Exercise-induced Muscle Damage Research Articles

Sex differences in the impact of resistance exercise load on muscle damage: A protocol for a randomised parallel group trial

IntroductionResistance training can induce skeletal muscle hypertrophy and strength gains, but is also associated with acute muscle damage, characterised by muscle soreness, impaired muscle function, and structural damage to muscle cell membranes and its components. These consequences can be detrimental to future exercise performance and dampen long-term training adaptations. Previous research has considered resistance exercise intensity as a factor in exercise-induced muscle damage (EIMD), though a clear direction of the findings has not yet been established. Further, female populations are heavily underrepresented in this field of study. Therefore, we here propose a study protocol designed to examine sex differences in the muscle damage response to resistance exercise performed with low or high loads in a population of untrained, young adults.MethodsThis study will employ a randomised parallel group design. Twenty-four males and 24 females will perform an acute leg-based resistance exercise session at either 30% (low-load) or 80% (high-load) of their pre-determined one-repetition maximum (1RM). Maximal leg strength will be determined by a 1RM test 3 wk before and 72 and 168 h after the exercise bout. Additionally, muscle damage will be assessed immediately before the exercise bout and immediately, 24, 48, 72, and 168 h after the exercise bout through measures of muscle soreness, limb circumference, range of motion, and serum concentrations of creatine kinase and interleukin-6. The outcomes of this trial could inform sex-specific resistance training recommendations and help bridge the sex data gap in sport and exercise science research.

The potential of Curcuma extract to alleviate muscle damage in amateur soccer players

Compounds with high bioactive are commonly used as a nutritional approach for accelerating muscle damage recovery after strenuous exercise. There are still inconsistent results of post-exercise antioxidant supplementation on the circulating muscle damage biomarker. This study aimed to examine the effect of post-exercise Curcuma extract supplementation in ice cream on muscle damage and inflammatory markers in amateur soccer players. Male amateur soccer athletes (aged 14 – 18 years) participated in a randomized double-blind placebo-controlled study under two conditions: control group (n = 10) and treatment group (n = 10). The treatment group was treated with Curcuma extract ice cream (250 mg/100 g) for 21 days. Blood samples were drawn before training, considered baseline, and 3 h after training on day 21. The level of creatine kinase, IL-6, haemoglobin (Hb), and lactic acid were quantified. There was a significant decrease in creatine kinase change in the treatment group compared to the control group (p <0.05). No change in IL-6 and Hb levels in the treatment group. Lactic acid decreased by 16.3% from baseline in the treatment group (p <0.05). Curcuma extract ice cream potentiates to ameliorate exercise-induced muscle damage.

Differential Effects Of Exercise Induced Muscle Damage On Multiple Noxious Stimuli

Many clinical musculoskeletal pain conditions are characterized by chronic inflammation. Inflammation leads to the release of inflammatory cytokines that activate or sensitizes nociceptors leading to pain sensitivity. An unresolved issue is whether inflammation affects all nociceptors in a similar manner. Exercise induced muscle damage in the days following a bout of eccentric exercise has been proposed as a valid model of simulating clinical inflammatory pain to be used in healthy samples. PURPOSE: We sought to induce localized inflammation using eccentric exercise to test various painful stimuli (pressure, thermal, and electrical) regarding an individual’s pain sensitivity in a limb that was eccentrically exercised versus a limb that was not exercised. METHODS: 18 healthy participants (9F, age: 24.6 ± 3.3) completed baseline pressure pain thresholds (PPT), thermal pain threshold (TPT), and nociceptive flexion reflex (NFR) in both legs and again 48 hours after a muscle damaging protocol. The participants performed a minimum of 6 rounds of 10 eccentric leg extension exercises to induce muscle damage and localized inflammation in the right quadriceps only. RESULTS: Significant main effect of time for PPT (%diff; -58.9 ± 23.1; p = 0.02, ηp2 = 0.28) but no main effect was observed for limb (%diff; -15.5 ± 23.9; p = 0.53, ηp2 = 0.02). In contrast there was a significant interaction between time and limb (p < 0.001, ηp2 = 0.47) whereby post hoc correction revealed participants had lower PPT’s in the right leg only after the damage protocol (%diff; -105.9 ± 29.2; p = 0.002). No main effects or interactions were observed for TPT and NFR. CONCLUSION: Those with chronic inflammatory pain usually have an increased sensitivity to pressure, thermal, and electrical stimuli whereas our sample with acute inflammation only had sensitivity to mechanical pain. Exercise induced inflammation may reflect a peripheral sensitivity localized to the damage muscle rather than a global sensitivity that those with chronic pain display.

