Physiological and metabolic responses as function of the mechanical load in resistance exercise

2014 ◽  
Vol 39 (3) ◽  
pp. 345-350 ◽  
Author(s):  
Sebastian Buitrago ◽  
Nicolas Wirtz ◽  
Ulrich Flenker ◽  
Heinz Kleinöder
Keyword(s):  
Resistance Exercise ◽  
Mechanical Load ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Maximum Velocity ◽  
Linear Increase ◽  
Detectable Effect ◽  
Turnover Rates ◽  
Post Exercise ◽  
The Relationship

The present study aimed to investigate the relationship between the mechanical load during resistance exercise and the elicited physiological responses. Ten resistance-trained healthy male subjects performed 1 set of resistance exercise each at 55%, 70%, and 85% of 1 repetition maximum for as many repetitions as possible and in 4 training modes: 4-1-4-1 (4 s concentric, 1 s isometric, 4 s eccentric, and 1 s isometric successive actions), 2-1-2-1, 1-1-1-1, and explosive (maximum velocity concentric). Mean concentric power and total concentric work were determined. Oxygen uptake (V̇O2) was measured during exercise and for 30 min post exercise. Total volume of consumed oxygen (O2 consumed) and excess post-exercise oxygen consumption (EPOC) were calculated. Maximum blood lactate concentration (LAmax) was also determined. V̇O2 exhibited a linear dependency on mean concentric power. Mean concentric power did not have a detectable effect on EPOC and LAmax. An augmentation of total concentric work resulted in significant linear increase of O2 consumed and EPOC. Total concentric work caused a significant increase in LAmax. In general, a higher mechanical load induced a larger physiological response. An increase in mean concentric power elicited higher aerobic energy turnover rates. However, a higher extent of total concentric work augments total energy cost covered by oxidative and (or) glycolytic pathways.

scholarly journals Sporting myths: the REAL role of lactate during exercise

2016 ◽  
Vol 19 (5) ◽  
Author(s):  
T Mann
Keyword(s):  
Lactate Concentration ◽  
Lactate Production ◽  
Blood Lactate Concentration ◽  
Endurance Performance ◽  
Post Exercise ◽  
Early Exercise ◽  
Important Intermediate ◽  
Lactate Formation ◽  
Exercise Muscle

Background. Lactate or, as it was customarily known, ‘lactic acid’ was one of the first molecules to attract the attention of early exercise scientists, mainly because blood lactate concentration could be measured and was shown to increase with increasing exercise intensity. This connection resulted in lactate being associated with numerous other events associated with high-intensity exercise including muscle cramps, fatigue, acidosis and post-exercise muscle soreness. Nobel prize-winning research by AV Hill and Otto Meyerhof provided a rational explanation linking lactate to anaerobiosis and acidosis, which resulted in this relationship being widely accepted as fact. It was only following isotopic tracer studies of George Brooks and others that the true role of lactate during rest and exercise was revealed. Conclusions. Lactate is now acknowledged as an important intermediate of carbohydrate metabolism, taken up from the blood by tissues such as skeletal and cardiac muscle as a substrate for oxidation. Furthermore, lactate formation consumes a proton, thereby buffering against muscle acidosis. For this reason, lactate production forms an essential aid to endurance performance rather than a hindrance.

An analysis of changes in blood pH following exhausting activity in the starry flounder, Platichthys stellatus

1977 ◽  
Vol 69 (1) ◽  
pp. 173-185
Author(s):  
C. M. Wood ◽  
B. R. McMahon ◽  
D. G. McDonald
Keyword(s):  
Time Course ◽  
Recovery Period ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Respiratory Acidosis ◽  
Temporal Separation ◽  
Post Exercise ◽  
Modest Contribution ◽  
Platichthys Stellatus ◽  
Blood Ph

