Threshold for muscle lactate accumulation during progressive exercise

ArticleinJournal of Applied Physiology 66(6):2710-6 · July 1989with40 Reads
DOI: 10.1249/00005768-198004001-00146 · Source: PubMed
Abstract
The purpose of this study was to investigate the relationship between muscle and blood lactate concentrations during progressive exercise. Seven endurance-trained male college students performed three incremental bicycle ergometer exercise tests. The first two tests (tests I and II) were identical and consisted of 3-min stage durations with 2-min rest intervals and increased by 50-W increments until exhaustion. During these tests, blood was sampled from a hyperemized earlobe for lactate and pH measurement (and from an antecubital vein during test I), and the exercise intensities corresponding to the lactate threshold (LT), individual anaerobic threshold (IAT), and onset of blood lactate accumulation (OBLA) were determined. The test III was performed at predetermined work loads (50 W below OBLA, at OBLA, and 50 W above OBLA), with the same stage and rest interval durations of tests I and II. Muscle biopsies for lactate and pH determination were taken at rest and immediately after the completion of the three exercise intensities. Blood samples were drawn simultaneously with each biopsy. Muscle lactate concentrations increased abruptly at exercise intensities greater than the "below-OBLA" stage [50.5% maximal O2 uptake (VO2 max)] and resembled a threshold. An increase in blood lactate and [H+] also occurred at the below-OBLA stage; however, no significant change in muscle [H+] was observed. Muscle lactate concentrations were highly correlated to blood lactate (r = 0.91), and muscle-to-blood lactate ratios at below-OBLA, at-OBLA, and above-OBLA stages were 0.74, 0.63, 0.96, and 0.95, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
    • "The difference of power outputs on the average was 39,4 watt, oxygen uptake – 2,6 ml·min·kg -1 (5,6%), heart rate – 15 bpm (139 bpm at lactate threshold and 154 bpm at ventilation threshold, respectively. The fi rst consequence of anaerobic glycolisis is the increase of lactate acid concentration in muscular cells and as a result – in the blood (Coyle et al., 1984; Beaver et al., 1986; Heck et al., 1985; Chawalbinska– Moneta et al., 1989; Soller et al., 2008; Klein et al., 2010; Lorenzo et al., 2011). It is known that lactate acid is more than 99% dissociated and buffered predominantly by the bicarbonate system of the blood. "
    Article · Apr 2016
    • "The comparative studies conducted by Chwalbińska-Moneta et al. [44] have demonstrated that the IAT method (individual anaerobic threshold) yields lower power values at the anaerobic threshold than LA 4.0 . Chwalbińska- Moneta [45] has found a similar relation between the threshold power values obtained from LA 4.0 and LT visual . "
    [Show abstract] [Hide abstract] ABSTRACT: Background & Study Aim: In the practice of sport training the anaerobic threshold (LT2) is sought using a whole range of methods. As a result, different LT2 values are obtained and applied to programme endurance training. The aim of the research are the relationships between the main indicators of the five methods applied to determine the lactate anaerobic threshold in judo athletes. Material & Methods: In the study, 19 judoists at international and national sport level going through a preparation period for competition performed a graded incremental exercise test (GXTs) that met the requirements of all five methods. The research used five methods that are usually applied in training practice to analyse the blood lactate concentration curve: LTvisual, LTloglog, LT4.0, LTdel1, and LTD-max. LT2 values generated by LTvisual, LTloglog, LT4.0, LTdel1, and LTD-max methods were used to build regression equations for determining LT2 based on LT4.0 values. Results: The experiment has showed that judoists, like other athletes, have a specific profile of running velocities at anaerobic threshold. The range of running velocities (VCR) at which their maximal oxygen uptake (VO2max) was recorded points to a relatively wide range of work rates that can be applied to build the aerobic endurance of judoists at similar levels of sport accomplishment. With the exception of LTD-max, the other methods of lactate curve analysis produced very similar running velocities at anaerobic threshold (VAT). Conclusions: This study shows which methods can be used interchangeably for training purposes without the risk of running velocities being considerably different. It has been found that VLT2 values obtained from LT4.0 method are the most similar to those generated by the other methods.
    Full-text · Article · Jan 2016
    • "It is possible that the higher [La -] observed following higher cycling intensities may be associated with the decrease in initial speed during subsequent running. Although we were unable to take muscle biopsies, it has been previously reported that blood [La -] changes during steady-state exercise parallel changes in muscle [La -] (Chwalbinska-Moneta et al. 1989 ). Furthermore , it has been suggested that increasing levels of La -, and the associated increase in H ? within the muscle, may affect performance via interfering with energy provision and/or muscle contraction processes (Nakamaru and Schwartz 1972). "
    [Show abstract] [Hide abstract] ABSTRACT: The aim of this study was to determine the effect of cycle intensity on subsequent running performance and combined cycle-run (CR) performance. Seven triathletes undertook a cycling graded exercise test to exhaustion, an isolated 500-kJ cycle time trial (CTT) and an isolated 5-km running time trial. Then they performed a series of CR tests, at various cycle intensities, followed by an all-out, 5-km run. The CR tests were separated into four categories based on the percentage of the CTT at which the cycle was performed (CR 81-85%, CR 86-90%, CR 91-95%, and CR 96-100%). Running performance was slower during CR 96-100% compared to CR 81-85% and CR 86-90% (20:45 ± 1:19 vs. 19:56 ± 0:40 and 19:46 ± 0:49 min; P < 0.05), but not CR 91-95% (20:19 ± 1:08 min; P > 0.05). CR performance was maximised during CR 96-100% when compared to CR 81-85, CR 86-90 and CR 91-95% (56:37 ± 4:04 vs. 62:40 ± 5:30, 59:53 ± 4:41 and 58:29 ± 4:40 min; P < 0.05). The results suggest that combined cycle and run performance is maximised when the cycle is completed at the highest sustainable intensity.
    Full-text · Article · Nov 2010
Show more

    Recommended publications

    Discover more