A new method for the evaluation of anaerobic running power in athletes

Summary A new maximal anaerobic running power (MARP) test was developed. It consisted ofn · 20-s runs on a treadmill with a 100-s recovery between the runs. During the first run the treadmill speed was 3.97 m · s^–1 and the gradient 5°. The speed of the treadmill was increased by 0.35 m · s^–1 for each consecutive run until exhaustion. The height of counter-movement jumps and blood lactate concentration ([1a^–]_b) were measured after each run. Submaximal ([la^– ] b = 3 mmol · l^–1 and 10 mmol · l^–1) and maximal speed and power ( , and , respectively) were calculated andW was expressed in oxygen equivalents according to the American College of Sports Medicine equation. Thirteen male athletes whose times over 400 m ranged from 47.98 s to 54.70 s served as subjects. In the MARP-test the speed at exhaustion was 6.89 (SD 0.28) m · s^–1 corresponding to a of 118 (SD 5) ml · kg^–1 · min^–1. The peak [1a^–]_b after exhaustion was 17.0 (SD 1.6) mmol · l^–1 . A significant correlation (r=0.89,P<0.001) was observed between the and the average speed in the 400-m sprint. The maximal 20-m sprinting speed on a track and correlated with both the and the 400-m speed. It was concluded that the new method allows the evaluation of several determinants of maximal anaerobic performance including changes in the force-generating capacity of leg muscles and [la^–]_b relative to the speed of the sprint running. The [1a^–]_b at submaximal sprinting speed was suggested as describing the anaerobic sprinting economy.     

Anaerobic and aerobic components during arm-crank exercise in sprint and middle-distance swimmers

Summary The purpose of this investigation was to compare anaerobic and aerobic components measured during arm exercise in sprint and middle-distance swimmers and to investigate whether the peak anaerobic power :peak aerobic power ratio (W _{an, peak} :W aer, peak) was related to specialization for the event and to performance. TheW _{an, peak} force at zero velocity (F ₀), and velocity at zero-force (₀),W _{aer, peak}, peak oxygen uptake ( O_2peak), and ventilatory threshold (Th _v ) were compared during arm exercise tests in sprint (group I,n = 8) and middle-distance (group II,n = 9) competitive male swimmers. Anaerobic indices were estimated by the force-velocity test, an anaerobic test using incremental braking forces; aerobic indices were measured during an incremental aerobic exercise test (30 W · min^–1). TheW _{an, peak} andW aer, peak were greater in group I [828 (SEM 70) W; 236 (SEM 12) W] than in group II [678 (SEM 28) W; 230 (SEM 5) W], but the differences were not significant. There were also no significant differences observed between the mean values ofF ₀, ₀, O_2peak, and Th _v . TheW _{an, peak}:W _{aer, peak}, however, was significantly higher in sprint swimmers (t = 3.08,P < 0.01). In seven of the swimmers, who had recently performed both the 100-m and 400-m front crawl, a relationship existed between their swim time and theW _{an, peak}:Waer,peak (100m:r = –0.80,P<0.05 and 400m:r=+0.75,P<0.05). In conclusion, during arm-crank exercise, we did not observe significant differences in anaerobic and aerobic components between sprint and middle-distance swimmers. However, the results of the present study demonstrated the usefulness of theW _{an, peak} :W _{aer, peak} in the physiological evaluation of swimmers as it reflects the proportion of anaerobic to aerobic systems involved in the supply of energy.     

