Optimal and freely chosen paddling rate during moderate kayak ergometry

Moderate paddling, as in long distance kayaking, constitutes an endurance activity, which shares energetic aspects with activities such as long distance running and road cycling. The aim of the present study was to investigate whether in moderate paddling there is a U-shaped relationship between oxygen uptake and stroke rate, and also whether elite kayakers apply a freely chosen stroke rate, which is energetically optimal. Eleven young male elite kayakers performed moderate kayak ergometry at preset target stroke rates of 65, 75, and 90 strokes min^-1, and at a freely chosen stroke rate, while physiological responses including oxygen uptake were measured. The results showed that considering average values calculated across all participants, there was an approximately U-shaped relationship between oxygen uptake and target stroke rate with a minimum at 75 strokes min^-1. The freely chosen stroke rate was 67.0 ± 6.1 strokes min^-1. Thus, the freely chosen stroke rate, for the group in total, appeared to be lower and require higher oxygen uptake as compared to the energetically optimal preset target stroke rate. Eight out of 11 participants had a higher oxygen uptake (5.1% ± 6.7%, p = 0.028, across all participants) at their freely chosen stroke rate than at the preset target stroke rate, which resulted in the lowest oxygen uptake. In conclusion, an approximately U-shaped relationship between oxygen uptake and stroke rate for young elite kayakers during moderate ergometer kayaking was found. Additionally, the freely chosen stroke rate was systematically lower and, consequently, required higher oxygen uptake than the preset stroke rate, which resulted in the lowest oxygen uptake.     

Shoulder muscle recruitment patterns during a kayak stroke performed on a paddling ergometer.

Precise muscle co-ordination is required to maintain normal shoulder function and alterations in synchrony between shoulder muscles can result in loss of full range of movement and pain. Although shoulder pain in kayakers is high with 53% of elite international paddlers reporting shoulder injuries, little information is available regarding the pattern of shoulder muscle recruitment during paddling. The aim of this study was to investigate the normal recruitment pattern of shoulder muscles during the kayak stroke. Nine recreational paddlers without shoulder pain were examined. EMG data from eight shoulder muscles of the dominant arm were collected simultaneously with video data during simulated paddling on an ergometer. EMG data was normalized to time and peak amplitude. Intersubject consistency was evaluated using Pearson correlation analysis. The results of this study indicated a fair to high correlation in at least one phase of the kayak stroke in five of the muscles examined: upper trapezius, supraspinatus, latissimus dorsi, serratus anterior and rhomboid major. This normative data will enable comparisons with the shoulder muscle recruitment patterns in kayakers with shoulder pain in order to determine the role of altered motor control in the painful kayaking shoulder.     

CHANGES IN MUSCLE DAMAGE MARKERS IN FEMALE BASKETBALL PLAYERS

The aim of the present study was to investigate changes in muscle soreness, blood muscle damage markers, muscle strength and agility following an official basketball match. Eleven elite female professional basketball players (27.4 ± 4.8 years, 179.5 ± 5.5 cm, 72.0 ± 7.8 kg) of a team participated in this study. The official match was the seventh match of the season in the first phase of the Brazilian National Female Basketball Championship. Muscle soreness, plasma creatine kinase activity (CK), and myoglobin concentration (Mb) were determined before and after the match (post-match, 24 and 48 hours after the match). The 1RM strength for bench press and leg press, and the agility T test were assessed before and at 24 and 48 hours after the match. Significant increases in muscle soreness, CK and Mb were observed at 24 and 48 hours post-match (p<0.05). No significant changes in the 1RM strength and T test were detected during recovery (24 and 48 hours after the match). These results suggest that a basketball match induced limited muscle damage with minimal effect on performance during recovery. The small increase in muscle damage markers following a basketball match did not affect strength and agility performance.     

Maximal strength on different resistance training rowing exercises predicts start phase performance in elite kayakers

This study aimed to examine the relationship existing between maximum strength values in 2 common resistance training row exercises (bilateral bench pull [BBP] and one-arm cable row [OACR]) and short sprint performance in elite kayakers. Ten junior kayakers (5 women and 5 men) were tested on different days for 1 repetition maximum (1RM) and maximal voluntary isometric contraction in both exercises. Moreover, a 12-m sprint kayak was performed in a dew pond to record split times (2, 5, and 10 m), peak velocity, distance completed considering the first 8 strokes, and mean acceleration induced by right blade and left blade strokes. No differences (p > 0.05) were observed when right and left arms were compared in sprint testing or strength testing variables. Maximal strength values in BBP and OACR were significantly correlated with short sprint performance variables, showing the bilateral exercise with slightly stronger correlation coefficients than the unilateral seated row. Moreover, the relationship between strength testing and sprint testing variables is stronger when maximal force is measured through a dynamic approach (1RM) in comparison with an isometric approach. In conclusion, maximal strength in BBP and OACR is a good predictor of the start phase performance in elite sprint kayakers, mainly the 1RM value in BBP.     

