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Exercise training offers possible nonpharmacological therapy for cardiovascular diseases including hypertension. High-intensity intermittent exercise (HIIE) training has been shown to have as much or even more beneficial cardiovascular effect in patients with cardiovascular diseases than moderate-intensity continuous exercise (CMIE) training. The aim of this study was to investigate the effects of the two types of training on cardiac remodeling of spontaneously hypertensive rats (SHR) induced by hypertension. Eight-week-old male SHR and normotensive Wistar-Kyoto rats (WKY) were divided into four groups: normotensive and hypertensive control (WKY and SHR-C) and hypertensive trained with CMIE (SHR-T CMIE) or HIIE (SHR-T HIIE). After 8 wk of training or inactivity, maximal running speed (MRS), arterial pressure, and heart weight were all assessed. CMIE or HIIE protocols not only increased final MRS and left ventricular weight/body weight ratio but also reduced mean arterial pressure compared with sedentary group. Then, left ventricular tissue was enzymatically dissociated, and isolated cardiomyocytes were used to highlight the changes induced by physical activity at morphological, mechanical, and molecular levels. Both types of training induced restoration of transverse tubule regularity, decrease in spark site density, and reduction in half-relaxation time of calcium transients. HIIE training, in particular, decreased spark amplitude and width, and increased cardiomyocyte contractility and the expression of sarco(endo)plasmic reticulum Ca2+-ATPase and phospholamban phosphorylated on serine 16. NEW & NOTEWORTHY High-intensity intermittent exercise training induces beneficial remodeling of the left ventricular cardiomyocytes of spontaneously hypertensive rats at the morphological, mechanical, and molecular levels. Results also confirm, at the cellular level, that this type of training, as it appears not to be deleterious, could be applied in rehabilitation of hypertensive patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fatigability measured and derived parameters are commonly used in research and clinical contexts to characterize performance during isokinetic fatigue protocols. The fatigability measured parameters are the best repetition, the total and the partial sums while the fatigability derived parameters are ratios and formula-based parameters. OBJECTIVES: To comprehensively evaluate the reproducibility of fatigability measured and derived parameter and to determine which of these is/are sufficiently interpretable for assessment of knee muscles. METHODS: Eighteen sedentary men underwent three isokinetic knee fatigability testing sessions with 7–10 days of rest between each session. Peak moment (PM) and maximal work (MW) were computed for each repetition and analyzed to calculate 54 measured and derived parameters. Relative (Intra-class Correlation Coefficients – ICC) and absolute (Coefficient of Variation of Method Error – CV ME %, standard error of measurement – SEM and minimum detectable change – MDC) parameters of reproducibility were determined to assess the inter-session agreement. RESULTS: All fatigability measured parameters (save one) were associated with a high relative and absolute reproducibility for knee extensors (ICC ⩾ 0.80; almost all SEM ⩽ SD 2 ; MDCs largely ranging 10–30%) and a high relative but weak absolute reproducibility for flexors (ICC ⩾ 0.70; SEM > SD 2 ; MDCs ranging 35–95%). On the other hand, all knee extensor and flexor fatigability derived parameters were characterized by low relative and absolute reproducibility (ICC extensors < 0.70 and ICC flexors < 0.50; all SEM > SD 2 ; MDCs largely ranging 30–100%). CONCLUSIONS: All fatigability measured parameters may be used for assessing knee extensors fatigue with either PM or MW; for assessing knee flexors, no measured parameters can be utilized. Above all, knee fatigability derived parameters, either PT- or MW-based, should not be used, for both the extensors and the flexors of the knee, due to clinically unacceptable reproducibility. [ABSTRACT FROM AUTHOR]

