Quels tests de terrain pour le suivi de la performance athlétique en sport collectif ?

Introduction

To monitor athletic performance throughout a team-sport season, strength and conditioning coaches are used to program various field tests that evaluate physiological variables predictive of performance in their activity. Nevertheless, performing all these field tests is time consuming and not well appropriated for frequent monitoring.

Synthesis of the facts

The present study investigated whether a single test can be used as a surrogate of overall team athletic performance.

Conclusion

It appears that the 30-15 Intermittent Fitness Test and a repeated sprint ability test, but not explosive power of lower limb or sprinting tests, are sensitive enough to differentiate different performance levels throughout the season.     

Effets d'une restriction hydrique et alimentaire prolongée (ramadan) sur la performance et les réponses cardiovasculaires au cours d'un exercice incrémental en milieu tropical chaud

Backgroung

Previous studies showed that maximal oxygen uptake and maximal heart rate were not different during prolonged fasting (ramadan) compared to normal feeding period. However, the effect of ramadan on the blood pressure response during incremental exercise has not been investigated.

Objective

This study aimed to evaluate the evolution of blood pressure during incremental trial in ramadan period.

Methods

Twelve young trained male aged 24 ± 4 yrs participated as voluntary subjects. Their anthropometric parameters, maximal aerobic power and maximal heart were measured in fasting and in normal feeding periods during incremental trial on cycle ergometer.

Results

No significant difference was observed in any anthropometric parameter. Maximal aerobic power of fasting period was significantly less (P < 0,05) compared to normal feeding. Heart rate at rest, at maximal exercise and during a 15 min period of recovery was not significantly affected. Systolic blood pressure of fasting period at maximal power was significantly lower than during the control period (P < 0,05).

Conclusion

Ramadan negatively influences the capacity of maximal power and cardiovascular response at maximal power.     

Uchi-komi avec charge,une approche physiologique d'un nouveau test spécifique au judo

Objective

The aim of this study was to elaborate and validate a specific test to evaluate the physical condition of judo players.

Subjects and methods

Twenty-three volunteers, males, aged 22 ± 3.62 years old took part in our experiment. They did the progressive test of Leger et al. (1984), vertical Jump test (Sargent test), Australian shuttle run test and a specific judo test.

Results

The observed results showed significant correlations between muscular power and the number of Uchi-komi on the judo test reference scale (R = 0.52, P < 0.01). Furthermore, there were other correlations between the number of Uchi-komi at the two first sets of specific judo test and the anaerobic power represented by the distance covered in 30s at the Australian shuttle test (R = 0.86, P < 0.01), also between the anaerobic capacity represented by the whole distance covered and the total number of Uchi-komi achieved at the judo test (R = 0.88, P < 0.01).

Conclusion

The test reproduces the physiological characteristics of judo fight. It is a good indicator of the judoka's physical fitness and their cardiovascular adaptation in a physical effort.     

Qualités physiques requises pour la performance en sprint avec changements de directions types sports collectifs

Purpose

To explore qualities necessary to succeed in (swerve-sprinting) sprints with changes of direction.

Method

Two biometric measurements (body mass (MC); lean body mass (MM)) and three tests (20 m sprint two-point start 20 Da, 20 m swerve-sprint: 20Dc on track equipped with a force platform, and half squat) are carried out by nine players of team sports.

Results

The multiple linear regression shows that 44% of 20Dc performance are explained by relative maximum force (developed on the 20 Da) and the MM relative.

Conclusion

Coordination could represent 50% of unexplained 20Dc performance.     

Puissance critique de l’enfant prépubère et de l’adulte

Aim

The aim of the study was to compare aerobic and anerobic abilities of prepubertal children and adults with the critical power concept.

Methods

Sixteen children (10.3 ± 0.9 years) and 15 adults (23.5 ± 3.6 years) performed five tests: a maximal-graded test and four constant load exercises until exhaustion. Critical power (CP) and anaerobic-work capacity (CTA) were determined from the power-1/time (P-t) linear relationship.