Movement demands in Australian rules football as indicators of muscle damage

The purpose of this study was to determine if there is an association between variables that describe movements in an Australian Rules football (ARF) game with muscle damage. Fourteen elite junior ARF players were monitored with a global positioning system (GPS) during a match, and muscle damage was estimated by determining creatine kinase (CK) 24 hours postmatch. The players were median split based on CK levels, into a high and low CK group, and the groups were compared with independent t-tests. The primary finding was that the group that experienced greater muscle damage (high CK group) generally covered significantly (p < 0.05) greater distances. This was the case for running speeds between 4 and 7 m·s(-1) and, with the exception of high acceleration, all intensities of acceleration and deceleration. The high, as compared with the low, CK group also produced a significantly greater (42%) "player load." All of these significant differences were accompanied by large effect sizes. Group-specific Pearson (r) correlations between CK level and GPS variables suggest that a certain volume of movement is required before the elicitation of a positive relationship beyond trivial or small. Correlations between CK and running speeds >4 m·s(-1) and moderate-high acceleration and deceleration were negative in the low CK (lesser volumes) group. With the exception of low-intensity acceleration/deceleration, the same relationships were positive and generally of a moderate-to-large magnitude in the high CK (greater volumes) group. It may be that a certain volume of movement is required for that movement to be strongly associated with CK levels. It was concluded that selected GPS variables obtained from ARF games can be used as indicators of muscle damage, and this information may be used to individualize recovery strategies after games.     

Hormonal Neuroendocrine and Vasoconstrictor Peptide Responses of Ball Game and Cyclic Sport Elite Athletes by Treadmill Test

ObjectiveOur objective was to evaluate complex hormonal response in ball game and cyclic sport elite athletes through an incremental treadmill test, since, so far, variables in experimental procedures have often hampered comparisons of data.MethodsWe determined anthropometric data, heart rate, maximal oxygen uptake, workload, plasma levels of lactate, adrenaline, noradrenaline, dopamine, cortisol, angiontensinogen and endothelin in control (n = 6), soccer (n = 8), handball (n = 12), kayaking (n = 9) and triathlon (n = 9) groups based on a Bruce protocol through a maximal exercise type of spiroergometric test.ResultsWe obtained significant increases for adrenaline, 2.9- and 3.9-fold by comparing the normalized means for soccer players and kayakers and soccer players and triathletes after/before test, respectively. For noradrenaline, we observed an even stronger, three-time significant difference between each type of ball game and cyclic sport activity.ConclusionsExercise related adrenaline and noradrenaline changes were more pronounced than dopamine plasma level changes and revealed an opportunity to differentiate cyclic and ball game activities and control group upon these parameters. Normalization of concentration ratios of the monitored compounds by the corresponding maximal oxygen uptake reflected better the differences in the response level of adrenaline, noradrenaline, dopamine and cortisol.     

Caffeine ingestion does not affect afternoon muscle power and fatigue during the Wingate test in elite judo players

The purpose of the present study was to evaluate the effect of caffeine ingestion on elite judo players’ mood states, simple reaction time, and muscle power during the Wingate test in the afternoon. Ten elite judo players (age: 21.08 ± 1.16 years, body mass: 83.75 ± 20.2 kg, height: 1.76 ± 0.07 m) took part in this study. The performance variables were measured during two test sessions scheduled at 17:00 h, after placebo or caffeine (5 mg/k) ingestion. The results revealed an increase in anxiety and vigour (p < 0.05) and a reduction in simple reaction time (p < 0.005) following caffeine ingestion. However, muscle power and fatigue during the Wingate test were unaffected. It is concluded that afternoon caffeine ingestion has no ergogenic effect on anaerobic performance.     

