Comparison of inflammatory responses to a soccer match between elite male and female players

The Relationship Between Cell-Free DNA and Resistance Training Volume Load

ABSTRACT

Lang, HM, Duffourc, MM, Bazyler, CD, Ramsey, MW, and Gentles, JA. The relationship between cell-free DNA and resistance training volume load. J Strength Cond Res 38(6): 1008-1012, 2024-The primary purpose of this study was to assess the sensitivity of cell-free DNA (cf-DNA) to different resistance training volume loads. The secondary purpose was to examine the relationship between change in cf-DNA and relative strength. Researchers hypothesized that (a) cf-DNA concentrations would increase with increasing volume load and (b) increases in relative strength would result in predicted decreases to %Δ of cf-DNA. Thirty subjects were recruited for this study, 15 men and 15 women. Blood was collected through venous draws into 4-ml vacutainers at 3 time points: immediately before (T1), after 3 sets (T2), and after 6 sets (T3) of the back squat exercise. A critical alpha of 0.05 was set for inferential statistics. A repeated-measures ANOVA showed that cf-DNA increased significantly from T1 (407.72 ± 320.83) to T2 (1,244.6 ± 875.83) ( p < 0.01) and T1 (407.72 ± 320.83) to T3 (1,331.15 ± 1,141.66) ( p < 0.01), whereas no difference was found from T2 to T3 ( p = 1.00). The linear regression model used to examine the predictive capabilities relative strength had on cf-DNA %Δ from T1 to T3 was found to be significant ( p = 0.04; R2 = 0.15). The results of this study demonstrate the short response of cf-DNA in relation to variations in resistance training volume load. Results also demonstrated the positive relationship between relative strength and cf-DNA %Δ. The current study builds on the body of research that cf-DNA provides insight regarding the level of immune response after exercise training.

Acute Responses of Youth Elite Players to a Football Match in Terms of Blood Markers

The current study verified the acute responses of participants to a football match in terms of blood markers. Sixteen elite U-18 male football players were divided into two groups: experimental (EG, n = 10), who played a friendly football match; and control (CG), who were not exposed to any physical exertion. Intravenous blood samples were collected from both groups at baseline, pre-match, half-time, and post-match. The blood analysis consisted of four groups: immunological (leukocytes, platelets, and cortisol), muscle damage (creatine kinase and lactate dehydrogenase), metabolic (lactate, glucose, erythrocytes, hematocrit, hemoglobin, and urea), and electrolytic (sodium, calcium, and potassium). Edwards' training impulse demonstrated that the first half was more demanding than the second half (p = 0.020). Significant changes between time points and groups were observed for leukocytes (pre-match: 6920 ± 1949; post-match: 13,890 ± 3292; p ≤ 0.05) and cortisol (pre-match: 10.78 ± 3.63; post-match: 19.15 ± 7.40; p ≤ 0.05). CK (pre-match: 516.50 ± 248.38; post-match: 713.70 ± 308.20; p ≤ 0.05) and LDH (pre-match: 348.80 ± 36.49; post-match: 414.80 ± 26.55; p ≤ 0.05) increased significantly across the time points for the EG, with no difference between the groups, however. Raised lactate (pre-match: 1.05 ± 0.32; post-match: 3.24 ± 1.60; p ≤ 0.05) and glucose (pre-match: 72.54 ± 9.76; post-match: 101.42 ± 19.87; p ≤ 0.05) differences between the groups at half-time were also observed. These current findings provide helpful information to better understand football match demands regarding physiological effects.

Time Course of Performance Indexes, Oxidative Stress, Inflammation, and Muscle Damage Markers after a Female Futsal Match

BACKGROUND

Our aims were to investigate the time-course effects of a futsal match on performance, oxidative stress, and muscle damage markers, as well as inflammatory and antioxidant responses during a 6-day post-match period.

METHODS

Thirty-four female high-level futsal players were assessed on several oxidative stress, inflammation, subjective muscle soreness, subjective rate perceived exertion, and performance tests before a futsal match, immediately after, and 24 h to 144 h after.

RESULTS

Counter movement jump, 20 m, and 10 m sprints performance significantly decreased immediately after the match (p < 0.05) and returned to baseline 72 h post-match (p > 0.05). Delayed onset muscle soreness peaked 24 h post-match and rate perceived exertion peaked post-match (p < 0.05) and returned to baseline 96 h post-match (p > 0.05). Inflammatory biomarkers peaked at 24 h (p < 0.05) and remained significantly elevated for 72 h after the match (p < 0.05). Muscle damage biomarkers peaked at 24 h (p < 0.05) and remained significantly (p < 0.05) elevated for at least 72 h after the match. Oxidative stress markers peaked at 24 h-48 h (p < 0.05) and returned to baseline 120 h post-match (p > 0.05). In respect to antioxidant responses, these peaked at 24 h-48 h post-match (p < 0.05) and returned to baseline 120 h after the match (p > 0.05).

CONCLUSIONS

A single futsal match induces short/mid-term changes in performance, inflammation, oxidative stress, and muscle damage markers for about 72 h-96 h post-match.