Whole Body Vibration And Blood Flow Restriction For Muscle Recovery Following Exercise-induced Muscle Damage

Whole Body Vibration And Blood Flow Restriction For Muscle Recovery Following Exercise-induced Muscle Damage

Genome-wide association analyses of physical activity and sedentary behavior provide insights into underlying mechanisms and roles in disease prevention

Although physical activity and sedentary behavior are moderately heritable, little is known about the mechanisms that influence these traits. Combining data for up to 703,901 individuals from 51 studies in a multi-ancestry meta-analysis of genome-wide association studies yields 99 loci that associate with self-reported moderate-to-vigorous intensity physical activity during leisure time (MVPA), leisure screen time (LST) and/or sedentary behavior at work. Loci associated with LST are enriched for genes whose expression in skeletal muscle is altered by resistance training. A missense variant in ACTN3 makes the alpha-actinin-3 filaments more flexible, resulting in lower maximal force in isolated type IIA muscle fibers, and possibly protection from exercise-induced muscle damage. Finally, Mendelian randomization analyses show that beneficial effects of lower LST and higher MVPA on several risk factors and diseases are mediated or confounded by body mass index (BMI). Our results provide insights into physical activity mechanisms and its role in disease prevention.

A Review on the Effect of Nutrition on Exercise-Induced Muscle Damage (EIMD)

A Review on the Effect of Nutrition on Exercise-Induced Muscle Damage (EIMD)

Influence Of Pistachios On Sports Performance And Oxidative Stress Following Exercise-induced Muscle Damage

Influence Of Pistachios On Sports Performance And Oxidative Stress Following Exercise-induced Muscle Damage

Is The Recovery Rate From Exercise-induced Muscle Damage Between Young And Middle-aged Active Men Comparable?

Is The Recovery Rate From Exercise-induced Muscle Damage Between Young And Middle-aged Active Men Comparable?

Macronutrients and Exercise-Induced Muscle Damage Recovery

Macronutrients and Exercise-Induced Muscle Damage Recovery

Pharmacological Inhibition Of Ryanodine Receptors Immediately After Eccentric Contractions Exercise Effectively Reduces Exercise-induced Muscle Damage In Rat Skeletal Muscle

Pharmacological Inhibition Of Ryanodine Receptors Immediately After Eccentric Contractions Exercise Effectively Reduces Exercise-induced Muscle Damage In Rat Skeletal Muscle

Early Muscle Gene Expression Changes With Eccentric Exercise Uniquely Associated With Peak Strength Loss

PURPOSE: Novel eccentric (ECC) exercise typically leads to strength loss that persists for several days after exercise, which varies widely between subjects. The mechanisms responsible for this variation are poorly understood. Here, we identified biological processes related to the extent of peak strength loss via global gene expression profiling. METHODS: In a previously published study, vastus lateralis biopsies were collected from 35 young men 3hr post-ECC exercise (100 maximal voluntary eccentric (ECC) actions on isokinetic dynamometer, non-exercised contralateral leg (CON) as a control). Maximal isometric strength of the knee extensors was assessed on a Biodex dynamometer. RNA isolated using the TRIzol method was used to generate global gene expression profiles on the Agilent Whole Genome Microarray platform. The current study is a retrospective analysis of the relationship between gene expression changes and peak strength loss from that previous study (GSE23697). Partek Genomics Suite correlated peak strength loss post-ECC (0-5d) with gene expression in ECC relative to intra-subject paired CON. Correlated genes (p<0.05) were analyzed using Ingenuity Pathway Analysis. RESULTS: Peak strength loss averaged 50.7±20.1% with a range of 9.7% to 96.0%. Pearson linear correlation detected 2333 genes (p<0.05) relating ECC (relative to CON) to peak strength loss, where 2201 and 132 genes were positively and negatively correlated to peak strength loss, respectively. Pathway analysis found 37 canonical pathways (p<0.05) associated with peak strength loss, including: glutamate receptor signaling (14 genes; -log p-value=3.22), serotonin receptor signaling (9 genes; -log p-value=2.22), GABA receptor signaling (18 genes; -log p-value=1.78), and cAMP mediated signaling (27 genes; -log p-value=1.58). CONCLUSION: In a model of moderate exercise-induced muscle damage, we assessed early changes in muscle gene expression and related these changes to variation in peak strength loss. Biological pathways that relate to the extent of muscle dysfunction include several neurotransmitter pathways, as well as cell signaling pathways such as cAMP. Insight into early drivers of strength loss could identify targets to reduce muscle dysfunction and optimize recovery in those prone to dysfunction following exercise.

