scholarly journals Effect of Blood Lactate Concentration and the Level of Oxygen Uptake Immediately before a Cycling Sprint on Neuromuscular Activation during Repeated Cycling Sprints

2006 ◽  
Vol 25 (4) ◽  
pp. 267-273 ◽  
Author(s):  
Ryouta Matsuura ◽  
Hisayoshi Ogata ◽  
Takahiro Yunoki ◽  
Takuma Arimitsu ◽  
Tokuo Yano
Keyword(s):  
Oxygen Uptake ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Neuromuscular Activation ◽  
Repeated Cycling

Treatment of Anaemia in Haemodialysis Patients with Erythropoietin: Long-Term Effects on Exercise Capacity

1993 ◽  
Vol 84 (4) ◽  
pp. 441-447 ◽  
Author(s):  
Peter Báaráany ◽  
Ulla Freyschuss ◽  
Erna Pettersson ◽  
Jonas Bergström
Keyword(s):  
Oxygen Uptake ◽  
Blood Lactate ◽  
Exercise Capacity ◽  
Recombinant Human Erythropoietin ◽  
Maximal Exercise ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Human Erythropoietin ◽  
Hb Concentration ◽  
Maximal Exercise Capacity

1. The effects of correcting anaemia on exercise capacity were evaluated in 21 haemodialysis patients (aged 39 ± 12 years) before starting treatment with recombinant human erythropoietin (Hb concentration, 73 ± 10 g/l; total Hb, 59 ± 12% of expected), after correction of the anaemia to a Hb concentration of 108 ± 7 g/l and a total Hb 82 ± 10% of expected, and in 13 of the patients after 12 months on maintenance recombinant human erythropoietin treatment (Hb concentration 104 ± 14 g/l, total Hb 79 ± 17% of expected). Fifteen healthy subjects (aged 41 ± 9 years), who took no regular exercise, constituted the control group. Maximal exercise capacity was determined on a bicycle ergometer. Oxygen uptake, respiratory quotient, blood lactate concentration, heart rate and blood pressure were measured at rest and at maximal workload. 2. After 6 ± 3 months on recombinant human erythropoietin, maximal exercise capacity increased from 108 ± 27 W to 130 ± 36 W (P < 0.001) and the maximal oxygen uptake increased from 1.24 ± 0.39 litres/min to 1.50 ± 0.45 litres/min (P < 0.001). No significant changes in respiratory quotient (1.16 ± 0.13 versus 1.18 ± 0.13) and blood lactate concentration (4.0 ± 1.8 versus 3.6 ± 1.1 mmol/l) at maximal workload were observed, but the blood lactate concentration in the patients was significantly lower than that in the control subjects (6.7 ± 2.3 mmol/l, P < 0.01). After the correction of anaemia, the aerobic power was still 38% lower in the patients than in the control subjects and 17% lower than the reference values. 3. After 12 months on maintenance recombinant human erythropoietin treatment (17 ± 3 months from the start of the study), no further significant changes were observed in maximal exercise capacity (before start, 112 ± 31 W, 6 ± 3 months, 134 ± 42 W, 17 ± 3 months, 134 ± 50 W), maximal oxygen uptake (before start, 1.33 ± 0.45 litres/min; 6 ± 3 months, 1.59 ± 0.54 litres/min; 17 ± 3 months, 1.75 ± 0.78 litres/min) or blood lactate concentration (before start, 4.4 ± 1.9 mmol/l; 6 ± 3 months, 4.0 ± 1.0 mmol/l; 17 ± 3 months, 4.7 ± 2.0 mmol/l). 4. Thus, in haemodialysis patients the improvement in maximal aerobic power after the correction of anaemia persists without marked changes during long-term treatment with recombinant human erythropoietin. We did not observe any effects on exercise capacity that could be attributed to a spontaneous increase in physical activity after treatment of anaemia.

Can measures of critical power precisely estimate the maximal metabolic steady-state?

2016 ◽  
Vol 41 (11) ◽  
pp. 1197-1203 ◽  
Author(s):  
Felipe Mattioni Maturana ◽  
Daniel A. Keir ◽  
Kaitlin M. McLay ◽  
Juan M. Murias
Keyword(s):  
Steady State ◽  
Oxygen Uptake ◽  
Blood Lactate ◽  
Critical Power ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Time To Exhaustion ◽  
Stable Oxygen ◽  
Young Subjects ◽  
Relationship Of