Global ventricular response to exercise may be useful in follow-up of patients with residual right outflow tract lesions after congenital heart disease repair. In this context, impedance cardiography is considered accurate for stroke volume (SV) measurement during exercise testing, however, to date, only partial assessment of its reliability has been reported. We retrospectively evaluated relative and absolute reliability of peak SV by impedance cardiography during exercise using intraclass correlation (ICC) and standard error of measurement (SEM) in this population. Peak SV was measured in 30 young patients (mean age 14.4 years ± 2.1) with right ventricular outflow tract reconstruction who underwent two cardiopulmonary exercise tests at a mean one-year interval. SV was measured using a signal morphology impedance cardiography analysis device (PhysioFlow) and was indexed to body surface area. ICC of peak indexed SV measurement was 0.80 and SEM was 10.5%. High heterogeneity was seen when comparing patients according to peak indexed SV; in patients with peak SV < 50 ml/m (15 patients), ICC rose to 0.95 and SEM dropped to 2.7%, while in patients with a peak SV > 50 ml/m relative and absolute reliability decreased (ICC = 0.45, SEM = 12.2%). Peak exercise SV assessment by a PhysioFlow device represents a highly reliable method in patients with residual right outflow tract lesions after congenital heart disease repair, especially in patients with peak SV < 50 ml/m. In this latter group, a peak SV decrease > 7.3% (corresponding to the minimum 'true' difference) should be considered a clinically-relevant decrease in global ventricular performance and taken into account when deciding whether to perform residual lesion removal. [ABSTRACT FROM AUTHOR]

Modification of source-sink ratios in tropical maize through detasseling is an ancestral agronomical practice used for increasing yields under stressful conditions. However, the mechanisms behind such effect are not well understood given the difficulties to determine physiological processes such as photosynthesis and whole-plant transpiration in the field. We have tested the potential ability of kernel δ18O to assess differences in grain yield ( GY) through changes in plant transpiration caused by the modification of water availability and source-sink modification treatments, (including removal of the tassel and different numbers of leaves) in three tropical maize hybrids differing in drought tolerance. Drought-tolerant genotypes displayed higher yields and lower kernel δ18O values than the drought-susceptible genotype under both well-watered ( WW) and water-stressed ( WS) conditions. Detasseling caused a positive increase in GY under well-watered (up to 8%) and water-deficit conditions (up to 36%). Reduction in leaf area (source) through defoliation treatments caused a large impact on GY showing a trade-off between maintaining a photosynthetic versus transpiring leaf area. Thus, while a reasonable reduction in leaf area significantly improved plant water availability (as shown by lower kernel δ18O values) and consequently GY under water deficit (up to 40%), it caused a maximum reduction of 25% in GY under well-watered conditions. Variations in GY were significantly ( p < .05) correlated with changes in δ18O under both well-watered ( r = −.67) and WS conditions ( r = .75 and .82). Our results also reinforce the utility of δ18O measured in mature kernels as a powerful ecophysiological tool for assessing genotypic differences in apical dominance, transpiration and yield under both WW and WS conditions in tropical maize. [ABSTRACT FROM AUTHOR]

The effectiveness of regular exercise in decreasing both systolic and diastolic blood pressure ( BP) is well-established. Our purpose was to assess the impact of both subject and physical activity program characteristics on ambulatory BP through a meta-analysis of the existing literature. Three databases ( PubMed, Embase, Web of Science) were searched using relevant terms and strategies. From 637 identified records, 37 studies met inclusion criteria: details about training intervention and participant characteristics, pre- and post-training ambulatory BP measurements, at home ( HBPM) or during 24-h ( ABPM). The weighted mean difference was for 24-h systolic/diastolic ABPM ( n = 847 participants): −4.06/−2.77 mmHg (95% CI: −5.19 to −2.93/−3.58 to −1.97; P < 0.001), for daytime ( ABPM or HBPM, n = 983): −3.78/−2.73 mmHg (95% CI: −5.09 to −2.47/−3.57 to −1.89; P < 0.001) and nighttime ABPM periods ( n = 796): −2.35/−1.70 mmHg (95% CI: −3.26 to −1.44/−2.45 to −0.95; P < 0.001). Characteristics significantly influencing BP improvement were: an initial office BP ≥130/85 mmHg and diet-induced weight-loss. We found no differences according to sex, age, or training characteristics (intensity, number of sessions, training duration). Antihypertensive effects of aerobic training assessed by ambulatory BP measurements appear significant and clinically relevant for both daytime and nighttime periods, in particular for participants with an office BP ≥130/85 mmHg. [ABSTRACT FROM AUTHOR]