Results

Determination coefficients for P-t were 0.94 ± 0.05 in children and 0.96 ± 0.04 in adults. PC values were significantly (p < 0.01) lower in children (2.7 ± 0.4 W/kg) than in adults (3.1 ± 0.3 W/kg). CTA values were significantly (p < 0.001) lower in children (136.4 ± 50.8 J/kg) than in adults (247.1 ± 45.7 J/kg).

Conclusion

Satisfying determination coefficients for CP and CTA were found in children and adults. Children have a lower CP and CTA than adults. This result is in accordance with literature.     

Effets d'une complémentation nutritionnelle en vitamines et minéraux sur la chute de force et les marqueurs biologiques consécutifs à un exercice excentrique chez des personnes âgées

Purpose

The effects of vitamins and minerals complex supplementation on maximal voluntary contraction decrease (FMV) and biological markers following an eccentric exercise at old people.

Method

Sixteen elderly subjects took either placebo (Pl group) or vitamins and minerals (Isoxan Senior, NHS, Rungis, France) (group S) for 21 d before an eccentric exercise and for 3 d after the exercise. The FMV and surface EMG activity (RMS) of the vastus lateralis (VL), vastus médialis (VM) and rectus fémoris (RF) were recorded before (Pre), immediately after (Post), 24 h (Post 24) and 48 h (Post 48) after the exercise. CCVThe creatine kinase (CK), lactate déshydrogénase, malondialdéhyde, and tumor necrosis Factor (TNFα) levels were analyzed.

Results

The reduced MVC (S: 11,2 ± 4,8%; Pl: 17,8 ± 10,4%, P < 0,01) after exercise was associated with a significant reduction in RMS VL, RMS VM and RMS RF values for both groups. A faster FMV recovery appeared at 48 h for the S group (P < 0.05). CK and TNFα values increased in post-exercise.

Conclusion

A dietary supplementation of a vitamin and mineral complex does not attenuate the loss of contractile function immediately after the running exercise, and it may accelerate the recovery of maximal force capacity after 48 h by limiting the post-exercise pro-inflammatory processes.     

Relation entre le five-jump test, l'épreuve de vitesse sur 30 m et la détente verticale

Aim

To study the relationship between the five-jump test (5JT) performance, 30 m sprint test and vertical jump performances.

Synthesis of facts

Thirteen male soccer players (15–16 years olds) performed the following tests: 5JT, 30 m sprint and 3 vertical jumps: SJ, CMJ and Free CMJ. The 5JT was strongly correlated with 30 m sprint (R = 0.83; P < 0.01), the SJ (R = 0.71; P < 0.01), the CMJ (R = 0.84; P < 0.01) and the free CMJ (R = 0.62; P < 0.05). The 5JT is also correlated with the index of explosiveness (R = 0.93; P < 0.01).

Conclusion

The 5JT can be used to evaluate muscular strength and explosivity of lower limbs in young soccer players.     

L’étude des forces de réaction au sol peut-elle être un indicateur de la stabilité de la chaussure lors de la locomotion ?

Objective

The aim of this study was to determine the influence of ground reaction forces on the footwear stability.

Material and methods

Twelve healthy men have walked on a treadmill ergometer ADAL with five different shoe models and in a barefoot condition. Here, the shoe called “shoe 1” is known for its capacity to stabilize the foot. Ground reaction forces (F_x, F_y, F_z) were recorded at constant speed (2, 4 and 6 km h⁻¹), and during transition phases (0 to 2, 0 to 4, 0 to 6 km h⁻¹). Two running conditions (8 km h⁻¹ at constant speed and 0 to 8 km h⁻¹ in transition) have completed this protocol. Then, each subject filled in a questionnaire to evaluate, for each shoe, different sensations: stability during walking and running, foot support, heightening of the rearfoot, width of shoe at the heel, general comfort, cushioning. At last, different geometrical parameters of each shoe were measured.