Perceived Muscle Soreness Does Not Modulate Corticospinal Excitability

Soreness due to exercise-induced muscle damage temporarily impairs motor performance. Transcranial magnetic stimulation (TMS) is often used to assess subtle changes in corticospinal excitability (CSE) and motor system input-output properties and demonstrates sensitivity to chronic pain. Nevertheless, the acute effects of muscle soreness on TMS-based measures of corticospinal excitability require further investigation. PURPOSE: To examine the relationship between perceived muscle soreness and CSE of postural and lower-extremity muscles. METHODS: 12 healthy adults (3 W, age: 27.2 ± 5.4 yr, ht: 175.6 ± 11.0 cm, wt: 72.6 ± 13.4 kg) completed three visits with maximal anaerobic lower extremity exercise. At the start of each visit, participants confirmed they abstained from any physical activity 24 hr prior, and rated their overall residual muscle soreness using a 100 mm visual analog scale. Visits were ranked based on muscle soreness with the highest and lowest soreness visits retained for analysis. To assess CSE, electromyographic motor-evoked potentials (MEPs) were recorded from the right rectus abdominis (RA) and vastus lateralis (VL). Active motor thresholds (AMT) were determined for each muscle during 15% of maximal voluntary isometric force using a biphasic stimulator and 96 mm curved double coil. To determine CSE, ten TMS pulses were applied to each M1 hotspot at 120% AMT with the resultant MEPs averaged based on peak-to-peak amplitude from 15-65 ms post-stimulus. Paired-samples t-test were used to assess mean differences in soreness, AMT, and MEP amplitudes. RESULTS: As expected, muscle soreness differed between visits (mean difference: 25.3 mm, t = 5.08, p < 0.01). Similar motor-thresholds were observed for the RA (mean difference: 0.3%, t = 0.26, p = 0.80) and VL (mean difference: 0.5%, t = 0.45, p = 0.66). MEP amplitudes were also similar for the RA (mean difference: 0.13 mV, t = 1.74, p = 0.12) and VL (mean difference: 0.01 mV, t = 0.30, p = 0.77). CONCLUSION: Day-to-day variation in CSE during lower extremity and axial contractions is not explained by differences in muscle soreness. Future work should examine CSE at multiple timepoints after acute exercise and use various submaximal intensities to further clarify whether CSE is responsive to muscle soreness.

Influence Of The Menstrual Cycle On Muscle Damage Marker And Leukocyte Reaction Following Eccentric Exercise

