scholarly journals The ramp and all-out exercise test to determine critical power: validity and robustness to manipulations in body position

2021 ◽  
Author(s):  
Richie P. Goulding ◽  
Denise M. Roche ◽  
Simon Marwood
Keyword(s):  
Exercise Test ◽  
Critical Power ◽  
Body Position ◽  
Cycle Ergometer ◽  
Limits Of Agreement ◽  
Cycle Exercise ◽  
Gold Standard Method ◽  
Highly Correlated ◽  
Single Laboratory

Abstract Purpose The purpose of the present study was to determine whether a contiguous ramp and all-out exercise test could accurately determine critical power (CP) in a single laboratory visit during both upright and supine cycle exercise. Methods Healthy males completed maximal ramp-incremental exercise on a cycle ergometer in the upright (n = 15) and supine positions (n = 8), with task failure immediately followed by a 3-min all-out phase for determination of end-test power (EP). On separate days, participants undertook four constant-power tests in either the upright or supine positions with the limit of tolerance ranging from ~ 2 to 15 min for determination of CP. Results During upright exercise, EP was highly correlated with (R2 = 0.93, P < 0.001) and not different from CP (CP = 221 ± 40 W vs. EP = 226 ± 46 W, P = 0.085, 95% limits of agreement − 30, 19 W). During supine exercise, EP was also highly correlated with (R2 = 0.94, P < 0.001) and not different from CP (CP = 140 ± 42 W vs. EP = 136 ± 40 W, P = 0.293, 95% limits of agreement − 16, 24 W). Conclusion The present data suggest that EP derived from a contiguous ramp all-out exercise test is not different from the gold-standard method of CP determination during both upright and supine cycle exercise when assessed at the group level. However, the wide limits of agreement observed within the present study suggest that EP and CP should not be used interchangeably.

Self-pacing increases critical power and improves performance during severe-intensity exercise

2015 ◽  
Vol 40 (7) ◽  
pp. 662-670 ◽  
Author(s):  
Matthew I. Black ◽  
Andrew M. Jones ◽  
Stephen J. Bailey ◽  
Anni Vanhatalo
Keyword(s):  
Critical Power ◽  
Cycle Ergometer ◽  
Exercise Tests ◽  
Mean Response Time ◽  
Pacing Strategy ◽  
Severe Intensity ◽  
Trial Protocols ◽  
Constant Work Rate ◽  
Duration Relationship

The parameters of the power-duration relationship for severe-intensity exercise (i.e., the critical power (CP) and the curvature constant (W′)) are related to the kinetics of pulmonary O2 uptake, which may be altered by pacing strategy. We tested the hypothesis that the CP would be higher when derived from a series of self-paced time-trials (TT) than when derived from the conventional series of constant work-rate (CWR) exercise tests. Ten male subjects (age, 21.5 ± 1.9 years; mass, 75.2 ± 11.5 kg) completed 3–4 CWR and 3–4 TT prediction trial protocols on a cycle ergometer for the determination of the CP and W′. The CP derived from the TT protocol (265 ± 44 W) was greater (P < 0.05) than the CP derived from the CWR protocol (250 ± 47 W), while the W′ was not different between protocols (TT: 18.1 ± 5.7 kJ, CWR: 20.6 ± 7.4 kJ, P > 0.05). The mean response time of pulmonary O2 uptake was shorter during the TTs than the CWR trials (TT: 34 ± 16, CWR: 39 ± 19 s, P < 0.05). The CP was correlated with the total O2 consumed in the first 60 s across both protocols (r = 0.88, P < 0.05, n = 20). These results suggest that in comparison with the conventional CWR exercise protocol, a self-selected pacing strategy enhances CP and improves severe-intensity exercise performance. The greater CP during TT compared with CWR exercise has important implications for performance prediction, suggesting that TT completion times may be overestimated by CP and W′ parameters derived from CWR protocols.

Dependence of the Nature of the Pedaling Activity on Maximal Aerobic Power in Cycling

2017 ◽  
Vol 12 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Anthony Bouillod ◽  
Julien Pinot ◽  
Flavien Soenen ◽  
Theo Ouvrard ◽  
Frederic Grappe
Keyword(s):  
Exercise Test ◽  
Environmental Conditions ◽  
Power Output ◽  
Aerobic Power ◽  
Cycle Ergometer ◽  
Maximal Aerobic Power ◽  
Limits Of Agreement ◽  
Incremental Test ◽  
Incremental Exercise Test ◽  
Adaptation To Training