Biomarkers of post-match recovery in semi-professional and professional football (soccer)

High-level football (soccer) players face intense physical demands that result in acute and residual fatigue, impairing their physical performance in subsequent matches. Further, top-class players are frequently exposed to match-congested periods where sufficient recovery times are not achievable. To evaluate training and recovery strategies, the monitoring of players' recovery profiles is crucial. Along with performance and neuro-mechanical impairments, match-induced fatigue causes metabolic disturbances denoted by changes in chemical analytes that can be quantified in different body fluids such as blood, saliva, and urine, thus acting as biomarkers. The monitoring of these molecules might supplement performance, neuromuscular and cognitive measurements to guide coaches and trainers during the recovery period. The present narrative review aims to comprehensively review the scientific literature on biomarkers of post-match recovery in semi-professional and professional football players as well as provide an outlook on the role that metabolomic studies might play in this field of research. Overall, no single gold-standard biomarker of match-induced fatigue exists, and a range of metabolites are available to assess different aspects of post-match recovery. The use of biomarker panels might be suitable to simultaneously monitoring these broad physiological processes, yet further research on fluctuations of different analytes throughout post-match recovery is warranted. Although important efforts have been made to address the high interindividual heterogeneity of available markers, limitations inherent to these markers might compromise the information they provide to guide recovery protocols. Further research on metabolomics might benefit from evaluating the long-term recovery period from a high-level football match to shed light upon new biomarkers of post-match recovery.

Fatigue and Recovery Time Course After Female Soccer Matches: A Systematic Review And Meta-analysis

BACKGROUND

This study aimed to analyze the extent of fatigue responses after female soccer matches and the ensuing recovery time course of performance, physiological, and perceptual responses.

METHODS

Three databases (PubMed, Web of Science, and SPORTDiscus) were searched in October 2020 and updated in November 2021. Studies were included when participants were female soccer players, regardless of their ability level. Further, the intervention was an official soccer match with performance, physiological, or perceptual parameters collected pre- and post-match (immediately, 12 h, 24 h, 48 h, or 72 h-post).

RESULTS

A total of 26 studies (n = 465 players) were included for meta-analysis. Most performance parameters showed some immediate post-match reduction (effect size [ES] = - 0.72 to - 1.80), apart from countermovement jump (CMJ; ES = - 0.04). Reduced CMJ performance occurred at 12 h (ES = - 0.38) and 24 h (ES = - 0.42) and sprint at 48 h post-match (ES = - 0.75). Inflammatory and immunological parameters responded acutely with moderate-to-large increases (ES = 0.58-2.75) immediately post-match. Creatine kinase and lactate dehydrogenase alterations persisted at 72 h post-match (ES = 3.79 and 7.46, respectively). Small-to-moderate effects were observed for increased cortisol (ES = 0.75) and reduced testosterone/cortisol ratio (ES = -0.47) immediately post-match, while negligible to small effects existed for testosterone (ES = 0.14) and estradiol (ES = 0.34). Large effects were observed for perceptual variables, with increased fatigue (ES = 1.79) and reduced vigor (ES = - 0.97) at 12 h post-match, while muscle soreness was increased immediately post (ES = 1.63) and at 24 h post-match (ES = 1.00).

CONCLUSIONS

Acute fatigue exists following female soccer matches, and the performance, physiological, and perceptual parameters showed distinctive recovery timelines. Importantly, physical performance was recovered at 72 h post-match, whereas muscle damage markers were still increased at this time point. These timelines should be considered when planning training and match schedules. However, some caution should be advised given the small number of studies available on this population.

REGISTRATION

The protocol for this systematic review was pre-registered on the International Prospective Register of Systematic Reviews (PROSPERO, Registration Number: CRD42021237857).

Muscle Damage and Performance after Single and Multiple Simulated Matches in University Elite Female Soccer Players

The present study aimed to compare changes in muscle damage and performance parameters after playing single versus multiple soccer matches to examine fixture congestion effects on performance. Twelve elite female university soccer players performed single, three and six consecutive 90-min bouts of the Loughborough Intermittent Shuttle Test (LIST) with ≥12-weeks between conditions in a pseudo-randomized order. Heart rate, blood lactate, rating of perceived exertion and covering distance in each LIST were examined. Changes in several types of muscle damage (e.g., maximal voluntary isometric torque of the knee extensors: MVC-KE) and performance measures (e.g., Yo-Yo Intermittent Recovery Test level 1: YYIR1) were taken before each LIST, 1 h, and 1–5 d after the last LIST. The total distance covered during the LIST was shorter (p < 0.05) in the 2nd–3rd, or 2nd–6th LISTs when compared with the 1st LIST. Changes (p < 0.05) in all measures were observed after the LIST, and the greatest changes were observed after the six than after the three LISTs followed by one LIST (e.g., largest changes in MVC-KE: −26 > −20 > −14%; YYIR1: −31 > −26 > −11%). Many of the variables did not recover to the baseline for 5 d after six LISTs. These suggest that fixture congestion induces greater muscle damage and performance decline than a single match.