PURPOSE:Ovarian hormone could inhibit exercise-induced muscle damage and leukocyte infiltration. Premenopausal women experience ovarian hormonal changes by the menstrual cycle (MC); therefore, MC could be related to muscle damage and leukocyte reaction, although it is not be clear. The purpose of this study was to investigate how MC could influence serum creatine kinase (CK) and leukocyte reaction following eccentric exercise. METHODS: Twenty-two untrained women with eumenorrhea (age 27.0 ± 6.4 years; height 160.1 ± 4.2 cm; weight 57.8 ± 7.0 kg; and body mass index 22.5 ± 2.3 kg/m2 [mean ± SD]) participated in the study. The subjects performed 10 sets of 6 repetitions of eccentric exercises with their nondominant arm in the early follicular phase (E-FP, n = 12) or midluteal phase (M-LP, n = 10). Blood samples were collected pre-exercise (PRE) and 4, 48, and 96 hours (h) post-exercise (POST) to analyze serum estradiol (E2) and progesterone (P4) concentration, serum CK, leukocyte count, and leukocyte fractionation (neutrophils, lymphocyte, monocyte, and other leukocytes). We assessed the isometric strength of elbow flexion, range of motion in the elbow joint, upper arm circumference and visual analog scale rating of perceived muscle soreness at PRE, immediately post, POST 4, 48, and 96 h. RESULTS: The serum E2 concentrations at PRE were significantly higher in the M-LP than the E-FP (E-FP 42.9 ± 18.6 vs. M-LP 186.4 ± 98.6 pg/mL; p < 0.01). The serum P4 concentrations at PRE were significantly higher in the M-LP than the E-FP (E-FP 0.2 ± 0.1 vs. M-LP 15.0 ± 3.1 ng/mL; p < 0.01). Significant time effects were present for serum CK at PRE to POST 48 h and 96 h (p < 0.05). No MC phase effect could be observed. The percent change in neutrophils at PRE to POST 4 h tended to be lower in the M-LP than the E-FP (E-FP 38.2 ± 32.6 vs. M-LP 11.4 ± 20.6%; p = 0.050). The serum E2 and P4 concentrations were not related to serum CK at all measurement points. A significant positive correlation could be observed between the PRE serum E2 concentration and PRE lymphocyte count (r = 0.470, p < 0.05). It was unrelated after the exercise. The POST 96 h serum CK was related to the POST 96 h neutrophil count (r = 0.469, p < 0.05). CONCLUSIONS: These results suggest that MC could affect the early leukocyte reaction following eccentric exercise without influencing the serum CK.

The effect of Tribulus terrestris supplementation on inflammation, oxidative stress, and performance of recreational runners: study protocol for a randomized placebo-controlled trial

BackgroundHigh intensity and endurance exercises lead to exercise-induced oxidative stress (EIOS), exercise-induced muscle damage (EIMD), and inflammation, which are the influencing factors on muscle soreness, localized swelling, and sports performance decrease. Therefore, the purpose of this study is to determine the effectiveness of Tribulus terrestris (TT) as an herbal supplement with antioxidant and anti-inflammatory properties on the nutritional, oxidative, inflammatory, and anti-inflammatory status, as well as the sports performance of recreational runners.Methods/designThis study is a double-blind, randomized, placebo-controlled trial, which will be conducted among recreational runners of Tabriz stadiums, Iran. Thirty-four recreational runners will be selected, and participants will be assigned randomly to two groups: to receive 500 mg TT supplement or placebo capsules twice daily for 2 weeks. Both groups will do high-intensity interval training (HIIT) workouts during the study. Baseline and post-intervention body composition, muscle pain, and aerobic and anaerobic performance will be assessed. In addition, assessment of malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant status (TOS), superoxide dismutase (SOD), glutathione peroxidase (GPx), uric acid (UA), 8-iso-prostaglandin F2α (8-iso-PGF2α), protein carbonyl (PC), catalase (CAT), glutathione (GSH), nitric oxide (NO), high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), creatine kinase (CK), myoglobin (MYO), lactate dehydrogenase (LDH), insulin-like growth factor-1 (IGF-1) irisin, cortisol, and brain-derived neurotrophic factor (BDNF) will be done during three blood samplings. Changes in oxidative stress, anti/inflammatory biomarkers, and sports performance will be assessed as primary outcomes.DiscussionThis study will be the first to assess the potential effects of TT on recreational runners. Our results will contribute to the growing body of knowledge regarding TT supplementation on the nutritional, oxidative, inflammatory, and anti-inflammatory status and sports performance in recreational runners.Trial registrationIranian Registry of Clinical Trials (www.irct.ir) (ID: IRCT20150205020965N8). Registration date: 13 February 2021.

Effects of nociceptive and mechanosensitive afferents sensitization on central and peripheral hemodynamics following exercise-induced muscle damage.

