Peak blood lactate and blood lactate vs. workload during acclimatization to 5,050 m and in deacclimatization

1996 ◽  
Vol 80 (2) ◽  
pp. 685-692 ◽  
Author(s):  
B. Grassi ◽  
M. Marzorati ◽  
B. Kayser ◽  
M. Bordini ◽  
A. Colombini ◽  
...  

Peak blood lactate ([Labl]peak) and blood lactate concentration ([Labl]) vs. workload (W) relationships during acclimatization to altitude and in the deacclimatization were evaluated in 10 Caucasian lowlanders at sea level (SL0); after approximately 1 wk (Alt1wk), 3 wk (Alt3wk), and 5 wk (Alt5wk) at 5,050 m; and weekly during the first 5 wk after return to sea level (SL1wk-SL5wk). Incremental bicycle ergometer exercises (30 W added every 4 min up to exhaustion) were performed. At Alt1wk and at Alt5wk, the experiments were repeated in hypobaric normoxia (Alt1wk-O2 and Alt5wk-O2). [Labl] was determined at rest and during the last approximately 30 s of each W. [Labl]peak was taken as the highest [Labl] during recovery. Acid-base status (pH and concentration of HCO-3 in arterialized capillary blood) was determined at rest. Mean [Labl]peak values were 11.5 (SL0), 8.0 (Alt1wk), 6.4 (Alt3wk), 6.3 (Alt5wk), 8.0 (SL1wk), 9.4 (SL2wk), 10.8 (SL3wk), 11.3 (SL4wk), and 11.6 (SL5wk) mM. At Alt1wk-O2 and Alt5wk-O2, peak W increased, compared with Alt1wk and Alt5wk, whereas no changes were observed for [Labl]peak. [Labl] vs. W was shifted to the left (i.e., higher [Labl] values were found for the same W) at Alt1wk compared with SL0 and partially shifted back to the right (i.e., lower [Labl] values were found for the same W) at Alt3wk and Alt5wk. At Alt1wk-O2 and Alt5wk-O2, [Labl] vs. W values were superimposed on that at SL0. At SL1wk-SL5wk, [Labl] vs. W values were shifted to the right compared with that at SL0. At Alt1wk, a condition of respiratory alkalosis was found, which was only partially compensated for during acclimatization. At SL1wk, the acid-base status was back to normal. We conclude that 1) the reduced [Labl]peak at altitude is still present for 2-3 wk after return from altitude; is not attributable to reduced peak W nor to hypoxia per se, nor to a reduced buffer capacity; alternatively, it could be related to some central determinants of fatigue. 2) The [Labl] vs. W leftward shift at altitude was due to hypoxia per se. 3) The factor(s) responsible for the [Labl] vs. W partial rightward shift during acclimatization could still be effective during the first weeks after return to sea level.

1997 ◽  
Vol 9 (1) ◽  
pp. 80-89 ◽  
Author(s):  
Michael Chia ◽  
Neil Armstrong ◽  
David Childs

Twenty-five girls and 25 boys (mean age 9.7 ± 0.3 years) each completed a 20- and 30-s Wingate Anaerobic Test (WAnT). Oxygen uptake during the WAnTs, and postexercise blood lactate samples were obtained. Inertia and load-adjusted power variables were higher (18.6–20.1% for peak, and 6.7–7.5% for mean power outputs, p < .05) than the unadjusted values for both the 20- and 30-s WAnTs. The adjusted peak power values were higher (7.7–11.6%, p < .05) in both WAnTs when integrated over 1-s than over 5-s time periods. The aerobic contributions to the tests were lower (p < .05) in the 20-s WAnT (13.7–35.7%) than in the 30-s WAnT (17.7–44.3%) for assumed mechanical efficiencies of 13% and 30%. Postexercise blood lactate concentration after the WAnTs peaked by 2 min. No gender differences (p > .05) in anaerobic performances or peak blood lactate values were detected.


2020 ◽  
Vol 5 (2) ◽  
pp. 37
Author(s):  
Daniel A. Marinho ◽  
Maria I. Ferreira ◽  
Tiago M. Barbosa ◽  
José Vilaça-Alves ◽  
Mário J. Costa ◽  
...  