A PILOT STUDY ON HOW DO ELITE SURFSKI PADLLERS MANAGE THEIR EFFORT AND HYDRATION PATTERN IN THE HEAT

To investigate thermal response, hydration behaviour and performance over flatwater kayaking races in tropical conditions (36.8°C and 68% rh). Five internationally-ranked subjects participated in the 2012 Surfski Ocean Racing World Cup in Guadeloupe to the “Ze Caribbean Race 2012” [i.e., a 35-km downwind race]. Core temperature (T°C) and heart rate (HR) were measured using portable telemetry units whereas water intake was deduced from backpacks absorption. The kayakers were asked to rate both their comfort sensation and thermal sensation on a scale before and after the race. The performance was related to an increase in T°C, high HR and low water intake (WI); and (2) high values of final T°C were related to high pre T°C and greater increases in T°C being obtained with low pre T°C and (3) WI being related to high pre T°C. The present study demonstrated that the fastest kayakers were those able to paddle at the highest intensities, increasing their T°C and drinking little water without any interference from thermal sensations. Water intake was positively related to pre-race T°C, which reinforces the importance of beginning surfski races with a low T°C. This study demonstrated that well-trained kayakers drinking ad libitum were able to anticipate their intensity/heat storage ratio to prevent heat illness and severe dehydration and maintain high performance.     

The mechanisms of the neutrophil suppression of creatine kinase and aspartate aminotransferase activities in rat skeletal muscles]

Abdominal neutrophils effect on rat skeletal muscle m. soleus was investigated in vitro. The incubation was carried out in Hanks balanced solution within 24 hrs. It was a release of proteins from m. soleus 1 hr later. Creatine kinase (CK) and aspartate aminotransferase (AAT) activities increase was detected in incubation medium. The neutrophils released their proteins quicker than muscles. A dramatic inhibition of CK and AAT activities took place during coincubation of m. soleus and neutrophils. Zymosan-activated cells had a higher inhibition potency in comparison to nonactivated neutrophils. Analysis of proteinase and myeloperoxidase activities in incubation medium has given evidence that CK and AAT inhibition by non-activated neutrophils mainly depends on cell-secreted proteinases. Zymosan-activated neutrophil inhibition of CK and AAT consists of proteinases and myeloperoxidase effects. AAT appeared to be more resistant than CK to the damage by neutrophils. The used approach failed to demonstrate the direct damage effect of neutrophils on m. soleus, but the described enzyme inhibition mechanism can take place in vivo during leukocyte infiltration of skeletal muscles after intensive muscular activity.     

Comparison of a kayaking ergometer protocol with an arm crank protocol for evaluating peak oxygen consumption

The purpose of this study was to compare a kayak ergometer protocol with an arm crank protocol for determining peak oxygen consumption (V(.-)O2). On separate days in random order, 10 men and 5 women (16-24 years old) with kayaking experience completed the kayak ergometer protocol and a standardized arm crank protocol. The kayak protocol began at 70 strokes per minute and increased by 10 strokes per minute every 2 minutes until volitional fatigue. The arm crank protocol consisted of a crank rate of 70 revolutions per minute, initial loading of 35 W and subsequent increases of 35 W every 2 minutes until volitional fatigue. The results showed a significant difference (p < 0.01) between the kayak ergometer and the arm crank protocols for relative peak V(.-)O2 (47.5 +/- 3.9 ml x kg(-1) x min(-1) vs. 44.2 +/- 6.2 ml x kg(-1) x min(-1)) and absolute peak V(.-)O2 (3.38 L x min(-1) +/- 0.53 vs. 3.14 +/- 0.64 L x min(-1)). The correlation between kayak and arm crank protocol was 0.79 and 0.90, for relative and absolute V(.-)O2 peak, respectively (both p < 0.01). The higher peak V(.-)O2 on the kayak ergometer may be due to the greater muscle mass involved compared to the arm crank ergometer. The kayak ergometer protocol may therefore be more specific to the sport of kayaking than an arm crank protocol.     