To assess the relationship between selected measures (the slope and average performance) obtained during a high intensity isokinetic fatigue test of the knee (FAT) and relevant measures of anaerobic and aerobic capacities. 20 well-trained cyclists performed 3 randomly ordered sessions involving a FAT consisting in 30 reciprocal maximal concentric contractions of knee flexors and extensors at 180°.s-1, a maximal continuous graded exercise test (GXT), and a Wingate anaerobic test (WAnT). The slope calculated from peak torque (PT) and total work (TW) of knee extensors was highly associated to maximal PT (r=-0.86) and maximal TW (r=-0.87) measured during FAT, and moderately associated to peak power output measured during the WAnT (r= -0.64 to -0.71). Average PT and average TW were highly associated to maximal PT (r=0.93) and maximal TW (r=0.96), to mean power output measured during WAnT (r=0.83-0.90) and moderately associated to maximal oxygen uptake (0.58-0.67). In conclusion, the slope is mainly determined by maximal anaerobic power, while average performance is a composite measure depending on both aerobic and anaerobic energy systems according to proportions that are determined by the duration of the test. [ABSTRACT FROM AUTHOR]

To examine the effects of body size on locomotor performance, 807 15-year-old French and 64 Qatari soccer players participated in the present study. They performed a 40-m sprint and an incremental running test to assess maximal sprinting (MSS) and aerobic speeds, respectively. French players were advanced in maturity, taller, heavier, faster and fitter than their Qatari counterparts (e. g., Cohen’s d = + 1.3 and + 0.5 for body mass and MSS). However, when adjusted for body mass (BM), Qatari players had possibly greater MSS than French players (d = + 0.2). A relative age effect was observed within both countries, with the players born in the first quarter of the year being taller, heavier and faster that those born during the fourth quarter (e. g., d = + 0.2 for MSS in French players). When directly adjusted for BM, these MSS differences remained (d = + 0.2). Finally, in both countries, players selected in National teams were taller, heavier, faster and fitter than their non-selected counterparts (e. g., d = + 0.6 for MSS in French players), even after adjustments for body size (d = + 0.5). Differences in locomotor performances between players with different phenotypes are likely mediated by differences in body size. However, when considering more homogeneous player groups, body dimensions are unlikely to substantially explain the superior locomotor performances of older and/or international players. [ABSTRACT FROM AUTHOR]

The purpose of this study was to characterize the effect of a 2-week overload period immediately followed by a 1-week taper period on different cognitive processes including executive and nonexecutive functions, and related heart rate variability. Eleven male endurance athletes increased their usual training volume by 100% for 2 weeks, and decreased it by 50% for 1 week. A maximal graded test, a constant speed test at 85% of peak treadmill speed, and a Stroop task with the measurement of heart rate variability were performed at each period. All participants were considered as overreached. We found a moderate increase in the overall reaction time to the three conditions of the Stroop task after the overload period (816 ± 83 vs 892 ± 117 ms, P = 0.03) followed by a return to baseline after the taper period (820 ± 119 ms, P = 0.013). We found no association between cognitive performance and cardiac parasympathetic control at baseline, and no association between changes in these measures. Our findings clearly underscore the relevance of cognitive performance in the monitoring of overreaching in endurance athletes. However, contrary to our hypothesis, we did not find any relationship between executive performance and cardiac parasympathetic control. [ABSTRACT FROM AUTHOR]

