Impressive anaerobic adaptations in elite karate athletes due to few intensive intermittent sessions added to regular karate training.

The aim of this study was to investigate the effects of adding a high-intensity intermittent session twice a week during a 7-week karate training (KT) on markers of aerobic and anaerobic metabolisms in elite class karate athletes. Two groups were studied: a KT group (n=8, age 20.1+/-0.9 years, 70.0+/-8.8 kg) that followed traditional KT, and a group that followed combined traditional karate and a high-intensity intermittent training (HIT group, n=9, age 24.4+/-3.1 years, 67.0+/-7.8 kg). The subjects undertook a supramaximal exercise and a maximal oxygen uptake test before and after the training. Blood lactate, pH and plasma ammonia were determined at rest, immediately at the end of the supramaximal exercise and during the recovery period at 2, 4, 6, 8, 10 and 15 min. After the training period, no changes occurred in the KT group. However, in the HIT group, the time to exhaustion, MAOD and in the maximal oxygen uptake test were significantly improved by 23.6%, 10.3% and 4.6%, respectively. A clear-cut discrepancy was observed in the time course of lactate and pH in the supramaximal test after the training in the HIT group. We observed a significantly higher peak for lactate and a lower extreme value for pH with a shorter delay of appearance. At the end of the test, the lactate concentration increased significantly (+53.7%) and pH declined significantly, when compared with the values obtained after the same test before the training period. Ammonia was not influenced. The addition of high-intensity intermittent sessions twice per week during the period of KT induced beneficial physiological adaptations in athletes, allowing improvement in the duration of intense physical exercise before a state of fatigue is reached.

Self-regulated running using perceived exertion in children.

AIM: The aim of this study was to examine the ability of 5- to 7-year-old female (n=16) and male (n=16) children to use perceived exertion in order to self-regulate their running intensity. An estimation-production paradigm was used to determine if 1) self-regulation of exercise using OMNI Scale could be administered in young children, 2) children were able to distinguish 3 different intermittent exercise intensities and 3) gender would differentiate the use of perceived exertion. METHODS: Children underwent 1) 1 estimation trial and 2) 3 production trials. During the estimation trial, perceived exertion was estimated at the end of each stage of an incremental running field test. Then, during the production test, the children were requested to run in random order 300 m bouts on an outdoor track at an exercise intensity based on their interpretation of levels 2, 6 and 10 of the OMNI Scale. Heart rate was continuously recorded during both trials. RESULTS: Heart rate did not differ significantly between estimation and production trials at the level 2 (124.1 SD 6 vs 125.3 SD 4 bpm), 6 (164.9 SD 5 vs 166.2 SD 6 bpm) and 10 (200.9 SD 8 vs 203.1 SD 8) of the OMNI scale. Furthermore, HR responses at OMNI 6 were significantly (p<0.05) higher than OMNI 2, and OMNI 10 were significantly (p<0.05) higher that OMNI 6. No significant difference was found between female and male children. CONCLUSIONS: The present investigation supports the view that the young female and male children tested in this study were able to use perceived exertion to self-regulate during intermittent running exercises.

Is the VO2 slow component dependent on progressive recruitment of fast-twitch fibers in trained runners?

The goal of this study was to use spectral analysis of EMG data to test the hypothesis that the O2 uptake VO2) slow component is due to a recruitment of fast fibers. Thirteen runners carried out a treadmill test with a constant speed, corresponding to 95% of the velocity associated with maximal VO2. The VO2 response was fit with the classical model including three exponential functions. Electrical activity of six lower limb muscles (vastus lateralis, soleus, and gastrocnemius of both sides) was measured using electromyogram surface electrodes. Mean power frequency (MPF) was used to study the kinetics of the electromyogram discharge frequency. Three main results were observed: 1) a common pattern of the MPF kinetics in the six muscles studied was noted; 2) MPF decreased in the first part of the exercise, followed by an increase for all the muscles studied, but only the vastus lateralis, and gastrocnemius muscles of both sides increased significantly (P < 0.05); and 3) the beginning of the MPF increase of the four muscles mentioned above corresponded with the beginning of the slow component. Our results suggest a progression in the average frequency of the motor unit discharge toward the high frequencies, which coheres with the hypothesis of the progressive recruitment of fast-twitch fibers during the VO2 slow component. However, this interpretation must be taken with caution because MPF is the result of a balance between several phenomena.

