Activity profile in elite Polish soccer players.

The aim of the present study was to determine and characterize the activity of male Polish Premier League soccer players during elite-level matches, depending on playing position, activity intensity range, and match period. The study sample comprised 1178 players. Amisco Pro® was used to track the match activity players. Statistical analysis of the total distance covered by players revealed that the greatest distance was covered by central midfielders (11894 ± 765 m) and external midfielders (11751 ± 686 m). In terms of velocity, the greatest distance was covered by players in the V1 range (0 ≤ V1 < 11 km · h-1, standing, walking), (7028 ± 294 m). The difference between the match periods was statistically non-significant, amounting to only 0.5%. As such they could prove useful for present and future comparisons between positions and represent the scientific basis for developing position-specific conditioning/training regimes for both clubs and individuals.

Effects of two recovery procedures after a football game on sensory and biochemical markers.

AIM: The aim of this study was to investigate recovery processes on pressure pain sensitivity and blood indicators in professional football players after three different post-game training modalities: standard recovery training, no physical activity, delayed onset muscle soreness reduction training. METHODS: Eleven male football field players participated in the present study. The experiment was performed in three sessions over three weeks after three football league games. The procedure was composed of the following assessments included in each session: measurement of pain pressure threshold, creatine kinase activity and myoglobin (Mb) concentration before, 24 and 48 hours after game. RESULTS: In standard recovery training there was no full recovery in deep structure sensitivity of the frontal thigh muscles at 48 hours after game (P=0.008). In the no physical activity session, sensitivity returned to its level before game. On the contrary, in the delayed onset muscle soreness reduction training sensitivity decreased 48 hours after game (P<0.001). Creatine kinase activity decreased significantly from 24 hours to 48 hours in session with no activity and delayed onset muscle soreness reduction training (P<0.05). None of the recovery methods had an influence on Mb concentration. CONCLUSION: The present study points towards a potent effect of delayed onset muscle soreness reduction training on recovery after a football game.

Principle component analysis of exposure variation analysis during computer work at presence of delayed onset muscle soreness.

Eleven healthy volunteers took part in three sessions where computer work was performed for 10 min in each session. The recordings were made on two consecutive days. After the first session, the subjects underwent a series of high intensity eccentric exercises of shoulder elevation to induce muscle soreness. The second session was performed immediately after the exercises and third session 24 hours after the exercise. Surface electromyography (EMG) of descending and ascending trapezius, deltoideus anterior and serratus anterior was recorded. Exposure variation analysis (EVA) centroid and marginal distribution was computed. Principle component analysis (PCA) was performed on both cases. Describing more than 80% of variance, first eight components for EVA marginal distributions and first four ones for EVA centroid were picked to be investigated. The sole EVA amplitude levels played a practically significant role to describe the variation in EVA marginal distribution. However, a significant pattern of load redistribution to superficial muscles was not found. This may suggest investigating the role of deep muscles in redistribution of load during computer work in response to high level eccentric contractions.

Influence of caffeine, cold and exercise on multiple choice reaction time.

RATIONALE: The effects of caffeine on psychomotor performance have been evaluated under resting conditions and in a thermoneutral environment. Our hypothesis was that these effects could be modified by factors enhancing the level of alertness, such as exercise and cold exposure. OBJECTIVE: The purpose of this study was to follow up changes in the multiple choice reaction time (RT) during exercise at room and low ambient temperatures after caffeine or placebo administered in a double blind manner. METHODS: Nine soccer players performed multistage, incremental exercise until volitional exhaustion on a bicycle ergometer at 22 degrees C or 4 degrees C, 1 h after ingestion of coffee with caffeine (CAF) or without it (PL). Immediately before exercise and at the end of each workload, RT and blood lactate (LA) were measured. Oxygen uptake (VO2) and heart rate (HR) were recorded continuously. Blood LA threshold and the workload associated with the shortest RT were determined. RESULTS: During exercise at 22 degrees C, RT was significantly shorter in CAF than in the PL test, while at 4 degrees C there were no differences in RT between CAF and PL trials. Cold exposure did not affect RT either at rest or during exercise. Neither caffeine nor cold exposure influenced the maximal VO2, the maximal HR and LA threshold. CONCLUSION: In the thermoneutral environment, caffeine ingestion improved psychomotor performance during exercise, whilst at low ambient temperature this effect was blunted. These findings suggest that the stimulating action of caffeine depends on the level and source of arousal.

Ginseng treatment improves psychomotor performance at rest and during graded exercise in young athletes.