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The purpose of this study was to assess the effect of resistance training cessation on strength performance through a meta-analysis. Seven databases were searched from which 103 of 284 potential studies met inclusion criteria. Training status, sex, age, and the duration of training cessation were used as moderators. Standardized mean difference ( SMD) in muscular performance was calculated and weighted by the inverse of variance to calculate an overall effect and its 95% confidence interval ( CI). Results indicated a detrimental effect of resistance training cessation on all components of muscular performance: [submaximal strength; SMD (95% CI) = −0.62 (−0.80 to −0.45), P < 0.01], [maximal force; SMD (95% CI) = −0.46 (−0.54 to −0.37), P < 0.01], [maximal power; SMD (95% CI) = −0.20 (−0.28 to −0.13), P < 0.01]. A dose-response relationship between the amplitude of SMD and the duration of training cessation was identified. The effect of resistance training cessation was found to be larger in older people (> 65 years old). The effect was also larger in inactive people for maximal force and maximal power when compared with recreational athletes. Resistance training cessation decreases all components of muscular strength. The magnitude of the effect differs according to training status, age or the duration of training cessation. [ABSTRACT FROM AUTHOR]

Further knowledge of the processes conditioning nitrogen use efficiency (NUE) is of great relevance to crop productivity. The aim of this paper was characterise C and N partitioning during grain filling and their implications for NUE. Cereals such as bread wheat ( Triticum aestivum L. cv Califa sur), triticale (× Triticosecale Wittmack cv. Imperioso) and tritordeum (× Tritordeum Asch. & Graebn line HT 621) were grown under low (LN, 5 m m NH4NO3) and high (HN, 15 m m NH4NO3) N conditions. We conducted simultaneous double labelling (12CO2 and 15NH415NO3) in order to characterise C and N partitioning during grain filling. Although triticale plants showed the largest total and ear dry matter values in HN conditions, the large investment in shoot and root biomass negatively affected ear NUE. Tritordeum was the only genotype that increased NUE in both N treatments (NUEtotal), whereas in wheat, no significant effect was detected. N labelling revealed that N fertilisation during post-anthesis was more relevant for wheat and tritordeum grain filling than for triticale. The study also revealed that the investments of C and N in flag leaves and shoots, together with the 'waste' of photoassimilates in respiration, conditioned the NUE of plants, and especially under LN. These results suggest that C and N use by these plants needs to be improved in order to increase ear C and N sinks, especially under LN. It is also remarkable that even though tritordeum shows the largest increase in NUE, the low yield of this cereal limits its agronomic value. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine whether the amplitude of the ?V O 2 slow component was dependent from Critical Power (CP; the slope of the linear time - distance relationship) in individuals matched for ?V O 2 peak. 30 moderatelytrained endurance athletes completed a maximal graded exercise test, 2 randomly ordered constant power tests at 90 and 100 % of peak power output (PPO), and 2 constant duration test of 6 min at 30 % of the diff erence between CP and PPO. Afterwards, participants were ranked according to their relative CP ( % PPO; a direct measure of aerobic endurance). The median third was excluded to form a low aerobic endurance group (LEG) and a high aerobic endurance group (HEG). A t-test revealed no diff erence between LEG and HEG in peak oxygen consumption, but a large diff erence in their relative CP (p < 0.001,eff ect size = 3.2). A ? 2 was similar between groups (626 ± 96 and 512 ± 176 ml, corresponding to 26 ± 4 and 24 ± 8 % of end exercise oxygen consumption, respectively; NS) and was not associated with relative CP (r = 0.10; NS). These results suggest that increasing CP probably extends the range of exercise intensities over which the ?V O 2 slow component does not develop, but does not decrease the amplitude of this phenomenon once it occurs. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether cognitive performance was a valid marker of overreaching. 10 well-trained male endurance athletes increased their training load by 100% for 2 weeks. They performed a maximal graded test, a constant speed test, a reaction time task and a computerized version of the Stroop color word-test before and after this overload period. Regarding performance results, five participants were considered as overreached and the five remaining were considered as well-trained. We found no significant differences between groups in performing the Stroop test. Noteworthy, we found a small increase in response time in the more complex condition in overreached athletes (1188±261 to 1297 ± 231 ms. effect size = 0.44), while it decreased moderately in the well- trained athletes (1066±175 to 963±171 ms, effect size=-0.59). Furthermore, we found an interaction between time and group on initiation time of the reaction time task, since it increased in overreached athletes after the overload period (246±24 to 264±26 ms, p<0.05), while it remained unchanged in well-trained participants. Participants made very few anticipation errors, whatever the group or the period (error rate <2%).We concluded that an unaccustomed increase in training volume which is accompanied by a decrement in physical performance induces a deterioration of some executive functions. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine absolute and relative reliability of fatigue measures calculated from peak torque or total work during 20, 30, 40 and 50 reciprocal maximal concentric contractions performed on an isokinetic dynamometer at 180°·s-1. Eighteen moderately active men performed 50 reciprocal maximal concentric contractions on three occasions with one 7-10 days recovery between each session. Peak torque and total work were computed for each con- traction and subsequently summed to compute cumulated performance after respectively 20, 30, 40 and 50 repetitions. Muscle fatigue was determined after 20, 30, 40 and 50 repetitions by the fatigue index, the percent decrease in performance and the slope. Reliability of average peak torque or average total work was similar and was not affected by the lengthening of the protocol, although a learning effect was evident for knee flexors. Reliability of fatigue measures calculated from peak torque or total work was similar, improved with the lengthening of the protocol and was better for knee extensors. Measuring average peak torque or average total work and the slope during a protocol involving 30 maximal reciprocal concentric contractions appear to represent a better compromise between reliability and physiological interpretability of the data. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare Anaerobic Work Capacity (AWC) measured on an isoinertial or an isokinetic bicycle ergometer. Twelve male participants completed two randomly ordered exercise testing sessions including a torque-velocity test followed by a 30-s all-out test on an isokinetic ergometer, or a force-velocity test followed by a Wingate Anaerobic Test on an isoinertial ergometer. Optimal load measured during the force-velocity test on the isomertial ergometer was 1.13 ±0.11 N.kg-1. Optimal cadence measured during the torque-velocity test on the isokinetic ergometerwas 107 ± 13rpm. Although Ppeak measures were significantly correlated (r=0.77), we found a large difference between them (effect size=2.85) together with wide limits of agreement (bias±95%LOA=24± 12%). The same observation was made with Pmean, but with a smaller magnitude of difference (bias ±95%LOA=4.2± 12%; effect size=0.51; r=0.73). This lack of agreement led us to the conclusion that AWC measures obtained during 30-s all-out tests performed on an isoinertial or an isokinetic bicycle ergometer are not necessarily similar and cannot be used interchangeably. [ABSTRACT FROM AUTHOR]