Effect of a Shock Micro-Cycle on Biochemical Markers in University Soccer Players

This study aimed to examine various biochemical biomarkers changes during a shock micro-cycle in soccer players from a university team. The study had 22 players (age: 22 ± 3 years; body mass: 68.6 ± 7.1 kg; height: 1.73 ± 0.07 m). The study measured total cholesterol (TC), triglycerides (TG), cholesterol linked to high-density lipoproteins (HDL), low-density lipoproteins (LDL), very low density lipoproteins (VLDL), arterial index (AI), creatine kinase (CK), glutamate-oxalacetate-transaminase (GOT), glutamate-pyruvate-transaminase (GPT), creatinine (Cr), catalase (CAT), superoxide dismutase (SOD), cytokines IL6 and TNFα, total antioxidant capacity (Cap antiox tot), hemolysis percentage and glomerular filtration rate (GFR); measurements were conducted during a shock micro-cycle. The lipid profile variables had no statistical significance when compared on day 1 with day 14. Except for TNFα, the other biomarkers compared with day one had progressive increments until day seven, with a subsequent reduction on day 14; however, none of the biomarkers returned to baseline values despite this decrease. The data shown herein suggest the need to research these biomarkers in distinct types of mesocycles, exercise, intensity, load, and duration to diminish fatigue and improve athlete performance.

Changes in γH2AX and H4K16ac levels are involved in the biochemical response to a competitive soccer match in adolescent players

The aim of this study was to examine novel putative markers of the response to the competitive soccer match in adolescent players, such as changes in global levels of γH2AX and H4K16ac in the chromatin of peripheral mononuclear blood cells (PMBCs) and a Fourier-transform infrared spectroscopy (FTIR)-based biochemical fingerprint of serum. These characteristics were examined with reference to the physiological and metabolic aspects of this response. Immediately post-match we noticed: (1) a systemic inflammatory response, manifesting as peaks in leukocyte count and changes in concentrations of IL-6, TNFα, and cortisol; (2) a peak in plasma lactate; (3) onset of oxidative stress, manifesting as a decline in GSH/GSSG; (4) onset of muscle injury, reflected in an increase in CK activity. Twenty-four hours post-match the decrease in GSH/GSSG was accompanied by accumulation of MDA and 8-OHdG, macromolecule oxidation end-products, and an increase in CK activity. No changes in SOD1 or GPX1 levels were found. Repeated measures correlation revealed several associations between the investigated biomarkers. The FTIR analysis revealed that the match had the greatest impact on serum lipid profile immediately post-game. In turn, increases in γH2AX and H4K16ac levels at 24 h post-match indicated activation of a DNA repair pathway.

Does High Volume of Exercise Training Increase Aseptic Vascular Inflammation in Male Athletes?

Aseptic vascular inflammation can be caused by high levels of various inflammatory and apoptotic factors such as tumor necrosis factor (TNFα), nitric oxide (NO), 3-nitrotyrosine (3-Nitro), and free and oxidized low-density lipoproteins (oxLDL) generated during intense exercise. Endothelial dysfunction resulting from enhanced inflammation has been implicated in cardiovascular disease (CVD). The purpose of the study was to observe the effects of high volume of exercise training on inflammatory mediators and their interaction with conventional CVD risk factors.

Blood samples were collected from highly-trained men (n = 16, 21.8 ± 4.0 years) as well as from nonactive men (n = 20, 21.1 ± 1.1 years). NO concentration did not differ between groups while TNFα, 3-Nitro, oxLDL, and CRP levels were significantly higher in athletes compared to nonathletes. TNFα reached even 7-fold higher level in athletes and was highly correlated with CVD risk factor such as TG, lipoproteins LDL and HDL as well as CRP. Approximately 50% of physically active men demonstrated a 20% increase in non-HDL caused by high levels of TC and LDL.

These findings suggest that athletes with a high exercise volume demonstrate increased levels of circulating biomarkers of vascular inflammation and may be more likely to have CVD.

Circulating Inflammatory Biomarkers and Endocrine Responses to Exercise in Female Soccer Players

The objective of the study to determine the effects of graded exercise on the cytokines and insulin-like growth factor-1 (IGF-1), growth hormone (hGH), testosterone (T), and cortisol (C) concentrations in the peripheral blood of female soccer players, and to evaluate if increased inflammatory biomarkers were related to these hormones and performance variables. Sixteen female soccer players (N = 16, age 19.3 ± 2.3 years) participated in this study. Blood samples were collected at three time points: pre-exercise, post-exercise, and in the 15th minute of recovery, to evaluate morphological and biochemical variables. The relative expression of IL-6 (interleukin 6) and serum concentrations of the cytokines were increased in the recovery period compared to pre-exercise levels (p = 0.03 and p=0.005, respectively). There was a significant effect of exercise on serum hGH level (p “ 0.001), T/C ratio (p = 0.001), and C level (p=0.02). Positive correlations were found between: post-exercise IL-1β (interleukin 1 beta) and IL-6 (R = 0.84, p = 0.000), and the IL-6 and TNF-α (tumor necrosis factor alpha) gene expression during recovery (R = 0.65, p = 0.009), and serum IL-1β post-exercise and maximal power (R = 0.68; p = 0.004). Exercise-induced serum C levels positively correlated with IGF-1 levels (R = 0.52 p = 0.05). Negative associations were revealed between post-exercise T/C ratio and IGF-1 (R = - 0.58, p = 0.03) and serum free T and IL- β (R = -0.56, p = 0.04) levels. The low level of pre-exercise genes and protein of the IL-1β, IL-6 and TNF-α indicate a lack of inflammation signs in the female soccer players. This study shows significant effects of exercise on hormone levels and pro-inflammatory markers, which could be used to identify the role of female sex steroids on the immune function.

