Claire Tourny-Chollet

Quality of life and obesity class relationships.

The aim of this study was to quantify the impact of obesity class on Health-Related Quality Of Life (HRQOL) and Total daily Energy Expenditure (TEE). 69 obese individuals were self-selected to 1 of 3 groups based upon Body Mass Index (BMI). Anthropometric parameters (height, weight, waist and hip circumference, fat mass, lean body mass), biological parameters (high density lipoprotein, low density lipoprotein, triglycerides, glycaemia, total cholesterol), and resting energy expenditure were assessed for each group. The Short Form Health Survey (SF-36) questionnaire and Hospital Anxiety Depression (HAD) scale were used to measure HRQOL, and TEE was estimated by Kurpads method. Class 3 obesity was associated with greater impairment of the physical aspects of the SF-36 (37.2±11.3), greater depression risk (8.2±4.1), and higher TEE (30.0±7.9 Kcal·day (-1)·kg (-1)) than the lower obesity classes. No difference was observed among the 3 groups in the mental and psychosocial aspects of HRQOL. Impaired physical functioning was correlated with fat mass, age, waist circumference, glycaemia control and bodily pain. TEE was positively correlated with BMI, weight, fat mass and lean body mass. The obesity class had a negative impact on the physical health aspect of HRQOL, depression risk and energy expenditure. These impairments were associated with excess fat mass, waist circumference and glycaemia parameters.

Effect of breathing pattern on arm coordination symmetry in front crawl.

Seifert, L, Chehensse, A, Tourny-Chollet, C, Lemaitre, F, Chollet, D. Effect of breathing pattern on arm coordination symmetry in front crawl. J Strength Cond Res 22(5): 1670-1676, 2008-This study analyzed the relationship between breathing pattern and arm coordination symmetry in 11 expert male swimmers who performed the front crawl at their 100-m race pace using seven randomized breathing patterns. Two indexes of coordination (IdCP and IdCNP) and a symmetry index (SI) based on the difference of IdCP − IdCNP were calculated. IdCP calculated the lag time between the beginning of arm propulsion on the nonpreferential breathing side and the end of arm propulsion on the preferential breathing side; IdCNP did the converse. The IdCP and IdCNP comparisons and the SI showed coordination asymmetries among the seven breathing patterns. Specifically, breathing to the preferential side led to an asymmetry, in contrast to the other breathing patterns, and the asymmetry was even greater when the swimmer breathed to his nonpreferential side. These findings highlight the effect of breathing laterality in that coordination was symmetric in patterns with breathing that was bilateral, axed (as in breathing with a frontal snorkel), or removed (as in apnea). One practical application is that arm coordination asymmetry can be prevented or reduced by using breathing patterns that balance the coordination.

Effect of Force Symmetry on Coordination in Crawl

The relationship between breathing laterality and motor coordination symmetry as a function of the symmetry of medial rotator muscle force in the shoulders was investigated. The principal objective was to distinguish swimmer profiles. Thirteen expert male swimmers performed the front crawl and were assessed for: (i) inter-arm coordination with the IdC and arm coordination symmetry with the Symmetry Index, (ii) breathing laterality, and (iii) the symmetry of the isokinetic force in the shoulder medial rotators. The results indicated that the relative duration of catch+pull was greater for the dominant arm (51.7%) than for the non-dominant arm (48.4%) for the swimmers with force asymmetry (p<0.05) and occurred on the side with the higher force (dominant arm). Two profiles were revealed: (i) swimmers for whom breathing laterality was related to force symmetry and stroke phase duration and (ii) swimmers for whom the impact of breathing laterality on force symmetry and stroke duration was low. The first profile corresponded to sprint specialists and the second profile corresponded more to middle-distance specialists.

Physiological and Perceived Exertion Responses during International Karate Kumite Competition.

