Walking for subjects with type 2 diabetes: A systematic review and joint AMD/SID/SISMES evidence-based practical guideline.

AIMS: Regular exercise is considered a cornerstone in the management of type 2 diabetes mellitus (T2DM). It improves glucose control and cardiovascular risk factors, contributes to weight loss, and also improves general well-being, likely playing a role in the prevention of chronic complications of diabetes. However, compliance to exercise recommendations is generally inadequate in subjects with T2DM. Walking is the most ancestral form of physical activity in humans, easily applicable in daily life. It may represent, in many patients, a first simple step towards lifestyle changes. Nevertheless, while most diabetic patients do not engage in any weekly walking, exercise guidelines do not generally detail how to improve its use. The aims of this document are to conduct a systematic review of available literature on walking as a therapeutic tool for people with T2DM, and to provide practical, evidence-based clinical recommendations regarding its utilization in these subjects. DATA SYNTHESIS: Analysis of available RCTs proved that regular walking training, especially when supervised, improves glucose control in subjects with T2DM, with favorable effects also on cardiorespiratory fitness, body weight and blood pressure. Moreover, some recent studies have shown that even short bouts of walking, used for breaking prolonged sitting, can ameliorate glucose profiles in diabetic patients with sedentary behavior. CONCLUSIONS: There is sufficient evidence to recognize that walking is a useful therapeutic tool for people with T2DM. This document discusses theoretical and practical issues for improving its use. This article is co-published in the journals Sport Sciences for Health and Nutrition, Metabolism and Cardiovascular Diseases.

Recurrence quantification analysis of heart rate variability during continuous incremental exercise test in obese subjects.

The present paper concerns a new description of changing in metabolism during incremental exercises test that permit an individually tailored program of exercises for obese subjects. We analyzed heart rate variability from RR interval time series (tachogram) with an alternative approach, the recurrence quantification analysis, that allows a description of a time series in terms of its dynamic structure and is able to identify the phase transitions. A transition in cardiac signal dynamics was detected and it perfectly reflects the aerobic threshold, as identified by gas exchange during an incremental exercise test, revealing the coupling from the respiratory system toward the heart. Moreover, our analysis shows that, in the recurrence plot of RR interval, it is possible to identify a specific pattern that allows to identify phase transitions between different dynamic regimes. The perfect match of the occurrence of the phase transitions with changes observed in the VO2 consumption, the gold standard approach to estimate thresholds, strongly supports the possibility of using our analysis of RR interval to detect metabolic threshold. In conclusion, we propose a novel nonlinear data analysis method that allows for an easy and personalized detection of thresholds both from professional and even from low-cost wearable devices, without the need of expensive gas analyzers.

Effects of an individualized home-based unsupervised aerobic training on body composition and physiological parameters in obese adults are independent of gender.

PURPOSE: Evaluation of the effects of an individualized home-based unsupervised aerobic training on body composition, physical and physiological parameters in female and male obese adults. METHODS: Two hundred and twenty obese adults (age 47.9 ± 12.4 years; BMI 38.0 ± 7.2 kg/m2) entered the 4-month training program. Body composition, physiological and functional capacities were assessed pre- and post-intervention. All subjects were requested to perform unsupervised aerobic training with the intensity based on heart rate, walking speed and OMNI-RPE score corresponding to the individual ventilatory threshold for at least 5 days/week. RESULTS: After 4-month study period, 40% of patients completed the protocol, 24% had high compliance (HC) (exercise ≥ 3 days/week), while 16% had low compliance (LC) to exercise prescription (exercise < than 3 days/week). In HC group, a significant improvement of body composition variables after training was performed. Moreover, oxygen uptake and metabolic equivalent at peak significantly increased after training. Six-minute walking test (6MWT) distance significantly increased while heart rate during 6MWT was significantly lower after training. No significant differences were found in LC group between pre- and post-intervention in all variables. Interestingly, gender does not influence the effects of training. CONCLUSIONS: Our results indicate that subjects, independent of gender, with high compliance to the aerobic training based on a new individualized method can achieve a significant reduction in weight loss and also an improvement in physical and physiological parameters. This innovative personalized prescription could be a valuable tool for exercise physiologist, endocrinologists, and nutritionists to approach and correct life style of obese subjects.