Neuromuscular,anaerobic, and aerobic performance characteristics of elite power athletes

Summary Various aspects of neuromuscular, anaerobic, and aerobic performance capacity were investigated in four powerlifters, seven bodybuilders, and three wrestlers with a history of specific training for several years. The data (means ± SD) showed that the three subject groups possessed similar values for maximal isometric force per unit bodyweight (50.7±9.6, 49.3±4.1, and 49.3±10.9 N/kg, respectively).However, significant (P<0.05) differences were observed in the times for isometric force production, so that e.g., times to produce a 30% force level were shorter for the wrestlers and bodybuilders (28.3±3.1 and 26.4±6.6 ms) than that (53.3±23.7 ms) for the powerlifters. Utilization of elastic energy by the wrestlers was significantly (P<0.05) better than that of the other two subject groups, as judged from differences between the counter-movement and squat jumps at 0, 40, and 100 kg's loads. No differences were observed between the groups in anaerobic power in a 1-min maximal test, but the values for max were higher (P<0.05) among the wrestlers and bodybuilders (57.8±6.6 and 50.8±6.8 ml·kg^–1·min^–1) as compared to the powerlifters (41.9±7.2 ml ·kg^–1·min^–1). Within the limitations of the subject sample, no differences of a statistical significancy were observed between the groups in fibre distribution, fibre areas, or the area ratio of fast (FT) and slow (ST) twitch fibres in vastus lateralis. In all subjects the vertical jumping height was positively (P<0.01) correlated with the FT fibre distribution, and negatively with the time of isometric force production (P<0.05). Maximal force was correlated (P<0.001) with thigh girth. Muscle cross-sectional area did not correlate with mean fibre area. It was assumed that the selected aspects of neuromuscular, anaerobic, and aerobic performance capacity may be influenced by muscle structure, but also specifically and/or simultaneously by training lasting for several years.     

Anaerobic and aerobic power of top athletes

Summary In this study the alactic anaerobic and aerobic power of top level sprinters, long-distance runners, and untrained students were compared. Maximal oxygen uptake was measured during a progressive test on a treadmill. The anaerobic power was estimated according to a newly developed bicycle ergometer technique. As reported elsewhere, the maximal oxygen uptake is very high in twelfe long-distance runners (77.6±2.7 ml/kg·min⁻¹) whereas the maximal oxygen uptake of six sprinters amounts to 60.1±5.9 ml/kg·min⁻¹. The average alactic anaerobic power of a control group of 32 students was 710 W or 10.1±1.2 W/kg. Significantly lower results were obtained by long-distance runners (551 W or 8.93 W/kg) whereas significantly higher results were obtained by sprinters (1,021 W or 14.16 W/kg). In top level athletes, but not in the control group, a negative relationship was found between aerobic power and anaerobic power.     

Peak anaerobic power in master athletes

Summary The age-related decline in maximal physical performance of healthy subjects may be attributed both to the aging process per se and/or to a progressive reduction in physical activity. In two groups of master athletes, power (P) or endurance (E) trained (n = 115; aged 40–78 years), the degree and rate of the age-related deterioration of the maximal instantaneous muscle power (peak power,W _peak, and the relative contribution ofquantitative (muscle mass) andqualitative factors possibly underlying such deterioration were determined. Two groups of young athletes (n = 20; 17–26 years) and healthy untrained subjects (U,n = 37; 22–67 years) were also tested for comparison. The following two variables were assessed, firstly the lower limb muscle plus bone volume (LMV) by anthropometry, and secondlyW _peak, by means of a standardized vertical jump off both feet, performed on a force platform. The results obtained were that LMV of E and P, as well as of U, was about the same between age 20 and 45 years, whereas at older ages a progressive reduction was observed; the LMV values were higher in P than in E and U. TheW _peak, expressed in W and in W·kg^–1 body mass, both in E and P, decreased linearly as a function of age, being at age 75 years about 50% of the value measured at age 20 years (corresponding to a reduction of about 1%year^–1); whenW _peak was expressed per kg of LMV, the percentage reduction between athletes aged 20 and 45 years was the same as that observed forW _peak, in W and W·kg^–1 body mass, whereas between age 45 and 75 years the difference was almost halved; in all age-groups (with the exception of the oldest)W _peak was higher in P than in E and in U. It was concluded that at 75 yearsW _peak was reduced, both in absolute units and per kg body mass, to about 50% of the value measured at age 20 years; up to about age 45 years such deterioration was mainly attributable toqualitative factors, whereas after that agequantitative (muscle mass) factors were also involved.     