Results and discussion

The results show that, in all tested conditions (constant speed and transition phases, walking and running), medial force peaks are significantly more important in barefoot condition than all shod conditions, except for the shoe 1. As the barefoot condition is, according to the literature, the best condition of stability and as the shoe 1 is known for its capacity to stabilize the foot, these results could suggest that a better stability could be associated with more important medial force peaks.     

Effet d'un entraînement en endurance sur les concentrations de l'IGF-1 plasmatique chez le rat

Introduction

The aim of this study was to determine the effects of endurance training on IGF-1, corticosterone and insulin levels in male sedentary and trained rats.

Facts

IGF-1 concentrations decrease after training (p < 0.05), those of corticosterone increase (p < 0.01) whereas insulin levels remain stable.

Conclusion

A short period of endurance training leads to catabolic state with a decrease in IGF-1 concentrations and increase in corticosterone levels.     

Contrairement à une idée reçue,les femmes n’oxydent pas plus de lipides à l’effort que les hommes,mais leur Lipoxmax survient à une puissance plus élevée

Aims

Several studies have shown that women, when they exercise at a given percentage of their aerobic capacity, oxidize more fat than men, thus saving their protein and glycogen stores. We wanted to characterize these differences in terms of levels of transition of balance of substrate oxidation and maximum lipid oxidation flow rate (MLOFR) during exercise.

Methods

Three groups (61 athletes, 196 sedentary and 47 type 2 diabetes mellitus [T2DM], in whom, men and women were matched for age, BMI and physical activity, performed a sub-maximal exercise test with four 6 min steady state steps for measurement of lipid and carbohydrate oxidation by indirect calorimetry. In all three groups MLOFRs are the same in both sexes (2 to 3 mg min⁻¹ kg⁻¹), but among athletes and sedentary women have a curve of oxidation of lipids shifted to the right, a crossover point of use of substrates (PCX, the power for which energy comes mainly from carbohydrates) occurring at a 10–15% higher percentage of VO_2max (p < 0.01). In DT2 this shift is no longer significant. The point of maximal lipid oxidation (Lipox_max) also occurs at a higher percentage of VO_2max (athletes: 44.27 ± 15.97% theoretical VO_2max versus 31.25 ± 15.66% in men, p < 0.001; sedentary: 50.29 ± 18.66% among women versus 36.75 ± 15.22% in men, p < 0.01; for T2DM these levels (42.8 ± 2.4 to 39.8 ± 3.7%) are not significantly different.

Conclusion

Gender-related differences are found on carefully matched subgroups, but are far to be major. They reflect a right shift by 10 to 15% of the curve of lipid oxidation as a function of VO_2max, while rates of oxidation at the Lipox_max do not differ between genders. In other words, women do not oxidize more lipids at exercise, but their ability to oxidize them reaches a maximum at a higher percentage of VO_2max. This discrepancy seems to disappear in T2DM.     

Reproducibilidad y exactitud en la cuantificación morfométrica y mecánica del hueso trabecular a partir de imágenes de resonancia magnética de Tesla

Objective

We used an animal model to analyze the reproducibility and accuracy of certain biomarkers of bone image quality in comparison to a gold standard of computed microtomography (μCT).

Material and methods

We used magnetic resonance (MR) imaging and μCT to study the metaphyses of 5 sheep tibiae. The MR images (3 Teslas) were acquired with a T1-weighted gradient echo sequence and an isotropic spatial resolution of 180 μm. The μCT images were acquired using a scanner with a spatial resolution of 7.5 μm isotropic voxels. In the preparation of the images, we applied equalization, interpolation, and thresholding algorithms. In the quantitative analysis, we calculated the percentage of bone volume (BV/TV), the trabecular thickness (Tb.Th), the trabecular separation (Tb.Sp), the trabecular index (Tb.N), the 2 D fractal dimension (D^2D), the 3 D fractal dimension (D^3D), and the elastic module in the three spatial directions (Ex, Ey and Ez).

Results

The morphometric and mechanical quantification of trabecular bone by MR was very reproducible, with percentages of variation below 9% for all the parameters. Its accuracy compared to the gold standard (μCT) was high, with errors less than 15% for BV/TV, D^2D, D^3D, and E_appx, E_appy and E_appz.

