Spatiotemporal analysis of 3D kinematic asymmetry in professional cycling during an incremental test to exhaustion.

This study investigated the influence of an incremental exercise on bilateral asymmetry through the spatio-temporal evolution of 3D joint angular displacement, using the Normalized Symmetry Index ([Formula: see text]) and cross-correlation methods. Twelve professional cyclists performed an incremental test to exhaustion, during which motion capture was used. Results revealed a decrease in range of motion between the first and last stages for twelve of the eighteen joint rotations, with the highest impact observed for right hip flexion/extension (61.8 ± 4.7° to 58.8 ± 4.1°, p < 0.05, ES = 0.68). For both stages, significant bilateral differences greater than 10° were observed for hip and knee flexion/extension (p < 0.05, ES>0.90) and ankle and hip internal/external rotation (p < 0.05, ES>0.25). Cross-correlation displayed the lowest pattern similarities for hip abduction/adduction and the highest similarities for knee flexion/extension, ankle plantarflexion/dorsiflexion and hip internal/external rotation. The cross-correlation method showed that the right leg was mostly ahead of time with respect to the left leg, a trend that was accentuated with power output increase. Instantaneous [Formula: see text] fluctuated up to 18% throughout the pedalling cycle, with different behaviour between the power and recovery phases. This study demonstrated the workload effects on side-to-side joint angular pattern similarity.

Influence of a Prolonged Tennis Match Play on Serve Biomechanics.

The aim of this study was to quantify kinematic, kinetic and performance changes that occur in the serve throughout a prolonged tennis match play. Serves of eight male advanced tennis players were recorded with a motion capture system before, at mid-match, and after a 3-hour tennis match. Before and after each match, electromyographic data of 8 upper limb muscles obtained during isometric maximal voluntary contraction were compared to determine the presence of muscular fatigue. Vertical ground reaction forces, rating of perceived exertion, ball speed, and ball impact height were measured. Kinematic and upper limb kinetic variables were computed. The results show decrease in mean power frequency values for several upper limb muscles that is an indicator of local muscular fatigue. Decreases in serve ball speed, ball impact height, maximal angular velocities and an increase in rating of perceived exertion were also observed between the beginning and the end of the match. With fatigue, the majority of the upper limb joint kinetics decreases at the end of the match. No change in timing of maximal angular velocities was observed between the beginning and the end of the match. A prolonged tennis match play may induce fatigue in upper limb muscles, which decrease performance and cause changes in serve maximal angular velocities and joint kinetics. The consistency in timing of maximal angular velocities suggests that advanced tennis players are able to maintain the temporal pattern of their serve technique, in spite of the muscular fatigue development.

Influence of Playing a Prolonged Tennis Match on Shoulder Internal Range of Motion.

BACKGROUND: Shoulder range of motion (ROM) deficits have been identified as an injury risk factor among tennis players. It is well known that shoulder internal rotation deficit increases with age and years of play, but there is a lack of knowledge regarding the influence of a prolonged tennis match on shoulder ROM. PURPOSE: To examine changes in shoulder ROM during a prolonged tennis match. STUDY DESIGN: Descriptive laboratory study. METHODS: Shoulder passive internal and external rotation ROM were measured on 8 male tennis players before, every 30 minutes during, and just after a 3-hour tennis match. Total ROM was calculated as the combination of shoulder internal and external rotations. Ball velocity on the serve was measured with a radar gun before, at midmatch, and just after the match. RESULTS: Decreases in shoulder internal rotation (-20.8°; P = .005), total ROM (-24.6°; P = .001), and serve velocity (-1.8 m/s; P = .002) were observed at the end of the match. No statistically significant difference was observed for shoulder external rotation after the match (P = .460). CONCLUSION: Passive shoulder internal rotation and total ROM are significantly decreased during a 3-hour tennis match. CLINICAL RELEVANCE: The results show that a prolonged tennis match play can modify values of shoulder ROM.

Is physical activity, practiced as recommended for health benefit, a risk factor for osteoarthritis?