Muscle Damage During a Soccer World Cup Preparatory and Competition Period

PURPOSE

To report creatine kinase ([CK]) responses during a soccer World Cup preparatory and first-leg period and to determine the influence of aerobic fitness on postmatch [CK] responses.

METHODS

Eleven national-team players were analyzed in this study. A lactate threshold test was performed during the first 3 d, whereas fingertip blood was drawn most mornings (21 out of 30 d) for [CK] measurements. One-way repeated-measures analysis of variance was used for determining the effect of time on [CK] measurements, whereas Pearson correlation coefficient was used for assessing associations between the changes in [CK] and velocities associated with blood lactate concentrations of 2 (v2) and 4 mmol·L-1 (v4).

RESULTS

Peak [CK] concentrations were consistently reached on the first day after the match with values of 474 (261), 520 (419), and 460 (126) U·L-1 but with no significant differences between them. [CK] concentrations returned to prematch values (331 [201] U·L-1) on the second day after the match. The change in [CK] concentration between prematch and postmatch day was largely correlated (r = .614, P = .044) with v2.

CONCLUSIONS

Top-level soccer players display low levels of muscle damage during official tournaments, and they recover before the next match. Postmatch muscle damage is greater in players with higher aerobic endurance because this fitness quality enables them to execute high-intensity activities known to be a major contributor to muscle damage.

High-Intensity Functional Training Improves Cardiorespiratory Fitness and Neuromuscular Performance Without Inflammation or Muscle Damage

Posnakidis, G, Aphamis, G, Giannaki, CD, Mougios, V, Aristotelous, P, Samoutis, G, and Bogdanis, GC. High-intensity functional training improves cardiorespiratory fitness and neuromuscular performance without inflammation or muscle damage. J Strength Cond Res XX(X): 000-000, 2020-We examined the effects of high-intensity functional training (HIFT) on cardiorespiratory and neuromuscular performance, as well as on inflammatory and muscle damage markers. Thirteen physically active healthy volunteers (aged 28.3 ± 3.8 years, 5 men and 8 women) underwent 8 weeks of a group HIFT program performed 3 times per week. Each session consisted of 4 rounds of a 9-exercise circuit (30-second exercise and 15-second recovery). During the first and last weeks of training, venous blood was sampled daily to monitor changes in serum C-reactive protein (CRP) and creatine kinase (CK). After 8 weeks of HIFT, body fat decreased by 0.64 ± 1.01 kg (p = 0.041), maximal oxygen uptake improved by 1.9 ± 2.2 ml·kg·min (p = 0.009), countermovement jump by 2.6 ± 1.5 cm (p = 0.001), bench press 1-repetition maximum (1RM) by 4.5 ± 3.8 kg (p = 0.001), maximum number of bench press repetitions at 65% 1RM by 4 ± 5 repetitions (p = 0.03), and abdominal muscle endurance by 6 ± 4 repetitions (p < 0.001). In both week 1 and week 8 of training, CK increased mildly in the morning after the first session of the week (main effect for day, p = 0.008), whereas no significant changes were observed in CRP (p = 0.31). During week 8, CK on all days was ∼32% lower compared with week 1 (160 vs. 235 U·L; main effect of week 1 vs. week 8, p = 0.027), whereas CRP remained unchanged (p = 0.225). This HIFT program was effective in improving cardiorespiratory and neuromuscular physical fitness without causing significant inflammation or muscle damage in physically active subjects.

Utility of Novel Hypochromia and Microcythemia Markers in Classifying Hematological and Iron Status in Male Athletes

In athletes, no reliable indices exist for an unambiguous evaluation of hematological and iron status. Therefore, the utility of some new red blood cell (RBC) parameters was explored in 931 elite male athletes aged 13–35 years. To diagnose iron status, the values of ferritin and soluble transferrin receptor (sTfR), total iron binding capacity (TIBC), and basic blood morphology were determined in blood. The new hematological markers included among others: mean cellular hemoglobin content in reticulocytes (CHr), percentage of erythrocytes (HYPOm) and reticulocytes (HYPOr) with decreased cellular hemoglobin concentration, percentage of erythrocytes (LowCHm) and reticulocytes (LowCHr) with decreased cellular hemoglobin content, mean volume of reticulocytes (MCVr), and percentage of erythrocytes with decreased volume (MICROm). Despite adverse changes in reticulocyte hypochromia indices (CHr, LowCHr, HYPOr; p < 0.001) in the iron depletion state, the area under the receiver operating characteristic curve (AUC-ROC) values calculated for them were relatively low (0.539–0.722). In iron-deficient erythropoiesis (IDE), unfavorable changes additionally concern microcythemia indices in both reticulocytes and erythrocytes (MCVr, MCV, MICROm, and red cell volume distribution width—RDW), with especially high values of AUC-ROC (0.947–0.970) for LowCHm, LowCHr, and CHr. Dilutional sports anemia was observed in 6.1% of athletes. In this subgroup, only hemoglobin concentration (Hb), hematocrit (Hct), and RBC (all dependent on blood volume) were significantly lower than in the normal group. In conclusion, the diagnostic utility of the new hematology indices was not satisfactory for the detection of an iron depletion state in athletes. However, these new indices present high accuracy in the detection of IDE and sports anemia conditions.