This study aims to test the separated and combined effects of mechanoreflex activation and nociception through exercise-induced muscle damage (EIMD) on central and peripheral hemodynamics before and during single passive leg movement (sPLM). Eight healthy young males undertook four experimental sessions, in which a sPLM was performed on the dominant limb while in each specific session the contralateral was: 1) in a resting condition (CTRL), 2) stretched (ST), 3) resting after EIMD called delayed onset muscle soreness (DOMS) condition, or 4) stretched after EIMD (DOMS + ST). EIMD was used to induce DOMS in the following 24-48 h. Femoral blood flow (FBF) was assessed using Doppler ultrasound whereas central hemodynamics were assessed via finger photoplethysmography. Leg vascular conductance (LVC) was calculated as FBF/mean arterial pressure (MAP). RR-intervals were analyzed in the time (root mean squared of successive intervals; RMSSD) and frequency domain [low frequency (LF)/high frequency (HF)]. Blood samples were collected before each condition and gene expression analysis showed increased fold changes for P2X4 and IL1β in DOMS and DOMS + ST compared with baseline. Resting FBF and LVC were decreased only in the DOMS + ST condition (-26 mL/min and -50 mL/mmHg/min respectively) with decreased RMSSD and increased LF/HF ratio. MAP, HR, CO, and SV were increased in ST and DOMS + ST compared with CTRL. Marked decreases of Δpeaks and AUC were observed for FBF (Δ: -146 mL/min and -265 mL respectively) and LVC (Δ: -8.66 mL/mmHg/min and ±1.7 mL/mmHg/min respectively) all P < 0.05. These results suggest that the combination of mechanoreflex and nociception resulted in decreased vagal tone and concomitant rise in sympathetic drive that led to increases in resting central hemodynamics with reduced limb blood flow before and during sPLM.NEW & NOTEWORTHY Exercise-induced muscle damage (EIMD) is a well-known model to study mechanical hyperalgesia and muscle peripheral nerve sensitizations. The combination of static stretching protocol on the damaged limb extensively increases resting central hemodynamics with reduction in resting limb blood flow and passive leg movement-induced hyperemia. The mechanism underlining these results may be linked to reduction of vagal tone with concomitant increase in sympathetic activity following mechano- and nociceptive activation.

Different Cryotherapy Modalities Demonstrate Similar Effects on Muscle Performance, Soreness, and Damage in Healthy Individuals and Athletes: A Systematic Review with Metanalysis.

Background: There are extensive studies focusing on non-invasive modalities to recover physiological systems after exercise-induced muscle damage (EIMD). Whole-body cryotherapy (WBC) and Partial-body cryotherapy (PBC) have been recommended for recovery after EIMD. However, to date, no systematic reviews have been performed to compare their effects on muscle performance and muscle recovery markers. Methods: This systematic review with metanalysis compared the effects of WBC and PBC on muscle performance, muscle soreness (DOMS), and markers of muscular damage following EIMD. We used Pubmed, Embase, PEDro, and Cochrane Central Register of Controlled Trials as data sources. Two independent reviewers verified the methodological quality of the studies. The studies were selected if they used WBC and PBC modalities as treatment and included muscle performance and muscle soreness (DOMS) as the primary outcomes. Secondary outcomes were creatine kinase and heart rate variability. Results: Six studies with a pooled sample of 120 patients were included. The methodological quality of the studies was moderate, with an average of 4.3 on a 0–10 scale (PEDro). Results: Both cryotherapy modalities induce similar effects without difference between them. Conclusion: WBC and PBC modalities have similar global responses on muscle performance, soreness, and markers of muscle damage.

Influence of Menstrual Cycle on Leukocyte Response Following Exercise-Induced Muscle Damage.

We investigated the influence of the menstrual cycle (MC) on leukocyte response after exercise-induced muscle damage (EIMD). During the early follicular (E-FP, n = 12) or mid-luteal phase (M-LP, n = 12), 24 untrained females with eumenorrhea performed 60 eccentric exercises using nondominant arms. Blood samples were collected at pre- and 4, 48, and 96 h postexercise to analyze estradiol and progesterone concentrations, leukocyte count and fractionation, and creatine kinase (CK) activity. We also assessed the maximal voluntary isometric contraction torque of elbow flexion, range of motion in the elbow joint, upper-arm circumference, and muscle soreness as indirect muscle damage markers at pre-; immediately post-; and 4, 48, and 96 h postexercise. The percent change in neutrophil counts from pre- to 4 h postexercise was lower in M-LP than in E-FP (E-FP, 30.7% [15.9–65.7%] vs. M-LP, 10.3% [−2.3–30.0%]; median [interquartile range: 25–75%]; p = 0.068). Progesterone concentration at pre-exercise was significantly negatively correlated with the percent change in neutrophil counts from pre- to 4 h postexercise in M-LP (r = −0.650, p = 0.022). MC did not affect CK activity or other muscle damage markers. Thus, progesterone concentration rather than MC may be related to neutrophil response following EIMD.