Effects of 8-week in-season upper and lower limb heavy resistance training on the peak power, throwing velocity, and sprint performance of elite male handball players

The aims of this study were to test the potential of in-season heavy upper and lower limb strength training to enhance peak power output (Wpeak), vertical jump, and handball related field performance in elite male handball players who were apparently already well trained, and to assess any adverse effects on sprint velocity. Twenty-four competitors were divided randomly between a heavy resistance (HR) group (age 20 ± 0.7 years) and a control group (C; age 20 ± 0.1 years). Resistance training sessions were performed twice a week for 8 weeks. Performance was assessed before and after conditioning. Peak power (W(peak)) was determined by cycle ergometer; vertical squat jump (SJ) and countermovement jump (CMJ); video analyses assessed velocities during the first step (V(1S)), the first 5 m (V(5m)), and between 25 and 30 m (V(peak)) of a 30-m sprint. Upper limb bench press and pull-over exercises and lower limb back half squats were performed to 1-repetition maximum (1RM). Upper limb, leg, and thigh muscle volumes and mean thigh cross-sectional area (CSA) were assessed by anthropometry. W(peak) (W) for both limbs (p < 0.001), vertical jump height (p < 0.01 for both SJ and CMJ), 1RM (p < 0.001 for both upper and lower limbs) and sprint velocities (p < 0.01 for V(1S) and V(5m); p < 0.001 for V(peak)) improved in the HR group. Upper body, leg, and thigh muscle volumes and thigh CSA also increased significantly after strength training. We conclude that in-season biweekly heavy back half-squat, pull-over, and bench-press exercises can be commended to elite male handball players as improving many measures of handball-related performance without adverse effects upon speed of movement.     

Sustained maximal ventilation after endurance exercise in athletes

Although impaired respiratory muscle performance that persists up to 5 min after exercise is stopped has been demonstrated during exhaustive exercise in normal young men, it is not known whether impaired respiratory muscle function follows endurance exercise to exhaustion in highly trained athletes. To study the effects of exercise on sustained maximal voluntary ventilation immediately after exercise, eight elite cross-country skiers performed a 4-min maximal sustained ventilation (MSV) test before and immediately after exhaustive exercise. Subjects were encouraged to maintain maximal ventilation (VE) throughout the MSV test. To encourage greater effort, rapid visual feedback of VE was provided on a computer terminal along with a target VE based on their 12-s maximum voluntary ventilation (MVV). The subjects (7 males, 1 female) were 18.5 +/- 0.9 yr old (mean +/- SD) and exercised for 62.5 +/- 16.7 min at 77 +/- 5% of their maximum oxygen consumption during which average VE was 106.7 +/- 24.2 l/min BTPS. The mean MVV was 196.0 +/- 29.9 l/min or 107% of their age- and height-predicted MVV. Before exercise the MSV was 86% of the MVV or 176.7 +/- 30.5 l/min, whereas after exercise the MSV was 90% of the MVV or 180.3 +/- 28.9 l/min (P = NS). The total volume of gas expired during the 4-min MSV was 706.7 +/- 121.9 liters before and 721.2 +/- 115.5 liters after exercise (P = NS). In this group of athletes, exhaustive exercise produced no deleterious effects on the ability to perform a 4-min MSV test immediately after exercise.     

Eccentric exercise-induced muscle damage impairs muscle glycogen repletion

Five healthy untrained young male subjects were studied before, immediately after, and 10 days after a 45-min bout of eccentric exercise on a cycle ergometer (201 W). The subjects were sedentary at all other times and consumed a eucaloric meat-free diet. Needle biopsies of the vastus lateralis muscle were examined for intracellular damage and glycogen content. Immediately after exercise, muscle samples showed myofibrillar tearing and edema. At 10 days, there was myofibrillar necrosis, inflammatory cell infiltration, and no evidence of myofibrillar regeneration. Glycogen utilization during the exercise bout was 33 mmol glycosyl units/kg muscle, consistent with the metabolic intensity of 44% of maximal O2 uptake; however, the significant glycogen use by type II fibers contrasted with concentric exercise performed at this intensity. At 10 days after exercise, muscle glycogen was still depleted, in both type I and II fibers. It is possible that the alterations in muscle ultrastructures were related to the lack of repletion of muscle glycogen. Damage produced by eccentric exercise was more persistent than previously reported, indicating that more than 10 days may be necessary for recovery of muscle ultrastructure and carbohydrate reserves.     

Estrogen effect on some enzymes in female rats after downhill running

The study investigates the effect of administered estrogen on plasma creatine kinase (CK) and lactate dehydrogenase (LD) levels in female ovariectomized rats after downhill running. Rats ovariectomized before sexual maturity were subcutaneously implanted with pellets containing 17 beta-estradiol or placebo. Three weeks later they were subjected to a 90-min intermittent downhill running protocol. Blood samples were obtained from the jugular vein immediately after and 72 h after exercise for determination of plasma CK, LD and 17 beta-estradiol levels. A two-way analysis of variance was used for data evaluation. Plasma CK and LD levels were significantly lower (p<0.05) in the estrogen-supplemented, ovariectomized animals which suggests that less muscle damage occurred compared to the controls immediately and 72 h after exercise. Estrogens may have a protective effect on muscle tissue possibly due to their antioxidant and membrane stabilizing properties.     

