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1.
葛根素对游泳训练小鼠红细胞和血红蛋白升高的消退作用   总被引：3，自引：0，他引：3  
邵邻相 《体育科学》2005,25(2):70-72
观察葛根素对游泳训练小鼠血液成分和运动能力的影响。将 4 0只小鼠随机分成对照组、葛根素对照组、游泳训练组和葛根素游泳训练组。游泳训练小鼠分别进行 6周每天 80 min的游泳训练 ,葛根素实验小鼠游泳训练开始后第 3周腹腔注射 6 0 m g/ kg葛根素 ,对照组注射等体积生理盐水 ,连续 3周 ,于游泳停止后 4 h进行尾静脉取血 ,测定白细胞、红细胞、血小板和血红蛋白等指标 ;次日进行一次性力竭游泳。结果表明 ,游泳训练组小鼠的血红蛋白浓度、红细胞数、血小板数都比对照组明显增加 (P<0 .0 5 ) ,而葛根素游泳训练组血红蛋白、红细胞数和血小板数与对照组之间则无明显差异。葛根素游泳训练组小鼠的力竭游泳时间与游泳训练组比较明显延长 (P<0 .0 5 )。说明葛根素可降低因运动训练引起的血红蛋白的升高、红细胞数和血小板数的增多 ,降低血液的粘度 ,延长力竭游泳的时间 ,提高机体的运动能力。  相似文献   

2.
The purpose of this study was to examine the effects of active recovery (AR) and passive recovery (PR) using short (2-min) and long (4-min) intervals on swimming performance. Twelve male competitive swimmers completed a progressively increasing speed test of 7?×?200-m swimming repetitions to locate the speed before the onset of curvilinear increase in blood lactate concentration (LT1). Subsequently, performance time of 6?×?50-m sprints was recorded during four different conditions: (i) 2-min PR (PR-2), (ii) 4-min PR (PR-4), (iii) 2-min AR (AR-2) and (iv) 4-min AR (AR-4) intervals. Blood lactate concentration was measured before the first and after the last 50-m repetition. AR was applied at an intensity corresponding to LT1. Performance as indicated by the time needed to complete 6?×?50-m sprints was impaired after AR-4 compared to PR-4 (AR-4: 28.65?±?1.04, PR-4: 28.17?±?0.72?s; mean% difference: MD% ±s; ±90% confidence limits: 90%CL, 1.71?±?3.01%; ±1.43%, p?=?.01) but was not different between AR-2 compared to PR-2 conditions (AR-2: 28.68?±?0.85, PR-2: 28.69?±?0.82 s; MD%: 0.03?±?1.61%; 90%CL?±?0.77%, p?=?.99). Performance in sprint-6 was improved after AR compared to PR independent of interval duration (AR: 28.55?±?0.81, PR: 29.01?±?1.03?s; MD%: 1.52?±?2.61%; 90%CL?±?1.2%; p?=?.03). Blood lactate concentration was lower after AR-4 compared to PR-4 but did not differ between AR-2 and PR-2 conditions. In conclusion, AR impaired performance after a 4-min but not after a 2-min interval. A better performance during sprint-6 after AR could be attributed to a faster metabolic recovery or anticipatory regulatory mechanisms towards the end of the series especially when adequate 4-min active recovery interval is applied.  相似文献   

3.
Abstract

Eight college swimmers were tested on a swimming ergometer to investigate the effects of body position on land and immersion in the water on the heart rate recovery after swimming exercise. The subjects swam at a predetermined work load for 5 min. and then assumed one of the four conditions for recovery (erect and supine on the deck, motionless and swimming in the water). Heart rates were recorded for the 3 min. of recovery. After the allowance for recovery, the subject was timed for a 200-yd. swim. No statistically significant differences were noted when comparing the recovery heart rates for the four conditions. The same was found true when comparing the 200-yd. swim times. It was noted that the swim was felt to be harder when recovery was completed in an erect or supine position than after light exercise in the water.  相似文献   