Purpose Investigate the physiological responses and rating of perceived exertion (RPE) in elite karate athletes and examine the relationship between a subjective method (Session-RPE) and two objective heart-rate (HR)-based methods to quantify training-load (TL) during international karate competition. Methods Eleven karatekas took part in this study, but only data from seven athletes who completed three matches in an international tournament were used (four men and three women). The duration of combat was 3 min for men and 2 min for women, with 33.6±7.6 min for the first interval period (match 1–2) and 14.5±3.1 min for the second interval period (match 2–3). HR was continuously recorded during each combat. Blood lactate [La-] and (RPE) were measured just before the first match and immediately after each match. Results Means total fights time, HR, %HRmax, [La-], and session-RPE were 4.7±1.6 min, 182±9 bpm, 91±3%, 9.02±2.12 mmol.L-1 and 4.2±1.2, respectively. No significant differences in %HRmax, [La-], and RPE were noticed across combats. Significant correlations were observed between RPE and both resting HR (r=0.60; P=0.004) and mean HR (r=0.64; P=0.02), session-RPE and Banister training-impulse (TRIMP) (r=0.84; P<0.001) and Edwards TL (r=0.77; P<0.01). Conclusion International karate competition elicited near-maximal cardiovascular responses and high [La-]. Training should therefore include exercise bouts that sufficiently stimulate the zone between 90 and 100% HRmax. Karate coaches could use the RPE-method to follow competitors competition loads and consider it in their technical and tactical training.

Mechanics of pole vaulting: a review

A good understanding of the mechanics of pole vaulting is fundamental to performance because this event is quite complex, with several factors occurring in sequence and/or in parallel. These factors mainly concern the velocities of the vaulter-pole system, the kinetic and potential energy of the vaulter and the strain energy stored in the pole, the force and torque applied by the athlete, and the pole design. Although the pole vault literature is vast, encompassing several fields such as medicine, sports sciences, mechanics, mathematics, and physics, the studies agree that pole vault performance is basically influenced by the energy exchange between the vaulter and pole. Ideally, as the athlete clears the crossbar, the vaulter mechanical energy must be composed of high potential energy and low kinetic energy, guaranteeing the high vertical component of the vault. Moreover, the force and torque applied by the vaulter influences this energy exchange and these factors thus must be taken into consideration in the analysis of performance. This review presents the variables that influence pole vault performance during the run-up, take-off, pole support, and free flight phases.

Static apnea effect on heart rate and its variability in elite breath-hold divers

BACKGROUND The diving response includes cardiovascular adjustments known to decrease oxygen uptake and thus prolong apnea duration. As this diving response is in part characterized by a pronounced decrease in heart rate (HR), it is thought to be vagally mediated. METHODS In five professional breath-hold divers (BHDs) and five less-trained controls (CTL), we investigated whether the diving response is in fact associated with an increase in the root mean square successive difference of the R-R intervals (RMSSD), a time-domain heart rate variability (HRV) index. HR behavior and arterial oxygen saturation (SaO2) were continuously recorded during one maximal apnea. Short-term changes in SaO2, HR, and RMSSD were calculated over the complete apnea duration. RESULTS BHDs presented bi-phasic HR kinetics, with two HR decreases (32 +/- 17% and 20 +/- 10% of initial HR). The second HR decrease, which was concomitant to the pronounced SaO2 decrease, was also simultaneous to a marked increase in RMSSD. CTL showed only one HR decrease (50 +/- 10% of initial HR), which appeared before the concomitant SaO2 and RMSSD changes. When all subject data were combined, arterial desaturation was positively correlated with total apnea time (r = 0.87, P < 0.01). CONCLUSION This study indicates that baroreflex stimulation and hypoxia may be involved in the bi-phasic HR response of BHDs and thus in their longer apnea duration.

Study of the Fatigue Curve in Quadriceps and Hamstrings of Soccer Players During Isokinetic Endurance Testing

Sangnier, S and Tourny-Chollet, C. Study of the fatigue curve in quadriceps and hamstrings of soccer players during isokinetic endurance testing. J Strength Cond Res 22(5): 1458-1467, 2008-Many studies have presented regression models of quadriceps (Q) muscle strength loss with fatigue development. Paradoxically, the hamstrings (H), which are the principal site of muscle injury in soccer players, have received little attention, and no regression model has been established. This study investigated strength loss in the Q and H to establish a regression model using the lowest number of flexions-extensions during isokinetic endurance testing. Twenty-four semiprofessional soccer players performed 50 flexion-extension movements at 180°·s−1 on an isokinetic dynamometer. The theoretical equations were calculated from the first 10, first 15, first 20, and first 25 contractions for each muscle group by several regression models (linear, quadratic, cubic). The linear model was the best fit to this exercise protocol to describe the strength loss in both muscle groups. The quadratic model was the best fit to predict the changes in the H/Q ratio. This study showed that a regression model can be established for both muscle groups. A minimum of 20 extensions and 15 flexions was needed to establish a linear model that represented strength loss in, respectively, Q and H. A minimum of 25 flexions-extensions was needed with the quadratic model to accurately determine the decrease in the H/Q ratio. Isokinetic endurance testing can be carried out with only 25 flexions-extensions. This reduction should facilitate the implementation of this protocol. Regular evaluation would contribute to the efforts to prevent muscle injury during competitive sports activity.