Effects of whole-body cryotherapy vs. far-infrared vs. passive modalities on recovery from exercise-induced muscle damage in highly-trained runners

Enhanced recovery following physical activity and exercise-induced muscle damage (EIMD) has become a priority for athletes. Consequently, a number of post-exercise recovery strategies are used, often without scientific evidence of their benefits. Within this framework, the purpose of this study was to test the efficacy of whole body cryotherapy (WBC), far infrared (FIR) or passive (PAS) modalities in hastening muscular recovery within the 48 hours after a simulated trail running race. In 3 non-adjoining weeks, 9 well-trained runners performed 3 repetitions of a simulated trail run on a motorized treadmill, designed to induce muscle damage. Immediately (post), post 24 h, and post 48 h after exercise, all participants tested three different recovery modalities (WBC, FIR, PAS) in a random order over the three separate weeks. Markers of muscle damage (maximal isometric muscle strength, plasma creatine kinase [CK] activity and perceived sensations [i.e. pain, tiredness, well-being]) were recorded before, immediately after (post), post 1 h, post 24 h, and post 48 h after exercise. In all testing sessions, the simulated 48 min trail run induced a similar, significant amount of muscle damage. Maximal muscle strength and perceived sensations were recovered after the first WBC session (post 1 h), while recovery took 24 h with FIR, and was not attained through the PAS recovery modality. No differences in plasma CK activity were recorded between conditions. Three WBC sessions performed within the 48 hours after a damaging running exercise accelerate recovery from EIMD to a greater extent than FIR or PAS modalities.     

Design of a controlled-release ergometer for the measurement of musculotendinous stiffness of the knee flexors

The stiffness of muscle-tendon units (MTUs) influences many aspects of human movement from athletic performance to injury risk. Presently the controlled-release technique of measuring MTU stiffness has been applied almost exclusively to the distal joints of the body, i.e., the ankle. This is primarily because of the mechanical limitations of implementing this technique. However, in order to better understand how the elastic properties of the MTU affect both performance and injury potential, measurements of MTU stiffness of the more proximal joints must be made. The knee flexors are a logical choice because of the integral role of MTU stiffness of this muscle group in both hamstring strains and knee injury. The purpose of this study was to modify a commercial ergometer so that it could be used to measure the musculotendinous stiffness of the knee flexors. Data are presented for a representative participant to illustrate the feasibility and capability of this ergometer, and the measured MTU stiffness was 519 N.m.rad(-1) at a knee flexion moment of 100 N.m. Our results indicate that it is indeed possible to modify a commercial ergometer and measure musculotendinous stiffness of large muscle groups crossing proximal joints.     

Effect of exhausting stretch-shortening cycle exercise on the time course of mechanical behaviour in the drop jump: possible role of muscle damage

The purpose of the present study was to investigate the effect of stretch-shortening-cycle-induced muscle damage on the time course of mechanical behaviour in the drop jump. Ten healthy male subjects performed submaximal stretch-shortening cycle (SSC) exercise on a special sledge apparatus. Exhaustion occurred on average within 3 min. A drop jump (DJ) test from a 50-cm height was performed before and immediately after the sledge exercise as well as 2 h, 2 days and 4 days later. The fatigue exercise showed relatively high blood lactate concentration [12.5 (SD 2.6) mmol x l(-1)] and an increase of serum creatine kinase (CK) activity delayed by 2 days [540 (SD 407) U x l(-1)]. The initial decline in the jump performance (before - immediately after) was related negatively to the early recovery in performance (immediately after 2 h) (P < 0.05). The early recovery of the knee joint moment at the end of stretch showed a negative correlation to the delayed decrease in DJ performance (2 h 2 days) (P < 0.01). Thus, the DJ performance showed an initial decline followed by an early recovery and a secondary decline. Both the initial decline and early recovery in the knee joint moment at the end of stretch were related to the corresponding initial (after 2 h) (P < 0.05) and secondary increases (2 h - 2 days) (P < 0.01) in CK. It is suggested that the early recovery as well as the initial decline in the knee joint function could depend on the degree of muscle damage. Delayed decrease in initial stiffness (2 h - 2 days) was negatively related to the corresponding changes in the knee joint angle at touch down in DJ (P < 0.001). These interactions would imply that the decrease in the stiffness regulation and the modulation of the prelanding motor control might be attributable to secondary muscle damage during 2 days after the SSC exercise. Therefore, it may be suggested that the changes in the DJ performance after the exhausting SSC exercise accompany the progress of muscle damage observed by the corresponding increase in serum CK concentration and the corresponding deterioration of stiffness regulation and motor control in DJ.     

