The effect of pre-test carbohydrate ingestion on the anaerobic threshold, as determined by the lactate-minimum test

2007 ◽  
Vol 32 (6) ◽  
pp. 1058-1064 ◽  
Author(s):  
Arie Rotstein ◽  
Raffy Dotan ◽  
Levana Zigel ◽  
Tally Greenberg ◽  
Yael Benyamini ◽  
...  

The purpose of this study was to investigate the effect of pre-test carbohydrate (CHO) ingestion on anaerobic-threshold assessment using the lactate-minimum test (LMT). Fifteen competitive male distance runners capable of running 10 km in 33.5–43 min were used as subjects. LMT was performed following CHO (2 × 300 mL, 7% solution) or comparable placebo (Pl) ingestion, in a double-blind, randomized order. The LMT consisted of two high-intensity 1 min treadmill runs (17–21 km·h–1), followed by an 8 min recovery period. Subsequently, subjects performed 5 min running stages, incremented by 0.6 km·h–1 and separated by 1 min blood-sampling intervals. Tests were terminated after 3 consecutive increases in blood-lactate concentration ([La]) had been observed. Finger-tip capillary blood was sampled for [La] and blood-glucose determination 30 min before the test’s onset, during the recovery phase following the 2 high-intensity runs, and following each of the subsequent 5 min stages. Heart rate (HR) and rating of perceived exertion (RPE) were recorded after each stage. The lactate-minimum speed (LMS) was determined from the individual [La]–velocity plots and was considered reflective of the anaerobic threshold. Pre-test CHO ingestion had no effect on LMS (13.19 ± 1.12 km·h–1 vs. 13.17 ± 1.08 km·h–1 in CHO and Pl, respectively), nor on [La] and glucose concentration at that speed, or on HR and RPE responses. Pre-test CHO ingestion therefore does not affect LMS or the LMT-estimated anaerobic threshold.

2018 ◽  
Vol 3 (4) ◽  
pp. 60 ◽  
Author(s):  
Ramires Tibana ◽  
Nuno de Sousa ◽  
Jonato Prestes ◽  
Fabrício Voltarelli

The aim of this study was to analyze blood lactate concentration (LAC), heart rate (HR), and rating perceived exertion (RPE) during and after shorter and longer duration CrossFit® sessions. Nine men (27.7 ± 3.2 years; 11.3 ± 4.6% body fat percentage and training experience: 41.1 ± 19.6 months) randomly performed two CrossFit® sessions (shorter: ~4 min and longer: 17 min) with a 7-day interval between them. The response of LAC and HR were measured pre, during, immediately after, and 10, 20, and 30 min after the sessions. RPE was measured pre and immediately after sessions. Lactate levels were higher during the recovery of the shorter session as compared with the longer session (shorter: 15.9 ± 2.2 mmol/L/min, longer: 12.6 ± 2.6 mmol/L/min; p = 0.019). There were no significant differences between protocols on HR during (shorter: 176 ± 6 bpm or 91 ± 4% HRmax, longer: 174 ± 3 bpm or 90 ± 3% HRmax, p = 0.387). The LAC was significantly higher throughout the recovery period for both training sessions as compared to pre-exercise. The RPE was increased immediately after both sessions as compared to pre-exercise, while there was no significant difference between them (shorter: 8.7 ± 0.9, longer: 9.6 ± 0.5; p = 0.360). These results demonstrated that both shorter and longer sessions induced elevated cardiovascular responses which met the recommendations for gains in cardiovascular fitness. In addition, both training sessions had a high metabolic and perceptual response, which may not be suitable if performed on consecutive days.


2021 ◽  
Vol 12 ◽  
Author(s):  
Tiago Cetolin ◽  
Anderson Santiago Teixeira ◽  
Juliano Fernandes da Silva ◽  
Alessandro Haupenthal ◽  
Fábio Yuzo Nakamura ◽  
...  