Exhausting activity results in a marked and immediate drop in blood pH which gradually returns to normal over the following 6h. The acidosis is caused largely by elevated Pco2 levels, which vary inversely with pH. Blood lactate concentration increases slowly, reaching a maximum at 2--4h post-exercise, and contributes significantly to the acidosis only late in the recovery period. The slow time course of lactic acid release into the blood permits temporal separation of the peak metabolic acidosis from the peak respiratory acidosis. Evidence is presented that a metabolic acid other than lactic also makes a modest contribution to the pH depression during the recovery period.

scholarly journals Changes in pulmonary function and feasibility of portable continuous laryngoscopy during maximal uphill running

2020 ◽  
Vol 6 (1) ◽  
pp. e000815
Author(s):  
Mette Engan ◽  
Ida Jansrud Hammer ◽  
Trine Stensrud ◽  
Hilde Gundersen ◽  
Elisabeth Edvardsen ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Vital Capacity ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Forced Expiratory Volume ◽  
Video Laryngoscope ◽  
Post Exercise ◽  
Technical Performance ◽  
Exercise Induced

ObjectiveTo evaluate changes in pulmonary function and feasibility of portable continuous laryngoscopy during maximal uphill running.MethodsHealthy volunteers participated in an uphill race. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were obtained before and 5 and 10 min after finishing the race. Capillary blood lactate concentration ([BLa-]) and Borg score for perceived exertion were registered immediately after the race. One participant wore a portable video-laryngoscope during the race, and the video was assessed for technical performance.ResultsTwenty adult subjects participated with a mean (SD) age of 40.2 (9.7) years. Mean (SD) race duration and post-exercise [BLa-] was 13.9 (2.3) min and 10.7 (2.1) mmol/L, respectively, and the median (range) Borg score for perceived exertion was 9 (5–10). Mean percentage change (95% CI) 5 and 10 min post-exercise in FEV1 were 6.9 (3.7 to 10.2) % and 5.9 (2.7 to 9.0) %, respectively, and in FVC 5.2 (2.3 to 8.1) % and 4.7 (1.6 to 7.9) %, respectively. The recorded video of the larynx was of good quality.ConclusionsMaximal aerobic field exercise induced bronchodilatation in the majority of the healthy non-asthmatic participants. It is feasible to perform continuous video-laryngoscopy during heavy uphill exercise.

Blood Lactate Concentration and Clearance in Elite Swimmers During Competition

2011 ◽  
Vol 6 (1) ◽  
pp. 106-117 ◽  
Author(s):  
Jason D. Vescovi ◽  
Olesya Falenchuk ◽  
Greg D. Wells
Keyword(s):  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Active Recovery ◽  
Competitive Swimming ◽  
Elite Swimmers ◽  
Lactate Removal ◽  
The Relationship ◽  
Competitive Swimmers ◽  
Effect Of Age

Purpose:Blood lactate concentration, [BLa], after swimming events might be influenced by demographic features and characteristics of the swim race, whereas active recovery enhances blood lactate removal. Our aims were to (1) examine how sex, age, race distance, and swim stroke influenced [BLa] after competitive swimming events and (2) develop a practical model based on recovery swim distance to optimize blood lactate removal.Methods:We retrospectively analyzed postrace [BLa] from 100 swimmers who competed in the finals at the Canadian Swim Championships. [BLa] was also assessed repeatedly during the active recovery. Generalized estimating equations were used to evaluate the relationship between postrace [BLa] with independent variables.Results:Postrace [BLa] was highest following 100–200 m events and lowest after 50 and 1500 m races. A sex effect for postrace [BLa] was observed only for freestyle events. There was a negligible effect of age on postrace [BLa]. A model was developed to estimate an expected change in [BLa] during active recovery (male = 0; female = 1): [BLa] change after active recovery = –3.374 + (1.162 × sex) + (0.789 × postrace [BLa]) + (0.003 × active recovery distance).Conclusions:These findings indicate that swimmers competing at an elite standard display similar postrace [BLa] and that there is little effect of age on postrace [BLa] in competitive swimmers aged 14 to 29 y.