4.
The purpose of this study was to examine the metabolic responses during submaximal swimming with self-selected normal breathing (N) and prolonged expiration along with reduced frequency breathing (RB). Ten male swimmers (age: 23.1 ± 2.2 years; VO2max: 47.3 ± 7.2 ml · kg?1 · min?1) performed 75-, 100-, 175-, 200-, 275-, 300-, 375- and 400-m trials with N and RB at intensity corresponding to 90% of the critical speed. In RB condition, all trials longer than 75 m were interspersed with 25 m of self-selected N in regular intervals. In RB, oxygen saturation during recovery was decreased compared to starting values after 75, 100, 175, 275 and 375 m (78–91%, P < 0.05), while it remained unchanged after all trials in N condition (98 ± 2%, P > 0.05). Lactate concentration was higher in RB than in N after 400 m (4.3 ± 1.5 vs. 3.3 ± 1.7 mmol · l?1, P < 0.05). During recovery after the 375-m trial, partial pressure of carbon dioxide was increased and pH was decreased in RB compared to N condition. Prolonged expiration along with RB provokes severe hypoxemia during the recovery period after swimming, which is restored with self-selected N during submaximal swimming.  相似文献   

5.
It has previously been shown that measurement of the critical speed is a non-invasive method of estimating the blood lactate response during exercise. However, its validity in children has yet to be demonstrated. The aims of this study were: (1) to verify if the critical speed determined in accordance with the protocol of Wakayoshi et al. is a non-invasive means of estimating the swimming speed equivalent to a blood lactate concentration of 4 mmol·l-1 in children aged 10-12 years; and (2) to establish whether standard of performance has an effect on its determination. Sixteen swimmers were divided into two groups: beginners and trained. They initially completed a protocol for determination of speed equivalent to a blood lactate concentration of 4 mmol·l-1. Later, during training sessions, maximum efforts were swum over distances of 50, 100 and 200 m for the calculation of the critical speed. The speeds equivalent to a blood lactate concentration of 4 mmol·l-1 (beginners = 0.82±0.09 m·s-1 , trained = 1.19±0.11 m·s-1; mean±s) were significantly faster than the critical speeds (beginners = 0.78±0.25·s-1 , trained = 1.08±0.04 m·s-1) in both groups. There was a high correlation between speed at a blood lactate concentration of 4 mmol·l-1 and the critical speed for the beginners (r = 0.96, P ? 0.001), but not for the trained group (r = 0.60, P > 0.05). The blood lactate concentration corresponding to the critical speed was 2.7±1.1 and 3.1±0.4 mmol·l-1 for the beginners and trained group respectively. The percent difference between speed at a blood lactate concentration of 4 mmol·l-1 and the critical speed was not significantly different between the two groups. At all distances studied, swimming performance was significantly faster in the trained group. Our results suggest that the critical speed underestimates swimming intensity corresponding to a blood lactate concentration of 4 mmol·l-1 in children aged 10-12 years and that standard of performance does not affect the determination of the critical speed.  相似文献   

6.
Male interscholastic swimmers (n = 8) completed a 4572 m training swim in 62 ±1.1 min (x ± s.e.) with terminal heart rate and blood lactate of 152 ± 6 beats min‐1 and 6.9±0.89 mM, respectively. Sweat rate (0.48±0.0951. h‐1) was lower than similar intensity cycling (1.5±0.13 1. h‐1) or running (1.1 ± 0.14 l.h‐1). Post‐swim serum urea N (11.6±0.71 mM) was elevated (P<0.05) vs pre‐swim (4.6±0.39 mM). Post‐swim urine volume (860±75 ml 24 h‐1) was reduced (P<0.07) and resulted in an elevated (P<0.05), but delayed (24–84 h), post‐exercise urea N excretion. Although the reduced urine and sweat production during the swim undoubtedly contributed to the elevated serum urea, there must be another explanation because together they could only account for 38% of the observed increase. On the basis of the magnitude of serum urea increase, it appears that the swim caused an increase in urea production (amino acid oxidation). The failure to observe larger increases in urinary urea during recovery indicates that either urea excretion following exercise continues for prolonged periods of time (>48 h) or another significant mode of nitrogen excretion exists.  相似文献   

7.
Abstract

This study was designed to investigate the swimming endurance trainability of smokers as compared to nonsmokers. Nonsmokers (N = 47) and smokers (N = 34) of college age were selected from intermediate swimming classes and timed while swimming distances of 100 yd. and 200 yd. prior to participation in an 8-week training program. After 4 weeks of training, swimming times were again recorded for these same distances. At the end of eight weeks, swimming times were taken for distances of 100, 200, and 400 yards. The mean changes of both smokers and nonsmokers during the pretraining to 4-week period, the 4-week to 8-week period, and the pretraining to 8-week period were all significant at the .05 level. However, no significant differences were found between the mean swimming times of smokers and nonsmokers for any of the pretraining, 4-week, or 8-week distances.  相似文献   