Physiological correlates of performance. Case study of a world-class rower

This report describes the changes in physiological capacity of a heavy-weight rower who obtained seven medals in World Championships and Olympic Games. The investigation was carried out over the last 6 years of the rower’s international competition career in comparison with peer champions, and the following 4 years. Over the first period, maximal oxygen uptake () remained above 6 l min⁻¹ which is an outstanding value. The training load measured over the last 18 months of the period increased from 119 to 142 km wk⁻¹ of rowing. Four years after the international competition period, had only declined by 3.6% although the training load had declined by 35%. These data suggest that the ability of this rower to compete at top level for years was related to ability to maintain an outstanding . Gross efficiency and ability to rely on anaerobic glycolysis did not emerge as relevant factors.     

A new approach to assessing maximal aerobic power in children: the Odense School Child Study

Summary In two experiments maximal aerobic power calculated from maximal mechanical power (W _max) was evaluated in 39 children aged 9–11 years. A maximal multi-stage cycle ergometer exercise test was used with an increase in work load every 3 min. In the first experiment oxygen consumption was measured in 18 children during each of the prescribed work loads and a correction factor was calculated to estimate using the equation . An appropriate increase in work rate based on height was determined for boys (0.16 W · cm^–1) and girls (0.15 W · cm^–1) respectively. In the second experiment 21 children performed a maximal cycle ergometer exercise test twice. In addition to the procedure in the first experiment a similar exercise test was performed, but without measurement of oxygen uptake. Calculated correlated significantly (p<0.01) with those values measured in both boys (r=0.90) and girls (r=0.95) respectively, and the standard error of estimation for (calculated) on (measured) wass less than 3.2%. Two expressions of relative work load (% and %W _max) were established and found to be closely correlated. The relative work load in % could be predicted from the relative work load in % W _max with an average standard error of 3.8%. The data demonstrate that calculated based on a maximal multi-stage exercise test provides an accurate and valid estimate of      

Critical velocity during continuous and intermittent exercises in children

The purpose of this study was to apply the “critical velocity” concept to short intermittent high-intensity running exercises in prepubescent girls and boys and to compare the running performances obtained either by intermittent or continuous exercise runs. Eleven 8 to 11-year-old children underwent a maximal graded field test to determine peak oxygen uptake (peakVO₂) and maximal aerobic velocity (MAV). During the six following sessions, they randomly performed three continuous runs (90, 100, and 110% of MAV) and three intermittent runs (120, 130, and 140% of MAV) until exhaustion. Intermittent exercises consisted of repeated 15 s runs each one separated by a 15 s passive recovery interval. For continuous as well as intermittent exercises, distance versus time to exhaustion (TTE) relationships were calculated to determine continuous (CVc) and intermittent (CVi) critical velocities. Values for peakVO₂ and MAV were 45.8 ± 5.3 ml·kg⁻¹·min⁻¹ and 10.5 ± 1.0 km h⁻¹, respectively. For the whole population, a significant relationship was found between the distance to exhaustion (DTE) and TTE for continuous (r ² = 0.99, P < 0.05) and intermittent exercises (r ² = 0.99, P < 0.05). Significant relationships were found between peakVO₂ and both CVc (r ² = 0.60, P < 0.01) and CVi (r ² = 0.47, P < 0.05). In conclusion, as for continuous exercises, a linear relationship was found between DTE and TTE for short high-intensity intermittent exercises. CVc was significantly related to peakVO₂, while a significant lower relationship was found between peakVO₂ and CVi.     