Critical power (CP) conceptually represents the highest power output (PO) at physiological steady-state. In cycling exercise, CP is traditionally derived from the hyperbolic relationship of ∼5 time-to-exhaustion trials (TTE) (CPHYP). Recently, a 3-min all-out test (CP3MIN) has been proposed for estimation of CP as well the maximal lactate steady-state (MLSS). The aim of this study was to compare the POs derived from CPHYP, CP3MIN, and MLSS, and the oxygen uptake and blood lactate concentrations at MLSS. Thirteen healthy young subjects (age, 26 ± 3years; mass, 69.0 ± 9.2 kg; height, 174 ± 10 cm; maximal oxygen uptake, 60.4 ± 5.9 mL·kg−1·min−1) were tested. CPHYP was estimated from 5 TTE. CP3MIN was calculated as the mean PO during the last 30 s of a 3-min all-out test. MLSS was the highest PO during a 30-min ride where the variation in blood lactate concentration was ≤ 1.0 mmol·L−1 during the last 20 min. PO at MLSS (233 ± 41 W; coefficient of variation (CoV), 18%) was lower than CPHYP (253 ± 44 W; CoV, 17%) and CP3MIN (250 ± 51 W; CoV, 20%) (p < 0.05). Limits of agreement (LOA) from Bland–Altman plots between CPHYP and CP3MIN (–39 to 31 W), and CP3MIN and MLSS (–29 to 62 W) were wide, whereas CPHYP and MLSS presented the narrowest LOA (–7 to 48 W). MLSS yielded not only the maximum PO of stable blood lactate concentration, but also stable oxygen uptake. In conclusion, POs associated to CPHYP and CP3MIN were larger than those observed during MLSS rides. Although CPHYP and CP3MIN were not different, the wide LOA between these 2 tests and the discrepancy with PO at MLSS questions the ability of CP measures to determine the maximal physiological steady-state.

Relationships between V̇O2 and blood lactate responses after all-out running exercise

2015 ◽  
Vol 40 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Rafael Alves de Aguiar ◽  
Rogério Santos de Oliveira Cruz ◽  
Tiago Turnes ◽  
Kayo Leonardo Pereira ◽  
Fabrizio Caputo
Keyword(s):  
Oxygen Uptake ◽  
Blood Lactate ◽  
Decay Time ◽  
Maximal Oxygen Uptake ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Time Constants ◽  
Recovery Curves ◽  
Lactate Removal ◽  
Endurance Runners

To verify the effects of training status and blood lactate concentration (BLC) responses on the early excess postexercise oxygen consumption (EPOC), 8 sprinters, 7 endurance runners, and 7 untrained subjects performed an incremental test to determine maximal oxygen uptake and a 1-min all-out test to determine BLC and oxygen uptake recovery curves. BLC kinetics was evaluated to assess the quantity of lactate accumulated during exercise (QlaA), lactate removal ability (k2), and quantity of lactate removed from 0 to 10 min postexercise (QlaR). Oxygen uptake off-kinetics was evaluated to assess the decay time constants (τ1 and τ2); moreover, EPOC was measured during the first 10 min after exercise. While sprinters had 98%–100% and 94%–100% likelihood of having the highest EPOC and decay time constants, endurance runners had 98%–100% and 95%–100% likelihood of having the lowest EPOC and decay time constants. EPOC was correlated with QlaA (r = 0.74) and QlaR (r = 0.61). τ1 and τ2 were correlated with maximal oxygen uptake (r > –0.57), k2 (r > –0.48), and QlaR relative to QlaA (r > –0.60). Our findings indicate that oxygen uptake recovery is associated with fast lactate removal and aerobic training. Furthermore, the metabolites derived from anaerobic energy production seem to induce a greater EPOC after all-out exercise.

Superior Physiological Adaptations After a Microcycle of Short Intervals Versus Long Intervals in Cyclists

2020 ◽  
pp. 1-7
Author(s):  
Bent R. Rønnestad ◽  
Sjur J. Øfsteng ◽  
Fabio Zambolin ◽  
Truls Raastad ◽  
Daniel Hammarström
Keyword(s):  
Confidence Interval ◽  
Oxygen Uptake ◽  
Blood Lactate ◽  
Power Output ◽  
Maximal Oxygen Uptake ◽  
High Intensity ◽  
Aerobic Training ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Endurance Performance