8.
Abstract

The effect of active and passive recovery on repeated-sprint swimming bouts was studied in eight elite swimmers. Participants performed three trials of two sets of front crawl swims with 5 min rest between sets. Set A consisted of four 30-s bouts of high-intensity tethered swimming separated by 30 s passive rest, whereas Set B consisted of four 50-yard maximal-sprint swimming repetitions at intervals of 2 min. Recovery was active only between sets (AP trial), between sets and repetitions of Set B (AA trial) or passive throughout (PP trial). Performance during and metabolic responses after Set A were similar between trials. Blood lactate concentration after Set B was higher and blood pH was lower in the PP (18.29 ± 1.31 mmol · l?1 and 7.12 ± 0.11 respectively) and AP (17.56 ± 1.22 mmol · l?1 and 7.14 ± 0.11 respectively) trials compared with the AA (14.13 ± 1.56 mmol · l?1 and 7.23 ± 0.10 respectively) trial (P < 0.01). Performance time during Set B was not different between trials (P > 0.05), but the decline in performance during Set B of the AP trial was less marked than in the AA or PP trials (main effect of sprints, P < 0.05). Results suggest that active recovery (60% of the 100-m pace) could be beneficial between training sets, and may compromise swimming performance between repetitions when recovery durations are short (< 2 min).  相似文献   

9.
To quantify swimwear-induced differences under triathlon-specific conditions, we compare the swimming performance, the metabolic cost, and the standardised passive drag of well-trained triathletes when wearing (1) five speedsuit models by different manufacturers from 2017, (2) usual swimming trunks/swimsuits (men/women), and (3) individually preferred competition trisuits. Because of the complexity of the underlying hydrodynamic and biomechanical effects, three separate experimental stages were realized, each with 6–12 well-trained short- and middle-distance triathletes (male and female, mean age 22?±?5 years) from the German national elite or junior elite level. All measurements were conducted on the basis of real athletes’ motion in the water to correctly account for all relevant effects, including skin and muscle vibrations. First, the athletes took part in a series of 100 m short-distance tests at maximal effort in a long-course pool to quantify swim-time differences in absolute terms. Second, the subjects completed multiple submaximal 400 m tests at 95% of their individual maximal speed in a swimming flume, with their swimwear-related differences in metabolic load being explored in terms of blood lactate and heart rate. Third, the passive drag of the triathletes was measured in the flume during a towing test under standardised conditions in velocity steps of 0.2 m/s within the triathlon-relevant range of 1.1–1.7 m/s. In all three test stages, the speedsuits exhibited performance advantages over trunks/swimsuits: in the 100 m maximal test, the mean swim time with speedsuits decreased by 0.99?±?0.30 s (????1.5%). During the 400 m submaximal flume test, the mean heart rate showed a reduction of 7?±?2 bpm (? ??4.0%), while the post-exercise blood lactate accumulation decreased by 1.0?±?0.2 mmol/L (? ??26.2%). Similarly, the passive drag in the towing test was lowered by 3.2?±?1.0 W (????6.9% as for normalised power and ??5.2% as for normalised force) for the speedsuits. Wearing speedsuits instead of usual trunks/swimsuits is shown to improve the swimming performance and to reduce the metabolic cost for well-trained triathletes under triathlon-specific test conditions. The reduction in passive drag of the passively towed athlete’s body due specific speedsuit surface textures seems to be only one reason for performance advantages: the effective reduction in muscular, soft tissue, and skin vibrations at the trunk and thighs during active propulsive motion of the swimmer seems to further contribute substantially.  相似文献   

10.
Abstract

The purpose of this study was to characterize changes and variability in test performance of swimmers within and between seasons over their elite competitive career. Forty elite swimmers (24 male, 16 female) performed a 7×200-m incremental swimming step test several times each 6-month season (10±5 tests, spanning 0.5–6.0?y). Mixed linear modeling provided estimates of percent change in the mean and individual responses (within-athlete variation as a coefficient of variation) for measures based on submaximal performance (fixed 4-mM lactate), maximal performance (the seventh step) and lean mass (from skinfolds and body mass). Submaximal and maximal swim speed increased within each season from pre to taper phase by ～2.2% for females and ～1.5% for males (95% confidence limits ±1.0%), with variable contributions from stroke rate and stroke length. Most of the gains in speed were lost in the off-season, leaving a net average annual improvement of ～1.0% for females and ～0.6% for males (±1.0%). For submaximal and maximal speed, individual variation between phases was ±2.2% and the typical measurement error was ±0.80%. Step test and anthropometric measures can be used to confidently monitor progressions in swimmers in an elite training program within and between seasons.  相似文献   