Association between anaerobic components of the maximal accumulated oxygen deficit and 30-second Wingate test

The purpose of this study was to analyze the relationship between the anaerobiccomponents of the maximal accumulated oxygen deficit (MAOD) and of the 30-secondWingate anaerobic test (30-WAnT). Nine male physical education students performed: a)a maximal incremental exercise test; b) a supramaximal constant workload test todetermine the anaerobic components of the MAOD; and c) a 30-WAnT to measure the peakpower (PP) and mean power (MP). The fast component of the excess post-exercise oxygenconsumption and blood lactate accumulation were measured after the supramaximalconstant workload test in order to determine the contributions made by alactic(AL_MET) and lactic (LA_MET) metabolism. Significantcorrelations were found between PP and AL_MET (r=0.71; P=0.033) and betweenMP and LA_MET (r=0.72; P=0.030). The study results suggested that theanaerobic components of the MAOD and of the 30-WAnT are similarly applicable in theassessment of AL_MET and LA_MET during high-intensityexercise.     

Effects of aerobic endurance training status and specificity on oxygen uptake kinetics during maximal exercise

The main purpose of this study was to analyze the effects of exercise mode, training status and specificity on the oxygen uptake (O₂) kinetics during maximal exercise performed in treadmill running and cycle ergometry. Seven runners (R), nine cyclists (C), nine triathletes (T) and eleven untrained subjects (U), performed the following tests on different days on a motorized treadmill and on a cycle ergometer: (1) incremental tests in order to determine the maximal oxygen uptake (O_2max) and the intensity associated with the achievement of O_2max (IO_2max); and (2) constant work-rate running and cycling exercises to exhaustion at IO_2max to determine the effective time constant of the O₂ response (O₂). Values for O_2max obtained on the treadmill and cycle ergometer [R=68.8 (6.3) and 62.0 (5.0); C=60.5 (8.0) and 67.6 (7.6); T=64.5 (4.8) and 61.0 (4.1); U=43.5 (7.0) and 36.7 (5.6); respectively] were higher for the group with specific training in the modality. The U group showed the lowest values for O_2max, regardless of exercise mode. Differences in O₂ (seconds) were found only for the U group in relation to the trained groups [R=31.6 (10.5) and 40.9 (13.6); C=28.5 (5.8) and 32.7 (5.7); T=32.5 (5.6) and 40.7 (7.5); U=52.7 (8.5) and 62.2 (15.3); for the treadmill and cycle ergometer, respectively]; no effects of exercise mode were found in any of the groups. It is concluded that O₂ during the exercise performed at IO_2max is dependent on the training status, but not dependent on the exercise mode and specificity of training. Moreover, the transfer of the training effects on O₂ between both exercise modes may be higher compared with O_2max.     

Energy system contribution in a maximal incremental test: correlations with pacing and overall performance in a 10-km running trial

This study aimed to verify the association between the contribution of energy systems during an incremental exercise test (IET), pacing, and performance during a 10-km running time trial. Thirteen male recreational runners completed an incremental exercise test on a treadmill to determine the respiratory compensation point (RCP), maximal oxygen uptake (V˙O2max), peak treadmill speed (PTS), and energy systems contribution; and a 10-km running time trial (T10-km) to determine endurance performance. The fractions of the aerobic (W_AER) and glycolytic (W_GLYCOL) contributions were calculated for each stage based on the oxygen uptake and the oxygen energy equivalents derived by blood lactate accumulation, respectively. Total metabolic demand (W_TOTAL) was the sum of these two energy systems. Endurance performance during the T10-km was moderately correlated with RCP, V˙O2maxand PTS (P<@0.05), and moderate-to-highly correlated with W_AER, W_GLYCOL, and W_TOTAL (P<0.05). In addition, W_AER, W_GLYCOL, and W_TOTAL were also significantly correlated with running speed in the middle (P<0.01) and final (P<0.01) sections of the T10-km. These findings suggest that the assessment of energy contribution during IET is potentially useful as an alternative variable in the evaluation of endurance runners, especially because of its relationship with specific parts of a long-distance race.     