Purpose:To analyze the effect of the pedaling activity in different 4-min time trials (TT4s) (laboratory and field conditions) and compare TT4 and maximal aerobic power (MAP) determined from the classical incremental exercise test in laboratory. It was hypothesized that the exercises performed on the field would determine higher physical (power output [PO]) and mental involvements due to different environmental conditions.Methods:Sixteen male cyclists underwent an incremental test to exhaustion and 3 TT4s under different conditions: cycle ergometer (CE), level ground (LG), and uphill (UP).Results:Correlation was observed for PO with a trivial effect size and narrow limits of agreement between MAP and CE TT4 (r = .96, P < .001). The comparison between the CE, LG, and UP tests indicates that PO was significantly higher in UP than in CE (+8.0%, P < .001) and LG (+11.0%, P < .001).Conclusions:The results suggest that PO depends on the nature of the pedaling activity. Moreover, PO under CE TT4 is a relevant predictor of MAP. It seems important to measure MAP by taking into account the cycling conditions, considering that coaches and scientists use this parameter to assess the aerobic potential of athletes and determine the exercise intensities useful for monitoring adaptation to training.

Intensity-dependent tolerance to exercise after attaining V̇o2 max in humans

2003 ◽  
Vol 95 (2) ◽  
pp. 483-490 ◽  
Author(s):  
Edward M. Coats ◽  
Harry B. Rossiter ◽  
James R. Day ◽  
Akira Miura ◽  
Yoshiyuki Fukuba ◽  
...  
Keyword(s):  
High Intensity ◽  
Critical Power ◽  
Load Cycle ◽  
Constant Load ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Hyperbolic Function ◽  
Exercise Tests ◽  
Ergometer Exercise

The tolerable duration of high-intensity, constant-load cycle ergometry is a hyperbolic function of power, with an asymptote termed critical power (CP) and a curvature constant (W′) with units of work. It has been suggested that continued exercise after exhaustion may only be performed below CP, where predominantly aerobic energy transfer can occur and W′ can be partially replenished. To test this hypothesis, six volunteers each performed cycle-ergometer exercise with breath-by-breath determination of ventilatory and pulmonary gas exchange variables. Initially, four exercise tests to exhaustion were made: 1) a ramp-incremental and 2) three high-intensity constant-load bouts at different work rates, to estimate lactate (θ̂L) and CP thresholds, W′, and maximum oxygen uptake (V̇o2 max). Subsequently, subjects cycled to the limit of tolerance (for ∼360 s) on three occasions, each followed by a work rate reduction to 1) 110% CP, 2) 90% CP, and 3) 80% θ̂L for a 20-min target. W′ averaged 20.9 ± 2.35 kJ or 246 ± 30 J/kg. After initial fatigue, 110% CP was tolerated for only 30 ± 12 s. Each subject completed 20 min at 80% θ̂L, but only two sustained 20 min at 90% CP; the remaining four subjects fatigued at 577 ± 306 s, with oxygen consumption at 89 ± 8% V̇o2 max. The results support the suggestion that replenishing W′ after fatigue necessitates a sub-CP work rate. The variation in subjects' responses during 90% CP was unexpected but consistent with mechanisms such as reduced CP consequent to prior high-intensity exercise, variation in lactate handling, and/or regional depletion of energy substrates, e.g., muscle glycogen.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

scholarly journals Determining the Optimal Workrate for Cycle Ergometer Verification Phase Testing in Males with Obesity

Sports ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 30
Author(s):  
Jenny M. Mahoney ◽  
Brett R. Baughman ◽  
Ailish C. Sheard ◽  
Brandon J. Sawyer
Keyword(s):  
Body Mass Index ◽  
Young Adult ◽  
Body Mass ◽  
Critical Power ◽  
Cycle Ergometer ◽  
Adult Males ◽  
Ramp Test ◽  
Young Adult Males ◽  
Main Effect ◽  
Vo2max Test

The aim of the present study was to assess the validity of verification phase (VP) testing and a 3 min all-out test to determine critical power (CP) in males with obesity. Nine young adult males with a body mass index (BMI) ≥ 30 kg·m−2 completed a cycle ergometer ramp-style VO2max test, four randomized VP tests at 80, 90, 100, and 105% of maximum wattage attained during the ramp test, and a 3 min all-out test. There was a significant main effect for VO2max across all five tests (p = 0.049). Individually, 8 of 9 participants attained a higher VO2max (L/min) during a VP test compared to the ramp test. A trend (p = 0.06) was observed for VO2max during the 90% VP test (3.61 ± 0.54 L/min) when compared to the ramp test (3.37 ± 0.39 L/min). A significantly higher VO2max (p = 0.016) was found in the VP tests that occurred below 130% of CP wattage (N = 15, VO2max = 3.76 ± 0.52 L/min) compared to those that were above (N = 21, VO2max = 3.36 ± 0.41 L/min). Our findings suggest submaximal VP tests at 90% may elicit the highest VO2max in males with obesity and there may be merit in using % of CP wattage to determine optimal VP intensity.