11.
The aim of this study was to examine the effects of active versus passive recovery on blood lactate disappearance and subsequent maximal performance in competitive swimmers. Fourteen male swimmers from the University of Virginia swim team (mean age 20.3 years, s= 4.1; stature 1.85 m, s= 2.2; body mass 81.1 kg, s= 5.6) completed a lactate profiling session during which the speed at the lactate threshold (V(LT)), the speed at 50% of the lactate threshold (V(LT.5)), and the speed at 150% of the lactate threshold (V(LT1.5)) were determined. Participants also completed four randomly assigned experimental sessions that consisted of a 200-yard maximal-effort swim followed by 10 min of recovery (passive, V(LT.5), V(LT), V(LT1.5)) and a subsequent 200-yard maximal effort swim. All active recovery sessions resulted in greater lactate disappearance than passive recovery (P < 0.0001 for all comparisons), with the greatest lactate disappearance associated with recovery at V(LT) (P= 0.006 and 0.007 vs. V(LT.5) and V(LT1.5) respectively) [blood lactate disappearance was 2.1 mmol l(-1) (s= 2.0), 6.0 mmol l(-1) (s=2.6), 8.5 mmol l(-1) (s= 1.8), and 6.1 mmol l(-1) (s= 2.5) for passive, V(LT.5), V(LT), and V(LT1.5) respectively]. Active recovery at VLT and V(LT1.5) resulted in faster performance on time trial 2 than passive recovery (P=0.005 and 0.03 respectively); however, only active recovery at V(LT) resulted in improved performance on time trial 2 (TT2) relative to time trial 1 (TT1) [TT2- TT1: passive +1.32 s (s= 0.64), V(LT.5) +1.01 s (s= 0.53), V(LT) -1.67 s (s= 0.26), V(LT1.5) -0.07 s (s = 0.51); P < 0.0001 for V(LT)). In conclusion, active recovery at the speed associated with the lactate threshold resulted in the greatest lactate disappearance and in improved subsequent performance in all 14 swimmers. Our results suggest that coaches should consider incorporating recovery at the speed at the lactate threshold during competition and perhaps during hard training sessions.  相似文献   

12.
Abstract

The aim of this study was to examine the effects of active versus passive recovery on blood lactate disappearance and subsequent maximal performance in competitive swimmers. Fourteen male swimmers from the University of Virginia swim team (mean age 20.3 years, s = 4.1; stature 1.85 m, s = 2.2; body mass 81.1 kg, s = 5.6) completed a lactate profiling session during which the speed at the lactate threshold (VLT), the speed at 50% of the lactate threshold (VLT.5), and the speed at 150% of the lactate threshold (VLT1.5) were determined. Participants also completed four randomly assigned experimental sessions that consisted of a 200-yard maximal-effort swim followed by 10 min of recovery (passive, VLT.5, VLT, VLT1.5) and a subsequent 200-yard maximal effort swim. All active recovery sessions resulted in greater lactate disappearance than passive recovery (P < 0.0001 for all comparisons), with the greatest lactate disappearance associated with recovery at VLT (P = 0.006 and 0.007 vs. VLT.5 and VLT1.5 respectively) [blood lactate disappearance was 2.1 mmol · l?1 (s = 2.0), 6.0 mmol · l?1 (s = 2.6), 8.5 mmol · l?1 (s = 1.8), and 6.1 mmol · l?1 (s = 2.5) for passive, VLT.5, VLT, and VLT1.5 respectively]. Active recovery at VLT and VLT1.5 resulted in faster performance on time trial 2 than passive recovery (P = 0.005 and 0.03 respectively); however, only active recovery at VLT resulted in improved performance on time trial 2 (TT2) relative to time trial 1 (TT1) [TT2?TT1: passive +1.32 s (s = 0.64), VLT.5+1.01 s (s = 0.53), VLT?1.67 s (s = 0.26), VLT1.5?0.07 s (s = 0.51); P < 0.0001 for VLT). In conclusion, active recovery at the speed associated with the lactate threshold resulted in the greatest lactate disappearance and in improved subsequent performance in all 14 swimmers. Our results suggest that coaches should consider incorporating recovery at the speed at the lactate threshold during competition and perhaps during hard training sessions.  相似文献   