This study was designed to determine the effect of ginseng treatment on multiple choice reaction time (RT) during exercise. Fifteen soccer players (age 19.07 +/- 0.62 yrs) were placed in a double-blind manner into one of two groups: ginseng (n = 7), receiving 350 mg of ginseng daily for 6 weeks, or placebo (n = 8), receiving a placebo daily for 6 weeks. Before and after the treatment all the subjects performed an incremental bicycle ergometer exercise with intensity increasing 50 W every 3 min until volitional exhaustion. RT was measured before exercise, and then in the last 2 min of each exercise load. Maximal oxygen uptake (VO2max) and lactate threshold (LAT) were also determined from the exercise test. Ginseng treatment was found to shorten RT at rest and during exercise, shifting the exercise load associated with the shortest RT toward higher exercise loads. Neither ginseng nor placebo influenced VO2 max and LAT. In conclusion, ginseng extract does improve psychomotor performance during exercise without affecting exercise capacity.

Psychomotor performance during prolonged exercise above and below the blood lactate threshold.

Previous investigations from this laboratory have demonstrated that during graded exercise with exercise intensities increasing every 3 min until exhaustion the multiple choice reaction time (RT) decreased until the intensity exceeded the lactate threshold (LT) by approximately 25%, and then rapidly increased. The aim of this study was to follow up changes in RT during prolonged exercise at constant intensities above and below LT and to relate these changes to changes in venous blood lactate [La-]b, and plasma catecholamine [CA]pl concentration responses to the exercise. For this purpose eight young soccer players exercised for 20-min on a cycle ergometer at 10% above LT, and nine exercised for 60 min at an intensity 30% below LT. During both tests RT, heart rate (HR), as well as [La-]b, and [CA]pl were measured. Above LT, RT decreased from the 5th min until the end of exercise, whilst HR, [La-]b, and [CA]pl increased progressively. Significant inverse correlations were ascertained between RT and plasma adrenaline (r = -0.651) and noradrenaline concentrations (r = -0.678). During exercise below LT, RT decreased up to approximately 40 min, then it reached a nadir, and stabilized at this level. This was accompanied by only small changes in [La-]b and [CA]pl. The present findings would indicate that young athletes are able to maintain for a relatively long time, or even increase, their psychomotor performance during endurance exercise both below and above the LT.

Choice reaction time during graded exercise in relation to blood lactate and plasma catecholamine thresholds.

Twenty-two male soccer players (mean age 21.3 yrs) performed an incremental, multistage bicycle ergometer exercise test with work load increasing by 50 W, until volitional exhaustion. The exercise stages lasted 3 min and were separated by 1 min resting periods. Before exercise and during each load an audio-visual five-choice reaction task was administered to assess subjects' psychomotor performance. During resting intervals venous blood samples were taken for lactate (LA), adrenaline (A) and noradrenaline (NA) determinations. It was found that reaction time (RT) decreased gradually during exercise reaching its minimum (approx. 87% of pre-exercise value) at load 236 W (approx. 75% VO2max, HR 164 beats/min). Then, it increased rapidly, exceeding the resting level by 18%. The work load and heart rate (HR) associated with the minimal RT were higher (p < 0.001) than work load and HR associated with the LA threshold (by 46 W and 17 beats/min, respectively). Plasma A and NA showed an exponential increase during exercise with thresholds at 204 and 208 W, respectively (HR 149 and 154 beats/min). Work load at which plasma NA threshold occurred was significantly higher than the LA threshold but it did not differ from the work load associated with the minimal RT. Conversely, plasma A threshold was lower than the load of the minimal RT but did not differ significantly from LA threshold. It is concluded that young athletes continue to improve their psychomotor performance during exercise even at heavy work loads exceeding anaerobic, and plasma adrenaline thresholds. A relationship between reaction time and plasma catecholamines fits the U-shape curve.

Assay of antioxidants by the quenching of the anthracene-sensitized electrochemiluminescence.

The kinetic and spectral characteristics (chemiluminescence and fluorescence spectra) of ultraweak luminescence accompanying the electrolysis of a sodium citrate-methanol-dissolved O2 solution and its application for the determination of antioxidants were examined. The energy transfer-assisted luminescence sensitized by anthracene provides a fast and sensitive assay for the determination of the concentration and kinetic parameters of antioxidants and free radical scavengers.

Effect of 400 ml blood loss on adaptation of certain functions of the organism to exercise.

