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.

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.

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.

scholarly journals Complex Interplay Between Determinants of Pacing and Performance During 20-km Cycle Time Trials

2012 ◽  
Vol 7 (2) ◽  
pp. 121-129 ◽  
Author(s):  
Andrew Renfree ◽  
Julia West ◽  
Mark Corbett ◽  
Clare Rhoden ◽  
Alan St Clair Gibson
Keyword(s):  
Negative Affect ◽  
Blood Lactate ◽  
Power Output ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Rating Of Perceived Exertion ◽  
Physiological Status ◽  
Pacing Strategy ◽  
And Performance

Purpose:This study examined the determinants of pacing strategy and performance during self-paced maximal exercise.Methods:Eight well-trained cyclists completed two 20-km time trials. Power output, rating of perceived exertion (RPE), positive and negative affect, and iEMG activity of the active musculature were recorded every 0.5 km, confidence in achieving preexercise goals was assessed every 5 km, and blood lactate and pH were measured postexercise. Differences in all parameters were assessed between fastest (FAST) and slowest (SLOW) trials performed.Results:Mean power output was significantly higher during the initial 90% of FAST, but not the final 10%, and blood lactate concentration was significantly higher and pH significantly lower following FAST. Mean iEMG activity was significantly higher throughout SLOW. Rating of perceived exertion was similar throughout both trials, but participants had significantly more positive affect and less negative affect throughout FAST. Participants grew less confident in their ability to achieve their goals throughout SLOW.Conclusions:The results suggest that affect may be the primary psychological regulator of pacing strategy and that higher levels of positivity and lower levels of negativity may have been associated with a more aggressive strategy during FAST. Although the exact mechanisms through which affect acts to influence performance are unclear, it may determine the degree of physiological disruption that can be tolerated, or be reflective of peripheral physiological status in relation to the still to be completed exercise task.

scholarly journals Optimizing Interval Training Through Power-Output Variation Within the Work Intervals

2020 ◽  
Vol 15 (7) ◽  
pp. 982-989
Author(s):  
Arthur H. Bossi ◽  
Cristian Mesquida ◽  
Louis Passfield ◽  
Bent R. Rønnestad ◽  
James G. Hopker
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
Perceived Exertion ◽  
Minute Ventilation ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Interval Training ◽  
Training Load ◽  
Constant Intensity ◽  
Varied Intensity

Purpose: Maximal oxygen uptake () is a key determinant of endurance performance. Therefore, devising high-intensity interval training (HIIT) that maximizes stress of the oxygen-transport and -utilization systems may be important to stimulate further adaptation in athletes. The authors compared physiological and perceptual responses elicited by work intervals matched for duration and mean power output but differing in power-output distribution. Methods: Fourteen cyclists ( 69.2 [6.6] mL·kg−1·min−1) completed 3 laboratory visits for a performance assessment and 2 HIIT sessions using either varied-intensity or constant-intensity work intervals. Results: Cyclists spent more time at during HIIT with varied-intensity work intervals (410 [207] vs 286 [162] s, P = .02), but there were no differences between sessions in heart-rate- or perceptual-based training-load metrics (all P ≥ .1). When considering individual work intervals, minute ventilation () was higher in the varied-intensity mode (F = 8.42, P = .01), but not respiratory frequency, tidal volume, blood lactate concentration [La], ratings of perceived exertion, or cadence (all F ≤ 3.50, ≥ .08). Absolute changes (Δ) between HIIT sessions were calculated per work interval, and Δ total oxygen uptake was moderately associated with (r = .36, P = .002). Conclusions: In comparison with an HIIT session with constant-intensity work intervals, well-trained cyclists sustain higher fractions of when work intervals involved power-output variations. This effect is partially mediated by an increased oxygen cost of hyperpnea and not associated with a higher [La], perceived exertion, or training-load metrics.