AquaTrainer® Snorkel does not Increase Hydrodynamic Drag but Influences Turning Time.

Our purpose was to verify if the use of the new AquaTrainer(®) respiratory snorkel lead to an increase of front crawl hydrodynamic drag and whether the constraint of using an adapted turning technique influences its corresponding turning time. 12 swimmers performed 2 (without and with snorkel) 12×25 front crawl repetitions from low to maximal velocity on the measuring active drag system. Complementarily, 3 swimming turns were compared: open turn with snorkel, tumble turn and open turn without snorkel. Drag values were similar without vs. with snorkel at 0.9, 1.1, 1.3, 1.5 and 1.7 m.s(-1) velocities: 15.84 ±5.32 vs. 16.18±4.81, 25.60±6.69 vs. 26.03±6.17, 38.37±8.04 vs. 38.88±7.56, 54.64±10.06 vs. 55.08±9.55, 74.77±14.09 vs. 74.92±13.14 N, (respectively, p≥0.05), and high agreement between conditions was observed (p<0.01). Front crawl swimming with snorkel using the open turn implied an increase in turning time of 14.2 and 5.1% than the tumble turn and open turn without the apparatus (p<0.01). AquaTrainer(®) snorkel does not lead to an increase in active drag during front crawl performed at a large range of velocities and, consequently, the metabolic energy necessary to overcome total drag will not be affected. However, turning with it requires an additional time that should be taken into account in scientific research and training conditions.

Acute physical activity and delayed attention in primary school students.

To examine the influence of different types of exertion on immediate and delayed attention in 116 primary school children divided in three groups of exertion [cognitive exertion - CE (school curricular lesson), physical exertion - PE (traditional physical education lesson), mixed cognitive and physical exertion - CPE (coordinative physical education lesson)]. CPE was the combination of physical load due to the practice of physical exercises and of cognitive load requested to perform movement-based problem solving tasks requiring accurate timing, temporal estimations, temporal production, and spatial adjustments. Children's attentional capacity was tested before (pre) and after (at 0 min and at 50 min post) a CE, a PE, or a CPE lesson, using the d2-test of attention, and analyzed using a 3 × 3 × 2 mixed analysis of covariance with exertion type and time as within factors, gender as between factor, and baseline data as covariate. Effect sizes were calculated as partial eta squared (ƞ(2)). Results showed that participants' attentional performance was significantly affected by exertion type (P < 0.0001), by time (P < 0.0001) and by exertion type × time interactions (P < 0.0001). The effect sizes ranged from medium (0.039) to large (0.437). Varying the type of exertion has different beneficial influences on the level of attention in school children.

Testosterone responses to standardized short-term sub-maximal and maximal endurance exercises: issues on the dynamic adaptive role of the hypothalamic-pituitary-testicular axis.

BACKGROUND: Few and conflicting data on the acute adaptive role of the hypothalamic-pituitary-testicular (HPT) axis to sub-maximal endurance exercise exist. AIMS: To investigate the acute HPT axis responses to standardized endurance exercises in a laboratory setting and the correlations between testosterone and classic adaptive hormones variations. SUBJECTS AND METHODS: 12 healthy male volunteers were recruited for this experimental study. Serum PRL, GH, ACTH, LH, cortisol, DHEAS, testosterone [total (TT), calculated free (cFT) and bioavailable (cBioT)], SHBG, and respective ratios, were evaluated before and after a 30-min sub-maximal exercise on cycle ergometer at individual anaerobic threshold (IAT) and a maximal exercise until exhaustion. Blood samples were collected before exercise (30, 15 min and immediately before), immediately after and at different time points during recovery (+15, +30 and +60 min) for hormones assays. Oxygen consumption and lactate concentration were evaluated. RESULTS: Testosterone (TT, cFT and cBioT) acutely increased in all volunteers after both exercises. Testosterone increased in parallel to GH after both exercises and to cortisol only after maximal exercise. Differently from other increased hormones, testosterone increases were not correlated to exercise-intensity-related variables. The anabolic/catabolic steroids ratios were higher after sub-maximal exercise, compared to maximal. CONCLUSIONS: A 30-min sub-maximal endurance exercise acutely increased serum testosterone similarly to maximal exercise, but without cortisol increases. Exercise-related testosterone peaks should be considered adaptive phenomena, but few data on their short- and long-term effects exist. Investigations on the mechanisms of adaptation to exercise in active individuals with physiological or pathological hypo-testosteronemia are warranted.

