ABSTRACT
Background: A 30-60 min rest after exercising is generally recommended before taking a bath. Although this was considered an appropriate bathing method, effects of pre-bath rest on recovery from exercise fatigue remain unclear. Here, we aimed to examine the effects on fatigue recovery of pre-bath rest after a workload, with the focus on changes in lactic acid levels. Methods and Results: Ten healthy adult men increased their blood lactic acid levels through a treadmill workload performed in accordance with the Bruce method, then took either a 60-min post-workload rest followed by a 10-min full-immersion 38°C bath (Experiment A) or a 10-min full-immersion 38°C bath followed by a 60-min rest (Experiment B). Body temperature, blood pressure, pulse rate, and blood lactic acid level were measured at three time points: before workload (Test 1), after workload (Test 2), and after bathing/resting (Test 3). Decreases and percent decreases in blood lactic acid levels were calculated by comparing Test 3 results with Test 2 results. These calculated values and the measured values in three tests were compared between Experiment A and Experiment B using paired-t test. There were no significant differences in maximum systolic blood pressure, maximum diastolic blood pressure, maximum workload attained, and maximum pulse rate measurements between Experiment A and Experiment B. Differences in systolic blood pressure and diastolic blood pressure measurements in Tests 1, 2, and 3 were not significant. The pulse rates measured at the final measurement (Test 3) were significantly higher in Experiment A than in Experiment B (90.4 ± 18.2 bpm vs 79.6 ± 11.6 bpm, p = 0.04). No significant differences were observed in other measurement timings. The body temperature measurements at the final measurement were slightly higher in Experiment A than in Experiment B (36.4 ± 0.4 vs 36.1 ± 0.3°C, p = 0.05). No significant differences were observed in other measurements. Blood lactic acid levels before workload (Test 1) were significantly higher in Experiment A (6.6 ± 4.7mmol/L) than in Experiment B (2.0 ± 1.4 mmol/L, p = 0.02), but those at other measurement points (Test 2 and Test 3) were similar. Neither decreases nor percentage decreases in blood lactic acid levels differed between Experiment A and Experiment B. Conclusions: Resting before a post-exercise bath did not change the decreases or percent decreases in blood lactic acid levels after bathing at 38°C, suggesting negligible effects of pre-bath resting on recovery from exercise fatigue.
ABSTRACT
<b>Background</b>: A 30-60 min rest after exercising is generally recommended before taking a bath. Although this was considered an appropriate bathing method, effects of pre-bath rest on recovery from exercise fatigue remain unclear. Here, we aimed to examine the effects on fatigue recovery of pre-bath rest after a workload, with the focus on changes in lactic acid levels. <BR><b>Methods and Results</b>: Ten healthy adult men increased their blood lactic acid levels through a treadmill workload performed in accordance with the Bruce method, then took either a 60-min post-workload rest followed by a 10-min full-immersion 38°C bath (Experiment A) or a 10-min full-immersion 38°C bath followed by a 60-min rest (Experiment B). Body temperature, blood pressure, pulse rate, and blood lactic acid level were measured at three time points: before workload (Test 1), after workload (Test 2), and after bathing/resting (Test 3). Decreases and percent decreases in blood lactic acid levels were calculated by comparing Test 3 results with Test 2 results. These calculated values and the measured values in three tests were compared between Experiment A and Experiment B using paired-t test. There were no significant differences in maximum systolic blood pressure, maximum diastolic blood pressure, maximum workload attained, and maximum pulse rate measurements between Experiment A and Experiment B. Differences in systolic blood pressure and diastolic blood pressure measurements in Tests 1, 2, and 3 were not significant. The pulse rates measured at the final measurement (Test 3) were significantly higher in Experiment A than in Experiment B (90.4 ± 18.2 bpm vs 79.6 ± 11.6 bpm, p = 0.04). No significant differences were observed in other measurement timings. The body temperature measurements at the final measurement were slightly higher in Experiment A than in Experiment B (36.4 ± 0.4 vs 36.1 ± 0.3°C, p = 0.05). No significant differences were observed in other measurements. Blood lactic acid levels before workload (Test 1) were significantly higher in Experiment A (6.6 ± 4.7mmol/L) than in Experiment B (2.0 ± 1.4 mmol/L, p = 0.02), but those at other measurement points (Test 2 and Test 3) were similar. Neither decreases nor percentage decreases in blood lactic acid levels differed between Experiment A and Experiment B.<BR><b>Conclusions</b>: Resting before a post-exercise bath did not change the decreases or percent decreases in blood lactic acid levels after bathing at 38°C, suggesting negligible effects of pre-bath resting on recovery from exercise fatigue.
