Hypohydration Adversely Affects Lactate Threshold in Endurance Athletes
24
Citation
0
Reference
10
Related Paper
Citation Trend
Abstract:
The purpose of this investigation was to observe the effect of hypohydration (-4% body mass) on lactate threshold (LAT) in 14 collegiate athletes (8 men and 6 women; age, 20.9 +/- 0.5 years; height, 171.1 +/- 2.4 cm; weight, 64.8 +/- 2.3 kg; V(O)2 max, 62.8 +/- 1.9 ml x kg(-1) x min(-1); percentage of fat, 11.4 +/- 1.5%). Subjects performed 2 randomized, discontinuous treadmill bouts at a dry bulb temperature (T(db)) of 22 degrees C to volitional exhaustion in 2 states of hydration, euhydrated and hypohydrated. The hypohydrated condition was achieved in a thermally neutral environment (T(db), 22 degrees C; humidity, 45%), with exercise conducted at a moderate intensity as defined by rating of perceived exertion (RPE, approximately 12) 12-16 hours before testing. On average, subjects decreased 3.9% of their body mass before the hypohydration test. Blood lactate, hematocrit, V(O)2, minute ventilation (VE), R value, heart rate (HR), and RPE were measured during each 4-minute stage of testing. In the hypohydrated condition, LAT occurred significantly earlier during exercise and at a lower absolute V(O)2, VE, respiratory exchange ratio, RPE, and blood lactate concentration. Also, the blood lactate concentration was significantly lower in the hypohydrated condition (6.7 +/- 0.8 mmol) compared with the euhydrated condition (10.2 +/- 0.9 mmol) at peak exercise. There were no differences in HR or percentage of maximum HR at LAT nor did plots of V(CO2):V(O)2 reveal differences in bicarbonate buffering during exercise between the 2 conditions. From these results, we speculate that hypohydration did not significantly alter cardiovascular function or buffering capacity but did cause LAT to occur at a lower absolute exercise intensity.Keywords:
Treadmill
Respiratory exchange ratio
The aim of this study was to examine the impacts on blood lactate concentration, measured heart rate and assessment of perceived exertion during split sessions of equal relative load, as also their relationship to the specific sport practised. Nineteen regional-level athletes (nine middle and long-distance runners (cyclic group) and ten field-sport team players (acyclic group)) performed four high-intensity interval training (HIIT) sessions with work-interval durations of 10 s, 50 s, 90 s and 130 s. The sessions were carried out at their usual training sites with a separation of at least 48 hours. Blood lactate concentration was measured at rest and 3 min after the completion of each protocol. Heart rate was measured continuously during all sessions with a sampling rate of 1 s, and rating of perceived exertion (RPE) was requested at the end of the trial. The results showed an increase in blood lactate concentration, peak heart rate and rating of perceived exertion during long protocols as compared with short ones. No differences were observed in dependent variables between cyclic and acyclic groups. Significant but moderate correlations were observed between post-exercise blood lactate concentration, peak heart rate and RPE.
Interval training
Perceived exertion
Intensity
Exertion
Work rate
High-Intensity Interval Training
Lactate threshold
Cite
Citations (29)
Blood lactate has been shown to be a reliable tool to monitor the exercise intensity and fatigue level. However, heart rate (HR) seems to be more convenience and noninvasive index compared with blood lactate. PURPOSE To examine the relation between blood lactate levels (BL), HR, and rating of perceived exertion (RPE) in professional kickboxers during different periods of competition. METHODS 12 male and 11 female professional kickboxers (mean ± SD; age 20.1 ± 1.8 years; height 173.2 ± 5.9 cm; body mass 62.0 ± 1.5 kg) participated in this study. The BL, HR and RPE were measured before, during and after the match at national level competition. Subjects also performed incremental cycling test until exhaustion at which similar measurements were made. RESULTS There was a moderate correlation between BL and HR before, during and after the match, and the maximal relative coefficients were 0.87 (P<0.05) in male and 0.93 (P<0.05) in female. BL was highly correlated to HR during the last 3 rounds (P<0.05) during the match. Similar result was found in cycling trial. Whereas, the relation between BL and RPE was low, with the maximal relative coefficients were 0.37 in male and 0.33 in female (P>0.05). The relation between HR and RPE was also not significant. CONCLUSION The results reconfirmed that there is a close relationship between HR and BL during kickboxing. HR could be viewed as a valid tool to monitor the exercise intensity and fatigue level during the game.