13.
Abstract

The effects of carbohydrate (CHO) ingestion during sports which require high levels of motor and cognitive skill, such as squash, have produced conflicting results. This study aimed to explore the effect of CHO ingestion on squash skill following short duration exercise simulating the demands of squash play. Sixteen male squash players of a high standard were recruited. Following a VO2max test, and familiarisation trial, subjects completed two further trials assessing skill pre- and post-exercise designed to simulate the demands of squash play. A squash skill test assessed accuracy of the forehand and backhand straight drives. Exercise consisted of 20 minutes of shuttle running at 82(±5)% HRmax, and 9 minutes of ghosting at 94(±4)% HRmax. Capillary blood samples (20 µl) were taken at five intervals for measurement of glucose and lactate. Cognitive function was measured with choice visual and auditory reaction time (RT) tests pre- and post-exercise, as was forearm wrist flexor MVC and fatigue profile. CHO drink (6.4% CHO) or matched placebo (PL) were administered after the initial skill test (500 ml), after the shuttle running (250 ml), and after the ghosting (250 ml) in a double blind crossover design. There was no overall effect of CHO ingestion on skill maintenance (p=0.10) however, significantly fewer balls landed outside the scoring zone (p=0.03) on the CHO ingestion trial. There was no change of visual RT pre- to post-exercise on PL (+0.01±0.03s), but a significant improvement (?0.07±0.05s) was observed in the CHO trial. Auditory RT improved pre- to post-exercise during both trials. MVC and fatigue profile of the wrist flexors was not different between trials but showed a force decrement pre- to post-exercise (p<0.05). A significant difference in blood glucose was observed between trials (p<0.01) but blood lactate response during both trials was similar. These results lend some support to a beneficial effect of CHO ingestion on skill during game sports.  相似文献   

14.
The aim of this study was to determine the influence of swim intensity on acute responses to dynamic apnoea. 9 swimmers performed one 50 m front crawl trial in four different conditions: at 400 m velocity (V400) with normal breathing (NB), at V400 in complete apnoea (Ap), at maximal velocity (Vmax) with NB and at Vmax in Ap. Peak heart rate (HRpeak), blood lactate concentration after exercise (Lacpost ex) and Borg rating of perceived exertion (RPE) were measured. Arterial oxygen saturation (SpO2) was monitored with a pulse oximeter at forehead level during and after exercise. In Ap, swimming at V400 induced a significantly lower HRpeak and Lacpost ex than swimming at Vmax whilst RPE and the kinetics of SpO2 were not different at V400 and at Vmax. The minimal value of SpO2 in Ap was reached 10 to 11 s after the end of V400 and Vmax (81.7 ± 10.1% and 84.4 ± 10.6%, respectively). Swimming a 50 m front crawl in Ap resulted in a large decrease in SpO2 which occurred only after the cessation of exercise. The higher duration of apnoea during submaximal exercise could explain why SpO2 and RPE reached the same values as for maximal exercise.?  相似文献   

15.
Abstract

Twelve college and high school varsity male swimmers swam 200 yd. for time once a day for 16 days following the ingestion of a large meal (673 g). Each subject performed under rotating experimental conditions, which involved a post-meal rest interval of ½ hr., 1 hr., 2 hr., or no eating for at least 3 hr. before swimming. A nonsignificant F of .53 was obtained when the data were subjected to a single-factor with repeated measures analysis of variance.

It was concluded that swimming performance time was not affected by the time interval between eating and swimming. No stomach cramps were reported; most cases of stomach nausea occurred in the ½-hr. interval group, and scattered minor physical disturbances occurred under the other conditions.  相似文献   

16.
We investigated the rotational effect of buoyant force around the body’s transverse axis, termed buoyant torque, during a 200m front crawl maximal swim. Eleven male swimmers of national or international level participated. One stroke cycle (SC) for each 50m was recorded with two above and four below water cameras. The following variables were analysed: swimming velocity; absolute and normalised buoyant force; minimum, average and maximum buoyant torque; SC and arm recovery times. The average value of buoyant torque was higher in the first 50m (14.2 ± 4.5Nm) than in the following 150m (9.3 ± 4.1Nm~10.9 ± 4.5Nm) and was directed to raise the legs and lower the head throughout the race. The change in its magnitude seemed to be linked to the shorter time spent proportionally in arm recovery (first 50m: 27.6% of SC time; next 150m: 23.3–24.4% of SC time). Most swimmers had periods of the SC where buoyant torque was directed to sink the legs, which accounted to 10% of SC time in the first 50m and about twice this duration in the next 150m. These periods were observed exclusively at some instances when the recovering arm had entered the water while the opposite arm was still underwater.  相似文献   