ABSTRACT
A study was conducted to clarify the exercise intensity and metabolic condition during a free routine of synchronized swimming with respect to heart rate (HR), blood lactate concentration (La) and the rate of perceived exertion (RPE) . Six well trained female synchronized swimmers participated as subjects. HR during the free routine was measured continuously. La and RPE during the free routine were measured intermittently from the start to end of each stage. Maximum heart rate (swimmingHRmax : S-HRmax) was determined by measurement of maximum oxygen uptake using a swimming flume. Peak blood lactate concentration (Peak La) was measured after the maximum front crawl stroke of 100 m. The average values and S. D. of S-HRmax and Peak La were 180.0±3.8 beats · min<SUP>-1</SUP> and 9.6 ± 1.0 mmol · 1<SUP>-1</SUP>, respectively. Average values, S. D. and ranges of HR and %S-HRmax during the free routine were 137.6±25.5 (60-180) beats · min<SUP>-1</SUP> and 76.5± 14.3 (34.5-96.8) %, respectively. HR during the free routine showed a decrease in the breath-holding phase. Average values and S. D. of La, %Peak La and RPE at the fourth stage were 5.4±1.2mmol·1<SUP>-1</SUP>, 57.0±17.2% and 17.7±0.8, respectively. La, %Peak La and RPE at the fourth stage were significantly higher than those at the other stages, and La, %Peak La and RPE at the third stage were significantly higher than those at the second stage. These results suggested that the overall intensity of the free routine was moderate, but that part of the free routine included high-intensity activity and the percentage of anaerobic metabolism during the free routine increased in the final stages
ABSTRACT
This study was designed to determine prediction equations of body density (BD) for athletes using anthropometric variables and to examine validity of the prediction equations. The subjects were 211 male and 198 female athletes aged 18 to 22 years. The subjects were measured for standing height, body weight, skinfold thickness, girth as well as body composition. Body composition was estimated from densitometry using underwater weighing method and pulmonary residual volume measurement. Skinfold thickness was measured at 9 sites on the right side of the body with an Eiken-type ski nfold caliper and 7 measures of girth were taken using a cloth tape. All measurements were done three times from April to October : pre-, mid- and post-competitive season, in order to find out a suitable site reflecting body composition change. Using multiple regression analysis, equations to estimate BD were obtained from standing height, body weight, skinfold thicknesses and girths. The effective prediction equations for BD were as follows : For Males<BR>ED=1.11104-0.00053 (sum of chest, abdomen and quadriceps skinfold thicknesses in mm) -0.00027 (waist girth in cm) .<BR>R=0.851, SEE=0.0051.<BR>For Females<BR>BD=1.11861-0.00054 (sum of abdomen, triceps and subscapula skinfold thicknesses in mm) -0.00054 (waist girth in cm) .<BR>R=0.826, SEE=0.0062.<BR>A cross-validation analysis of these prediction equations for BD correlated highly with hydrodensitometrically determined BD (r=0.832, SEE=0.0053 for males and r=0.812, SEE= 0.0062 for females) . Thus the prediction equations developed in the present study will be applicable to athletes.