This study aimed to examine the acute physiological effect of shuttle-run-based high-intensity intermittent exercise (HIIE) performed at the same relative speed (i. e., 100% PST−CAR) on sand (SAND) and grass (GRASS) in male junior soccer players. Seven Under-23 Brazilian national league (“Série A”) soccer players completed four testing sessions in either SAND or GRASS surface condition. The first two testing sessions consisted of performing a maximal progressive shuttle-run field protocol until volitional exhaustion (Carminatti's test, T-CAR), whereas the third and fourth sessions comprised a HIIE session on each ground surface. The HIIE session consisted of three 5-min bouts [12 s shuttle-run (with a direction change every 6 s)/12 s of passive rest] performed at 100% of T-CAR peak speed (PST−CAR) with 3 min of passive recovery between sets. Measurements of oxygen uptake (VO2), heart rate (HR), blood lactate concentration ([La]), and rating of perceived exertion (RPE) were performed during all conditions. The SAND condition elicited significantly higher %VO2peak (94.58 ± 2.73 vs. 87.45 ± 3.31%, p < 0.001, d = 2.35), %HRpeak (93.89 ± 2.63 vs. 90.31 ± 2.87%, p < 0.001, d = 1.30), RPE (8.00 ± 0.91 vs. 4.95 ± 1.23 a.u., p < 0.001, d = 2.82), and [La] (10.76 ± 2.37 vs. 5.48 ± 1.13 mmol/L, p < 0.010, d = 2.84). This study showed that higher internal workloads are experienced by the players during a single HIIE session performed on a softer surface as SAND, even when the exercise intensity was individualized based on 100%PST−CAR.


1993 ◽  
Vol 3 (2) ◽  
pp. 127-139 ◽  
Author(s):  
Konstantinos Tsintzas ◽  
Raymond Liu ◽  
Clyde Williams ◽  
Ian Campbell ◽  
George Gaitanos

Seven experienced endurance runners completed a 30-km road race on two occasions separated by 10 days. On each occasion the subjects consumed 250 ml of either a 5% carbohydrate (CHO) solution or nonflavored tap water (W) immediately prior to the start of the race, and 150 ml of the assigned fluid every 5 km thereafter. Performance time for the CHO trial was faster compared with the time recorded for the W trial (128.3 ± 19.9 min vs. 131.2 ± 18.7 min [p<0.01] respectively). Running speed was maintained throughout the race in the CHO trial, whereas a decrease in the running speed occurred after 25 km (p<0.05) in the W trial. No difference was found between the two trials in blood glucose concentration, plasma electrolyte concentrations, body weight loss, change in plasma volume, and rating of perceived exertion. Blood lactate concentration was higher at 25 km during the CHO trial compared with the W trial (p<0.01), but plasma FFA and glycerol concentrations were lower at 30 km during the CHO trial than during the W trial (p<0.05). In conclusion, this study shows that performance time for a 30-km road race is improved after ingesting a 5% CHO solution.


2016 ◽  
Vol 11 (5) ◽  
pp. 602-607 ◽  
Author(s):  
Jeanne Dekerle ◽  
James Paterson

Purpose:To examine muscle fatigue of the shoulder internal rotators alongside swimming biomechanics during long-duration submaximal swimming sets performed in 2 different speed domains.Methods:Eight trained swimmers (mean ± SD 20.5 ± 0.9 y, 173 ± 10 cm, 71.3 ± 10.0 kg) raced over 3 distances (200-, 400-, 800-m races) for determination of critical speed (CS; slope of the distance–time relationship). After a familiarization with muscle isokinetic testing, they subsequently randomly performed 2 constant-speed efforts (6 × 5-min blocks, 2.5-min recovery) 5% above (T105) and 5% below CS (T95) with maximal voluntary contractions recorded between swimming blocks.Results:Capillary blood lactate concentration ([La]), rating of perceived exertion (RPE), peak torque, stroke length, and stroke rate were maintained throughout T95 (P < .05). [La], RPE, and stroke rate increased alongside concomitant decreases in maximal torque and stroke length during T105 (P < .05) with incapacity of the swimmers to maintain the pace for longer than ~20 min. For T105, changes in maximal torque (35.0 ± 14.9 to 25.8 ± 12.1 Nm) and stroke length (2.66 ± 0.36 to 2.23 ± 0.24 m/cycle) were significantly correlated (r = .47, P < .05).Conclusion:While both muscle fatigue (shoulder internal rotators) and task failure occur when swimming at a pace greater than CS, the 2.5-min recovery period during the sub-CS set possibly alleviated the development of muscle fatigue for the pace to be sustainable for 6 × 5 min at 95% of CS. A causal relationship between reduction in stroke length and loss of muscle strength should be considered very cautiously in swimming.