Acute effects of recreational soccer on inflammatory response and cardiac and skeletal muscle damage indicators

Introduction: Previous studies have indicated that acute bouts of strenuous, long duration exercise induce significant increases in the inflammatory profile and cardiovascular risk markers. Although recreational soccer (RS) is a widespread activity, there are no data on this topic. Thus, the aim of this study was to examine RS-induced changes in inflammatory, cardiac, and skeletal muscle damage indicators in young and middle-aged males.

Methods: Twelve young and 11 middle-aged males participated in the study. The participants played 6v6 1 h RS, where heart rate (HR) responses and external loads (distance covered, number of accelerations/decelerations) were determined. Blood samples were taken immediately prior to and following the matches, and 2 h, 4 h, 24 h, 48 h, and 72 h later.

Results: Absolute HR responses and the number of accelerations and decelerations were higher in young participants than the middle-aged participants (p < 0.05). RS increased high sensitivity cardiac troponin I (hs-cTnI) in almost all participants. A total of 83.3% of the young participants exceeded the upper reference limit (URL), whereas none of the middle-aged participants exceeded the URL. Hs-cTnI levels returned to baseline after 24 and 48 h in the middle-aged and young participants, respectively. High sensitivity C-reactive protein (hs-CRP) and creatine kinase (CK) increased in the middle-aged participants (p < 0.05), and in the young participants, though not significantly (p > 0.05). RS also led to significant increases in lactate dehydrogenase (LDH) in both groups (p < 0.05). Hs-CRP, CK, and LDH values returned to baseline levels within 48 to 72 h, except for the LDH values of the young participants.

Conclusion: RS induced short-term increases in cardiac and skeletal muscle damage markers and the inflammatory profile in young and middle-aged RS participants.

Acute and Residual Soccer Match-Related Fatigue: A Systematic Review and Meta-analysis

BACKGROUND

Understanding soccer players' match-related fatigue and recovery profiles likely helps with developing conditioning programs that increase team performance and reduce injuries and illnesses. In order to improve match recovery (the return-to-play process and ergogenic interventions) it is also pivotal to determine if match simulation protocols and actual match-play lead to similar responses.

OBJECTIVES

(1) To thoroughly describe the development of fatigue during actual soccer match play and its recovery time course in terms of physiological, neuromuscular, technical, biochemical and perceptual responses, and (2) to determine similarities of recovery responses between actual competition (11 vs. 11) and match simulations.

METHODS

A first screening phase consisted of a systematic search on PubMed (MEDLINE) and SportDiscus databases until March 2016. Inclusion criteria were: longitudinal study with soccer players; match or validated protocol; duration > 45 min; and published in English.

RESULTS

A total of 77 eligible studies (n = 1105) were used to compute 1196 effect sizes (ES). Half-time assessments revealed small to large alterations in immunological parameters (e.g. leukocytes, ES = 1.9), a moderate decrement in insulin concentration (ES = - 0.9) and a small to moderate impairment in lower-limb muscle function (ES = - 0.5 to - 0.7) and physical performance measures (e.g. linear sprint, ES = - 0.3 to - 1.0). All the systematically analyzed fatigue-related markers were substantially altered at post-match. Hamstrings force production capacity (ES = - 0.7), physical performance (2-4%, ES = 0.3-0.5), creatine kinase (CK, ES = 0.4), well-being (ES = 0.2-0.4) and delayed onset muscle soreness (DOMS, ES = 0.6-1.3) remained substantially impaired at G + 72 h. Compared to simulation protocols, 11 vs. 11 match format (CK, ES = 1.8) induced a greater magnitude of change in muscle damage (i.e. CK, ES = 1.8 vs. 0.7), inflammatory (IL-6, ES = 2.6 vs. 1.1) and immunological markers and DOMS (ES = 1.5 vs. 0.7) than simulation protocols at post-assessments. Neuromuscular performances at post-match did not differ between protocols.

CONCLUSION

While some parameters are fully recovered (e.g. hormonal and technical), our systematic review shows that a period of 72 h post-match play is not long enough to completely restore homeostatic balance (e.g. muscle damage, physical and well-being status). The extent of the recovery period post-soccer game cannot consist of a 'one size fits all approach'. Additionally, the 'real match' (11 vs. 11 format) likely induces greater magnitudes of perceptual (DOMS) and biochemical alterations (e.g. muscle damage), while neuromuscular alterations were essentially similar. Overall, coaches must adjust the structure and content of the training sessions during the 72-h post-match intervention to effectively manage the training load within this time-frame.