Purpose: To compare the effects of a 1-week high-intensity aerobic-training shock microcycle composed of either 5 short-interval sessions (SI; n = 9, 5 series with 12 × 30-s work intervals interspersed with 15-s recovery and 3-min recovery between series) or 5 long-interval sessions (LI; n = 8, 6 series of 5-min work intervals with 2.5-min recovery between series) on indicators of endurance performance in well-trained cyclists. Methods: Before and following 6 days with standardized training loads after the 1-week high-intensity aerobic-training shock microcycle, both groups were tested in physiological determinants of endurance performance. Results: From pretraining to posttraining, SI achieved a larger improvement than LI in maximal oxygen uptake (5.7%; 95% confidence interval, 1.3–10.3; P = .015) and power output at a blood lactate concentration of 4 mmol·L−1 (3.8%; 95% confidence interval, 0.2–7.4; P = .038). There were no group differences in changes of fractional use of maximal oxygen uptake at a workload corresponding to a blood lactate concentration of 4 mmol·L−1, gross efficiency, or the 1-minute peak power output from the maximal-oxygen-uptake test. Conclusion: The SI protocol may induce superior changes in indicators of endurance performance compared with the LI protocol, indicating that SI can be a good strategy during a 1-week high-intensity aerobic-training shock microcycle in well-trained cyclists.

scholarly journals Acute Effect of Repeated Sprint Exercise With Blood Flow Restriction During Rest Periods on Muscle Oxygenation

2021 ◽  
Vol 12 ◽  
Author(s):  
Chihiro Kojima ◽  
Keiichi Yamaguchi ◽  
Hiroto Ito ◽  
Nobukazu Kasai ◽  
Olivier Girard ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Power Output ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Rest Period ◽  
Muscle Oxygenation ◽  
Rest Periods ◽  
Repeated Cycling

PurposeThis study aimed to examine the effect of applying BFR during rest periods of repeated cycling sprints on muscle oxygenation.MethodsSeven active males performed 5 × 10-s maximal pedaling efforts with 40-s passive rest, with or without BFR application during rest period. BFR was applied for 30 s between sprints (between 5 and 35 s into rest) through a pneumatic pressure cuff inflated at 140 mmHg. Vastus lateralis muscle oxygenation was monitored using near-infrared spectroscopy. In addition, blood lactate concentration and heart rate were also evaluated.ResultsThe BFR trial showed significantly lower oxyhemoglobin (oxy-Hb) and tissue saturation (StO2) levels than the CON trial (P &lt; 0.05). However, power output and blood lactate concentration did not significantly differ between the two trials (P &gt; 0.05).ConclusionApplying BFR during rest periods of repeated cycling sprints decreased muscle oxygenation of active musculature, without interfering with power output during sprints.

scholarly journals Predicting Blood Lactate Concentration and Oxygen Uptake from sEMG Data during Fatiguing Cycling Exercise

Sensors ◽  
2015 ◽  
Vol 15 (8) ◽  
pp. 20480-20500 ◽  
Author(s):  
Petras Ražanskas ◽  
Antanas Verikas ◽  
Charlotte Olsson ◽  
Per-Arne Viberg
Keyword(s):  
Oxygen Uptake ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Cycling Exercise

scholarly journals Comparison of perceptual and physiological variables of running on a track, motorized treadmill, and non-motorized curved treadmill at increasing velocity

2016 ◽  
Vol 22 ◽  
pp. 20 ◽  
Author(s):  
Veronika Myran Wee ◽  
Erna Von Heimburg ◽  
Roland Van den Tillaar
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Blood Lactate ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Treadmill Running ◽  
Male Athletes ◽  
Physiological Variables ◽  
The Difference

The aim of this study was to compare perceptual and physiological variables between running on three different modalities — an indoor athletics track, a motorized treadmill, and a non-motorized curved treadmill — for 1000 m at three different velocities. Ten male athletes (age 24±3 years, body mass 69.8±6.91 kg, height 1.80±0.06 m, VO2peak 69.0±6.70 ml/kg/ min) conducted three 1000 m laps at increasing velocity on three different running modalities. The athletes had a 3-minute recovery between each lap, where the rate of perceived exertion (RPE) was registered and the blood lactate concentration and heart rate were measured. Oxygen uptake was measured using a portable metabolic analyser. The physiological (oxygen uptake, heart rate, and blood lactate concentration) and perceptual (RPE) variables were higher when running on a non-motorized curved treadmill compared with running on the track or a motorized treadmill. No differences were found between running on a motorized treadmill and the track except for the RPE, which was lower when running on the track compared with the motorized treadmill. Running on a non-motorized curved treadmill at three different velocities results in a higher oxygen uptake (37%) and heart rate (22%) and is subjectively much harder than running on a track or a motorized treadmill at the same velocities. The difference is around 4 km/h when comparing the physiological and perceptual responses. Thus, when performing training sessions on a non-motorized curved treadmill, subjects should subtract 4 km/h from their regular pace on a track or motorized treadmill to get the same response considering oxygen uptake, heart rate, RPE and blood lactate concentration.

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