Conclusions

Our experimental results in animals confirm that the parameters of BV/TV, D^2D, D^3D, and E_appx, E_appy and E_appz obtained by MR have excellent reproducibility and accuracy and can be used as imaging biomarkers for the quality of trabecular bone.     

Effet du port d'une combinaison intégrale et d'une trifonction sur la vitesse de nage et l'amplitude du cycle de bras en triathlon

Introduction

The purpose of this study was to compare the influence of complete wetsuit and tri-function on the swimming speed and arm stroke characteristics in crawl by triathletes.

Synthesis

Seven triathletes have executed three randomised trials of 400 m front crawl at maximal intensity: without wetsuit, complete wetsuit and tri-function.

Conclusion

Results pointed out that the complete suit allows a significant improvement of the performance and of the distance per cycle by report the swimming with a tri-function.     

Relation entre la puissance et la raideur musculotendineuse chez les sportifs de haut niveau

Goal

The aim of this study was to test the relation between the reactive power and the stiffness of the legs in high trained athletes (sprinters and skiing racers).

Method

A simple method to measure, in field conditions, the leg stiffness during maximal bouncing was used on twenty-eight sprinters, and twenty-nine skiing racers. In addition, the mechanical power called reactive power was calculated according to the method proposed by Bosco. The relationship between stiffness and power was observed in the different groups.

Results

The value of stiffness obtained was 29,866 ± 7372 N.m⁻¹. The power was equal to 52.33 ± 8,72 W.kg⁻¹. The main result of this study was that a relation between stiffness and power was obtained only in the sprinters (r² = 0,68, P < 0,001). This result stressed the influence of the sport speciality on the stiffness control.

Conclusion

The power measured during maximal bouncing, called reactive power is correlated with the leg's stiffness when subjects are trained to produce power in similar conditions. No correlation was obtained in skiing racers. The stiffness measurement was then a complementary test in the physical evaluation of the athletes.     

Effet d’une hyperventilation volontaire préexercice sur la performance lors de l’épreuve de Wingate

Aim

To determine the effect of a preexercise hyperventilation (HV) on performance measured during the Wingate test.

Protocol

Seven subjects realized the Wingate test whether in normal condition or after the realization of six maximal respiration cycles realized in 30 s. Gas exchanges were recorded breath by breath throughout the test.

Results

Pic power measured during the test was not significantly different after HV. In opposite, the fatigability index (FI) was significantly higher after HV.

Conclusion

A HV does not affect maximal power, but seems to reduce aerobic contribution, which may explain the higher FI observed after HV.     

La technique de Didier Patte dans les luxations récidivantes de l’épaule : notre expérience à propos de 35 cas avec un suivi d’une dizaine d’années

Aims

Authors report their personal experience on the surgical treatment of repeated anterior shoulder dislocations, using an anterior bone block in accordance with the procedure suggested by Didier Patte.

Results

From the year 1988 and during 10 years, 35 patients suffering from repeated anterior shoulder dislocations were surgically treated by this procedure. It was appropriate to retrospectively review the clinical and functional outcomes after Patte repair for recurrent anterior glenohumeral instability. The mean follow-up was approximately 10 years, with a mean percentage of 75% for the observance. There was no recurrence after surgery. Moreover, 88% of patients had good outcomes, according to the scale suggested by Butel et al., with total resumption of work and physical activities. The occurrence of chronic complication such as osteoathrosis was scarce (only one case for the series), while 20% of subjects showed apprehension during some specific shoulder movements.

Conclusion

In order to expect best functional outcomes, the choice of the surgical procedure should take into account the extent of initial injury. Considering these ground requirements, the Patte procedure seems to provide very satisfactory long-term functional outcomes.     

Secuencia de disparo único eco de gradiente en fase y fase opuesta con preparación de la magnetización: descripción y optimización de la técnica con equipo de 1,5 T

Purpose

To implement in-phase and out-of-phase (IP/OP) techniques with Magnetization-Prepared Gradient Recalled Echo (MP-GRE) and to evaluate the feasibility and diagnostic image quality among pre and post-optimized MP-GRE sequences, including patients unable to cooperate with breath-hold requirements.