In this critical narrative review, we examine the role of physical activity (PA), recreational and elite sports in the development of knee/hip osteoarthritis (OA), taking into account the role of injury in this relationship. The process of article selection was unsystematic. Articles were selected on the basis of the authors' expertise, self-knowledge, and reflective practice. In the general adult population, self-reported diagnosis of knee/hip OA was not associated with low, moderate or high levels of PA. For studies using radiographic knee/hip OA as a primary outcome, the incidence of asymptomatic radiographic OA was higher for subjects with the highest quartile of usual PA than the least active subjects. The risk of incident radiographic knee/hip OA features was increased for subjects with a history of regular sports participation (for osteophyte formation but not joint space narrowing). This risk depended on the type of sport (team and power sports but not endurance and running), and certain conditions (high level of practice) were closely related to the risk of injury. The prevalence of radiographic OA was significantly higher, especially the presence of osteophytes, in former elite athletes than controls. The risk of OA was higher with participation in mixed sports, especially soccer or power sports, than endurance sport. However, the prevalence of clinical OA between former elite athletes and controls was similar, with less hip/knee disability in former athletes. Moderate daily recreational or sport activities, whatever the type of sport, are not a consistent risk factor for clinical or radiographic knee/hip OA. Risk of injury in different sports may be the key factor to understanding the risk of OA related to sport.

Energy flow analysis during the tennis serve: comparison between injured and noninjured tennis players.

BACKGROUND: Energy flow has been hypothesized to be one of the most critical biomechanical concepts related to tennis performance and overuse injuries. However, the relationships among energy flow during the tennis serve, ball velocity, and overuse injuries have not been assessed. PURPOSE: To investigate the relationships among the quality and magnitude of energy flow, the ball velocity, and the peaks of upper limb joint kinetics and to compare the energy flow during the serve between injured and noninjured tennis players. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: The serves of expert tennis players were recorded with an optoelectronic motion capture system. The forces and torques of the upper limb joints were calculated from the motion captures by use of inverse dynamics. The amount of mechanical energy generated, absorbed, and transferred was determined by use of a joint power analysis. Then the players were followed during 2 seasons to identify upper limb overuse injuries with a questionnaire. Finally, players were classified into 2 groups according to the questionnaire results: injured or noninjured. RESULTS: Ball velocity increased and upper limb joint kinetics decreased with the quality of energy flow from the trunk to the hand + racket segment. Injured players showed a lower quality of energy flow through the upper limb kinetic chain, a lower ball velocity, and higher rates of energy absorbed by the shoulder and elbow compared with noninjured players. CONCLUSION: The findings of this study imply that improper energy flow during the tennis serve can decrease ball velocity, increase upper limb joint kinetics, and thus increase overuse injuries of the upper limb joints.

Professional tennis players' serve: correlation between segmental angular momentums and ball velocity.

The purpose of the study was to identify the relationships between segmental angular momentum and ball velocity between the following events: ball toss, maximal elbow flexion (MEF), racket lowest point (RLP), maximal shoulder external rotation (MER), and ball impact (BI). Ten tennis players performed serves recorded with a real-time motion capture. Mean angular momentums of the trunk, upper arm, forearm, and the hand-racket were calculated. The anteroposterior axis angular momentum of the trunk was significantly related with ball velocity during the MEF-RLP, RLP-MER, and MER-BI phases. The strongest relationships between the transverse-axis angular momentums and ball velocity followed a proximal-to-distal timing sequence that allows the transfer of angular momentum from the trunk (MEF-RLP and RLP-MER phases) to the upper arm (RLP-MER phase), forearm (RLP-MER and MER-BI phases), and the hand-racket (MER-BI phase). Since sequence is crucial for ball velocity, players should increase angular momentums of the trunk during MEF-MER, upper arm during RLP-MER, forearm during RLP-BI, and the hand-racket during MER-BI.

Identification of temporal pathomechanical factors during the tennis serve.

PURPOSE: The purpose of this study was twofold: (a) to measure the effects of temporal parameters on both ball velocity and upper limb joint kinetics to identify pathomechanical factors during the tennis serve and (b) to validate these pathomechanical factors by comparing injured and noninjured players. METHODS: The serves of expert tennis players were recorded with an optoelectronic motion capture system. These experts were then followed during two seasons to identify overuse injuries of the upper limb. Correlation coefficients assessed the relationships between temporal parameters, ball velocity, and peaks of upper limb joint kinetics to identify pathomechanical factors. Temporal parameters and ball velocity were compared between injured and noninjured groups. RESULTS: Temporal pathomechanical factors were identified. The timings of peak angular velocities of pelvis longitudinal rotation, upper torso longitudinal rotation, trunk sagittal rotation, and trunk transverse rotation and the duration between instants of shoulder horizontal adduction and external rotation were significantly related to upper limb joint kinetics and ball velocity. Injured players demonstrated later timings of trunk rotations, improper differences in time between instants of shoulder horizontal adduction and external rotation, lower ball velocities, and higher joint kinetics. CONCLUSIONS: The findings of this study imply that improper temporal mechanics during the tennis serve can decrease ball velocity, increase upper limb joint kinetics, and thus possibly increase overuse injuries of the upper limb.