A Comparison of Different Prerace Warm-Up Strategies on 1-km Cycling Time-Trial Performance

2020 ◽  
Vol 15 (8) ◽  
pp. 1109-1116
Author(s):  
Mathias T. Vangsoe ◽  
Jonas K. Nielsen ◽  
Carl D. Paton
Keyword(s):  
Blood Lactate ◽  
Power Output ◽  
Peak Power ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Time Trial ◽  
Peak Power Output ◽  
Warm Up ◽  
Performance Time ◽  
Competitive Cyclists

Purpose: Ischemic preconditioning (IPC) and postactivation potentiation (PAP) are warm-up strategies proposed to improve high-intensity sporting performance. However, only few studies have investigated the benefits of these strategies compared with an appropriate control (CON) or an athlete-selected (SELF) warm-up protocol. Therefore, this study examined the effects of 4 different warm-up routines on 1-km time-trial (TT) performance with competitive cyclists. Methods: In a randomized crossover study, 12 well-trained cyclists (age 32 [10] y, mass 77.7 [4.6] kg, peak power output 1141 [61] W) performed 4 different warm-up strategies—(CON) 17 minutes CON only, (SELF) a self-determined warm-up, (IPC) IPC + CON, or (PAP) CON + PAP—prior to completing a maximal-effort 1-km TT. Performance time and power, quadriceps electromyograms, muscle oxygen saturation (SmO2), and blood lactate were measured to determine differences between trials. Results: There were no significant differences (P > .05) in 1-km performance time between CON (76.9 [5.2] s), SELF (77.3 [6.0] s), IPC (77.0 [5.5] s), or PAP (77.3 [5.9] s) protocols. Furthermore, there were no significant differences in mean or peak power output between trials. Finally, electromyogram activity, SmO2, and recovery blood lactate concentration were not different between conditions. Conclusions: Adding IPC or PAP protocols to a short CON warm-up appears to provide no additional benefit to 1-km TT performance with well-trained cyclists and is therefore not recommended. Furthermore, additional IPC and PAP protocols had no effect on electromyograms and SmO2 values during the TT or peak lactate concentration during recovery.

Monitoring Blood Lactate Concentration during High Intensity Exercise in Youth Swimmers

2020 ◽  
Vol 18 (2) ◽  
pp. 1327-1335
Author(s):  
Hee-Jeong Son ◽  
◽  
Hyeong-Tae Kwon ◽  
Hyo-Sik Kim
Keyword(s):  
Blood Lactate ◽  
High Intensity ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
High Intensity Exercise

Critical power in adolescent boys and girls — an exploratory study

2008 ◽  
Vol 33 (6) ◽  
pp. 1105-1111 ◽  
Author(s):  
Craig A. Williams ◽  
Jeanne Dekerle ◽  
Kerry McGawley ◽  
Serge Berthoin ◽  
Helen Carter
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Critical Power ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Random Order ◽  
Constant Load ◽  
Peak Oxygen Uptake ◽  
Time To Exhaustion ◽  
Intensity Of Exercise

The purpose of the study was to identify critical power (CP) in boys and girls and to examine the physiological responses to exercise at and 10% above CP (CP+10%) in a sub-group of boys. Nine boys and 9 girls (mean age 12.3 (0.5) y performed 3 constant-load tests to derive CP. Eight of the boys then exercised, in random order, at CP and CP+10% until volitional exhaustion. CP was 123 (28) and 91 (26) W for boys and girls, respectively (p < 0.02), which was equivalent to 75 (6) and 72 (10) % of peak oxygen uptake, respectively (p > 0.47). Boys’ time to exhaustion at CP was 18 min 37 s (4 min 13 s), which was significantly longer (p < 0.007) than that at CP+10% (9 min 42 s (2 min 31 s)). End-exercise values for blood lactate concentration (B[La]) and maximal oxygen uptake were higher in the CP+10% trial (5.0 (2.4) mmol·L–1 and 2.15 (0.4) L·min–1, respectively) than in the CP trial, (B[La], 4.7 (2.1) mmol·L–1; maximal oxygen uptake, 2.05 (0.35) L·min–1; p > 0.13). Peak oxygen uptake (expressed as a percentage of the peak value) was not attained at the end of the trials (94 (12) and 98 (14) % for CP and CP+10%, respectively). These results provide information about the boundary between the heavy and severe exercise intensity domains in children, and have demonstrated that CP in a group of boys does not represent a sustainable steady-state intensity of exercise.

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