Materials and methods

Institutional review board approval with waiver of informed consent was obtained for this HIPAA-compliant retrospective study. Two groups of patients were included in the study, before and after optimization of MP-GRE parameters, with seventy-three (24 noncooperative/49 cooperative) and sixty-four (22 noncooperative/42 cooperative) consecutive patients, respectively. The motion-insensitive sequence used in this study was a single-shot 2D MP-GRE. Two radiologists qualitatively evaluated the sequences to identify the presence of phase cancellation artifact in OP images and to determine image quality, extent of artifacts (respiratory ghosting, bounce-point artifact, spatial misregistration and pixel graininess) and lesion conspicuity on the various sequences. The ability to visually detect liver steatosis and fatty adrenal adenomas was evaluated. Qualitative analyses were compared using the Wilcoxon and Mann-Whitney tests.

Results

There were statistically significant differences between all MP-GRE sequences concerning phase cancellation artifact (P<.0001) which was present in MP-GRE OP sequences and negligible to absent in the pre (IP₁) and post-optimized (IP₂) MP-GRE IP sequences, respectively, in all patients.Bounce point artifacts were significantly more pronounced in MP-GRE IP₁ (P<.0001). Spatial misregistration was slightly more prominent in noncooperative patients with MP-GRE IP₂ (P=.0027). MP-GRE OP and MP-GRE IP₂ showed significantly higher overall image quality (P<.0001).MP-GRE sequences subjectively identified hepatic steatosis (n=20) and adrenal adenomas (n=5) based on signal loss from IP to OP sequence.

Conclusion

Single shot IP/OP MP-GRE is feasible and allows motion resistant imaging with adequate diagnostic image quality. This technique is able to provide IP and OP information in patients unable to suspend respiration.     

Modification du patron locomoteur pendant la grossesse : étude d’une population rurale africaine

Introduction

The aim of this experiment was to examine the walking gait variability during pregnancy.

Subjects and methods

One hundred and twenty-four sedentary pregnant women of 26 ± 4.6 years participated in this study. Gait analysis at preferred speed was performed among eight periods from the second month to the ninth month of the pregnancy (P2–P9). Each month body mass, body fat were recorded and distance covered, number of steps, duration, step length, speed of walk were measured; step rate, and step variability were calculated.

Results and discussion

The results indicated, on the one hand, a significant effect of the period of pregnancy on the locomotor pattern with a decrease in speed and rate step and an increase in the variability of the step. On the other hand, these variations are correlated significantly only with the increase in body fat. These findings suggest that this effect, related mainly to control of the increase in body fat during pregnancy, is comparable with the addition of external load with a modification of the locomotor pattern increasing the solicitation of the muscular system.     

Aspects biologiques des interactions de l’exercice et de la récupération

Subject

The use of Fourier transform infrared spectrometry technique (FT-IR) as a pitch technique of the biological control of short and intense exercises close to those of Rugby matches.

Material and method

In reference to 28 rugbymen of international level, the biological results of three short and intense exercises and two periods of recovery were analyzed by TF-IR. The exercises are: (1) sprints; (2) 12 × 20 m of swerve running; (3) 6 × 30 s of shuttle run.

Results

Lactate, glucose, urea, and to a lesser degree, triglycerides showed a significant evolution. If the evolution of the two first was in conformity with the literature, the increase of urea probably results from the activation of the purins–nucleotides cycle, whereas the evolution of triglycerides is explained by their probable muscular use during periods of active recovery. Among proteins related to the healthy sportsman, only haptoglobin presents a significant variation difficult to explain whereas CRP, orosomucoid and immunoglobulins A, G and M remain close to their rest values.

Conclusion

With the use of FT-IR technique, it is possible to intervene directly on the pitches of the sporting practice to control the biological incidences and to adjust the loads individually. It is also possible to detect inflammatory and immunological problems related to the biomechanical and physiological stresses.