Comparison of oxygen uptake kinetics during concentric and eccentric cycle exercise.

O2 uptake (VO2) kinetics and electromyographic (EMG) activity from the vastus medialis, rectus femoris, biceps femoris, and medial gastrocnemius muscles were studied during constant-load concentric and eccentric cycling. Six healthy men performed transitions from baseline to high-intensity eccentric (HE) exercise and to high-intensity (HC), moderate-intensity (MC), and low-intensity (LC) concentric exercise. For HE and HC exercise, absolute work rate was equivalent. For HE and LC exercise, VO2 was equivalent. VO2 data were fit by a two- or three-component exponential model. Surface EMG was recorded during the last 12 s of each minute of exercise to obtain integrated EMG and mean power frequency. Only in the HC exercise did VO2 increase progressively with evidence of a slow component (phase 3), and only in HC exercise was there evidence of a coincident increase with time in integrated EMG of the vastus medialis and rectus femoris muscles (P < 0.05) with no change in mean power frequency. The phase 2 time constant was slower in HC [24.0 +/- 1.7 (SE) s] than in HE (14.7 +/- 2.8 s) and LC (16.7 +/- 2.2 s) exercise, while it was not different from MC exercise (20.6 +/- 2.1 s). These results show that the rate of increase in VO2 at the onset of exercise was not different between HE and LC exercise, where the metabolic demand was similar, but both had significantly faster kinetics for VO2 than HC exercise. The VO2 slow component might be related to increased muscle activation, which is a function of metabolic demand and not absolute work rate.

Influence of the age on self regulation of static grip forces from perceived exertion values.

The investigation of self-regulation of grip force provides indirect cues about the developmental neurobiology of the subject. The aim of this study was to examine the ability of subjects of different ages to produce different forces based on their perceived exertion during a grip force task by using a test and a randomised re-test procedure. Eighteen young children (aged 6.5 years), 18 adolescents (13.5 years) and 18 adults (28.5 years) performed a graded hand grip strength test (GST) at four intensities. Perceived exertion (RPE-C) was recorded at the end of each load level. Then, subjects were scheduled for a randomised grip strength test performed in the same experimental conditions than GST. Statistical analysis revealed no significant effect in grip strength for test in the three groups. However, a significant main effect for intensities was obtained in the three groups (P < 0.0001). Significant correlations were observed between GST and RPE-C (r(2) = 0.62, P < 0.0001; r(2) = 0.53, P < 0.0001; r(2) = 0.51, P < 0.0001), in the children, adolescent and adult groups, respectively. However at low grip force intensities, it appears that children have some difficulties to rate their perceived exertion. The results of this study suggest that the neurodevelopmental level of 6-year-old children do not affect the ability to produce reliably moderate to intense forces from perceived exertion during a grip force task.

Simplified deceleration method for assessment of resistive forces in cycling.

PURPOSE: The purpose of this study was to develop and test a simplified deceleration technique for measurement of aerodynamic and rolling resistances in cycling. METHODS: Coast-down tests were performed in level hallways with an experienced cyclist as the rider. Average initial velocities were 2.5-12.8 m x s(-1)) The deceleration technique was simplified by the use on only three switches and a derivation that did not require an assumption that deceleration is constant. The effective frontal area (AC(D)) and coefficient of rolling resistance (CR) were then calculated through a derivation from the equation for resistive forces opposing motion. Method reproducibility was tested by comparison of results for four tests of 30 trials under identical conditions. Method sensitivity was tested by performing 30 trials with three different rider head positions and four different transported mass conditions. RESULTS: Analysis of variance revealed that there were no differences among the results in the reproducibility study for either AC(D) or C(R). Furthermore, the reproducibility tests revealed mean errors of only 0.66% and 0.70% for AC(D) and CR, respectively. ANOVA identified a significant increase (P < 0.001) in rolling resistance with external loading and a significant effect (P < 0.001) of head position on AC(D). Mean (+/-SD) values for AC(D) and C(R) from tests in a racing aeroposture with the head up, the head in line with the trunk, and the head in an intermediate position were 0.304 +/- 0.011, 0.268 +/- 0.010, and 0.262 +/- 0.013 m2, respectively. C(R) averaged 0.00368 in the three head positions. CONCLUSIONS: The findings indicate that this simplified deceleration technique is satisfactorily reproducible and sensitive for measurement of aerodynamic and rolling resistances in cycling.