17.
The aim of this study was to examine the effects of ingesting a carbohydrate‐electrolyte solution on endurance capacity during a prolonged intermittent, high‐intensity shuttle running test (PIHSRT). Nine trained male games players performed two exercise trials, 7 days apart. On each occasion, they completed 75 min exercise, comprising of five 15‐min periods of intermittent running, consisting of sprinting, interspersed with periods of jogging and walking (Part A), followed by intermittent running to fatigue (Part B). The subjects were randomly allocated either a 6.9% carbohydrate‐electrolyte solution (CHO) or a non‐carbohydrate placebo (CON) immediately prior to exercise (5 ml kg‐1 body mass) and every 15 min thereafter (2 ml kg‐1 body mass). Venous blood samples were obtained at rest, during and after each PIHSRT for the determination of glucose, lactate, plasma free fatty acid, glycerol, ammonia, and serum insulin and electrolyte concentrations. During Part B, the subjects were able to continue running longer when fed CHO (CHO = 8.9 ± 1.5 min vs CON = 6.7 ± 1.0 min; P < 0.05) (mean ± s.e.m.). These results show that drinking a carbohydrate‐electrolyte solution improves endurance running capacity during prolonged intermittent exercise.  相似文献   

18.
目的:观察补充活性肽对大鼠骨骼肌细胞结蛋白和波形蛋白免疫染色和血清酶活性的影响,研究活性肽对运动性骨骼肌微结构损伤的保护作用。方法:雄性SD大鼠100只,依分别补充安慰剂和活性肽,运动与不运动,以及运动后0h、12h、24h和48h等不同时间随机分为10组,所有动物膳食平衡1周后,进行实验。运动组大鼠以(20±1)m/min的速度,坡度为-16,°持续性跑台训练120min。实验组和对照组所有动物在膳食平衡期间每天分别进行灌胃15%活性肽饮料2mL和等量的安慰剂。结果:补充活性肽可减轻大鼠离心运动后骨骼肌结蛋白免疫染色的丢失,增强波形蛋白的免疫染色,明显减少血清酶CK、LDH的漏出。  相似文献   

19.
大豆皂甙饮料缓解体力疲劳作用的实验研究   总被引：1，自引：0，他引：1  
目的:研究大豆皂甙饮料的缓解体力疲劳作用。方法:采用雄性ICR小鼠,大豆皂甙饮料按33.3ml/kg.bw、66.7ml/kg.bw、100.0ml/kg.bw连续灌胃30d,测定小鼠负重游泳时间、血乳酸、血清尿素氮和肝糖原含量。结果:100.0ml/kg.bw剂量组小鼠负重游泳时间显著长于对照组(P<0.05).66.Tml/kg.bw剂量组游泳后0min血乳酸含量和3个时点血乳酸曲线下面积显著低于对照组(P<0.05、P<0.01)。33.3ml/kg.bw剂量组肝糖原含量显著高于对照组(P相似文献   

20.
The aim of this study was to investigate the effect of pre-induced inspiratory muscle fatigue (IMF) on race-paced swimming and acid-base status. Twenty-one collegiate swimmers performed two discontinuous 400-m race-paced swims on separate days, with (IMF trial) and without (control trial) pre-induced IMF. Swimming characteristics, inspiratory and expiratory mouth pressures, and blood parameters were recorded. IMF and expiratory muscle fatigue (P < 0.05) were evident after both trials and swimming time was slower (P < 0.05) from 150-m following IMF inducement. Pre-induced IMF increased pH before the swim (P < 0.01) and reduced bicarbonate (P < 0.05) and the pressure of carbon dioxide (PCO2) (P < 0.05). pH (P < 0.05), bicarbonate (P < 0.01) and PCO2 (P < 0.05) were lower during swimming in the IMF trial. Blood lactate was similar before both trials (P > 0.05) but was higher (P < 0.01) in the IMF trial after swimming. Pre-induced IMF induced respiratory alkalosis, reduced bicarbonate buffering capacity and slowed swimming speed. Pre-induced and propulsion-induced IMF reflected metabolic acidosis arising from dual role breathing and propulsion muscle fatigue.  相似文献   

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