2020 ◽  
pp. 1-8
Author(s):  
Jeanette M. Ricci ◽  
Todd A. Astorino ◽  
Katharine D. Currie ◽  
Karin A. Pfeiffer

The majority of studies examining children’s responses to high-intensity interval exercise primarily utilized running; however, this modality does not require/include other important aspects of physical activity including muscular fitness. Purpose: To compare acute responses between a body weight resistance exercise circuit (CIRC) and treadmill-based (TM) high-intensity interval exercise. Method: A total of 17 boys (age = 9.7 [1.3] y) completed a graded exercise test to determine peak heart rate, peak oxygen uptake (VO2peak), and maximal aerobic speed. Sessions were randomized and counterbalanced. CIRC required 2 sets of 30-second maximal repetitions of 4 exercises. TM included eight 30-second bouts of running at 100% maximal aerobic speed. Both included 30-second active recovery between bouts. Blood lactate concentration was measured preexercise and postexercise. Rating of perceived exertion, affective valence, and enjoyment were recorded preexercise, after intervals 3 and 6, and postexercise. Results: Participants attained 88% (5%) peak heart rate and 74% (9%) VO2peak for CIRC and 89% (4%) peak heart rate and 81% (6%) VO2peak for TM, with a significant difference in percentage of VO2peak (P = .003) between protocols. Postexercise blood lactate concentration was higher following CIRC (5.0 [0.7] mM) versus TM (2.0 [0.3] mM) (P < .001). Rating of perceived exertion, affective valence, and enjoyment responses did not differ between protocols (P > .05). Conclusion: HR responses were near maximal during CIRC, supporting that this body-weight circuit is representative of high-intensity interval exercise.


Author(s):  
Erik P. Andersson ◽  
Irina Hämberg ◽  
Paulo Cesar Do Nascimento Salvador ◽  
Kerry McGawley

Abstract Purpose This study aimed to compare physiological factors and cycle characteristics during cross-country (XC) roller-skiing at matched inclines and speeds using the double-poling (DP) and diagonal-stride (DS) sub-techniques in junior female and male XC skiers. Methods Twenty-three well-trained junior XC skiers (11 women, 12 men; age 18.2 ± 1.2 yr.) completed two treadmill roller-skiing tests in a randomized order using either DP or DS. The exercise protocols were identical and included a 5 min warm-up, 4 × 5 min submaximal stages, and an incremental test to exhaustion, all performed at a 5° incline. Results No significant three-way interactions were observed between sex, submaximal exercise intensity, and sub-technique. For the pooled sample, higher values were observed for DP versus DS during submaximal exercise for the mean oxygen uptake kinetics response time (33%), energy cost (18%), heart rate (HR) (9%), blood lactate concentration (5.1 versus 2.1 mmol·L−1), rating of perceived exertion (12%), and cycle rate (25%), while cycle length was lower (19%) (all P < 0.001). During the time-to-exhaustion (TTE) test, peak oxygen uptake ($$\dot{V}$$ V ˙ O2peak), peak HR, and peak oxygen pulse were 8%, 2%, and 6% lower, respectively, for DP than DS, with a 29% shorter TTE during DP (pooled data, all P < 0.001). Conclusion In well-trained junior XC skiers, DP was found to exert a greater physiological load than DS during uphill XC roller-skiing at submaximal intensities. During the TTE test, both female and male athletes were able to ski for longer and reached markedly higher $$\dot{V}$$ V ˙ O2peak values when using DS compared to DP.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ibrahim Ouergui ◽  
Emerson Franchini ◽  
Hamdi Messaoudi ◽  
Hamdi Chtourou ◽  
Anissa Bouassida ◽  
...  