Effects of 2-chloropropionate on venous plasma lactate concentration and anaerobic power during periods of incremental intensive exercise in humans

We investigated the effects of a stimulation of pyruvate dehydrogenase (PDH) activity induced by 2-chloropropionate (2-CP) on venous plasma lactate concentration and peak anaerobic power (W _{an, peak}) during periods (6 s) of incremental intense exercise, i.e. a force-velocity (F-) test known to induce a marked accumulation of lactate in the blood. TheF- test was performed twice by six subjects according to a double-blind randomized crossover protocol: once with placebo and once with 2-CP (43 mg · kg^–1 body mass). Blood samples were taken at ingestion of the drug, at 10, 20, and 40 Min into the pretest period, at the end of each period of intense exercise, at the end of each 5-min recovery period, and after completion of theF- test at 5, 10, 15, and 30 min. During theF- test, venous plasma lactate concentrations with both placebo and 2-CP increased significantly when measured at the end of each period of intense exercise (F = 33.5,P < 0.001), and each 5-min recovery period (F = 24.6,P < 0.001). Venous plasma lactate concentrations were significantly lower with 2-CP at the end of each recovery period (P < 0.01), especially for high braking forces, i.e. 8 kg (P < 0.05), 9 kg (P < 0.02), and maximal braking force (P < 0.05). After completion of theF- test, venous plasma lactate concentrations were also significantly lower with 2-CP (P < 0.001). The percentage of lactate decrease between 5- and 30-min recovery was significantly higher with 2-CP than with the placebo [59 (SEM 4)% vs 44.6 (SEM 5.5)%,P < 0.05]. Furthermore,W _{an, peak} was significantly higher with 2-CP than with the placebo [1016 (SEM 60) W vs 957 (SEM 55) W,P < 0.05]. In conclusion, PDH activation by 2-CP attenuated the increase in venous plasma lactate concentration during theF- test. Ingestion of 2-CP led to an increasedW _{an, peak}.     

Differences in cardio-respiratory responses to exhaustive exercise between athletes and non-athletes

Summary To study the factors limiting the O₂ supply in heavy exercise, O₂ uptake at exhaustion was determined by progressive loading method with a bicycle ergometer in 33 well-trained male runners and 34 male sedentary adults. Pulmonary ventilation, oxygen removal, respiratory rate, tidal volume, pulmonary diffusing capacity, alveolar-capillary oxygen difference, cardiac output, arterial-venous oxygen difference, stroke volume and heart rate were measured. It was found that pulmonary diffusing capacity, cardiac output and stroke volume were correlated with the difference in O₂ uptake at exhaustion between athletes and non-athletes.     

Oxygen uptake during running as related to body mass in circumpubertal boys: a longitudinal study

Summary To investigate the effect of endurance training on physiological characteristics during circumpubertal growth, eight young runners (mean starting age 12 years) were studied every 6 months for 8 years. Four other boys served as untrained controls. Oxygen uptake ( O ₂) and blood lactate concentrations were measured during submaximal and maximal treadmill running. The data were aligned with each individual's age of peak height velocity. The maximal oxygen uptake ( O _2max; ml · kg^–1 · min^–1) decreased with growth in the untrained group but remained almost constant in the training group. The oxygen cost of running at 15 km · h^–1 ( O ₂₁₅, ml · kg^–1 · min^–1) was persistently lower in the trained group but decreased similarly with age in both groups. The development of O _2max and O ₂₁₅ (1 · min^–1) was related to each individual's increase in body mass so that power functions were obtained. The mean body mass scaling factor was 0.78 (SEM 0.07) and 1.01 (SEM 0.04) for O _2max and 0.75 (SEM 0.09) and 0.75 (SEM 0.02) for O ₂₁₅ in the untrained and trained groups, respectively. Therefore, expressed as ml · kg^–0.75 · min^–1, O ₂₁₅ was unchanged in both groups and O _2max increased only in the trained group. The running velocity corresponding to 4 mmol · 1^–1 of blood lactate ( _la4) increased only in the trained group. Blood lactate concentration at exhaustion remained constant in both groups over the years studied. In conclusion, recent and the present findings would suggest that changes in the oxygen cost of running and O _2max (ml · kg^–1 · min^–1) during growth may mainly be due to an overestimation of the body mass dependency of O ₀₂ during running. The O ₂ determined during treadmill running may be better related to kg^0.75 than to kg¹.     