Perceived exertion
Cycling
Cite
Citations (0)
Blood lactate has been shown to be a reliable tool to monitor the exercise intensity and fatigue level. However, heart rate (HR) seems to be more convenience and noninvasive index compared with blood lactate. PURPOSE To examine the relation between blood lactate levels (BL), HR, and rating of perceived exertion (RPE) in professional kickboxers during different periods of competition. METHODS 12 male and 11 female professional kickboxers (mean ± SD; age 20.1 ± 1.8 years; height 173.2 ± 5.9 cm; body mass 62.0 ± 1.5 kg) participated in this study. The BL, HR and RPE were measured before, during and after the match at national level competition. Subjects also performed incremental cycling test until exhaustion at which similar measurements were made. RESULTS There was a moderate correlation between BL and HR before, during and after the match, and the maximal relative coefficients were 0.87 (P<0.05) in male and 0.93 (P<0.05) in female. BL was highly correlated to HR during the last 3 rounds (P<0.05) during the match. Similar result was found in cycling trial. Whereas, the relation between BL and RPE was low, with the maximal relative coefficients were 0.37 in male and 0.33 in female (P>0.05). The relation between HR and RPE was also not significant. CONCLUSION The results reconfirmed that there is a close relationship between HR and BL during kickboxing. HR could be viewed as a valid tool to monitor the exercise intensity and fatigue level during the game.
Perceived exertion
Exertion
Intensity
Cite
Citations (0)
McGinnes, C.; Stoudemire, N.; Pass, K.; Wideman, L.; Weltman, A. FACSM; Gaesser, G. A. FACSM Author Information
Perceived exertion
Constant (computer programming)
Exertion
Cite
Citations (1)
Active recovery has proven an effective means in reducing blood lactate concentration ([La−]) after various activities, yet its effects on performance are less clear. We investigated the effects of passive and active recovery on blood [La−], rating of perceived exertion (RPE), and performance during a resistance training workout. Fifteen resistance-trained males completed 3 workouts, each consisting of 6 sets of parallel squat exercise performed at 85% of 10 repetition maximum (10RM). Each set was separated by a 4-minute recovery period. Recovery was randomly assigned from the following: passive sitting; pedaling at 25% of onset of blood lactate accumulation (OBLA) exercise intensity (25%-OBLA); and pedaling at 50% of OBLA exercise intensity (50%-OBLA). Active recovery was performed on a bicycle ergometer at 70 rev·min−1. Performance was determined postworkout by a maximal repetition performance (MRP) squat test using 65% of 10RM. Blood samples were collected: prewarm-up; post-second, postfourth, postsixth, and MRP sets; and postsecond, postfourth, and postsixth recovery periods. Significant differences (p ≤ 0.05) were observed in [La−], and RPE among the 3 recoveries, with 25%-OBLA lower than passive and 50%-OBLA. Total repetitions to exhaustion for the MRP were: passive (24.1 ± 1.8); 25%-OBLA (29.3 ± 1.8); and 50%-OBLA (23.1 ± 1.7), with 25%-OBLA being significantly greater than passive and 50%-OBLA. In this investigation, active recovery at 25%-OBLA proved to be the most effective means of reducing [La−] during recovery and increasing performance following a parallel squat workout.