Time Course of Oxidative Stress, Inflammation, and Muscle Damage Markers for 5 Days After a Soccer Match: Effects of Sex and Playing Position

Souglis, A, Bogdanis, GC, Chryssanthopoulos, C, Apostolidis, N, and Geladas, ND. Time course of oxidative stress, inflammation and muscle damage markers for 5 days after a soccer match: Effects of sex and playing position. J Strength Cond Res 32(7): 2045-2054, 2018-This study examined the influence of sex and playing position on the time course of selected oxidative stress, inflammation, and muscle damage markers after an official soccer match. Sixty professional soccer players (30 men and 30 women) were divided into 3 groups, according to their playing position: defenders, midfielders, and attackers. Each group consisted of 10 male and 10 female players. Sixty healthy volunteers (30 men and 30 women) served as control. Blood samples were taken before and after the match and daily for 5 days after the match. Analysis of variance revealed different responses over time between sex and playing positions, as shown by the 3-way interaction, for creatine kinase (CK), protein carbonyls (PCs), catalase, fibrinogen, uric acid (UA), lactate dehydrogenase, reduced glutathione, C-reactive protein, and interleukin 6 (p < 0.01). Male players had higher values compared with women of the same playing position, for all oxidative, inflammatory, and muscle damage indices (p < 0.01). Also, in both sexes, midfielders had higher peaks in all indices compared with defenders (p < 0.05). Five days after the game CK and UA concentrations had not returned to pregame levels in any exercise group, whereas PCs were still elevated in male midfielders and attackers (p < 0.05). These results show that sex and playing position influence the time course of selected oxidative stress, inflammation, and muscle damage markers after an official soccer game. This information should be taken into account by practitioners for the design of training programs after match play.

Can compression stockings reduce the degree of soccer match-induced fatigue in females?

Soccer-induced fatigue and performance are different between the sexes. The effect of compression stockings (CS) use on fatigue during the soccer match in females is unknown. Thus, we evaluated the impact of CS use during a female soccer match on match-induced fatigue. Twenty soccer players were randomly allocated to two groups (n = 10 for each group): CS and Control (regular socks), and equally distributed within two teams. At rest (baseline 48-h before the match) and immediately post-match, we assessed agility T-test, standing heel-rise test and YoYo Intermittent Endurance Test level 2 (YoYoIE2) performance. Effort during the match (heart rate and rating of perceived exertion) was similar (p > 0.05) between groups. The YoYoIE2 performance was decreased post-match (p < 0.05) equally for both groups. Otherwise, the CS group exhibited a greater post-match performance (p < 0.05) for the agility T-test and heel-rise test (large effect sizes). Therefore, we conclude that the use of CS during an amateur female soccer match resulted in less match-induced fatigue.

Variations of perceived load and well-being between normal and congested weeks in elite case study handball team

The aim of this study was two-fold: (i) to analyze the variations in internal load and well-being in professional handball players between normal and congested weeks and (ii) to analyze the variations between training days within weeks. Twenty male players (26.5 ± 4.9 yo) were monitored during a full season. MD-1 (match day -1) revealed larger decreases in muscle soreness (-17.3%, [-26.6;-6.9]) and fatigue (-16.6%, [-24.8;-7.4]) in congested weeks. Regarding MD-2, larger decreases in DOMS (-19.9%, [-30.5;-7.6]), fatigue (-19.7%, [-30.0;-7.9] and the Hooper index (-16.7%, [-25.6;-6.7]) were found in congested weeks. The results of this study reveal that larger variations between normal and congested weeks occurred in MD-2 and MD-3, with greater values of load and lower levels of well-being occurring in normal weeks. Within-weeks changes revealed greater loads occurring on MD-3 and MD-2 in comparison to MD-1; in the opposite way, greater values of muscle soreness and fatigue occurred on MD-1.

Dynamics of Recovery of Physiological Parameters After a Small-Sided Game in Women Soccer Players

Purpose: Training methods based on small-sided game (SSG) seem to promote physiological and tactical benefits for soccer players as they present characteristics more specific to the game. Thus, the main objective of the present study was to analyze the hormonal, biochemical, and autonomic parameters in an acute manner and the recovery dynamics (up to 72 h after) in a SSG. Methods: Thirteen professional female soccer players participated in the study (18.8 ± 0.8 years, body mass 59.4 ± 6.2 kg, and height 1.68 ± 0.05 m). During and after the SSG session (4 min × 4 min separated by 3 min of passive interval and 120 m² coverage per player), autonomic modulation was analyzed in the time and frequency domains using heart rate variability, and blood samples (5 ml) were collected before (0 h) and after (10 min and 24, 48, 72 h) the SSG for biochemical and hormonal analysis. Results: The SSG induced an increase effect for LF (low frequency) (92,52%; Very likely increase) and a decrease effect for HF (high frequency) values (-65,72%; Very likely decrease), after 10 min of recovery. The LF/HF increase after 10 min of recovery (386,21%; Very likely increase). The RMSSD (square root of the mean squared differences of the successive N-N intervals) and pNN50 (measure of the number of adjacent NN intervals which differ by more than 50 ms) values presented a decrease effect 10 min after SSG (61,38%; Very likely decrease and-90%; Very likely decrease). The CK (creatine kinase) values presented no changes 10 min after SSG. The LDH (lactate dehydrogenase) values presented an increase effect 10 min after the SSG (19,22%; Likely increase). Both testosterone and cortisol concentrations presented the same behavior after SSG, where no alterations were observed with after 10 min (<0,37%; Most likely trivial). Conclusion: The SSG promoted significant cardiovascular stress that was restored within the first 24 h of recovery. Parasympathetic parameters continued to increase while sympathetic parameters declined significantly during the 72 h of recovery. In addition, the reduced game did not alter biochemical or hormonal responses during the 72 h.