Application of force-velocity cycle ergometer test and vertical jump tests in the functional assessment of karate competitor.

AIM: The aim of this study was to analyze the links between tests performances (vertical jump and force-velocity sprint on cycle ergometer) and 2 different karate level groups in order to propose a test battery adjusted to karate. METHODS: Twenty-two karate competitors (10 national junior team (IJ) and 12 national competition level (NL)) performed 4 maximal squat jumps (SJ), 4 maximal counter movement jumps (CMJ) on an ergojump and 3 8-s sprints on a friction braked cycle ergometer (friction loads of 0.5, 0.7, 0.9 N x kg(-1)). The maximal theoretical force (F(0)) and velocity (V(0)), the maximal power output (P(max)) and the optimal pedalling velocity (V(opt)) were derived from both the force -- velocity and the power -- velocity relationships plotted from all the 3 friction loads data. V(0), F(0), V(opt), P(max) and the best SJ and CMJ, were compared between IJ and NL groups. RESULTS: The IJ group was characterised by significantly higher values of V(0) (+13%) and SJ (+14.3%) compared to NL group, whereas no significant difference was observed between groups for F(0). Thus, karate performance would depend on maximal velocity and explosive strength. In addition, V(opt) was significantly higher in IJ group compared to NL group (135.4 rpm vs 119.2 rpm, p<0.001). Although based upon indirect evidence, these results accounted for mechanical functional capabilities of experts which could be particularly valuable when monitoring training of karate competitor. CONCLUSIONS: A force-velocity and a vertical jump tests may be applied in the functional assessment of karate competitor.

A perceptive individual time trial performed by triathletes to estimate the anaerobic threshold. A preliminary study.

AIM: The aim of the study was to test the ability to estimate the power output (PO) and heart rate (HR) associated with ''anaerobic threshold'' levels for triathletes by means of a 30-min perceptive individual time trial (PITT30). METHODS: Thirteen triathletes (8 males and 5 females) performed an incremental exercise test to estimate maximal parameters such as oxygen uptake, power output and heart rate. From this incremental exercise test, the individual anaerobic threshold (IAT) and ventilatory threshold (VT) for all subjects were estimated. Then, the subjects completed a PITT30 at self-selected work intensity on a stationary ergometer equipped with the SRM Training System. Mean values of PO, HR, and pedalling cadence were recorded continuously between the 5th and the 30th min of the test. RESULTS: Significant correlations were observed between the mean PO recorded during PITT30 and PO measured at IAT (r=0.88; p<0.0001) and at VT (r=0.89; p<0.0001). Furthermore, bias and limits of agreement confirm the degree of association between the 3 METHODS: However, PITT30 over-estimated HR values compared to the values obtained at IAT and VT. CONCLUSION: It was concluded that, for triathletes, mean PO measured with PITT30 allows a partial valid estimation of PO associated with 2 known methods of ''anaerobic threshold'' determination. The application of PITT30 may offer a useful tool for athletes and coaches to estimate the ''anaerobic threshold'' in order to control accurately the training effects.

Surface electromyography of nine shoulder muscles in two iron cross conditions in gymnastics.