Perceived exertion
Exertion
Cite
Citations (34)
Treadmill
Perceived exertion
Exertion
Intensity
Running economy
Cite
Citations (27)
The purpose of this research was to study effect of small-sided games training on heart rate (HR), blood lactate (BL) and rating perceived exertion (RPE). Twelve male futsal players age between 18-25 years were the subjects of the research. The participants were divided into 3 teams and completed two different pitch size of a small-sided games training (20x20 m. and 20x28 m.). The games consisted in 4x3 min. bouts interspersed with 3 min. active recovery and each games lasted 24-hour on separate occasions. HR was measured throughout the game. BL and RPE were recorded immediately after training. RPE using the Borg Scale (0-10 Scale). Data were statistically analyzed by mean, standard deviation and matched paired t-test. All testing used the 0.05 level of significant. The result showed the mean of HR and BL were significantly different between pitch sizes (p 0.05) (the 20x20 m. of training RPE = 4.3±0.7 and 20x28 m. training RPE =4.3±0.5). In conclusion, the pitch size 20x28 m. of training might be used for practice and give maximum benefit. (Journal of Sports Science and Technology 2014;14(1): 93 -104) KEYWORD: Small-Sided Futsal Games Training, Heart Rate, Blood Lactate, Rating Perceived Exertion
Perceived exertion
Exertion
Cite
Citations (0)
This study aimed to assess the efficacy of critical metabolic power derived from variable-speed movement for classifying intensity in team sport activity.Elite male hockey players (n = 12) completed a series of time trials (100 yards, 400 yards, 1500 yards) and a 3-min all-out test to derive both critical speed (CS) and critical power (CP). Heart rate (HR), blood lactate, and rating of perceived exertion were measured during each protocol. Participants (n = 10) then played two competitive hockey matches. Time spent greater than 85% of maximum HR was compared with time spent above CS (from the time trials) and CP (from the 3-min test).Between protocols, there was a moderate and nonsignificant association for CS (r = 0.359, P = 0.252) and a very large association for CP (r = 0.754, P = 0.005); the association was very large for peak HR (r = 0.866, P < 0.001), large for blood lactate (r = 0.506, P = 0.093), and moderate for rating of perceived exertion (rho = 0.441, P = 0.152). Time trials produced higher CS (4.3 vs 2.0 m·s, P < 0.001) and CP (18.3 vs 10.5 W·kg, P < 0.001) values than did the 3-min test. In matches, there was a very large association between time spent above 85% of maximum HR and time spent above both CS (r = 0.719, P < 0.001) and CP (r = 0.867, P < 0.001). This relationship was stronger for CP compared with CS (Z = 3.29, P = 0.0007).Speed is not an appropriate parameter for the classification of team sport activity comprising continual changes in speed and direction; however, critical metabolic power derived from variable-speed activity seems useful for this purpose.
Time trial
Perceived exertion
Intensity
Team sport
Cite
Citations (25)
To examine the game characteristics and physiological (ie, blood lactate concentration) and perceptual (ie, rating of perceived exertion, RPE) responses during actual tennis competition in professional performers.Eight trained and internationally ranked (Association of Tennis Professionals rankings) male tennis players were studied during singles matches (best of three sets) played on an outdoor clay court surface during a professional, invitational tournament. Blood lactate concentrations (n = 53) and RPE (n = 113) were determined at selected change-overs during the game. The variables describing the characteristics of the matches, (a) duration of rallies (DRs); (b) rest time (RT); (c) effective playing time (EPT); and (d) shots per rally (SR), were determined from video recordings.The mean (SD) values for the match-play activity variables were DR 7.5 (7.3) s, RT 16.2 (5.2) s, EPT 21.5 (4.9%), SR 2.7 (2.2) shots. Average blood lactate concentration and RPE values were 3.8 (2.0) mmol/l and 13 (2). Blood lactate concentrations and RPE values were significantly higher (p<0.01) in service games than in receiving games. Both blood lactate concentration and RPE values were significantly correlated with SR and DR (r = 0.80 to 0.28; p<0.001).Blood lactate concentrations and RPE were found to be influenced by the characteristics of the match and the playing situation (ie, serving or returning). These specific situations might be used to alter the overload training stimulus during tennis on-court practice.
Perceived exertion
Exertion
Tournament
Match play
Cite
Citations (119)
1214 The purpose of this study was to investigate whether blood lactate concentrations (BLCs) could be reproduced corresponding to previously measured BLCs by using Borg's rate of perceived exertion (RPE) scale to determine exercise intensity at three different levels during a single 30 min exercise bout. Twelve subjects (4 M, 8 F; age: 26.5 ± 3.7 yr; Ht: 168.9 ± 8.3 cm; Wt: 68.2 ± 14.1 kg) completed an RPE estimation trial (a 3 min stage incremental treadmill protocol to volitional fatigue), practiced running at the workloads corresponding to their RPEs of 11, 14, and 16, and, one week after the practice run, completed the production trial (a continuous self-selected intensity run for 10 min at each RPE target value). Although the absolute BLCs at each RPE were higher than anticipated, dependent t-tests indicated that there was no significant difference in BLC, VO2, or HR between the two trials. (Table)TableThe results demonstrate that Borg's RPE scale can be used for self-regulated production of previously determined BLC levels and that intensity can be changed during a single bout of exercise to reflect different BLCs. These findings suggest that RPE may be used for exercise prescription when constant monitoring of BLC is neither desirable nor possible if individual BLC-RPE relationships have been pre-determined.
Exercise prescription
Perceived exertion
Treadmill
Exercise intensity
Intensity
Exertion
Incremental exercise
Cite
Citations (0)