Postmatch recovery of physical performance and biochemical markers in team ball sports: a systematic review

Background

Insufficient postmatch recovery in elite players may cause an increased risk of injuries, illnesses and non-functional over-reaching.

Objective

To evaluate postmatch recovery time courses of physical performance and biochemical markers in team ball sport players.

Study design

Systematic review.

Data sources

PubMed and Web of Science.

Eligibility criteria for selecting studies

This systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Critical Review Form for Quantitative Studies was used to evaluate quality. Studies were included if they met the following criteria: (1) original research evaluated players’ physical recovery postmatch; (2) team/intermittent sports; and (3) at least two postmeasurements were compared with baseline values.

Results

Twenty-eight studies were eligible. Mean methodological quality was 11.2±1.11. Most used performance tests and biochemical markers were the countermovement jump test, sprint tests and creatine kinase (CK), cortisol (C) and testosterone (T), respectively.

Summary/conclusions

The current evidence demonstrates that underlying mechanisms of muscle recovery are still in progress while performance recovery is already reached. CK recovery time courses are up to ≥72 hours. Soccer and rugby players need more time to recover for sprint performance, CK and C in comparison to other team ball sports. There are more high-quality studies needed regarding recovery in various team sports and recovery strategies on an individual level should be evaluated.

Clinical relevance

Ongoing insufficient recovery can be prevented by the use of the presented recovery time courses as specific practical recovery guidelines.

A comparison of isomaltulose versus maltodextrin ingestion during soccer-specific exercise

Purpose

The performance and physiological effects of isomaltulose and maltodextrin consumed intermittently during prolonged soccer-specific exercise were investigated.

Methods

University soccer players (n = 22) performed 120 min of intermittent exercise while consuming 8% carbohydrate–electrolyte drinks (equivalent to ~ 20 g h⁻¹) containing maltodextrin (Glycaemic Index: 90–100), isomaltulose (Glycaemic Index: 32) or a carbohydrate-energy-free placebo in a manner replicating the practices of soccer players (i.e., during warm-up and half-time). Physical (sprinting, jumping) and technical (shooting, dribbling) performance was assessed.

Results

Blood glucose and plasma insulin (both P < 0.001) concentrations varied by trial with isomaltulose maintaining > 13% higher blood glucose concentrations between 75 and 90 min versus maltodextrin (P < 0.05). A decline in glycaemia at 60 min in maltodextrin was attenuated with isomaltulose (−19 versus −4%; P = 0.015). Carbohydrates attenuated elevations in plasma epinephrine concentrations (P < 0.05), but isomaltulose proved most effective at 90 and 120 min. Carbohydrates did not attenuate IL-6 increases or reductions in physical or technical performances (all P > 0.05). Ratings of abdominal discomfort were influenced by trial (P < 0.05) with lower values for both carbohydrates compared to PLA from 60 min onwards.

Conclusions

Although carbohydrates (~ 20 g h⁻¹) did not attenuate performance reductions throughout prolonged soccer-specific exercise, isomaltulose maintained higher blood glucose at 75–90 min, lessened the magnitude of the exercise-induced rebound glycaemic response and attenuated epinephrine increases whilst maintaining similar abdominal discomfort values relative to maltodextrin. When limited opportunities exist to consume carbohydrates on competition-day, low-glycaemic isomaltulose may offer an alternative nutritional strategy for exercising soccer players.

Fatigue and Recovery in Soccer: Evidence and Challenges

Background:

Soccer presents physiological, metabolic, physical and psychological demands which can deteriorate players’ performance due to fatigue. The high variability in physiological, metabolic, physical and psychological responses also influences the magnitude of exercise-induced muscle damage, with symptoms negatively affecting neuromuscular function during recovery or subsequent training sessions or matches. Consequently, more precise and consistent knowledge is required in this area to optimize training and performance.

Objective:

Therefore, the purpose is to sum-up current evidence on fatigue and recovery in soccer players, to shed light on factors that can affect players’ performance, and to suggest applications for coaches and further research.

Method:

A comprehensive review of the scientific literature on the field was conducted.

Results:

Physical performance decrements during matches have traditionally been associated with physiological fatigue, but the magnitude of the symptoms in soccer players is unclear and depends on several factors. Moreover, the decline in physical performance during a soccer match is related to specific demands of each match. These could explain inter-individual variability in acute fatigue or training recovery processes when comparing players from the same team. Recovery counteracts the effects of fatigue, both peripheral and central, but there is a lack of consensus about the usefulness of tests used to monitor fatigue and recovery kinetics.

Conclusion:

Although fatigue and recovery in soccer has been extensively studied, there are still uncertainties about the underlying mechanisms because they are influenced by physiological and match-related demands.