Searching for an operational definition of frailty: a Delphi method based consensus statement: the frailty operative definition-consensus conference project.

BACKGROUND: There is no consensus regarding the definition of frailty for clinical uses. METHODS: A modified Delphi process was used to attempt to achieve consensus definition. Experts were selected from different fields and organized into five Focus Groups. A questionnaire was developed and sent to experts in the area of frailty. Responses and comments were analyzed using a pre-established strategy. Statements with an agreement more than or equal to 80% were accepted. RESULTS: Overall, 44% of the statements regarding the concept of frailty and 18% of the statements regarding diagnostic criteria were accepted. There was consensus on the value of screening for frailty and about the identification of six domains of frailty for inclusion in a clinical definition, but no agreement was reached concerning a specific set of clinical/laboratory biomarkers useful for diagnosis. CONCLUSIONS: There is agreement on the usefulness of defining frailty in clinical settings as well as on its main dimensions. However, additional research is needed before an operative definition of frailty can be established.

How does the tennis serve technique influence the serve-and-volley?

In tennis, a high ball velocity and a fast run toward the net are key features to successful performance of "serve-and-volley" players. For the serve, tennis players can use two techniques: the foot-up (FU) or foot-back (FB) technique. The aim of this study was to determine if the running time toward the net after the serve and the ball velocity (V(ball)) vary between these two techniques. Moreover we analysed the angular momentum values of the trunk and of the arm holding the racquet. Fifteen expert tennis players performed six successful serve-and-volleys with both techniques. Running time to the net is significantly lower for FB, whereas V(ball) is significantly higher for FU. Trunk and arm angular momentums about the transverse axis are significantly higher with FU before ball impact. A significant correlation (r = 0.81, P < 0.001) exists between changes in the maximal trunk angular momentum and in running time to the net between the two serve techniques. A significant correlation (r = 0.84, P < 0.001) also exists between changes in the maximal trunk angular momentum and in V(ball) between the two serve techniques. According to these results, FB is the best technique for moving as quickly as possible to the net because of a lower trunk angular momentum.

Inverse relationship between percentage body weight change and finishing time in 643 forty-two-kilometre marathon runners.

OBJECTIVE: The purpose of this study was to determine the relationship between athletic performance and the change in body weight (BW) during a 42 km marathon in a large cohort of runners. METHODS: The study took place during the 2009 Mont Saint-Michel Marathon (France). 643 marathon finishers (560 males and 83 females) were studied. The change in BW during the race was calculated from measurements of each runner's BW immediately before and after the race. RESULTS: BW loss was 2.3 ± 2.2% (mean±SEM) (p<0.01). BW loss was -3.1 ± 1.9% for runners finishing the marathon in less than 3 h; -2.5 ± 2.1% for runners finishing between 3 and 4 h; and -1.8 ± 2.4% for runners who required more than 4 h to complete the marathon. The degree of BW loss was linearly related to 42 km race finishing time (p<0.0000001). Neither age nor gender influenced BW loss during the race. CONCLUSIONS: BW loss during the marathon was inversely related to race finishing time in 643 marathon runners and was >3% in runners completing the race in less than 3 h. These data are not compatible with laboratory-derived data suggesting that BW loss greater than 2% during exercise impairs athletic performance. They match an extensive body of evidence showing that the most successful athletes in marathon and ultra-marathon running and triathlon events are frequently those who lose substantially more than 3-4% BW during competition.

Intense exercise training induces adaptation in expression and responsiveness of cardiac ß-adrenoceptors in diabetic rats.