OBJECTIVE: A meta-analysis was conducted on the effect of overload training on resting HR, submaximal and maximal exercise HR (HR), and heart rate variability (HRV), to determine whether these measures can be used as valid markers of over-reaching. METHODS: Six databases were searched using relevant terms and strategies. Criteria for study inclusion were: participants had to be competitive athletes, an increased training load intervention had to be used, and all necessary data to calculate effect sizes had to be available. An arbitrary limit of 2 weeks was chosen to make the distinction between short-term and long-term interventions. Dependent variables were HR and HRV (during supine rest). Standardised mean differences (SMD) in HR or HRV before and after interventions were calculated, and weighted according to the within-group heterogeneity to develop an overall effect. RESULTS: In these competitive athletes, short-term interventions resulted in a moderate increase in both resting HR (SMD = 0.55; p = 0.01) and low frequency/high frequency ratio (SMD = 0.52; p = 0.02), and a moderate decrease in maximal HR (SMD = -0.75; p = 0.01). Long-term interventions resulted in a small decrease in HR during submaximal (SMD = -0.38; p = 0.006) and maximal exercise (SMD = -0.33; p = 0.007), without alteration of resting values. CONCLUSION: The small to moderate amplitude of these alterations limits their clinical usefulness, as expected differences may fall within the day-to-day variability of these markers. Consequently, correct interpretation of HR or HRV fluctuations during the training process requires the comparison with other signs and symptoms of over-reaching to be meaningful. [ABSTRACT FROM AUTHOR]