Which are the best VO2 sampling intervals to characterize low to severe swimming intensities?

Cardiorespiratory response in swimming has been used to better understand aerobic performance, especially by assessing oxygen uptake (VO2). The current study aimed to compare different VO2 time-averaging intervals throughout low to severe swimming intensities, hypothesizing that VO2 values are similar for different time averages at low to moderate and heavy swimming intensities, but not for the severe domain. 20 male trained swimmers completed an incremental protocol of 7×200 m until exhaustion (0.05 m/s increments and 30 s intervals). VO2 was measured by a portable gas analyser connected to a snorkel system. 6 time average intervals (breath-by-breath, 5, 10, 15, 20 and 30 s) were compared for all the protocol steps. Breath-by-breath and 5 s average exhibited higher VO2 values than averages≥10 s for all swimming intensities (P≤0.02; partial η(2)≤0.28). VO2 values did not differ between 10, 15, 20 and 30 s averages throughout the incremental protocol (P>0.05; partial η(2)≤0.05). Furthermore, 10 and 15 s averages showed the lowest VO2 mean difference (0.19 mL( · )kg(-1 · )min(-1)). For the 6 time average intervals analysed, 10 and 15 s averages were those that showed the lowest changes on VO2 values. We recommended the use of 10 and 15 s time averaging intervals to determine relevant respiratory gas exchange parameters along a large spectrum of swimming intensities.

Effects of Fitlight training on cognitive-motor performance in élite judo athletes.

Aims: The aims of this study were to verify if a 5-week cognitive-motor training (CMT) using FitlightsTM induced changes in young adult judo athletes compared to a non-intervention group. Specifically, it was verified if CMT influenced executive functions (EFs), physical fitness and brain-derived neurotrophic factor (BDNF) levels. Additionally, athletes' competitive results were compared between groups. Method: Twenty-seven athletes (14 males and 13 females; age = 19.5 ± 2.0 years) were assigned to the Fitlight (FG) and control (CG) groups which performed 5 weeks of CMT, respectively, including 25 min per day of Fitlight training or traditional judo practice. All participants performed cognitive (flanker task and forward/backward digit span) and fitness tests (counter movement jump, handgrip test, dynamic and isometric chin up). In addition, BDNF was collected by saliva sampling and competitive results after the intervention period were considered. Results: RM-ANOVA showed significant differences in FG for the accuracy of flanker (p = 0.028) and backward digit span (p < 0.001). Moreover, significant differences in FG were found for relative dynamic chin up (p = 0.027) and counter movement jump (p = 0.05). In addition, a significant difference in FG was found for competitive results after the intervention period (p < 0.01).No significant differences were found for BDNF and other cognitive and fitness measures (p > 0.05). Conclusion: A 5-week judo-specific CMT improved EFs and motor performance in élite judo athletes. It seems that CMT with Fitlight™ could be considered an additional support to coaches during the training period.

Is the new AquaTrainer® snorkel valid for VO2 assessment in swimming?