BACKGROUND: Informations about the effects of intense exercise training on diabetes-induced myocardial dysfunctions are lacking. We have examined the effects of intense exercise training on the cardiac function of diabetic rats, especially focusing on the Langendorff ß-adrenergic responsiveness and on the ß-adrenoceptors protein expression. METHODS: Control or Streptozotocin induced-diabetic male Wistar rats were randomly assigned to sedentary or trained groups. The training program consisted of 8 weeks running on a treadmill (10° incline, up to 25 m/min, 60 min/day) and was considered to be intense for diabetic rats. RESULTS: This intense exercise training amplified the in vivo diabetes-induced bradycardia. It had no effect on Langendorff basal cardiac contraction and relaxation performances in control and diabetic rats. In diabetic rats, it accentuated the Langendorff reduced responsiveness to ß-adrenergic stimulation. It did not blunt the diabetes-induced decrease of ß1-adrenoceptors protein expression, displayed a significant decrease in the ß2-adrenoceptors protein expression and normalized the ß3-adrenoceptors protein expression. CONCLUSIONS: Intense exercise training accentuated the decrease in the myocardial responsiveness to ß-adrenergic stimulation induced by diabetes. This defect stems principally from the ß2-adrenoceptors protein expression reduction. Thus, these results demonstrate that intense exercise training induces specific effects on the ß-adrenergic system in diabetes.

Body mass index and body fat in Lebanese female adolescents.

OBJECTIVE: The aim of this study is to investigate the relation between body mass index (BMI) and body fat (BF) among Lebanese female adolescents. METHODS: 51 Lebanese females aged 12 to 18 years participated in this study. BMI was calculated as weight/height. Adiposity was measured by dual energy X-ray absorptiometry (DEXA). RESULTS: Correlation coefficient of percent body fat (%BF) with BMI is 0.82. Correlation coefficient of fat mass (BF) with BMI is 0.93. The two linear regression formulas are: %BF = 6.89 + (1.1 *BMI) and BF = - 0.425 + (129 *BMI). CONCLUSION: Correlations of BMI with DEXA measurements were higher with BF than %BF. For a given BMI, Lebanese girls have a higher than expected %BF. Based on the current findings, there may be a need to develop new cutoff points. From a public health perspective, this may considerably increase the prevalence of obesity among Lebanese female adolescents.

A new system for analyzing swim fin propulsion based on human kinematic data.

The use of swim fins has become popular in various water sport activities. While numerous models of swim fin with various innovative shapes have been subjectively designed, the exact influence of the fin characteristics on swimming performance is still much debated, and remains difficult to quantify. To date, the most common approach for evaluating swim fin propulsion is based on the study of "swimmer-fins" as a global system, where physiological and/or biomechanical responses are considered. However, reproducible swimming technique is difficult (or even impossible) to obtain on human body and may lead to discrepancies in data acquired between trials. In this study, we present and validate a new automat called HERMES which enables an evaluation of various swim fins during an adjustable, standardized and reproducible motion. This test bench reliably and accurately reproduces human fin-swimming motions, and gives resulting dynamic measurements at the ankle joint. Seven fins with various geometrical and mechanical characteristics were tested. For each swim fin, ankle force and hydromechanical efficiency (useful mechanical power output divided by mechanical power input delivered by the motors) were calculated. Efficiencies reported in our study were high (close to 70% for some swim fins) over a narrow range of Strouhal number (St) and peaks within the interval 0.2

Activity, inactivity and quality of life among Lebanese adolescents.

BACKGROUND: The aim of the present study was to investigate recent overweight and obesity prevalence rates for Lebanese adolescents, and to examine differences in physical activity, screen time (sum of time spent in front of TV, computer, and videogames), and health-related quality of life (HRQOL) for the first time among normal, overweight, and obese adolescents. METHODS: One thousand Lebanese adolescents (14-18 years old) from nine schools participated in the study. Height, weight, physical activity, screen time, and HRQOL variables were assessed using validated self-report questionnaires. RESULTS: A total of 7.8% of boys and 1.75% of girls were obese, and 22.5% of boys and 12.47% of girls were overweight. Normal-weight boys reported higher physical activity scores at health clubs than obese boys. Normal-weight girls reported higher leisure time and total physical activity scores than obese girls. In the normal-weight group, boys reported higher total screen time than girls. Normal-weight boys reported higher physical functioning scores than their obese peers. Normal-weight girls reported higher physical functioning and average HRQOL scores than obese girls. Normal-weight and overweight boys reported higher average HRQOL scores than girls. CONCLUSION: The present study is the first to provide data on physical activity, screen time, and HRQOL among Lebanese adolescents. Despite the need for further research, all those concerned with the pediatric population are urged to develop and implement effective strategies to increase physical activity and improve HRQOL among adolescents based on the present findings.