Objective: A meta-analysis was conducted on the effect of overload training on resting HR. submaximal and maximal exercise HR (HA), and heart rate variability (HRV), to determine whether these measures can be used as valid markers of over-reaching. Methods: Six databases were searched using relevant terms and strategies. Criteria for study inclusion were: participants had to be competitive athletes, an increased training load intervention had to be used, and all necessary data to calculate effect sizes had to be available. An arbitrary limit of 2 weeks was chosen to make the distinction between short-term and long-term interventions. Dependent variables were HR and HRV (during supine rest). Standardised mean differences (SMD) in HR or HRV before and after interventions were calculated, and weighted according to the within-group heterogeneity to develop an overall effect. Results: In these competitive athletes, short-term interventions resulted in a moderate increase in both resting HR (SMD = 0.55; p = 0.01) and low frequency! high frequency ratio (SMD = 0.52; p = 0.02), and a moderate decrease in maximal HR (SMD = -0.75; p = 0.01). Long-term interventions resulted in a small decrease in HR during submaximal (SMD = -0.38; p = 0.006) and maximal exercise (SMD = -0.33; p = 0.007), without alteration of resting values. Conclusion: The small to moderate amplitude of these alterations limits their clinical usefulness, as expected differences may fall within the day-to-day variability of these markers. Consequently, correct interpretation of HR or HRV fluctuations during the training process requires the comparison with other signs and symptoms of over-reaching to be meaningful. [ABSTRACT FROM AUTHOR]

Passive postexercise heart rate (HR) recovery is currently used in the assessment of endurance athletes to determine changes in performance or in the clinical setting as a predictor of all-cause mortality. The purpose of this investigation was to assess the reliability of HR recovery. Thirty healthy subjects performed two maximal and two submaximal treadmill exercises, followed by 5 minutes of passive recovery. HR signal was used to compute raw and Δ (exercise - recovery) HR after 1, 2, 3, and 5 minutes of exercise cessation. A mono-exponential function was fitted to the data using the least squares procedure. We found no significant bias between repeated measures. Relative reliability was lower for Δ HR when compared with raw HR (0.43

Intervals between two consecutive cardiac beats (R-R intervals) and the subsequent analysis of heart rate variability (HRV) obtained simultaneously from the Polar S810 heart rate monitor (HRM) and an electrocardiogram (ECG) in a supine position were compared in twelve children (age 9.6±0.9 years) before and after protocol correction. R-R intervals were significantly different between the ECG and the HRM uncorrected and corrected signal (p<0.001, effect size [ES] = 0.005, and 0.005, respectively). However, the bias (95% confidence interval) was 0.80 (-124.76-123.16) ms and 0.80 (- 12.76-11.16) ms, respectively. HRV parameters derived from both signals were not different (p>0.05) and well correlated (r>0.99, p<0.05), except SD2 (p<0.05, ES= 0.000; r=0.99). These data support the validity of the Polar S810 HRM to measure R-R intervals and make the subsequent HRV analysis in a supine position in children. [ABSTRACT FROM AUTHOR]