The Cosmed AquaTrainer® snorkel, in connection with the K4b2 analyzer, is the most recent instrument used for real time gas analysis during swimming. This study aimed to test if a new AquaTrainer® snorkel with 2 (SV2) or 4 (SV4) valves is comparable to a standard face mask (Mask) being valid for real time gas analysis under controlled laboratory and swimming pool conditions. 9 swimmers performed 2 swimming and 3 cycling tests at 3 different workloads on separate days. Tests were performed in random order, at constant exercise load with direct turbine temperature measurements, breathing with Mask, SV4 and SV2 while cycling, and with SV2 and SV4 while swimming. A high agreement was obtained using Passing - Bablok regression analysis in oxygen consumption, carbon dioxide production, tidal volumes, pulmonary ventilation, expiratory fraction of oxygen and carbon dioxide, and heart rate comparing different conditions in swimming and cycling. Proportional and fixed differences were always rejected (95% CI always contained the value 1 for the slope and the 0 for the intercept). In conclusion, the new SV2 AquaTrainer® snorkel, can be considered a valid device for gas analysis, being comparable to the Mask and the SV4 in cycling, and to the SV4 in swimming.

Exercise intensity and gender difference of 3 different salsa dancing conditions.

The aims of this study were to estimate the difference in exercise intensity (METs), energy cost (EE) and gender difference between a typical salsa lesson (TSL), rueda de casino lesson (RCL), and salsa dancing at a night club (SDN). Subjects performed 1 pre-testing session and 3 testing conditions. During the pre-testing session height, weight and V˙O2max were assessed. During the testing conditions all subjects performed 3 different kinds of salsa dance. Heart rate was assessed during each dance condition. The exercise intensity of the 3 salsa dancing conditions was moderate ranging from 3.9 to 5.5 METs. A significant difference between genders for HRpeak (P=0.01), max%HRR (P=0.006) and mean EE (P=0.02) were observed. Significant gender×condition interactions for HRpeak (P=0.03), mean %HRR (P=0.02), mean METs (P=0.02) and mean EE (P=0.02) were found. In addition, a significant main effect for each condition was found in all variables (P<0.01). Our results showed that the exercise intensities of all 3 salsa dancing conditions were moderate. Findings showed some significant differences in exercise intensity between males and females and within conditions. Salsa dancing could be useful in achieving a significant training effect in people who have a low level of fitness.

Different VO2max time-averaging intervals in swimming.

We aimed to determine the effect of sampling interval strategy on VO(2max) assessment to establish a standard time averaging method that allows a better identification of the VO(2) plateau incidence in swimming. To this end, 3 incremental protocols utilizing different step lengths for each sampling interval were used to compare VO(2max)measurements. 11 trained male swimmers performed 3 repetitions of a front crawl intermittent incremental protocol until exhaustion (increments of 0.05 m.s(-1), with 30 s and 24-48 h intervals between steps and tests, respectively) with 200, 300 and 400-m step lengths. VO(2) was directly measured, and 6 sampling intervals were compared: bxb and averages of 5, 10, 15, 20 and 30 s. Shorter sampling intervals (≤ 15 s) allowed the highest incidence of the VO(2) plateau, independent of the step lengths used; the 200 and 300-m step protocols accounted for higher percentage of VO(2) plateau incidence, and higher VO(2max) values, compared to the 400-m step protocol. As an optimal sampling interval should be used for the validation of the research findings, and considering that swimmers and coaches prefer less time-consuming protocols, the use of the 10 s time-average interval (once bxb and 5 s samplings present high variability) in a 200-m step incremental protocol for VO(2max) assessment in swimming is suggested.

Does living setting influence training adaptations in young girls?