This study investigated the effect of area sizes (4 × 4, 6 × 6, and 8 × 8 m) and effort-pause ratios (free combat vs. 1:2) variation on the physiological and perceptive responses during taekwondo combats (Study 1). In a second study, the effects on physical performance of 8 weeks of small combat-based training added to regular taekwondo training were investigated (Study 2). In random order, 32 male taekwondo athletes performed six (i.e., two effort-to-pause ratios × three area sizes conditions) different 2-min taekwondo combats (Study 1). Thereafter (Study 2), they were randomly assigned to three experimental groups (4 × 4, 6 × 6, and 8 × 8 m) and an active control group (CG). Regarding Study 1, blood lactate concentration [La] before and after each combat, mean heart rate (HRmean) during each combat, and rating of perceived exertion (CR-10) immediately after each combat were assessed. Regarding Study 2, progressive specific taekwondo (PSTT) to estimate maximum oxygen consumption (VO2max), taekwondo-specific agility, and countermovement jump (CMJ) tests were administered before and after 8 weeks of training. Study 1 results showed that 4 × 4 m elicited lower HRmean values compared with 6 × 6 m (d = −0.42 [small], p = 0.030) and free combat induced higher values compared with the 1:2 ratio (d = 1.71 [large], p &lt; 0.001). For [La]post, 4 × 4 m area size induced higher values than 6 × 6 m (d = 0.99 [moderate], p &lt; 0.001) and 8 × 8 m (d = 0.89 [moderate], p &lt; 0.001) and free combat induced higher values than 1:2 ratio (d = 0.69 [moderate], p &lt; 0.001). Higher CR-10 scores were registered after free combat compared with 1:2 ratio (d = 0.44 [small], p = 0.007). For Study 2, VO2max increased after training [F(1, 56) =30.532, p &lt; 0.001; post-hoc: d = 1.27 [large], p &lt; 0.001] with higher values for 4 × 4 m compared with CG (d = 1.15 [moderate], p = 0.009). Agility performance improved after training [F(1, 56) = 4.419, p = 0.04; post-hoc: d = −0.46 [small], p = 0.04] and 4 × 4 m induced lower values in comparison with 6 × 6 m (d = −1.56 [large], p = 0.001) and CG (d = −0.77 [moderate], p = 0.049). No training type influenced CMJ performance. Smaller area size elicited contrasting results in terms of metabolic demand compared with larger sizes (i.e., lower HRmean but higher [La] and CR-10), whereas free combat induced variables' consistently higher values compared with imposed 1:2 ratio (Study 1). Taekwondo training is effective to improve VO2max and agility (Study 2), but small combat training modality should be investigated further.


Author(s):  
O.A.B. Soares ◽  
G.C. Ferraz ◽  
C.B. Martins ◽  
D.P.M. Dias ◽  
J.C. Lacerda-Neto ◽  
...  

The anaerobic threshold is a physiologic event studied in various species. There are various methods for its assessment, recognized in the human and equine exercise physiology literature, several of these involving the relationship between blood lactate concentration (LAC) and exercise load, measured in a standardized exercise test. The aim of this study was to compare four of these methods: V2, V4, individual anaerobic threshold (IAT) and lactate minimum speed (LMS) with the method recognized as the gold standard for the assessment of anaerobic threshold, maximal lactate steady-state (MLSS). The five tests were carried out in thirteen trained Arabian horses, in which velocities and associated LAC could be measured. The mean velocities and the LAC associated with the anaerobic threshold for the five methods were respectively: V2 = 9.67±0.54; V4 = 10.98±0.47; V IAT = 9.81±0.72; V LMS = 7.50±0.57 and V MLSS = 6.14±0.45m.s-1 and LAC IAT = 2.17±0.93; LAC LMS = 1.17±0.62 and LAC MLSS = 0.84±0.21mmol.L-1. None of the velocities were statistically equivalent to V MLSS (P<0.05). V2, V4 and V LMS showed a good correlation with V MLSS , respectively: r = 0.74; r = 0.78 and r = 0.83, and V IAT did not significantly correlate with V MLSS. Concordance between the protocols was relatively poor, i.e., 3.28±1.00, 4.84±0.30 and 1.43±0.32m.s-1 in terms of bias and 95% agreement limits for V2, V4 and LMS methods when compared to MLSS. Only LAC LMS did not differ statistically from LAC MLSS. Various authors have reported the possibility of the assessment of anaerobic threshold using rapid protocols such as V4 and LMS for humans and horses. This study corroborates the use of these tests, but reveals that adjustments in the protocols are necessary to obtain a better concordance between the tests and the MLSS.