The Relationship Between Freely Chosen Cadence and Optimal Cadence in Cycling

2012 ◽  
Vol 7 (4) ◽  
pp. 375-381 ◽  
Author(s):  
Umberto Emanuele ◽  
Tamara Horn ◽  
Jachen Denoth
Keyword(s):  
Power Output ◽  
Body Position ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peripheral Fatigue ◽  
External Power ◽  
The Relationship ◽  
Optimal Cadence ◽  
Cycling Condition ◽  
Constant Power Output

Purpose:The main aim of this study was to compare the freely chosen cadence (FCC) and the cadence at which the blood lactate concentration at constant power output is minimized (optimal cadence [Copt]). The second aim was to examine the effect of a concomitant change of road incline and body position on FCC, the maximal external power output (Pmax), and the corresponding Copt.Methods:FCC, Copt, and Pmax were analyzed under 2 conditions: cycling on level ground in a dropped position (LGDP) and cycling uphill in an upright position (UHUP). Seven experienced cyclists participated in this study. They cycled on a treadmill to test the 2 main hypotheses: Experienced cyclists would choose an adequate cadence close to Copt independent of the cycling condition, and FCC and Copt would be lower and Pmax higher for UHUP than with LGDP.Results:Most but not all experienced cyclists chose an adequate cadence close to Copt. Independent of the cycling condition, FCC and Copt were not statistically different. FCC (82.1 ± 11.1 and 89.3 ± 10.6 rpm, respectively) and Copt (81.5 ± 9.8 and 87.7 ± 10.9 rpm, respectively) were significantly lower and Pmax was significantly higher (2.0 ± 2.1%) for UHUP than for LGDP.Conclusion:Most experienced cyclists choose a cadence near Copt to minimize peripheral fatigue at a given power output independent of the cycling condition. Furthermore, it is advantageous to use a lower cadence and a more upright body position during uphill cycling.

scholarly journals Detection of the Lactate Threshold in Runners: What is the Ideal Speed to Start an Incremental Test?

2015 ◽  
Vol 45 (1) ◽  
pp. 217-224 ◽  
Author(s):  
José Luiz Dantas ◽  
Christian Doria
Keyword(s):  
Blood Lactate ◽  
Lactate Threshold ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Endurance Athletes ◽  
Incremental Test ◽  
Average Speed ◽  
Third Stage ◽  
The Relationship ◽  
The Ideal

Abstract Incremental tests on a treadmill are used to evaluate endurance athletes; however, no criterion exists to determine the intensity at which to start the test, potentially causing the loss of the first lactate threshold. This study aimed to determine the ideal speed for runners to start incremental treadmill tests. The study consisted of 94 runners who self-reported the average speed from their last competitive race (10-42.195 km) and performed an incremental test on a treadmill. The speeds used during the first three test stages were normalised in percentages of average competition speed and blood lactate concentration was analysed at the end of each stage. The relationship between speed in each stage and blood lactate concentration was analysed. In the first stage, at an intensity corresponding to 70% of the reported average race speed, only one volunteer had blood lactate concentration equal to 2 mmol·L-1, and in the third stage (90% of the average race speed) the majority of the volunteers had blood lactate concentration ≥2 mmol·L-1. Our results demonstrated that 70% of the average speed from the subject’s last competitive race - from 10 to 42.195 km - was the best option for obtaining blood lactate concentration <2 mmol·L-1 in the first stage, however, 80% of the average speed in marathons may be a possibility. Evaluators can use 70% of the average speed in competitive races as a strategy to ensure that the aerobic threshold intensity is not achieved during the first stage of incremental treadmill tests.

scholarly journals Resistance Exercise Intensity Does Not Influence Neurotrophic Factors Response in Equated Volume Schemes

2020 ◽  
Vol 74 (1) ◽  
pp. 227-236
Author(s):  
Leandro Lodo ◽  
Alexandre Moreira ◽  
Reury Frank P Bacurau ◽  
Carol D Capitani ◽  
Wesley P Barbosa ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Effect Size ◽  
Neurotrophic Factors ◽  
Salivary Cortisol ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Total Load ◽  
Post Exercise ◽  
Acute Responses ◽  
Serum Bdnf