To assess whether rural or urban setting may influence young girls' fitness and coordinative abilities training adaptations following dance training. Forty-four dancers aged 11-12 years (21 urban, 23 rural) attended a 6-month dance training while continuing to practice their habitual physical activities (PA). Dancers' fitness and motor coordination abilities were assessed by pre- and post-intervention tests (anthropometric measures, 1-mile run/walk, sit and reach, standing long jump, hand grip and four field tests of kinaesthetic discrimination and response orientation). PA was assessed using a self-report recall measure. After the intervention period, rural dancers significantly improved in 1-mile run/walk, lower limb kinaesthetic discrimination and response orientation ability tests. Significant differences between two groups in upper limb response orientation ability test were found. Both groups showed a significant increase in body height and weight. Multiple regression analysis indicated that time in nonorganized PA predicted some fitness and coordinative changes (1-mile run/walk, lower limb response orientation and kinaesthetic discrimination ability tests) following the training period, although the percentage of variance it could explain was moderate. Our results showed that training adaptations of some fitness and coordinative performances could be influenced by setting characteristics that provided opportunities for different types of PA.

Effects of music during exercise in different training status.

AIM: This study examined the interaction of exercise and music to establish the impact of these factors on state-anxiety and time to exhaustion comparing trained and active participants. METHODS: Twenty-six university students (13 trained, 13 active) completed the State-anxiety Inventory questionnaire before and after a submaximal treadmill running until volitional exhaustion in both music and no-music condition. RESULTS: ANOVA showed that both trained and active groups significantly reduced their State-Anxiety scores after exercise tasks (P<0.01, partial η2=0.26) independently by the presence of music. Finding also revealed that active group reported a higher significant reduction of their state anxiety score after exercise in music condition compared to no-music task (P<0.05, d=0.80), while this effect in trained group was not significant. Moreover, data showed that only active-subjects significantly prolonged their exercise experience in presence of music (P<0.05, d=0.47), while trained group did not. CONCLUSION: This study supports the general finding that exercise is associated with state-anxiety reduction, and suggests that music during exercise may improve this effect in active but not in trained participants. Further, listening to music during exercise may prolong the participants' exercise experience but different training status seems to qualify differently this response.

Linking coordinative and fitness training in physical education settings.

To assess whether an enrichment of the coordinative demands of physical education (PE) during the curricular time may more efficiently improve coordinative abilities than the traditional PE program. One hundred and fifty-two middle school students aged 11-12 years were randomly assigned either to an experimental (n=77) or to a traditional (n=75) PE program lasting 5 months. The experimental intervention was structured in different modules focused on co-ordination abilities. Pre- and post-intervention tests assessed students' fitness (1 mile run/walk, curl-up, flexed arm hang, trunk lift, sit and reach, 30 m run, standing long jump, basketball forward throw) and motor co-ordination abilities (four field tests of kinesthetic discrimination and response orientation ability). After the intervention period, both groups showed a significant increment in most fitness tests. However, only the experimental group showed a significant improvement or a significantly more pronounced improvement than the control group in coordinative performances. The results show that both experimental and traditional PE interventions lead to increase physical fitness levels, but only the experimental one also improves coordinative abilities. Thus, focusing on a multivariate PE approach linking co-ordination and fitness training seems to add quality to students' experiences without reducing their effectiveness in terms of physical fitness.

Assessing basketball ability in players with mental retardation.

BACKGROUND: Although athletes with mental retardation (MR) have achieved an important role, literature concerning the evaluation tests in basketball is still poor. OBJECTIVE: To assess basketball ability before and after a 4-month training performed before championship for athletes with MR and to correlate ability variations with MR levels. METHODS: 15 trained basketball players with MR (11 men and 4 women; age range 21-43 years; MR: 3 mild, 8 moderate, 8 severe and 1 profound). Athletes were tested before (pre) and after (post) 4 month training preceding the championship. The tests assessed 4 levels of ability, each one characterised by 4 fundamental areas of this game: ball handling, reception, passing and shooting. Each area was divided into 5 specific components. RESULTS: The team average score, based on the score of each athlete's 4 levels, improved by 6.6 points (41.6 (SD 11.9) vs 48.2 (14.7)). The comparison between pre and post scores in each level showed increases (p<0.01), especially in level II (14.4 (3.5) vs 16.5 (3.3)) and in level III (7.1 (5.7) vs 9.2 (6.6)). Within level II, ball handling (3.67 (1.2) vs 4.37 (0.5); p<0.05) and passing (3.20 (1.2) vs 3.97 (1.3); p<0.01) improved; in level III reception (3.21 (1.1) vs 3.73 (1.1); p = 0.01) and shooting (1.82 (1.1) vs 2.45 (1.3); p<0.05) increased. CONCLUSIONS: A 4 month training caused a general improvement, especially evident in levels II and III. Total score reached in level II was negatively correlated with MR level (r = -0.56; p<0.05), indicating that athletes with lower MR obtained higher scores.