Water scarcity and nitrogen shortage are the main constraints on durum wheat productivity. This paper examines the combined effects of a constant water deficit and nitrogen supply (NS) on growth, photosynthesis, stomatal conductance ( gs) and transpiration, instantaneous and time-integrated water use efficiency (WUE) and nitrogen use efficiency (NUE) and carbon isotope discrimination (Δ13C) in durum wheat genotypes grown in pots under greenhouse conditions. Three water levels (40%, 70% and 100% container capacity), two nitrogen doses (high and low N) and four genotypes were assayed in a total of 24 experimental treatments. Water and nitrogen treatments were imposed 2 weeks after plant emergence. The growth, nitrogen content and Δ13C of the shoot and the gas exchange in the flag leaf were determined about 2 weeks after anthesis. As expected, both water and NS had a strong positive effect on growth. However, a reduction in water supply had low effect decreasing photosynthesis and transpiration, Δ13C and NUE and increasing WUE. On the contrary, increasing the level of nitrogen supplied had a significant negative effect on gs, which decreased significantly the ratio of intercellular to ambient CO2 concentrations and Δ13C, and increased both instantaneous and time-integrated WUE. In addition, a higher N level also negatively affected the instantaneous and time-integrated NUE. The Δ13C of shoots correlated significantly and negatively with either instantaneous or time-integrated measurements of WUE. Moreover, within each NS, Δ13C also correlated negatively with the integrated NUE. We concluded that under our experimental conditions, Δ13C gives information about the efficiency with which not just water but also nitrogen are used by the plant. In addition, this study illustrates that a steady water limitation may strongly affect biomass without consistent changes in WUE. The lack of effect of the different water regimes on gas exchange, WUE and Δ13C illustrate the importance of how stress is imposed during growth. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the effect of twelve weeks of aerobic training and eight weeks of training cessation on Heart Rate Variability (HRV). Ten healthy young men (Age: 21.7 +/- 2.2 years; Height: 179.2 +/- 6.9 cm; Mass 72.7 +/- 11.1 kg) completed an incremental test and a 60 degrees tilt test during which R-R intervals were recorded before (T0) and after (T12) 12 weeks of intensive training, and after 2, 4 and 8 weeks of training cessation (D2, D4 and D8, respectively). HRV was computed in time and frequency domains. Training resulted in a significant increase in estimated VO2max after T12 (p < 0.01), followed by a significant decrease during D2 and D8 (p < 0.05). Total power (LF + HF) and low frequency power (LF) increased significantly in the supine position after the training period (p < 0.05) and decreased moderately after D2 (p > 0.05) to stabilize afterwards. LF + HF and LF were not different from T0 at D8 (p > 0.05). It was concluded that eight weeks of training cessation allow to reverse the cardiovascular autonomic adaptations induced by 12 weeks of intensive training in healthy young men. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the effect of twelve weeks of aerobic training and eight weeks of training cessation on Heart Rate Variability (HRV). Ten healthy young men (Age: 21.7±2.2 years; Height: 179.2±6.9cm; Mass 72.7 ± 11.1 kg) completed an incremental test and a 600 tilt test during which R-R intervals were recorded before (TO) and after (112) 12 weeks of intensive training, and after 2, 4 and 8 weeks of training cessation (D2, D4 and D8, respectively). HRV was computed in time and frequency domains. Training resulted in a significant increase in estimated VO2max after T12 (p <0.01), followed by a significant decrease during D2 and D8 (p <0.05). Total power (LF + HF) and low frequency power (LF) increased significantly in the supine position after the training period (p<0.05) and decreased moderately after D2 (p>0.05) to stabilize afterwards. LF+HF and LF were not different from TO at D8 (p >0.05). It was concluded that eight weeks of training cessation allow to reverse the cardiovascular autonomic adaptations induced by 12 weeks of intensive training in healthy young men. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare .VO2 kinetics of highly- versus recreationally-trained subjects during a constant velocity test of supramaximal intensity. Eighteen trained male subjects were recruited to one of two groups: highly trained (HT, n = 8, .VO(2max) = 70.1 +/- 6.5 ml . min (-1) . kg (-1)) and recreationally trained (RT, n = 10, .VO(2max) = 63.2 +/- 6.4 ml . min (-1) . kg (-1)). All subjects performed an incremental test to exhaustion for the determination of .VO(2max) and peak treadmill velocity (PTV), two constant velocity tests at 110% of PTV to determine .VO2 kinetics and oxygen deficit (O(2)def), and a 800-m time trial to determine running performance (mean velocity over the distance, V (800 m)). We found significant differences between HT and RT for the on-transient of the .VO2 response (tau, 24.7 +/- 3.3 and 30.9 +/- 7.0 s, respectively), the amplitude of the .VO2 response (60.0 +/- 5.0 and 53.5 +/- 5.7 ml . min (-1) . kg (-1), respectively) and V (800 m) (6.27 +/- 2.1 and 5.45 +/- 0.38 m . s (-1), respectively). O(2)def (24.6 +/- 2.7 and 27.7 +/- 7.8 ml . kg (-1), respectively) and the gain of the .VO2 response (193 +/- 14 and 194 +/- 13 ml . kg (-1) . m (-1), respectively) were similar between groups. tau was associated with O(2)def (r = 0.90, p < 0.05), but not with V (800 m) (r = 0.30, p > 0.05). It was concluded that HT subjects exhibited faster on-kinetics and higher amplitude than their RT counterparts. The higher amplitude was not thought to reflect any difference in underlying physiological mechanisms. The faster tau, whose exact mechanisms remain to be elucidated, may have practical implications for coaches. [ABSTRACT FROM AUTHOR]