Reticulocyte and erythrocyte hypochromia markers in detection of iron deficiency in adolescent female athletes

The aim of this study was to analyse the effectiveness of new haematology parameters related to reticulocytes and mature red blood cells to differentiate pre latent and latent iron deficiency. The study included 219 female athletes (aged 15-20 years) representing volleyball, handball, cycling, canoeing, cross-country skiing, swimming and judo. To assess iron status the concentration of ferritin, soluble transferrin receptor (sTfR), iron and total iron binding capacity (TIBC) were determined in serum. In addition to blood morphology, the mean cellular haemoglobin content in erythrocytes (CH) and reticulocytes (CHr), mean cellular haemoglobin concentration in reticulocytes (CHCMr), the percentage of erythrocytes (HYPOm) and reticulocytes (HYPOr) with decreased cellular haemoglobin concentration, the percentage of erythrocytes (LowCHm) and reticulocytes (LowCHr) with decreased cellular haemoglobin content, and percentage of erythrocytes with decreased volume (MICROm) were determined. Subjects with ferritin <30 ng/ml were classified as having stage I (pre-latent) iron deficiency (ID). The second stage (latent ID) was diagnosed when low ferritin was accompanied by elevated sTfR and/or elevated TIBC values. The frequency of ID (without anaemia symptoms) was high, amounting to 60% (stage I in 45%, stage II in 15% of subjects). In subjects with stage I ID significant changes in haematological variables concerned mainly reticulocytes: CHCMr (p<.001), CHr (p<.05), LowCHr (p<.05), HYPOr (p<.001) in comparison to normal iron stores. In athletes with latent ID, there were also significant changes (p<.001) in many indices of mature red blood cells, i.e. haemoglobin concentration (Hb), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), CH, %LowCHm, as well as %MICROm (p<.01) in relation to the group without iron deficiency. The main finding of this study was that the diminished or exhausted iron stores had already caused changes in reticulocytes, and intensified iron deficiency (stage II) increased changes in both reticulocytes’ and erythrocytes’ hypochromia indices, while microcythaemia symptoms appeared later. This suggests that the markers of hypochromia relating especially to reticulocytes are useful for diagnosis of early ID in athletes with absence of an acute phase reaction.

THE EFFECT OF CAFFEINE SUPPLEMENTATION ON TRAINED INDIVIDUALS SUBJECTED TO MAXIMAL TREADMILL TEST

Background:

Intense physical training increases oxidative stress and inflammation, resulting into muscle and cellular damage. The aim of this study was to analyze the effect of caffeine supplementation on trained young individuals subjected to two treadmill maximal tests.

Materials and Methods:

It was a double-blind and crossover study comprising 24 active individuals within the age group 18-30 years. The comparisons were conducted: the effect of exercise (week 1 x 2) and caffeine intake (GC x GP) on thiobarbituric acid (TBARS), interleukin 6 (IL-6), interleukin 10 (IL-10) and superoxide dismutase (SOD) variables during pre-exercise time (30 min. after caffeine or placebo intake) and post-exercise (5 min after treadmill test).

Results:

The comparison between weeks 1 and 2 showed increase in the first week, in the following items: TBARS, IL-6 and IL-10 in the GC and GP groups. The comparison within the same week showed that GC individuals presented lower post-exercise TBARS values in the first and second weeks; IL- 6 presented higher post-exercise values in the GC group in both weeks. The paired analysis comparing pre- and post-exercise, with and without caffeine showed that IL-6 presented higher post-exercise values in the GC group.

Conclusion:

Caffeine used by athletes can decrease oxidative stress. The increased IL-6 suggest that this ergogenic supplement may stimulate muscle hypertrophy, since IL-6 has myokine effect. However, the caffeine effect on IL-6 level and muscle hypertrophy increase should be better investigated in future studies.

Timing of carbohydrate ingestion did not affect inflammatory response and exercise performance during prolonged intermittent running

Background

Carbohydrate ingestion during exercise is known to attenuate exercise-induced elevation of plasma IL-6 concentration. However, the influence of timing of carbohydrate ingestion remains unclear.

Purpose

The present study investigated the influence of different timing of carbohydrate ingestion during a simulated soccer game on exercise performance, metabolic and inflammatory responses.

Methods

Seven active males performed 3 exercise trials in a randomized order. The exercise consisted of two consecutive bouts of 45 min running (4–16 km/h), separated with 15 min rest period between bouts. The subjects ingested carbohydrate gel (1.0 g/kg) immediately before the first bout of exercise (ONE), immediately before first and second bouts of exercise (0.5 g/kg for each ingestion) (TWO) or placebo immediately before exercise (PLA) Time course changes of maximal jump height, peak power output during 6-s maximal pedaling, perceived fatigue and heart rate (HR) were monitored. Blood samples were also drawn to determine blood glucose, serum insulin, free fatty acid (FFA), myoglobin (Mb), creatine kinase (CK) and plasma IL-6 concentrations.

Results

Blood glucose and serum insulin concentrations were significantly higher in the ONE trial after first bout of 45 min exercise compared with PLA trial (P < 0.05), while serum FFA concentration was significantly elevated in PLA compared with ONE and TWO trials after second bout of exercise (P < 0.05). However, changes of jump height, peak power output during 6-s maximal pedaling, perceived fatigue, HR, or indirect muscle damage (Mb, CK) and inflammatory (IL-6) markers were not significantly different among three trials (P > 0.05).

Conclusions

The timing of carbohydrate ingestion did not affect exercise performance, exercise-induced muscle damage or inflammatory response during a simulated soccer game.