Is explosive performance influenced by androgen concentrations in young male soccer players?

OBJECTIVE: There is growing interest in the implementation and assessment of strength and conditioning programmes among young children. The purpose of this study was to examine the association between given anthropometric characteristics, pubertal development, salivary androgen hormones and explosive leg power in young soccer players. METHODS: 51 (age range 10-14 years) soccer players were investigated. The relations between age, pubertal developmental stages, testicular volume, weight, height, body fat, fat free mass, salivary DHEAS concentrations, salivary testosterone concentrations and lower limb explosive power were evaluated. RESULTS: Standing long jump length was positively correlated (p<0.05) with age (11.7 (SD 1.2) years, r = 0.66), pubertal developmental stages (mode and range: 1 (1-4), r = 0.64), testicular volume (8.8 (5.2) ml, r = 0.58), height (1.50 (0.10) m, r = 0.34), weight (43.7 (9.1) kg, r = 0.34), fat free mass (35.4 (7.2) kg, r = 0.67), salivary DHEAS concentrations (4.4 (1.2) ng/ml, r = 0.38) and negatively correlated with body fat (18.6 (7.0) kg; r = -0.49, p<0.05). There was no significant correlation between salivary testosterone concentrations (0.3 (0.1) ng/ml, r = 0.12) and standing long jump. CONCLUSIONS: Results of the present investigation demonstrated that age, pubertal developmental stages, testicular volume, weight, height, fat free mass, and salivary DHEAS concentrations were associated with standing long jump performance. In addition, salivary testosterone concentrations were not related to explosive leg power. Results of the present investigation suggest that the teacher/coach should evaluate long jump performance relative to the subject's given biological characteristics, and not simply established standards based on chronological age.

Effect of tadalafil on anaerobic performance indices in healthy athletes.

OBJECTIVE: Given the therapeutic and non-therapeutic use of the tadalafil, (phosphodiesterase-5 inhibitor, PDE-5i), we examined its effects on anaerobic performance indices. METHODS: In total, 12 well-trained subjects reported to the laboratory on two occasions 1 week apart to perform a 30 s Wingate anaerobic power test (WAnT) on a bicycle ergometer. The day before the WAnT, the subjects were double-blinded to receive an oral dose of tadalafil (20 mg) or placebo. Blood lactate value at rest and 1, 3, 6 and 10 minutes of recovery phase, mean power, peak power, time to peak power and fatigue index were assessed for each WAnT. RESULTS: Blood lactate values at the 3-min recovery WAnT increased significantly in the tadalafil condition (mean (SD) 13.9 (1.7) v 12.8 (1.3) mmol/l; p<0.05) and time to peak power decreased significantly (6.3 (1.3) v 5.7 (1.5) s; p = 0.05). No differences were observed in any other parameters between the two conditions. CONCLUSION: The primary finding of this investigation was that the administration of a single dose of a long-term PDE-5i does not substantially influence anaerobic performance indices. However, results demonstrated both an increase in lactate values at the 3-min point of the recovery phase and a decrease in time to peak power.

Leaping ability and body composition in rhythmic gymnasts for talent identification.