Background: The current study aimed to verify the changes in performance, physiological and biomechanical variables throughout a season in master swimmers. Methods: Twenty-three master swimmers (34.9 ± 7.4 years) were assessed three times during a season (December: M1, March: M2, June: M3), in indoor 25 m swimming pools. An incremental 5 × 200 m test was used to evaluate the speed at 4 mmol·L−1 of blood lactate concentration (sLT), maximal oxygen uptake (VO2max), peak blood lactate ([La-]peak) after the test, stroke frequency (SF), stroke length (SL), stroke index (SI) and propelling efficiency (ηp). The performance was assessed in the 200 m front crawl during competition. Results: Swimming performance improved between M1, M2 (2%, p = 0.03), and M3 (4%, p < 0.001). Both sLT and VO2max increased throughout the season (4% and 18%, p < 0.001, respectively) but not [La-]peak. While SF decreased 5%, SL, SI and ηp increased 5%, 7%, and 6% (p < 0.001) from M1 to M3. Conclusions: Master swimmers improved significantly in their 200 m front crawl performance over a season, with decreased SF, and increased SL, ηp and SI. Despite the improvement in energetic variables, the change in performance seemed to be more dependent on technical than energetic factors.


1994 ◽  
Vol 76 (2) ◽  
pp. 610-615 ◽  
Author(s):  
R. S. Mazzeo ◽  
G. A. Brooks ◽  
G. E. Butterfield ◽  
A. Cymerman ◽  
A. C. Roberts ◽  
...  

We examined the extent to which epinephrine influences blood lactate adjustments to exercise during both acute (AC) and chronic (CH) high-altitude exposure. Eleven male sea level residents were divided into a control group (n = 5) receiving a placebo or a drug group (n = 6) receiving 240 mg/day of propranolol. All subjects were studied at rest and during 45 min of submaximal exercise (approximately 50% of sea level maximal O2 uptake) at sea level (SL) and within 4 h of exposure to and after 3 wk residence at 4,300 m (summit of Pikes Peak). Blood samples were collected from the femoral artery for epinephrine and lactate concentration. Exercising blood lactate concentration was significantly different across all altitude conditions such that AC > CH > SL (P < 0.05). For a given arterial O2 saturation, mean exercising blood lactates were lower for the beta-blocked group compared with controls; however, both groups demonstrated similar patterns across all conditions. Epinephrine levels during exercise followed a similar pattern to that of lactate, averaging 0.67, 0.43, and 0.29 ng/ml for AC, CH, and SL, respectively. The correlation between lactate and epinephrine was 0.93 and 0.84 for control and beta-blocked subjects, respectively. Whereas during exercise epinephrine was consistently higher for the beta-blocked group than controls, this difference was only significant during CH exposure. The epinephrine response was related to the extent of hypoxia in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)


2015 ◽  
Vol 40 (6) ◽  
pp. 623-631 ◽  
Author(s):  
Florian Azad Engel ◽  
Billy Sperlich ◽  
Christian Stockinger ◽  
Sascha Härtel ◽  
Klaus Bös ◽  
...  

This study characterized the impact of high-intensity interval training on the kinetics of blood lactate and performance in trained boys and men. Twenty-one boys (11.4 ± 0.8 years) and 19 men (29.4 ± 5.0 years) performed a set of four 30-s sprints with 2-min of rest and a single 30-s sprint on 2 separate occasions (randomized order) with assessment of performance. Blood lactate was assayed after each sprint and during 30 min of recovery from both tests. The individual time-curves of blood lactate concentration were fitted to the biexponential function as follows: [Formula: see text], where the velocity parameters γ1and γ2reflect the capacity to release lactate from the previously active muscle into the blood and to subsequently eliminate lactate from the organism, respectively. In both tests, peak blood lactate concentration was significantly lower in the boys (four 30-s sprints: 12.2 ± 3.6 mmol·L−1; single 30-s sprint: 8.7 ± 1.8 mmol·L−1) than men (four 30-s sprints: 16.1 ± 3.3 mmol·L−1; single 30-s sprint: 11.5 ± 2.1; p < 0.001). The boys exhibited faster γ1(1.4531 ± 0.65 min; p < 0.001) and γ2(0.059 ± 0.023 min; p = 0.01) in the single 30-s sprint and faster γ2(0.049 ± 0.016 min; p = 0.01) in the four 30-s sprints. The worsening of performance from the first to the last of the four 30-s sprints was less pronounced in boys (9.2% ± 13.9%) than men (19.2% ± 11.5%; p = 0.01). In the present study boys, when compared with men, exhibited lower Peak blood lactate concentration; less pronounced decline in performance during the sprints concomitantly with more rapid release and elimination during the single 30-s sprint; and faster elimination of lactate following the four 30-s sprints.


