10. No significant time main effects were seen for anabolic biomarkers (p > 0.05). Significant time effects were seen for catabolic biomarkers throughout the season (p = 0.001). No changes in body weight, VO_2max, vertical jump, and deadlift occurred. Squat and bench press improved (p = 0.01 and p = 0.02, respectively) with a decline in percent body fat (p = 0.03) and a trend for increased fat free mass (p = 0.09). Additionally, total cortisol (TCORT) negatively correlated with fat free mass (r = −0.48; p = 0.03) and positively correlated with VO_2max (r = 0.47; p = 0.04). A trend was shown for a positive correlation between both TCORT and free cortisol (FCORT) and percent body fat (r = 0.39; r = 0.40; p = 0.08, respectively). IGF-1 and growth hormone positively correlated to deadlift (r = 0.57; P = 0.02 and r = 0.59; p = 0.03), whereas creatine kinase showed a trend for a positive correlation with deadlift (r = 0.49; p = 0.06). IL-6 negatively correlated with bench press (r = −0.53; p = 0.03). These findings support a relationship between biomarkers, performance outcomes, and body composition. Biomarker monitoring may be useful to detect individual player's physiological response to an athletic season and may help provide insights in efforts to optimize performance outcomes.

Match Demands of Women's Collegiate Soccer

Research describing the match and specific positional demands during match play in women's collegiate soccer is limited. The purpose of the study was to quantify the match demands of National Collegiate Athletic Association (NCAA) Division III soccer and assess position differences in movement kinematics, heart rate (HR), and energy expenditure. Twenty-five Division III women soccer players (height: 1.61 ± 0.3 m; body mass: 66.7 ± 7.5 kg; fat-free mass: 50.3 ± 6.5 kg; body fat%: 25.6 ± 5.1%) were equipped with a wearable global positioning system to assess the demands of 22 matches throughout a season. Players were categorized by position (goal keepers (GK), center defenders (CB), flank players (FP), forwards (F), and center midfielders (CM)). Players covered 9807 ± 2588 m and 1019 ± 552 m at high speeds (>249.6 m·m-1), with an overall average speed of 62.85 ± 14.7 m·m-1. This resulted in a mean HR of 74.2 ± 6% HR max and energy expenditure of 1259 ± 309 kcal. Significant and meaningful differences in movement kinematics were observed across position groups. CM covered the most distance resulting in the highest training load. FP covered the most distance at high speeds and mean HR values were highest in CM, CB, and FP positions.

Blood Biomarkers of Recovery Efficiency in Soccer Players

Physical exercise strongly affects human metabolism and causes biochemical changes. This study aimed to investigate the relationship between routine plasma biomarker levels and recovery efficiency in soccer players during an entire competitive match season. The players participating in the study were divided into a midfielder/defender group (seven midfielders and seven defenders) and a goalie/substitute group (six persons—goalkeepers and players with a short cumulative match-time). The fasting capillary blood samples were taken 17–24 h after each competitive match. The blood plasma was used to determine the creatinine, urea, alkaline phosphatase, creatine kinase, lactate dehydrogenase, aspartate and alanine aminotransferase, iron and magnesium levels of the athletes. The levels of (AST) (aspartate aminotransferase), (ALT) (alanine aminotransferase) and (Cr) creatinine were higher in the midfielder/defender group than in the control group, but only AST and Cr significantly varied over time (AST decreased, and Cr increased with time). The (LDH) (lactate dehydrogenase) activity and urea level were significantly lower in the midfielder/defender group than in the goalie/substitute group, and it significantly varied over time (LDH decreased, and urea increased with time). No differences in the (CK) creatine kinase and (ALP) alkaline phosphatase activities between the groups was found, although CK increased significantly with time in the midfielder/defender group (particularly midfielders in the spring round). In midfielders, the AST activity and the iron level were significantly lower in the spring than in the autumn round. On the contrary, ALT, CK, urea and magnesium levels were significantly higher in the spring than in autumn round. A long-term measurement of biochemical parameters in elite soccer players indicated that AST, CK, LDH and creatinine levels, when analyzed together, could constitute a useful set of markers for monitoring recovery periods.

Seasonal Accumulated Workloads in Collegiate Men's Soccer: A Comparison of Starters and Reserves

Curtis, RM, Huggins, RA, Benjamin, CL, Sekiguchi, Y, Arent, S, Armwald, B, Pullara, JM, West, CA, and Casa, DJ. Seasonal accumulated workloads in collegiate men's soccer: a comparison of starters and reserves. J Strength Cond Res XX(X): 000-000, 2019-The purpose of this investigation was to quantify and compare player's season total-, match-, and training-accumulated workload by player status characteristics (i.e., starter vs. reserve) in American collegiate men's soccer. Global positioning system (GPS) and heart rate (HR)-derived workloads were analyzed from 82 collegiate male soccer athletes from 5 separate teams over the 2016 and 2017 seasons. Differences in total physical and physiological workloads (i.e., total distance, accelerations, and weighted HR-zone training impulse [TRIMP] score) as well as workloads over a range of intensity zones were examined using multilevel mixed models, with mean difference (MD) and effect size (ES) reported. Starters accumulated substantially more total distance (MD = 82 km, ES = 1.23), TRIMP (MD = 2,210 au, ES = 0.63), and total accelerations (MD = 6,324 n, ES = 0.66) over the season. Total accumulated distance in all velocity zones (ES [range] = 0.87-1.08), all accelerations zones (ES [range] = 0.54-0.74), and time spent at 70-90% HRmax (ES [range] = 0.60-1.12) was also greater for starters. Reserves accumulated substantially more total distance (MD = 20 km, ES = 0.43) and TRIMP (MD = 1,683 au, ES = 0.79) during training. Although reserves show elevated physical and physiological loads during training compared with starters, there is an imbalance in overall workloads between player roles, with starters incurring substantially more match and total seasonal workloads. These results indicate managing player workloads in soccer requires attention to potential imbalances between players receiving variable match times. Coaches and practitioners in collegiate men's soccer may consider implementing strategies to reduce discrepancies in loading between starters and reserves. Individualized monitoring of training and match workloads may assist in the implementation of more balanced load management programs.