AIM: Aim of this study was to investigate leaping ability and morphological characteristics in rhythmic gymnastics, in order to verify which parameters are useful indicators for the talent identification. METHODS: Twenty-five national gymnasts of international level (age 14.7+/-2.2 years) underwent three testing sessions: anthropometric measurements, vertical jumps (counter movement jump and hopping test), and three technical split leaps with stretched legs (SL), with ring (RG) and with back bend of the trunk (BBT). RESULTS: Elite had significantly different values (P < 0.05) of stature (1.65+/-0.03 vs 1.55+/-0.09 m), thigh length (0.42+/-0.03 vs 0.39+/-0.02 m) and FFM(42.42+/-2.81 vs 35.84+/-5.66 kg) compared to sub-elite. The height of hopping test was significantly higher in elite than sub-elite gymnasts (0.34+/-0.05 vs 0.27+/-0.04 m; P < 0.05), but no significant differences in counter movement jump between two groups were found. Ground contact time of hopping test was significantly correlated (P < 0.01) with SL (r = 0.613), RG (r = 0.632), and BBT (r = 0.542) values. By multiple regression analysis, among anthropometric and vertical jump variables, the hopping ground contact time was the strongest predictor of ground contact time of the three technical leaps (SL, RG, BBT) accounting for 26-37% of variance. CONCLUSION: Some anthropometric measurements are good indicators for the better performance in rhythmic gymnastics. Level of muscle compliance (stiffness) evaluated by hopping test is a good parameter for athletes selection and for monitoring leaps training.

Effect of creatine on swimming velocity, body composition and hydrodynamic variables.

AIM: Creatine supplementation (CS) has been reported to increase body weight and improve performance during high intensity, short duration, exercise tasks. However, none of the published studies has investigated the influence of CS on performance related hydrodynamic variables during swimming. To investigate the effect of oral CS on swimming velocity, body composition and hydrodynamic variables during the period of final preparation of competitive junior female swimmers. METHODS: In a double blind and randomized manner, 16 female swimmers, were supplemented with 20 g day(-1) of creatine monohydrate (CS group), or a maltodextrin placebo (PL group) for 21 days. Just pre- and post-21 days of supplementation, subjects performed 2x25 swimming bouts at maximum velocity with a 3 min recovery between bouts. The variables measured were 25 m swimming velocity (MSV(25)); active drag force (D(f)); hydrodynamic coefficient (C(x)); power output (P(o)). Body measures were also analysed: body weight (kg), fat-mass (% FAT), body water (% H(2)O), and fat free mass (FFM). RESULTS: Significant differences were observed in hydrodynamic values: the CS group showed a significant reduction (approximately =25%), in D(f), C(x) and P(o) values, when comparing pretest with post-test. No differences were found in variables related to body composition and performance between CS group and PL group, as well as for CS group during the experimental period. CONCLUSIONS: These data suggest that 21 days of CS produced significant effects on gross and/or propelling efficiency during swimming in female athletes. However, CS did not influence performance, body weight and body composition.

Slow component of VO(2) during level and uphill treadmill running: relationship to aerobic fitness in endurance runners.

AIM: The aim of this study was to compare the oxygen uptake (VO(2)) slow component (SC) during level and uphill running in endurance runners, and to identify associations between the SC and the following aerobic fitness indicators: peak VO(2), running speed associated with the peak VO(2) (Vpeak), running speed at the lactic threshold and the VO(2) fraction elicited at the lactic threshold. METHODS: Fourteen male endurance-trained runners underwent several 6-min bouts of level (LTR) and 10.5% uphill treadmill running. VO(2) SC was calculated as the difference between mean VO(2) during the 6th and the 3rd minutes. RESULTS: The highest mean values for the SC were 181.9+/-240.2 mL x min(-1) for level running at approximately 94% peak VO(2)2 and 105.4+/-154.6 mL x min(-1) for uphill running at approximately 90% peak VO(2). The SC observed during the last bout of the LTR correlated with peak VO(2) and with Vpeak (-0.71 and -0.76, P<0.05, respectively). CONCLUSION: The results show that for endurance-trained runners the magnitude of the SC is not affected by the treadmill gradient and that within a homogeneous sample of endurance-trained runners the SC does not correlate with indicators of aerobic fitness.