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.

scholarly journals Physiological responses and cycle characteristics during double-poling versus diagonal-stride roller-skiing in junior cross-country skiers

2021 ◽  
Author(s):  
Erik P. Andersson ◽  
Irina Hämberg ◽  
Paulo Cesar Do Nascimento Salvador ◽  
Kerry McGawley
Keyword(s):  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peak Oxygen Uptake ◽  
Submaximal Exercise ◽  
Rating Of Perceived Exertion ◽  
Time To Exhaustion ◽  
Double Poling ◽  
Cross Country

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.

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.

Reliability of time-to-exhaustion and selected psycho-physiological variables during constant-load cycling at the maximal lactate steady-state

2017 ◽  
Vol 42 (2) ◽  
pp. 142-147 ◽  
Author(s):  
Oliver Faude ◽  
Anne Hecksteden ◽  
Daniel Hammes ◽  
Franck Schumacher ◽  
Eric Besenius ◽  
...  
Keyword(s):  
Steady State ◽  
Oxygen Uptake ◽  
Blood Lactate ◽  
Maximal Oxygen Uptake ◽  
Perceived Exertion ◽  
Constant Load ◽  
Time To Exhaustion ◽  
Maximal Lactate Steady State ◽  
Physiological Variables ◽  
Load Tests

The maximal lactate steady-state (MLSS) is frequently assessed for prescribing endurance exercise intensity. Knowledge of the intra-individual variability of the MLSS is important for practical application. To date, little is known about the reliability of time-to-exhaustion and physiological responses to exercise at MLSS. Twenty-one healthy men (age, 25.2 (SD 3.3) years; height, 1.83 (0.06) m; body mass, 78.9 (8.9) kg; maximal oxygen uptake, 57.1 (10.7) mL·min−1·kg−1) performed 1 incremental exercise test, and 2 constant-load tests to determine MLSS intensity. Subsequently, 2 open-end constant-load tests (MLSS 1 and 2) at MLSS intensity (3.0 (0.7) W·kg−1, 76% (10%) maximal oxygen uptake) were carried out. During the tests, blood lactate concentrations, heart rate, ratings of perceived exertion (RPE), variables of gas exchange, and core body temperature were determined. Time-to-exhaustion was 50.8 (14.0) and 48.2 (16.7) min in MLSS 1 and 2 (mean change: −2.6 (95% confidence interval: −7.8, 2.6)), respectively. The coefficient of variation (CV) was high for time-to-exhaustion (24.6%) and for mean (4.8 (1.2) mmol·L−1) and end (5.4 (1.7) mmol·L−1) blood lactate concentrations (15.7% and 19.3%). The CV of mean exercise values for all other parameters ranged from 1.4% (core temperature) to 8.3% (ventilation). At termination, the CVs ranged from 0.8% (RPE) to 11.8% (breathing frequency). The low reliability of time-to-exhaustion and blood lactate concentration at MLSS indicates that the precise individual intensity prescription may be challenging. Moreover, the obtained data may serve as reference to allow for the separation of intervention effects from random variation in our sample.

Acute Cardiometabolic and Perceptual Responses to Individual and Group-Based Body-Weight Resistance Exercise in Girls

2021 ◽  
pp. 1-10
Author(s):  
Jeanette M. Ricci ◽  
Katharine D. Currie ◽  
Todd A. Astorino ◽  
Karin A. Pfeiffer
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Oxygen Uptake ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peak Oxygen Uptake ◽  
Acute Responses ◽  
Maximal Aerobic Speed ◽  
The Mean

Girls’ acute responses to group-based high-intensity interval exercise (HIIE) are not well characterized. Purpose: To compare acute responses to treadmill-based HIIE (TM) and body-weight resistance exercise circuit (CIRC) and to CIRC performed in a small-group setting (group CIRC). Method: Nineteen girls (9.1 [1.1] y) completed exercise testing on a TM to determine peak oxygen uptake, peak heart rate (HRpeak), and maximal aerobic speed. The TM involved eight 30-second sprints at 100% maximal aerobic speed. The CIRC consisted of 8 exercises of maximal repetitions performed for 30 seconds. Each exercise bout was followed by 30 seconds of active recovery. The blood lactate concentration was assessed preexercise and postexercise. The ratings of perceived exertion, affective valence, and enjoyment were recorded at preexercise, Intervals 3 and 6, and postexercise. Results: The mean heart rate was higher during group CIRC (92% [7%] HRpeak) than CIRC (86% [7%] HRpeak) and TM (85% [4%] HRpeak) ( = .49). The mean oxygen uptake equaled 76% (11%) of the peak oxygen uptake for CIRC and did not differ from TM (d = 0.02). The CIRC elicited a greater postexercise blood lactate concentration versus TM (5.8 [1.7] vs 1.4 [0.4] mM, d = 3.61). The perceptual responses were similar among conditions (P > .05), and only the rating of perceived exertion increased during exercise ( = .78). Conclusion: Whether performed individually or in a small group, CIRC represents HIIE and may be a feasible alternative to running-based HIIE.