AIM: The rules of gymnastics impose an element of static strength such as an iron cross (IC) on the rings. For IC training, coaches use a custom made device -- the herdos -- to simulate the conditions of competition. The purpose was to compare muscle activity and coordination during IC performed both on the rings and using herdos. Secondly, we tried to determine whether herdos usage induced functional adaptations of the shoulder muscles. METHODS: Six male gymnasts performed 10 IC in each condition. Surface electromyogram of muscles pectoralis major, latissimus dorsi, teres major, infraspinatus, rhomboideus, trapezius, serratus anterior, biceps brachii, and triceps brachii in the right shoulder were analysed using root-mean-square (RMS), and muscle part's in each condition. Muscle part represents the contribution of each of the 9 shoulder muscles studied in each condition. Total muscle activity (SUM) was also used to compare the 2 conditions. RESULTS: Except for the muscle teres major, the RMS decreases (p<0.05) when using the herdos. The SUM also decreases (p<0.05) when using this device. The muscle parts indicate that the contribution of the muscle latissimus dorsi decreases (p<0.05) when using the herdos. These results suggest that the herdos modified shoulder coordination. But their usage does not seem to induce any functional adaptations of these muscles. CONCLUSIONS: The herdos do not seem to provide a valid method to reproduce the same shoulder coordination as on the rings. Therefore IC training with this special device could be called in question.

Recovery kinetics of oxygen uptake following severe-intensity exercise in runners.

BACKGROUND: This investigation sought to characterise the oxygen uptake (VO2) off-transient kinetics from severe exercise and to clarify discrepancies between on- and off-transient kinetics for VO2 seen in humans. METHODS: Eleven competitive endurance athletes underwent treadmill running until exhaustion at work-rates corresponding to the speed that elicited approximately 95% of maximal VO2. Gas exchange variables were determined breath-by-breath. Computerised non-linear regression techniques were used to fit the VO2 on- and off-transient kinetics. A 3-exponential model described the VO2 on-transient. VO2 off-transient was analysed to each response time course using 3 different models: a single-exponential model for the entire period and 2 3-exponential models where exponential terms starting either together after a common time delay or after independent time delays. RESULTS: Both 3-exponential models provided an excellent fit (r2>0.90) to the off-transient data. Compared with on-transient, VO2 off-transient kinetics was associated with a slower primary phase (time constant: 16+/-4 vs 39+/-13 sec, p<0.01) but was similar both in time delay and amplitude. CONCLUSIONS: These data indicate that there is no general symmetry between the exercise and recovery kinetics for VO2 because the response of the primary phase of VO2 off-transient resolves to a greater time constant, reflecting altered tissue metabolism. However, the mechanism(s) for the slow component is slow both in developing and to recover within the severe exercise domain.

Maximal accumulated oxygen deficit and blood responses of ammonia, lactate and pH after anaerobic test: a comparison between international and national elite karate athletes.

The purpose of this study was to compare maximal accumulated oxygen deficit (MAOD) and the time course of blood markers of the anaerobic metabolism in response to exhaustive supramaximal test in two elite (international vs. national) class karate athletes. Ten male international competitors from the French national team (Int, age 21.2 +/- 3.1 years, 71.9 +/- 11.4 kg) and eight national class (Nat, 23.7 +/- 2.4 years, 70.7 +/- 12.2 kg) athletes with a similar maximal oxygen uptake of 57.6 and 59.4 ml . kg (-1) . min (-1), respectively, were involved in this study. The MAOD was determined after an exhaustive supramaximal exercise (2 - 3 min at 140 % of their VO2max velocity) on a treadmill ergometer. Blood lactate, pH and plasma ammonia were determined at rest, immediately at the end of exercise and during the recovery period at 2, 4, 6, 8, 10 and 15 min. After the supramaximal exercise, a dramatic higher increase in the blood concentration of ammonia until its peak was observed in the Nat compared with the Int. Time course of [NH4+] and [La] reveals significant (p < 0.01) differences between the two groups. Peak values for [H+] (89.2 +/- 6.7 vs. 75.9 +/- 8.8 nmol . l (-1); p < 0.01), [NH4+] (180 +/- 67.9 vs. 118.7 +/- 22.7 micromol . l (-1); p < 0.05) and [La] (20.7 +/- 2.7 vs. 17.9 +/- 1.1 mmol.l (-1); p < 0.05) were higher in Nat compared with Int group, respectively. However, the MAOD was similar in both groups (67.8 +/- 8 ml . kg (-1) and 64.5 +/- 6.4 for Int and Nat groups, respectively). These data suggest that ammonia and lactate accumulation are sensitive to the level of performance in karate. Higher concentrations of these metabolites in blood after supramaximal exhaustive exercise may be related to either higher anaerobic contribution to energy supply in Nat or higher removal ability in the Int group.