Eighteen men aged 19-23 years, volunteer blood donors, donated 400 ml of blood. Twenty-four hours before donation, one hour and 24 hours after it they performed a 10-minute exercise on Monark cycle ergometer at workloads raising the heart rate to 170/min. During the exercise the oxygen uptake (VO2), carbon dioxide elimination (VCO2), respiratory quotient (RQ), oxygen uptake to maximal oxygen uptake ratio (VO2/VO2 max), heart rate (HR) and systolic and diastolic arterial blood pressure (Ps and Pd) were determined. The obtained results were compared with the values of haemoglobin concentration and erythrocyte count. One hour after blood donation raised values of HR and Pd were obtained (p less than 0.05) with decreased Ps (p less than 0.05) and VO2 (p less than 0.05). Twenty-four hours after blood loss these parameters were not different from the initial ones (p less than 0.05). Submaximal exercise performed 1 hour after blood loss produced a significantly greater increase of the heart rate than this exercise performed before blood loss. The values of VO2, VCO2, and VO2/VO2 max were slightly lower and those of RQ and HRXPs slightly higher than during control exercise (p less than 0.05). Exercise performed 24 hours after blood loss caused identical changes in these parameters as during control tests.

Plasma biochemical changes and acid-base equilibrium changes in capillary blood nursing frequency repeated submaximal physical exercise in untrained subjects.

The reported investigations were carried out on healthy men aged 20--22 years in two groups: group A of 11 subjects and group B of 12 subjects. Both groups performed five times at 50-minute intervals submaximal physical exercise during 10 minutes on a Monark ergometer. Group A performed the exercise at a steady heart rate of about 170/min with variable workload, while group B performed it at a steady workload but changing heart rate. At rest and after each exercise the plasma concentrations of free fatty acids, glucose and amino-acid nitrogen were determined in both groups, and changes in the parameters of acid-base equilibrium were studied in capillary blood. It was found that after each consecutive exercise the concentration of free fatty acids (FFA) increased ever more and the rise of the haematocrit index decreased. Glucose concentration decreased after the 1st, 2nd and 3rd exercises, but increased after the remaining two exercises. The concentration of amino-acid nitrogen showed an increasing tendency after exercise in both groups. The changes in the acid-base equilibrium, that is its shifting towards metabolic acidosis were greatest after the first exercise. In group A each consecutive exercise caused less pronounced disturbances of acid-base equilibrium. In group B the intensity of metabolic acidosis was lower in consecutive exercises in relation to the first one, but it was greater than in group A.

Effect of moderate hyperglycaemia on left-ventricular systolic time intervals during submaximal exercise of steady workload in healthy subjects.

The effect of submaximal exercise at steady workload on left-ventricular systolic time intervals (STI) was studied in healthy subjects. In group I (22 subjects) 20% glucose solution was injected intravenously in a dose of 2.5 ml/kg of body weight before the exercise. In group II (20 subjects) the same exercise was preceded by intravenous injection of normal saline 2.5 ml/kg of body weight. The left ventricular systolic time intervals were determined by the polycardiographic metod of Blumberger modified by Holldack and Weissler. It was found that glucose administration before the exercise improved myocardial contractility during the exercise. During hyperglycaemia the secondary impairment of myocardial contractility was less pronounced than in the control group. Postexercise changes in left ventricular systolic function regressed more rapidly in the group receiving glucose than in controls.

[Effect of short submaximal stable-load exertion on blood serum insulin and human growth hormone concentration as well as on various biochemical and acid-base blood parameters in healthy individuals]. / Wplyw krótkotrwalego submaksymalnego wysilku fizycznego o stalej mocy na stezenie insuliny, hormonu wzrostu, niektórych parametrów biochemicznych krwi oraz na równowage kwasowo-zasadowa u osob zdrowych.

The studies on effect of short-term submaximal physiol exercise with stable load on blood serum concentrations of insulin, human growth hormone, free fatty acids, glucose and aminoacid nitrogen were carried out on 20 healthy men, aged 19--21 years. In addition, lactic and pyruvic acid concentrations and some parameters of capillary blood acid-base equilibrium were determined. It was found that short-term submaximal exercise with stable load caused the increase of HGH concentration and the decrease of IRI concentration. During such an exercise blood serum free fatty acid concentrations also decreased, while blood serum glucose and aminoacid nitrogen ones did not change significantly. Blood serum lactic and pyruvic acid concentrations and hydrogen ion concentration increased. Simultaneously, carbon dioxide partial pressure decreased and base excess increased. This pattern of changes indicates metabolic acidosis compensated partially by hyperventilation.

Effect of physical exercise on gastric basal secretion in healthy men.

Behaviour of basal gastric secretion of electrolytes, lactic acid and pyruvic acid was studied in twenty-minute portions in 14 healthy men in rest, during exercise and restitution. On bicycle ergometer in sitting position all studied men performed the average work 15 120 +/- 1800 kpm during 20 minutes. It was found that basic gastric secretion didn't change significantly during exercise, but its significant decrease occurred during twenty-minute restitution after exercise. During restitution secretion of Cl, Mg and Ca also significantly decreased while their concentrations didn't change in gastric juice. During physical exercise it was found the increase of lactic acid secretion in gastric juice; it was statistically significantly higher during restitution than in rest period (p less than 0.001) and during exercise (p less than 0.02).