Effect of Paddling Cadence on Time to Exhaustion and Kinetics at the Intensity Associated With in Elite White-Water Kayakers

2002 ◽  
Vol 27 (6) ◽  
pp. 602-611 ◽  
Author(s):  
Jean Michel Leveque ◽  
Jeanick Brisswalter ◽  
Olivier Bernard ◽  
Claude Goubault
Keyword(s):  
Gas Exchange ◽  
Exercise Test ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Constant Load ◽  
Time To Exhaustion ◽  
Exponential Equation ◽  
Post Exercise ◽  
Load Tests ◽  
White Water

The influence of paddling cadence on the time to exhaustion (t.lim) and [Formula: see text] kinetics at the intensity associated with [Formula: see text] [Formula: see text] was examined in seven highly-trained white water kayakers. All subjects were engaged in national or international competitions. Subjects took part in three constant-load tests at [Formula: see text], each test performed at a different paddling cadence (50, 60 or 70 cycles ∙ min−1). The [Formula: see text] kinetics recorded during these constant-load tests at [Formula: see text] were fitted with a mono-exponential equation. A significant increase in t.lim (P <.05) was observed as the paddling cadence increased from 50 to 70 cycles·min−1. No effect was found either on values of [Formula: see text] post-exercise blood lactate concentration, or on the time at which [Formula: see text] was attained [Formula: see text]. Our results suggest that experienced kayakers may choose a high paddling cadence during physiological assessments at [Formula: see text] Further experiments are needed in order to identify the physiological significance of t.lim at [Formula: see text] Key words: performance, exercise test, pulmonary gas exchange, locomotory pattern, kayaking

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.

How to test maximal oxygen uptake: a study on timing and testing procedure of a supramaximal verification test

2011 ◽  
Vol 36 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Friederike Scharhag-Rosenberger ◽  
Anja Carlsohn ◽  
Michael Cassel ◽  
Frank Mayer ◽  
Jürgen Scharhag
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Testing Procedure ◽  
Peak Oxygen Uptake ◽  
Time To Exhaustion ◽  
Maximal Velocity ◽  
Testing Session ◽  
Incremental Test ◽  
Testing Procedures ◽  
Verification Test

Verification tests are becoming increasingly common for confirming maximal oxygen uptake (VO2 max) attainment. Yet, timing and testing procedures vary between working groups. The aims of this study were to investigate whether verification tests can be performed after an incremental test or should be performed on a separate day, and whether VO2 max can still be determined within the first testing session in subjects not satisfying the verification criterion. Forty subjects (age, 24 ± 4 years; VO2 max, 50 ± 7 mL·min–1·kg–1) performed a maximal incremental treadmill test and, 10 min afterwards, a verification test (VerifDay1) at 110% of maximal velocity (vmax). The verification criterion was a VerifDay1 peak oxygen uptake (VO2 peak) ≤5.5% higher than the incremental test value. Subjects not achieving the verification criterion performed another verification test at 115% vmax (VerifDay1′) 10 min later, trying to confirm VerifDay1 VO2 peak as VO2 max. All other subjects exclusively repeated VerifDay1 on a separate day (VerifDay2). Of the 40 subjects, 6 did not satisfy the verification criterion. In 4 of them, attainment of VO2 max was confirmed by VerifDay1′. VO2 peak was equivalent between VerifDay1 and VerifDay2 (3722 ± 991 mL·min–1 vs. 3752 ± 995 mL·min–1, p = 0.56), whereas time to exhaustion was significantly longer in VerifDay2 (2:06 ± 0:22 min:s vs. 2:42 ± 0:38 min:s, p < 0.001, n = 34). The verification test VO2 peak does not seem to be affected by a preceding maximal incremental test. Incremental and verification tests can therefore be performed within the same testing session. In individuals not achieving the verification criterion, VO2 max can be determined by means of a subsequent, more intense verification test in most but not all cases.