Degree of coordination between breathing and rhythmic arm movements during hand rim wheelchair propulsion.

This study aimed (i) to quantify the spontaneous coordination between breathing and hand rim wheelchair propulsion, (ii) to manipulate arm movement frequency and assess its effects on spontaneous coordination, and (iii) to investigate the hypothesis that entrainment of breathing improves economy of locomotion and leads to a lower rate of perceived exertion (RPE) compared with spontaneous breathing. Nine male, able-bodied participants completed four bouts of 6 min submaximal steady state exercise at 60 % of maximal propulsion velocity on a wheelchair ergometer, with spontaneous breathing and arm frequencies (Fspont), with 20 % higher and lower arm frequencies (F +20 and F -20, respectively) compared to Fspont accompanied with spontaneous breathing frequency, and by synchronising expiration phase with pushing time and inspiration phase with upper limb recovery time (C). Oxygen uptake and propulsion frequency were continuously recorded. The degree of coordination was expressed as a percentage of inspiration starting in the same phase of the wheelchair propulsion cycle (i.e. pushing and recovery times). No difference in degree of coordination was observed between Fspont, F -20 and F +20 conditions (49.2 +/- 12.1 %, 49.1 +/- 29.0 % and 48.2 +/- 29.4 %, respectively). Oxygen uptake increased significantly during C condition while RPE was significantly lower for C and F -20 (p < 0.05) compared to F +20 conditions. Contrary to what we expected, entrainment of breathing using a monofrequency ratio (C) induced a higher energy cost probably due to the mechanical properties of the wheelchair propulsion activity itself. In conclusion, this study showed that the same locomotor-respiratory coupling occurred during hand rim wheelchair propulsion regardless of the arm movement frequency, and that entrainment of breathing did not improve economy of locomotion.

Modelling the relationships between training, anxiety, and fatigue in elite athletes.

This study investigated the effects of 40-week training on anxiety and perceived fatigue in four elite triathletes. Anxiety and perceived fatigue were self-reported by the subjects twice a week by the way of a specific questionnaire and were linked by a mathematical model to the training loads calculated from the exercise heart rate. A significant relationship (r=0.32; p<0.001) between the training loads and anxiety was identified using a two-component model: a first, negative (i.e., anxiety decreased) short-term (tau (1)=23 days) function and a second, positive long-term (tau (2)=59 days) function. The relationship between the training loads and perceived fatigue was significant (r=0.30; p<0.001), with one negative function (tau (1)=4 days). This mathematical model can potentially describe the relationships between training loads and anxiety or perceived fatigue and may improve both the adjustment of the duration of tapering and the early detection of staleness.

[Influence of the sickle cell trait heterozygote on energy abilities]. / Influence de la drépanocytose hétèrozygote sur les aptitudes énergétiques.

The sickle cell trait (SCT) is a genetic abnormality of the red blood cell which mainly affects people of African descent. It is due to the mutation of only one parental gene (one glutamic acid of the chain beta of the globin is substituted by one valin). The prevalence of SCT in the black US population is within the range of 8-9%. It is increasing in Europe and in Africa where it may reach up to 40% in some regions. The rate of prevalence of SCT in athletic populations was found to be similar to that of the general sedentary population in west African countries. SCT is usually asymptomatic. However, SCT has been associated with a higher risk of sudden death during exercise. In fact, the substitution of one amino-acid modifies the properties of haemoglobin and produces physiological disorders such as sickling, less solubility of the deoxidized form and the reduction of affinity for oxygen. The sickling phenomenon (formation of sickle cells) mainly occurs in some conditions related to the practise of sport (intense and/or prolonged exercise, exercise in hypoxic conditions, exercise in heat conditions). These sickled red blood cells reduce the speed of capillary flow or obstruct the blood vessels which, because of the lack of oxygen, become altered. The physical ability of sickle cell trait carriers (HbAS) who practise sport should be different from the physical ability of subjects with normal haemoglobin (HbAA) because of: 1) potential risks due to their haemoglobinopathy and 2) the eventual modification of their performance ability. These two aspects have caused controversies among many researchers particularly in line with their investigation methods. Nevertheless, the following results seem to be established: 1) the ability to perform sprint exercises is not altered in the HbAS subjects. Their performances in these events are similar to those of HbAA subjects; 2) The ability of HbAS subjects to perform intense and prolonged exercise is decreased. Our former results have shown that prolonged aerobic efforts in hypobaric hypoxic conditions may be associated with a deleterious effect on the performance of HbAS subjects. The damaging consequences on their performance in these conditions could be due to tissue oxygen delivery limitations.