Early advancing age alters plasma glucose and glucoregulatory hormones in response to supramaximal exercise.

After the age of 60, the decrease in physical activity and the increase in fat mass (FM) are two essential factors contributing to the alteration of glucose, insulin, and catecholamines responses induced by exercise. To discard these two factors, we compared the glucoregulatory responses in three different groups of men between the ages 21 and 34, and matched pairs: trained groups (T34 and T21) were matched for training level; T21 and U21 (U for untrained) were matched for age; T34 and U21 were matched for FM. The glucoregulatory responses were determined by venous plasma concentrations of glucose ([GLU]), insulin ([INS]), and catecholamines (adrenaline: [A], noradrenaline: [NA]) before and after a Wingate test. [GLU], [INS], and [A] did not differ between T21 and U21, indicating that high-level training had no effects on these parameters. On the other hand, T34 compared to T21 and U21, had higher GLU associated with lower INS post-exercise concentrations. Moreover, [A(max)] was significantly lower in this group. Consequently, T34 only exhibited a significant alteration in glucose and glucoregulatory responses after a Wingate test, which could not be explained by the usual decrease in physical activity and/or the increase in FM. Therefore, aging alone seems to be one main factor of this deterioration.

Does the Level of Graphical Detail of a Virtual Handball Thrower Influence a Goalkeeper's Motor Response?

The authors investigated how different levels of detail (LODs) of a virtual throwing action can influence a handball goalkeeper's motor response. Goalkeepers attempted to stop a virtual ball emanating from five different graphical LODs of the same virtual throwing action. The five levels of detail were: a textured reference level (L0), a non-textured level (L1), a wire-frame level (L2), a point-light-display (PLD) representation (L3) and a PLD level with reduced ball size (L4). For each motor response made by the goalkeeper we measured and analyzed the time to respond (TTR), the percentage of successful motor responses, the distance between the ball and the closest limb (when the stopping motion was incorrect) and the kinematics of the motion. Results showed that TTR, percentage of successful motor responses and distance with the closest limb were not significantly different for any of the five different graphical LODs. However the kinematics of the motion revealed that the trajectory of the stopping limb was significantly different when comparing the L1 and L3 levels, and when comparing the L1 and L4 levels. These differences in the control of the goalkeeper's actions suggests that the different level of information available in the PLD representations (L3 and L4) are causing the goalkeeper to adopt different motor strategies to control the approach of their limb to stop the ball. Key pointsVirtual reality technology can be used to analyze sport performance because it enables standardization and reproduction of sport situations.Defining a minimal graphical level of detail of a virtual action could decrease the real time calculation of a virtual reality system.A Point Light Display graphical representation of a virtual throwing motion seems to influence the regulation of action of real handball goalkeepers.

Catecholamines and the effects of exercise, training and gender.

Stress hormones, adrenaline (epinephrine) and noradrenaline (norepinephrine), are responsible for many adaptations both at rest and during exercise. Since their discovery, thousands of studies have focused on these two catecholamines and their importance in many adaptive processes to different stressors such as exercise, hypoglycaemia, hypoxia and heat exposure, and these studies are now well acknowledged. In fact, since adrenaline and noradrenaline are the main hormones whose concentrations increase markedly during exercise, many researchers have worked on the effect of exercise on these amines and reported 1.5 to >20 times basal concentrations depending on exercise characteristics (e.g. duration and intensity). Similarly, several studies have shown that adrenaline and noradrenaline are involved in cardiovascular and respiratory adjustments and in substrate mobilization and utilization. Thus, many studies have focused on physical training and gender effects on catecholamine response to exercise in an effort to verify if significant differences in catecholamine responses to exercise could be partly responsible for the different performances observed between trained and untrained subjects and/or men and women. In fact, previous studies conducted in men have used different types of exercise to compare trained and untrained subjects in response to exercise at the same absolute or relative intensity. Their results were conflicting for a while. As research progressed, parameters such as age, nutritional and emotional state have been found to influence catecholamine concentrations. As a result, most of the recent studies have taken into account all these parameters. Those studies also used very well trained subjects and/or more intense exercise, which is known to have a greater effect on catecholamine response so that differences between trained and untrained subjects are more likely to appear. Most findings then reported a higher adrenaline response to exercise in endurance-trained compared with untrained subjects in response to intense exercise at the same relative intensity as all-out exercise. This phenomenon is referred to as the 'sports adrenal medulla'. This higher capacity to secrete adrenaline was observed both in response to physical exercise and to other stimuli such as hypoglycaemia and hypoxia. For some authors, this phenomenon can partly explain the higher physical performance observed in trained compared with untrained subjects. More recently, these findings have also been reported in anaerobic-trained subjects in response to supramaximal exercise. In women, studies remain scarce; the results are more conflicting than in men and the physical training type (aerobic or anaerobic) effects on catecholamine response remain to be specified. Conversely, the works undertaken in animals are more unanimous and suggest that physical training can increase the capacity to secrete adrenaline via an increase of the adrenal gland volume and adrenaline content.