Day-to-day changes in oxygen uptake kinetics at the onset of exercise during strenuous endurance training

Summary The aim of this study was to assess the effect of strenuous endurance training on day-to-day changes in oxygen uptake (VO₂) on-kinetics (time constant) at the onset.of exercise. Four healthy men participated in strenuous training, for 30 min·day^–1, 6 days·week^–1 for 3 weeks. The VO₂ was measured breath-by-breath every day except Sunday at exercise intensities corresponding to the lactate threshold (LT) and the onset of blood lactate accumulation (OBLA) which were obtained before training. Furthermore, an incremental exercise test was performed to determine LT, OBLA and maximal oxygen uptake (VO_2max) before and after the training period and every weekend. The 30-min heavy endurance training was performed on a cycle ergometer 5 days·week^–1 for 3 weeks. Another six men served as the control group. After training, significant reductions of the VO₂ time constant for exercise at the pretraining LT exercise intensity (P<0.05) and at OBLA exercise intensity (P<0.01) were observed, whereas the VO₂ time constants in the control group did not change significantly. A high correlation between the decrease in the VO₂ time constant and training day was observed in exercise at the pretraining LT exercise intensity (r=–0.76; P<0.001) as well as in the OBLA exercise intensity (r= –0.91; P<0.001). A significant reduction in the blood lactate concentration during submaximal exercise and in the heart rate on-kinetics was observed in the training group. Furthermore, VO₂ at LT, VO₂ at OBLA and VO_2max increased significantly after training (P<0.05) but such was not the case in the control group. These findings indicated that within a few weeks of training a rapidly improved VO₂ on-kinetics may be observed. This may be explained. by some effect of blood lactate during exercise on VO₂ on-kinetics, together with significantly improved cardiovascular kinetics at the onset of exercise.     

Validity of criteria for establishing maximal O<Subscript>2</Subscript> uptake during ramp exercise tests

The incremental or ramp exercise test to the limit of tolerance has become a popular test for determination of maximal O₂ uptake However, many subjects do not evidence a definitive plateau of the -work rate relationship on this test and secondary criteria based upon respiratory exchange ratio (RER), maximal heart rate (HR_max) or blood [lactate] have been adopted to provide confidence in the measured We hypothesized that verification of using these variables is fundamentally flawed in that their use could either allow underestimation of (if, for any reason, a test were ended at a sub-maximal ), or alternatively preclude subjects from recording a valid Eight healthy male subjects completed a ramp exercise test (at 20 W/min) to the limit of tolerance on an electrically braked cycle ergometer during which pulmonary gas exchange was measured breath-by-breath and blood [lactate] was determined every 90 s. Using the most widely used criterion values of RER (1.10 and 1.15), as determined during the ramp test (4.03 ± 0.10 l/min) could be undermeasured by 27% (2.97 ± 0.24 l/min) and 16% (3.41 ± 0.15 l/min), respectively (both P < 0.05). The criteria of HR_max (age predicted HR_max ± 10 b/min) and blood [lactate] (≥8 mM) were untenable because they resulted in rejection of 3/8 and 6/8 of the subjects, most of whom (5/8) had demonstrated a plateau of at These findings provide a clear mandate for rejecting these secondary criteria as a means of validating on ramp exercise tests.     