Evaluation of fitness level by the oxygen uptake efficiency slope after a short-term intermittent endurance training.

Several indicators are used as indices of cardiorespiratory reserve. Among them, oxygen uptake (VO(2)) at peak and ventilatory threshold (VAT) levels are the most common used. In the present study, endurance training was used to evaluate and compare the usefulness of a new index, the Oxygen Uptake Efficiency Slope (OUES) as an alternative to the previous ones. Fifteen physical education student women participated in the study (8 as a trained group [T: age (mean +/- SD) 21.9 +/- 3.3 y, height 165.1 +/- 5.5 cm, weight 60.4 +/- 3.3 kg] and 7 as a control group [C: age 21.7 +/- 1.9 y, height 165.4 +/- 7.2 cm, weight 59.6 +/- 8.6 kg]). Before and after 6 weeks of the Square-Wave Endurance Exercise Test (SWEET) training program or daily activities, they performed an incremental test (30 W/3 min) on a cycle ergometer to determined VO(2), power output and parameters associated with breathing efficiency (the respiratory equivalents, and the ventilatory dead space to tidal volume ratio [Vd/Vt]) at peak- and VAT-levels. The slope of the relationship between ventilation and carbon dioxide production was also calculated. OUES, derived from the logarithmic relationship between VO(2) and minute ventilation (V(E)), was determined at 75 % (OUES75), 90 % (OUES90) and 100 % (OUES100) of exercise duration. After endurance training in T, VO(2) and power output were significantly improved at peak- and VAT-levels while all breathing efficiency indices remained unchanged. No changes were observed in C after 6 weeks. Despite significant correlation between OUES values and VO(2) at peak- and VAT-levels, OUES75, OUES90 and OUES100 did not significantly change after endurance training. While VO(2) and power output at peak- and VAT-levels increased in all T, training-induced changes in OUES appeared more variable. We concluded that OUES was not sufficiently sensitive to highlight improvement of cardiorespiratory reserve after endurance training whereas VO(2) at peak and VAT levels did.

Oxidation-reduction potential studies: a new method in pharmacology principles, materials, and methods.

Oxidation-reduction (redox) potential measurement is not used in pharmacology at the present time. However, it represents a physicochemical parameter that may be as important as the other currently used physicochemical parameters, such as pH and pKa. Redox potential variations include conformational modifications that may influence bioavailability of drugs. We report here an original and convenient equilibrium method to determine this potential in biological fluids, especially in blood.

[Recent data on the mechanism of action of theophylline]. / Données récentes sur le mécanisme d'action de la théophylline.

Since Sutherland's work simply based on the inhibition of phosphodiesterase was questioned, other researches have been carried out, indicating that many mechanisms located in the nervous system, the smooth muscle, and the immunity system interfere. The participation of receptors to adenosine, intracellular calcium ions, regulating calciproteins and autacoids such as prostaglandins was the purpose of numerous experimental researches that allow today to fill up the gap left by the fact that the inhibitor of phosphodiesterase was questioned. However, there are not sufficient but there are many seducing research and hypotheses.

Optimal pedalling velocity characteristics during maximal and submaximal cycling in humans.