scholarly journals The Effects of Sub‐Technique and Pole Length on Classic Roller Skiing Performance and Physiological Responses at Steep Uphill Inclination

2021 ◽  
Vol 77 (1) ◽  
pp. 97-105
Author(s):  
Per-Øyvind Torvik ◽  
Johan Persson ◽  
Roland van den Tillaar
Keyword(s):  
Heart Rate ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peak Oxygen Uptake ◽  
Rating Of Perceived Exertion ◽  
Time To Exhaustion ◽  
Double Poling ◽  
Cross Country ◽  
Improved Performance

Abstract The aims of this study were to compare performance with physiological and perceptual responses on steep uphill inclines between double poling and diagonal stride and to investigate the effects of pole length when double poling. Eight male, competitive cross-country skiers (22 ± 1.1 yrs, peak oxygen uptake (VO2peak) in the diagonal stride: 69.4 ± 5.5 ml·kg-1·min-1) performed four identical tests, one in the diagonal stride, and three in double poling with different pole lengths (self-selected, self-selected -5 cm and self-selected +10 cm). Each test was conducted at a fixed speed (10 km/h), with inclination rising by 1%, starting with 7%, each until voluntary exhaustion. VO2peak, the heart rate, blood lactate concentration, and the rating of perceived exertion were determined for each pole length in each test. The peak heart rate (p < 0.001) and VO2peak (p = 0.004) were significantly higher in the diagonal stride test compared with double poling with all pole lengths. Time to exhaustion (TTE) differed significantly between all four conditions (all p < 0.001), with the following order from the shortest to the longest TTE: short poles, normal poles and long poles in double poling, and the diagonal stride. Consequently, a significantly higher slope inclination was reached (p < 0.001) using the diagonal stride (17%) than for double poling with long poles (14%), normal (13%) and short (13%) poles. The current study showed better performance and higher VO2peak in the diagonal stride compared to double poling in steep uphill terrain, demonstrating the superiority of the diagonal stride for uphill skiing. However, in double poling, skiers achieved improved performance due to greater skiing efficiency when using long poles, compared to normal and short poles.

Is maximal lactate steady state during intermittent cycling different for active compared with passive recovery?

2012 ◽  
Vol 37 (6) ◽  
pp. 1147-1152 ◽  
Author(s):  
Camila Coelho Greco ◽  
Luis Fabiano Barbosa ◽  
Renato Aparecido Corrêa Caritá ◽  
Benedito Sérgio Denadai
Keyword(s):  
Steady State ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Work Rate ◽  
Active Recovery ◽  
Maximal Lactate Steady State ◽  
Passive Recovery

The purpose of this study was to analyze the effect of recovery type (passive vs. active) during prolonged intermittent exercises on the blood lactate concentration (MLSS) and work rate (MLSSwint) at maximal lactate steady state. Nineteen male trained cyclists were divided into 2 groups for the determination of MLSSwint using passive (maximal oxygen uptake = 58.1 ± 3.5 mL·kg–1·min–1; N = 9) or active recovery (maximal oxygen uptake = 60.3 ± 9.0 mL·kg–1·min–1; N = 10). They performed the following tests, on different days, on a cycle ergometer: (i) incremental test until exhaustion to determine maximal oxygen uptake; (ii) 2 to 3 continuous submaximal constant work rate tests (CWRT) for the determination of the work rate at continuous maximal lactate steady state (MLSSwcont); and (iii) 2 to 3 intermittent submaximal CWRT (7 × 4 min and 1 × 2 min, with 2-min recovery) with either passive or active recovery for the determination of MLSSwint. MLSSwint was significantly higher when compared with MLSSwcont for both passive recovery (294.7 ± 32.2 vs. 258.7 ± 24.5 W, respectively) and active recovery groups (300.5 ± 23.9 vs. 273.2 ± 21.5 W, respectively). The percentage increments in MLSSwint were similar between conditions (passive = 13% vs. active = 10%). MLSS (mmol·L–1) was not significantly different between MLSSwcont and MLSSwint for either passive recovery (4.50 ± 2.10 vs. 5.61 ± 1.78, respectively) and active recovery (4.06 ± 1.49 vs. 4.91 ± 1.91, respectively) conditions. We can conclude that using a work/rest ratio of 2:1, MLSSwint was ∼10%–13% higher than MLSSwcont, irrespective of the recovery type performed during prolonged intermittent exercises.

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