Peak power output predicts maximal oxygen uptake and performance time in trained cyclists

Summary The purposes of this study were firstly to determine the relationship between the peak power output (W _peak) and maximal oxygen uptake (VO_2max) attained during a laboratory cycling test to exhaustion, and secondly to assess the relationship betweenW _peak and times in a 20-km cycling trial. One hundred trained cyclists (54 men, 46 women) participated in the first part of this investigation. Each cyclist performed a minimum of one maximal test during whichW _max andVO_2max were determined. For the second part of the study 19 cyclists completed a maximal test for the determination ofW _peak, and also a 20-km cycling time trial. Highly significant relationships were obtained betweenW _peak andVO_2max (r=0.97,P<0.0001) and betweenW _peak and 20-km cycle time (r= –0.91,P<0.001). Thus,W _peak explained 94% of the variance in measuredVO_2max and 82% of the variability in cycle time over 20 km. We concluded that for trained cyclists, theVO_2max can be accurately predicted fromW _peak, and thatW _peak is a valid predictor of 20-km cycle time.     

Influence of resistive load on power output and fatigue during intermittent sprint cycling exercise in children

This study examined the effects of two resistive loads on fatigue during repeated sprints in children. Twelve 11.8 (0.2) year old boys performed a force–velocity test to determine the load (Fopt) corresponding to the optimal pedal rate. On two separate occasions, ten 6-s sprints interspersed with 24-s recovery intervals were performed on a friction-loaded cycle ergometer, against a load equal to Fopt or 50%Fopt. Although mean power output (MPO) was higher in the Fopt [397 (24) and 356 (19) W, P < 0.01], the decline in MPO over the 10 sprints was similar in Fopt [8.8 (1.9) %] and 50%Fopt [9.0 (2.4) %]. In contrast, peak power (PPO) was not different in sprint 1 between the two conditions [459 (24) and 460 (28) W], but was decreased only in 50%Fopt [11.4 (3.2) %, P < 0.01], while it was maintained in the Fopt despite the higher total work during each sprint. Fatigue within each sprint (percent drop from peak to end power output) was also higher in the 50%Fopt compared with the Fopt [32 (2.5) vs. 10 (1.6) %, P < 0.01]. Peak and mean pedal rate in Fopt condition were close to the optimum (Vopt), while a large part of the sprint time in 50%Fopt was spent far from Vopt. The present study shows that sprinting against Fopt reduces fatigue within and between repeated short sprints in children. It is suggested that fatigue during repeated sprints is modified when pedal rate is not close to Vopt, according to the parabolic power versus pedal rate relationship.     

Differences in performance between trained and untrained subjects during a 30-s sprint test in a wheelchair ergometer

Summary To compare physiological responses and propulsion technique of able bodied subjects with no prior experience of wheelchairs (AB) and wheelchair dependent subjects (WD), ten AB and nine WD performed a 30-s sprint test in a wheelchair ergometer. The WD had spinal cord injuries with a lesion at T8 or lower. The WD and AB did not show significantly different physiological responses. The power values averaged for the right wheel over the 30 s of the test were 50.2 (SD 14.7) W and 48.0 (SD 4.4) W for WD and AB, respectively. No significant differences in torque application could be discerned, although WD subjects seemed to have a more flattened torque curve with a smaller negative deflection at the beginning of the push. The WD applied a significantly higher horizontal propulsive force to the handrims but did not apply force more effectively. The percentages of effective force to total propulsive force were 61 (SD 16)% for WD and 57 (SD 4)% for AB. With regard to the kinematic parameters, AB followed the handrims significantly longer than WD (end angle AB 65°, WD 44°), started the push phase with their arms more in retroflexion and flexed their trunks further forward. The AB did however show a movement pattern comparable to that of wheelchair athletes measured in a comparable experiment. It could not be decided conclusively that inexperience in wheelchair propulsion led to a less effective propulsion technique. Despite the selection of WD with respect to lesion level, interindividual differences in terms of level of training may have been responsible for the absence of significant results.