Exercise training and cardiovascular risk factors in type 1 diabetic adolescent girls.

Sixteen postmenarcheal Type 1 diabetic adolescent girls were randomized into training (involving aerobic and strength exercises) and nontraining groups. Body composition (skinfold thickness), aerobic fitness (PWC170), plasma lipids, serum apolipoproteins, lipoprotein(a), leptin, and adiponectin were assessed before and after the 6-month period. After the 6-month period, fat mass and leptin increased significantly in the nontraining group but not in the training group. Conversely, in the latter group, fat-free mass increased (P < .01). Moreover, PWC170 improved and apolipoproteinB:apolipoproteinA-1 ratio decreased with physical training (P < .05). Thus, physical training reduces cardiovascular risks and the increase of insulin resistance risk factors in diabetic adolescent girls.

Sex effect on catecholamine responses to sprint exercise in adolescents and adults.

The purpose of this study was to clarify the effect of sex on plasma catecholamine responses to sprint exercise in adolescents and adults. Thirty-six untrained participants took part in this study-9 girls and 10 boys (Tanner Stage 4) and 9 women and 8 men. Each participant performed a 6-s sprint test on a cycle ergometer. Plasma adrenaline (A) and noradrenaline (NA) concentrations were determined successively at rest (A0 and NA0), immediately after the 6-s sprint test (AEX and NAEX), and after 5 min of recovery (A5 and NA5). Peak power, expressed in absolute values or relative to body weight and fat-free mass, was significantly higher in boys than in girls and higher in men than in women (p < .001). No sex effect was observed in AEX in the adolescents, but the NA increase was significantly higher in boys in response to the 6-s sprint (p < .05). In adults, no sex difference was found in NAEX, but AEX was significantly higher in men than in women (p < .05). NAEX was significantly higher in women than in girls (p < .05), and AEX was significantly higher in men than in boys (p < .01). The results of this study suggest that male and female adolescents and young adults might exhibit different catecholamine responses to sprint exercise.

[Influence of menstrual cycle phase on catecholamine response to sprint exercise in the woman]. / Influence de la phase du cycle menstruel sur les réponses en catécholamines à l'exercice de sprint chez la femme.

The aim of the present study was to verify the menstrual cycle phase influence on catecholamine concentrations (adrenaline (A) and noradrenaline (NA)), peak power (P(pic)), and peak lactatemia (La(pic)) in response to a 6 s sprint exercise on a cycle ergometer in eight untrained women (19.1 +/- 0.9 years, 167.7 +/- 5.4 cm, 59.5 +/- 4.7 kg). All women realize the 6 s sprint test in the morning, within the same menstrual cycle, in the follicular (PF) and the luteal phase (PL). Plasma catecholamine concentrations were determined at rest (A0 and NA0), immediately at the end of the sprint exercise (AEX and NAEX), and after 5 min of recovery (A5 and NA5). P(pic) and La(pic) were not significantly affected by the menstrual cycle phase. Catecholamine concentrations measured at rest, in response to the 6 s sprint test and after 5 min of recovery were not significantly different in PF and PL. Significant relationships were observed between AEX and La(pic) (r = 0.53, p < 0.01) and between AEX and P(pic) (r = 0.70, p < 0.01). In conclusion, this study demonstrated that the menstrual cycle phase did not alter performance, lactatemia, and sympatho-adrenergic responses to a short sprint exercise in untrained women.