1997 ◽  
Vol 9 (3) ◽  
pp. 210-222 ◽  
Author(s):  
Peter Pfitzinger ◽  
Patty Freedson

Part 1 reviews the literature concerning peak blood lactate responses to exercise in children. After a brief overview of lactate metabolism, an analysis is presented comparing children to adults regarding peak blood lactate concentration. Possible factors accounting for lower blood lactate concentrations during maximal exercise in children are considered.


Author(s):  
Subir Gupta ◽  
Arkadiusz Stanula ◽  
Asis Goswami

Purpose: To determine (1) the time of arrival of peak blood lactate concentration ([BLa]peak) followed by various track events and (2) significant correlation, if any, between average velocity and [BLa]peak in these events. Methods: In 58 under-20 male track athletes, heart rate was recorded continuously and blood lactate concentration was determined at various intervals following 100-m (n = 9), 200-m (n = 8), 400-m (flat) (n = 9), 400-m hurdles (n = 8), 800-m (n = 9), 1500-m (n = 8), 3000-m steeplechase (n = 7), and 5000-m (n = 10) runs. Results: The [BLa]peak, in mmol/L, was recorded highest following the 400-m run (18.27 [3.65]) followed by 400-m hurdles (16.25 [3.14]), 800-m (15.53 [3.25]), 1500-m (14.71 [3.00]), 200-m (14.42 [3.40]), 3000-m steeplechase (11.87 [1.48]), 100-m (11.05 [2.36]), and 5000-m runs (8.65 [1.60]). The average velocity of only the 400-m run was found to be significantly correlated (r = .877, p < 0.05) with [BLa]peak. The arrival time of [BLa]peak following 100-m, 200-m, 400-m, 400-m hurdles, 800-m, 1500-m, 3000-m steeplechase, and 5000-m runs was 4.44 (0.83), 4.13 (0.93), 4.22 (0.63), 3.75 (0.83), 3.34 (1.20), 2.06 (1.21), 1.71 (1.44), and 1.06 (1.04) minutes, respectively, of the recovery period. Conclusion: In under-20 runners, (1) [BLa]peak is highest after the 400-m run, (2) the time of appearance of [BLa]peak varies from one event to another but arrives later after sprint events than longer distances, and (3) the 400-m (flat) run is the only event wherein the performance is significantly correlated with the [BLa]peak.


2017 ◽  
Vol 12 (9) ◽  
pp. 1256-1263 ◽  
Author(s):  
Carlo Castagna ◽  
Lorenzo Francini ◽  
Susana C.A. Póvoas ◽  
Stefano D’Ottavio

Purpose:To examine the acute effects of generic drills (running drills [RDs]) and specific (small-sided-games [SSGs]) long-sprint-ability (LSA) drills on internal and external load of male soccer players. Methods:Fourteen academy-level soccer players (mean ± SD age 17.6 ± 0.61 y, height 1.81 ± 0.63 m, body mass 69.53 ± 4.65 kg) performed four 30-s LSA bouts for maintenance (work:rest 1:2) and production (1:5) with RDs and SSGs. Players’ external load was tracked with GPS technology (20-Hz), and heart rate (HR), blood lactate concentration (BLc), and rating of perceived exertion (RPE) were used to characterize players’ internal load. Individual peak BLc was assessed with a 30-s all-out test on a nonmotorized treadmill (NMT). Results:Compared with SSGs, the RDs had a greater effect on external load and BLc (large and small, respectively). During SSGs players covered more distance with high-intensity decelerations (moderate to small). Muscular RPE was higher (small to large) in RDs than in SSGs. The production mode exerted a moderate effect on BLc while the maintenance condition elicited higher cardiovascular effects (small to large). Conclusion:The results of this study showed the superiority of generic over specific drills in inducing LSA-related physiological responses. In this regard production RDs showed the higher postexercise BLc. Individual peak blood lactate responses were found after the NMT 30-s all-out test, suggesting this drill as a valid option to RDs. The practical physiological diversity among the generic and specific LSA drills here considered enable fitness trainers to modulate prescription of RD and SSG drills for LSA according to training schedule.


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