Well-Trained Elders Have Antioxidant Responses and an Equal Magnitude of EIMD as Young Adults

Aim The aim of the study was to investigate acute and chronic effects of a two-week eccentric concentric, dynamometric training concerning the time-course changes of blood antioxidant parameters (total antioxidant capacity, catalase enzyme activity, thiol concentration), and to compare the adaptability of young and older muscle to this type of training. Methods Seventeen moderately trained young and older men participated in this research. Subjects performed six eccentric concentric exercise bouts during the training period and maximal voluntary isometric contraction torque, plasma CK and intensity of muscle soreness were determined before and 24 h after the first exercise. During five testing sessions (baseline, 24 h, 48 h, week 1, week 2) the level of blood antioxidants were measured. Results No significant changes were registered in total antioxidant capacity and catalase enzyme activity for any time points; furthermore, no difference was found between groups during the training period. However, total thiol concentrations measured two weeks after the first exercise bout significantly differed between the young and elderly groups. Plasma CK and the subjective intensity of soreness elevated significantly 24 h following the first training, while maximal voluntary isometric contraction torque decreased at the same time. Conclusions Our results do not support previous findings that chronic, short-term eccentric concentric training programs enhance the antioxidant defense of well-trained older and young men. This type and setting of exercise did not cause a different time course of changes in the markers of exercise-induced muscle damage (EIMD) in the studied population. Subjects may already have adapted to maintain constant levels of antioxidants and isometric torque due to their active lifestyle.

Curcumin: A dietary phytochemical for boosting exercise performance and recovery.

Curcumin, as the main natural compound in the turmeric plant (Curcuma longa), is a yellowish polyphenol that has been used traditionally in Asian countries as a medicinal herb for various types of disease and pathological conditions caused by inflammation and oxidative stress. In the present review, we conducted a comprehensive literature search for evidence that shows the effect of curcumin on factors influencing exercise performance, including muscle damage, muscle soreness, inflammation, and oxidative stress. During exercise, reactive oxygen species and inflammation are increased. Thus, if there is no balance between endogenous and exogenous antioxidants and increases in oxidative stress and inflammation, which is important for maintaining redox homeostasis in skeletal muscle, it can lead to muscle soreness and muscle damage and ultimately result in reduced exercise performance. Due to the anti-oxidant and anti-inflammatory properties of curcumin, it can increase exercise performance and decrease exercise-induced muscle soreness and muscle damage. It appears that curcumin supplementation can have positive effects on exercise performance and recovery, muscle damage and pain, inflammation, and oxidative stress. However, there is still a need to precisely evaluate factors to more accurately assess/quantify the beneficial therapeutic effects of curcumin with regard to enhancing exercise performance and recovery.

Appropriateness of indirect markers of muscle damage following lower limbs eccentric-biased exercises: A systematic review with meta-analysis.

The aim of this review was to (1) characterize the time-course of markers of exercise-induced muscle damage (EIMD) based on the level of maximal voluntary contraction torque loss at 24-48h post-exercise (MVCloss24-48h), (2) identify factors (e.g., exercise and population characteristics) affecting the level of MVCloss24-48h, and (3) evaluate the appropriateness of EIMD markers as indicators of MVCloss24-48h. Magnitude of change of each EIMD markers was normalized using the standardized mean differences method to compare the results from different studies. Time-course of EIMD markers were characterized according to three levels of MVCloss24-48h based on a clustering analysis of the 141 studies included. Association between MVCloss24-48h levels and participant´s characteristics or exercise type/modalities were assessed. Meta-regressions were performed to investigate the associations between MVCloss24-48h and EIMD markers changes at <6h, 24h, 48h, 72h and >96h after exercise. Time-course of EIMD markers recovery differs between levels of MVCloss24-48h. Training status and exercise type/modality were associated with MVCloss24-48h level (p<0.05). MVCloss24-48h was correlated to changes in myoglobin concentration (<6h), jump height (24h) and range of motion (48h) (p<0.001). As the exercise could differently affect markers as function of the EIMD severity (i.e., MVCloss24-48h levels), different markers should be used as function of the timing of measurement. Mb concentration should be used during the first hours after the exercise (<6h), whereas jump height (24h) and range of motion (48h) could be used as surrogate for maximal voluntary contraction later. Moreover, training status and exercise type/modality could influence the magnitude of MVCloss24-48h.