Copyright of Oncologie (Tech Science Press) is the property of Tech Science Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A variety of testing procedures are used to assess the effects of particular treatments on the training status of athletes. The present study aims to investigate the reproducibility of selected tests in swimming. Sixteen trained swimmers performed three kinds of test: 1) Constant Distance Test (CDT), 2) Constant Time Test (CTT), and 3) Constant Velocity Test (CVT). The analysis of the reproducibility was based on a test-retest procedure. The test-re- test performances were highly correlated for the three kinds of test (r=0.98, 0.98, and 0.93 for CDT, CIT and CVT, respectively). The mean Coefficient of Variation (CV) was computed between test-retest for each subject and each procedure A repeated measures one-way ANOVA showed that CVT was significantly less reliable (CV=6.46±6.24%) than CDT and CTT (CV=0.56± 0.60% and 0.63±0.54% respectively) (p<0.001). Psychological factors and a lack of familiarity with CVT (not extensively used during training session) could explain its greater variability. Thus, CDT and CIT seem to be the most reliable tests to detect the smallest meaningful change in the training status of swimmers. Post-hoc power calculations of the experimental design showed the sample size would have to increase to 80, 113, and 228 subjects for CWT, CDT and CPT respectively, to reach a power of 80%. The minimal detectable differences have to be calculated to ensure a real effect of a particular treatment on a group of swimmers, according to the kind of test used. [ABSTRACT FROM AUTHOR]

Physiological testing of elite athletes requires the correct identification and assessment of sports-specific underlying factors. It is now recognised that performance in long-distance events is determined by maximal oxygen uptake (O), energy cost of exercise and the maximal fractional utilisation of O in any realised performance or as a corollary a set percentage of O that could be endured as long as possible. This later ability is defined as endurance, and more precisely aerobic endurance, since O sets the upper limit of aerobic pathway. It should be distinguished from endurance ability or endurance performance, which are synonymous with performance in long-distance events. The present review examines methods available in the literature to assess aerobic endurance. They are numerous and can be classified into two categories, namely direct and indirect methods. Direct methods bring together all indices that allow either a complete or a partial representation of the power-duration relationship, while indirect methods revolve around the determination of the so-called anaerobic threshold (AT). With regard to direct methods, performance in a series of tests provides a more complete and presumably more valid description of the power-duration relationship than performance in a single test, even if both approaches are well correlated with each other. However, the question remains open to determine which systems model should be employed among the several available in the literature, and how to use them in the prescription of training intensities. As for indirect methods, there is quantitative accumulation of data supporting the utilisation of the AT to assess aerobic endurance and to prescribe training intensities. However, it appears that: there is no unique intensity corresponding to the AT, since criteria available in the literature provide inconsistent results; and the non-invasive determination of the AT using ventilatory and heart rate data instead of blood lactate concentration ([La]) is not valid. Added to the fact that the AT may not represent the optimal training intensity for elite athletes, it raises doubt on the usefulness of this theory without questioning, however, the usefulness of the whole [La]-power curve to assess aerobic endurance and predict performance in long-distance events. [ABSTRACT FROM AUTHOR]

Copyright of Oncologie (Tech Science Press) is the property of Tech Science Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An abstract of the study "Effect of Training Intensity on Heart Rate Variability in Prepubescent Children," by F.-X. Gamelin, G. Baquet, S. Berthoin, D. Thevenet, C. Nourry, S. Nottin and L. Bosquet is presented.

Presents guidelines of the organizing committee Standards, Options and Recommendations for the use of positron emission tomography with 2-[[sup]18F]fluoro-2-deoxy-D-glucose (FDP-PET scanning) in oncology. Definition of Standards, Options and Recommendations and level of evidence; Advantages of positron emission tomography; Availability of scientific data and the development of Standards, Options, and Recommendations for the role of and indications for FDG-PET scanning in oncology.