The aim of this study was to compare optimal pedalling velocities during maximal (OVM) and submaximal (OVSM) cycling in human, subjects with different training backgrounds. A group of 22 subjects [6 explosive (EX), 6 endurance (EN) and 10 non-specialised subjects] sprint cycled on a friction-loaded ergometer four maximal sprints lasting 6 s each followed by five 3-min periods of steady-state cycling at 150 W with pedalling frequencies varying from 40 to 120 rpm. The OVM and OVSM were defined as the velocities corresponding to the maximal power production and the lowest oxygen consumption, respectively. A significant linear relationship (r2 = 0.52, P < 0.001) was found between individual OVM [mean 123.1 (SD 11.2) rpm] and OVSM [mean 57.0 (SD 4.9) rpm, P < 0.001] values, suggesting that the same functional properties of leg extensor muscles influence both OVM and OVSM. Since EX was greater than EN in both OVM and OVSM (134.3 compared to 110.9 rpm and 60.8 compared to 54.0 rpm, P < 0.01 and P < 0.05, respectively) it could be hypothesised that the distribution of muscle fibre type plays an important role in optimising both maximal and submaximal cycling performance.

Effects of an interval training programme of the upper limbs on a wheelchair ergometer in able-bodied subjects.

The effects of a 6 weeks interval training with a wheelchair ergometer on the power and endurance of the upper limbs (UL) were studied in ten young able-bodied males. All subjects performed a maximal progressive test (10 W/2 min) on a wheelchair ergometer to measure the ventilation (VE), respiratory exchanges (VO2, VCO2) and oxygen pulse (O2p) at the maximal tolerated power (MTP) and ventilatory threshold (VT). Endurance capacity was measured with the tailored 45 min Square Wave Endurance Exercise Test (SWEET) from MTP and VT. Arm and forearm perimeters, diameters and skinfold thickness were also measured. The subjects were divided into a control group (CG n = 5) and a training group (TG n = 5; 3 SWEET sessions/week/6-week) with matched physical characteristics. Training the UL resulted in significant increases of parameters at MTP (power + 63%, peak VO2 + 33%, O2 pulse + 25%) and at VT (power + 125%, VO2 + 48%, O2 pulse + 33%). The UL diameter and perimeter significantly increased, and the skinfold thickness decreased. None of these variables showed a significant change in the CG. We conclude that this training improves specific force and endurance of the UL, by acting centrally as reflected by oxygen pulse increase, as well as peripherally as shown by morphologic changes.

Effect of cycling position on ventilatory and metabolic variables.

Three positions are generally used by cyclists: upright posture (UP), dropped posture (DP) and aero posture (AP). They determine different angles of trunk flexion which could be associated with physiological changes. The purpose of this study was to analyse the effect of these rider positions on ventilatory and metabolic variables. Nine male competitive cyclists (26.3+/-3yrs, mean+/-SD) exercised on a cycle ergometer. Subjects performed three 10 min exercise bouts at 70% VO2max (maximal oxygen uptake, I x min(-1)) in UP, DP and AP, in a randomized order. Each bout was separated by a 5 min active recovery period (50% of VO2max). Ventilatory and gas exchange responses to exercise were averaged every min. Blood lactate concentration ([La]b, mM), blood pH were analysed at the 5th and the 10th min. The ventilation, respiratory exchange ratio, mean inspiratory flow, [La]b and perceived exertion were significantly higher in DP (88.4+/-11.41 x min(-1), 0.96+/-0.05 ml x s(-1), 2.52+/-0.84 Mm and 13.6+/-1.2) than in UP (84.8+/-12.31 x min(-1), 0.94+/-0.05 ml x s(-1), 2.14+/-0.99Mm and 12.1+/-1.5). VO2, tidal volume, carbon dioxide output, respiratory rate, inspiratory duty cycle, heart rate and pH remained unchanged between all riding positions (averaged values for the three positions: 3.09+/-0.0061 x min(-1), 2.34+/-0.0061 x br(-1), 3.01+/-0.041 x min(-1), 37.4+/-0.8 br x min(-1), 0.47+/-0, 162+/-1 beat x min(-1) and 7.38+/-0.015). These results showed that the greater changes in ventilatory and metabolic variables occurred in DP. AP appears to be the more suitable position when the aerodynamic drag becomes predominant.