Are Gender Differences in Upper-Body Power Generated by Elite Cross-Country Skiers Augmented by Increasing the Intensity of Exercise?

In the current study, we evaluated the impact of exercise intensity on gender differences in upper-body poling among cross-country skiers, as well as the associated differences in aerobic capacity, maximal strength, body composition, technique and extent of training. Eight male and eight female elite skiers, gender-matched for level of performance by FIS points, carried out a 4-min submaximal, and a 3-min and 30-sec maximal all-out test of isolated upper-body double poling on a Concept2 ski ergometer. Maximal upper-body power and strength (1RM) were determined with a pull-down exercise. In addition, body composition was assessed with a DXA scan and training during the previous six months quantified from diaries. Relative to the corresponding female values (defined as 100%), the power output produced by the men was 88%, 95% and 108% higher during the submaximal, 3-min and 30-sec tests, respectively, and peak power in the pull-down strength exercise was 118% higher (all P<0.001). During the ergometer tests the work performed per cycle by the men was 97%, 102% and 91% greater, respectively, and the men elevated their cycle rate to a greater extent at higher intensities (both P<0.01). Furthermore, men had a 61% higher VO₂peak, 58% higher 1RM, relatively larger upper-body mass (61% vs 56%) and reported considerably more upper-body strength and endurance training (all P<0.05). In conclusion, gender differences in upper-body power among cross-country skiers augmented as the intensity of exercise increased. The gender differences observed here are greater than those reported previously for both lower- and whole-body sports and coincided with greater peak aerobic capacity and maximal upper-body strength, relatively more muscle mass in the upper-body, and more extensive training of upper-body strength and endurance among the male skiers.     

A study of physical demands in riding

Thirteen experienced riders and three elite riders underwent bicycle ergometer tests at submaximal and maximal workloads. Oxygen uptake, pulmonary ventilation and heart rate were also studied during riding at a walk, a trot and a canter. The mean maximal oxygen uptake of the experienced riders in the ergometer test (2.71 . min-1) was superior to the average maximal oxygen uptake of other groups of the same age and sex. The average oxygen uptake of the experienced riders in trot sitting was 1.701 . min-1, trot rising 1.681 . min-1 and in canter 1.801 . min-1. The experienced riders used at least 60% of their maximal aerobic power in trot and canter, which is an exercise intensity that may induce some training effect. Two elite riders consistently had lower oxygen uptakes in riding than the other riders. The heart rate -- oxygen uptake relationships in riding and in the ergometer tests were similar, except during trot sitting when the heart rate tended to be higher, indicating a larger share of static muscle contraction in this gait. Static muscle strength was measured in nine riders and seven non-riders. Six muscle groups were investigated, but no significant difference in muscle strength could be demonstrated between riders and controls.     

Evaluation of gene polymorphisms in exercise-induced oxidative stress and damage

Abstract

Many potentially significant genetic variants related to oxidative stress have been identified and performance in endurance sports is a multi-factorial phenotype. Thus, it was decided to investigate the influences of the haptoglobin (Hp), MnSOD (Val9Ala), CAT (21A/T), GPX1 (Pro198Leu), ACE, glutathione S-transferases M1 (GSTM1) and T1 (GSTT1) genes' polymorphisms on the oxidative stress and damage suffered by human athletes (runners). Blood samples taken immediately after a race were submitted to genotyping, comet and TBARS assays, biochemical analyses of creatine kinase (CK), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). MnSOD significantly influenced results of CK and a possible association between Hp1F-1S and Hp1S-2 genotypes with a superior TBARS values was found. Higher or lower TBARS and CK values or DNA damage also depended on the interaction between Hp and ACE or GST genotypes, indicating that MnSOD and Hp polymorphisms can be determining factors in performance, at least for runners.