Abstract The aim of the present study was to evaluate the effects of 2 different intensities of resistance training (RT) bouts, performed with the equated total load lifted (TLL), on the acute responses of neurotrophic factors (NFs) (brain-derived neurotrophic factor [BDNF]; and nerve growth factor [NGF]), as well as on metabolic (lactate concentration) and hormonal (salivary cortisol concentration) responses. Thirty participants (males, 22.8 ± 2.3 years old, 177 ± 6.8 cm, 75.5 ± 7.9 kg, n = 15; and females, 22.2 ± 1.7 years, 163.7 ± 6.5 cm, 57 ± 7.6 kg, n = 15) performed 2 separate acute RT bouts with one week between trials. One bout consisted of 4 sets of 5 submaximal repetitions at 70% of 1RM and the other of 4 sets of 10 submaximal repetitions at 35% of 1RM for each exercise. Both RT bouts were conducted using the bench press and squat exercises. The TLL in each bout (determined by sets x repetitions x load [kg]) was equated. Serum BDNF, serum NGF, salivary cortisol, and blood lactate concentration were determined pre- and post-RT. No significant pre- to post-exercise increase in neurotrophic factors (p > 0.05; BDNF; effect size = 0.46 and NGF; effect size = 0.48) was observed for either of the RT bouts. A similar increase in blood lactate concentration was observed pre- to post-exercise for both RT bouts (p < 0.05). Cortisol increased similarly for both RT bouts, when compared to the resting day condition (p < 0.05). In conclusion, the results suggest that, despite differences in RT schemes, a similar acute neurotrophic, metabolic and hormonal response was observed when the TLL is equated.

scholarly journals Reliability of the Urine Lactate Concentration After Alternating-Intensity Interval Exercise

Proceedings ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 1 ◽  
Author(s):  
Ioannis Kosmidis ◽  
Stefanos Nikolaidis ◽  
Alexandros Chatzis ◽  
Kosmas Christoulas ◽  
Thomas Metaxas ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Submaximal Exercise ◽  
Physically Active ◽  
Post Exercise ◽  
Interval Exercise ◽  
Average Value ◽  
Ad Libitum ◽  
Active Adults

Aim: Our previous studies have shown that the post-exercise urine lactate concentration is a reliable exercise biomarker under controlled post-exercise hydration conditions. However, the reliability of the urine lactate concentration has been examined only after brief maximal exercise. As a result, there is no information about the reliability of this biomarker after prolonged submaximal exercise. Thus, the aim of the present study was to examine the reliability of the urine lactate concentration after interval exercise of alternating intensity under controlled or ad libitum hydration during exercise. Material & Method: Twenty-eight physically active adults (16 men and 12 women) performed three identical 45-min running tests (2 sets of 22.5 min with 3 min rest interval) on the treadmill with alternating speed and inclination at 19–24 °C, spaced three days apart. The participants drank the same amount of water during exercise in two of tests and ad libitum in the other test, in random, counterbalanced order. Blood samples were collected before exercise and 1, 3, as well as 5 min post-exercise. The highest lactate value among the post-exercise samples of each individual was recorded as his/her peak post-exercise value. Urine samples were collected before exercise and 10 as well as 60 min post-exercise and the average value of the post-exercise samples was recorded. Blood and urine lactate were analyzed spectrophotometrically. Results: The peak post-exercise blood lactate concentration was 5.5 1.7 mmol/L (mean SD throughout) for men and 4.7 1.8 mmol/L for women. The post-exercise urine lactate concentration was 1.6 1.0 mmol/L for men and 1.5 1.0 mmol/L for women. The reliability of the blood lactate concentration at the three tests was high (ICC 077–0.88), being higher under controlled hydration. However, the reliability of the urine lactate concentration was low or non-significant (ICC 0.29–0.36). Conclusions: The urine lactate concentration after prolonged submaximal exercise was lower than the corresponding blood lactate concentration and showed unsatisfactory reliability regardless of the hydration pattern during exercise. Thus, it cannot be used as a biomarker for this kind of exercise.

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