Relevance of the measure of perceived exertion for the rehabilitation of obese patients.

The most common tool used for measuring effort perception is the rating scale of perceived exertion (RPE) developed by Borg. This scale is also used for various outcomes in the general population. The validity and reliability of this scale have already been reported in obese patients. However, the relevance of measuring perceived exertion in obese patients is still poorly known. This review of the literature presents the Borg RPE scale (i.e., validity, reliability and recommendations) and its main advantages during graded exercise tests (e.g., comparison of physical capacity, predicting physiological variables, verifying exhaustion and exercise safety) and rehabilitation programs (e.g., individualized exercise intensity, evaluation of the impact of a rehabilitation program and even determining the perceptual preference) in obese patients. This review of the literature underlines the relevance and usefulness of the Borg RPE scale, which is still underused in obese patients. However, additional studies are still necessary before using this scale routinely in all obese patients (regardless of the severity of their obesity or associated complications).

Apnea Training Effects on Swimming Coordination

Lemaître, F, Seifert, L, Polin, D, Juge, J, Tourny-Chollet, C, and Chollet, D. Apnea training effects on swimming coordination. J Strength Cond Res 23(6): 1909-1914, 2009-Triathletes and elite breath-hold divers show an adaptive response to hypoxia induced by repeated epochs of breath holding. We hypothesized that hypoxic training could also improve swimming coordination. Before and after a 3-month breath-hold training program, 4 male swimmers performed a maximal incremental test on bicycle and a 50-m front crawl race at maximal speed without breathing so that interarm coordination could be assessed. Swim velocity, stroke rate (SR), stroke length (SL), and the arm stroke phases were calculated from video analysis. Arm coordination was quantified in terms of an index of coordination (IdC) based on the time gap between the propulsive phases of each arm. After apnea training, the forced expiratory volume in 1 second was higher (4.85 ± 0.78 vs. 4.94 ± 0.81 L, p < 0.05), with concomitant increases in &OV0312;o2peak, minimal arterial oxygen saturation, and respiratory compensation point values (W and W·kg−1) during the incremental test. Swimming performance was not improved (clean velocity and time on 50 m); however, SR was decreased and SL and IdC were increased. These results indicate that apnea training improves effectiveness at both peak exercise and submaximal exercise and can also improve swimming technique by promoting greater propulsive continuity.

Effect of the upper limbs muscles activity on the mechanical energy gain in pole vaulting

The shoulder muscles are highly solicited in pole vaulting and may afford energy gain. The objective of this study was to determine the bilateral muscle activity of the upper-limbs to explain the actions performed by the vaulter to bend the pole and store elastic energy. Seven experienced athletes performed 5-10 vaults which were recorded using two video cameras (50Hz). The mechanical energy of the centre of gravity (CG) was computed, while surface electromyographic (EMG) profiles were recorded from 5 muscles bilateral: deltoideus, infraspinatus, biceps brachii, triceps, and latissimus dorsi muscles. The level of intensity from EMG profile was retained in four sub phases between take-off (TO1) and complete pole straightening (PS). The athletes had a mean mechanical energy gain of 22% throughout the pole vault, while the intensities of deltoideus, biceps brachii, and latissimus dorsi muscles were sub phases-dependent (p<0.05). Stabilizing the glenohumeral joint (increase of deltoideus and biceps brachii activity) and applying a pole bending torque (increase of latissimus dorsi activity) required specific muscle activation. The gain in mechanical energy of the vaulter could be linked to an increase in muscle activation, especially from latissimusdorsi muscles.