2018 ◽  
Vol 13 (10) ◽  
pp. 1324-1330
Author(s):  
Enzo Hollville ◽  
Vincent Le Croller ◽  
Yoshihiro Hirasawa ◽  
Rémi Husson ◽  
Giuseppe Rabita ◽  
...  

Purpose: To evaluate the effect of multiple sets of repeated-sprint-ability (RSA)-induced fatigue on subsequent passing-skill performance in field hockey players. Methods: A total of 10 elite U-21 (under-21) male field hockey players performed 5 sets of a combination of RSA test (6 × 20 m, 20 s of passive recovery) followed by a 1-min passing-skill test (passing reception with subsequent passes at a predesigned target). Data on fastest sprint time and cumulated sprint time for RSA test; total number of balls played, targeted, and passing accuracy (number of balls targeted/total number of balls played) for passing-skill test; heart rate (HR), blood lactate concentration (BLa), and rating of perceived exertion (RPE)  were collected throughout the protocol. Results: RSA performance was significantly impaired from set 1 to set 5 (fastest sprint time +4.1%, P < .001; cumulated sprint time +2.3%, P < .01). For a similar average number of balls played (12.8 [1.4]) during each set, number of balls targeted (−1.7%, P < .05) and passing accuracy (−3.1%, P < .05) decreased up to the third set before reimproving over the last 2 sets. Psychophysiological responses (HR, BLa, and RPE) progressively increased (P < .05) toward protocol cessation. The decrease in passing accuracy with increasing RSA cumulated sprint time was fitted to a 2nd-order polynomial function (r2 = .94, P < .05). Conclusion: Multiple-set RSA-induced fatigue was accompanied by passing-skill adjustment variation, suggesting a complex interaction between physiological and psychological/cognitive function to preserve passing skill under fatigued condition.


Sports ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 23
Author(s):  
Gavriil G. Arsoniadis ◽  
Ioannis S. Nikitakis ◽  
Petros G. Botonis ◽  
Ioannis Malliaros ◽  
Argyris G. Toubekis

Background: Physiological and biomechanical parameters obtained during testing need validation in a training setting. The purpose of this study was to compare parameters calculated by a 5 × 200-m test with those measured during an intermittent swimming training set performed at constant speed corresponding to blood lactate concentration of 4 mmol∙L−1 (V4). Methods: Twelve competitive swimmers performed a 5 × 200-m progressively increasing speed front crawl test. Blood lactate concentration (BL) was measured after each 200 m and V4 was calculated by interpolation. Heart rate (HR), rating of perceived exertion (RPE), stroke rate (SR) and stroke length (SL) were determined during each 200 m. Subsequently, BL, HR, SR and SL corresponding to V4 were calculated. A week later, swimmers performed a 5 × 400-m training set at constant speed corresponding to V4 and BL-5×400, HR-5×400, RPE-5×400, SR-5×400, SL-5×400 were measured. Results: BL-5×400 and RPE-5×400 were similar (p > 0.05), while HR-5×400 and SR-5×400 were increased and SL-5×400 was decreased compared to values calculated by the 5 × 200-m test (p < 0.05). Conclusion: An intermittent progressively increasing speed swimming test provides physiological information with large interindividual variability. It seems that swimmers adjust their biomechanical parameters to maintain constant speed in an aerobic endurance training set of 5 × 400-m at intensity corresponding to 4 mmol∙L−1.


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