Effect of fat emulsion infusion and fat feeding on muscle glycogen utilization during cycle exercise

1993 ◽  
Vol 75 (4) ◽  
pp. 1513-1518 ◽  
Author(s):  
M. D. Vukovich ◽  
D. L. Costill ◽  
M. S. Hickey ◽  
S. W. Trappe ◽  
K. J. Cole ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Muscle Glycogen ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Serum Triglyceride ◽  
Cycle Ergometer ◽  
Fat Emulsion ◽  
Cycle Exercise ◽  
Glycogen Utilization ◽  
Fat Feeding

Elevated plasma fatty acids have been shown to spare muscle glycogen during exercise. However, on the basis of recent findings, the saturation of fatty acids may influence this response. The purpose of this study was to determine whether saturated or unsaturated fatty acids affected muscle glycogenolysis to varying degrees during cycle exercise. Five healthy men completed three 60-min cycle ergometer trials (EX) at approximately 70% maximal O2 uptake (VO2max). Triglyceride levels were elevated by a fat feeding (FF) composed of 90% saturated fatty acids (heavy whipping cream, 90 g) or by the infusion of Intralipid (IL; Clintec Nutrition; 45 ml/h of 20% IL, 9.0 g), which was 85% unsaturated. A control trial (CON) consisted of a light breakfast (43 g carbohydrate and 1 g fat). Heparin (2,000 U) was administered 15 min before EX in FF and IL trials, resulting in one- and threefold increases in free fatty acid (FFA) levels in IL and FF, respectively. Pre-EX muscle glycogen did not differ. The utilization of muscle glycogen during 60 min of EX was less (P < 0.05) during the FF (60.0 +/- 5.2 mmol/kg wet wt) and IL (58.6 +/- 6.2 mmol/kg wet wt) compared with CON (81.8 +/- 7.5 mmol/kg wet wt). There was no difference between FF and IL in the amount of glycogen utilized. Serum triglyceride levels were greater (P < 0.05) at preheparin in FF (1.58 +/- 0.37 mmol/l) and IL (0.98 +/- 0.13 mmol/l) compared with CON (0.47 +/- 0.14 mmol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle Na+-K+-ATPase response during 16 h of heavy intermittent cycle exercise

2007 ◽  
Vol 293 (2) ◽  
pp. E523-E530 ◽  
Author(s):  
H. J. Green ◽  
T. A. Duhamel ◽  
G. P. Holloway ◽  
J. W. Moule ◽  
J. Ouyang ◽  
...  
Keyword(s):  
Aerobic Power ◽  
Intermittent Exercise ◽  
Binding Capacity ◽  
Vastus Lateralis ◽  
Intrinsic Activity ◽  
Cycle Exercise ◽  
Maximum Binding Capacity ◽  
Phosphatase Assay ◽  
Quantitative Immunoblotting

This study investigated the effects of a 16-h protocol of heavy intermittent exercise on the intrinsic activity and protein and isoform content of skeletal muscle Na+-K+-ATPase. The protocol consisted of 6 min of exercise performed once per hour at ∼91% peak aerobic power (V̇o2 peak) with tissue sampling from vastus lateralis before (B) and immediately after repetitions 1 (R1), 2 (R2), 9 (R9), and 16 (R16). Eleven untrained volunteers with a V̇o2 peak of 44.3 ± 2.3 ml·kg−1·min−1 participated in the study. Maximal Na+-K+-ATPase activity ( Vmax, in nmol·mg protein−1·h−1) as measured by the 3- O-methylfluorescein K+-stimulated phosphatase assay was reduced ( P < 0.05) by ∼15% with exercise regardless of the number of repetitions performed. In addition, Vmax at R9 and R16 was lower ( P < 0.05) than at R1 and R2. Vanadate-facilitated [3H]ouabain determination of Na+-K+-ATPase content (maximum binding capacity, pmol/g wet wt), although unaltered by exercise, increased ( P < 0.05) 8.3% by R9 with no further increase observed at R16. Assessment of relative changes in isoform abundance measured at B as determined by quantitative immunoblotting showed a 26% increase ( P < 0.05) in the α2-isoform by R2 and a 29% increase in α3 by R9. At R16, β3 was lower ( P < 0.05) than at R2 and R9. No changes were observed in α1, β1, or β2. It is concluded that repeated sessions of heavy exercise, although resulting in increases in the α2- and α3-isoforms and decreases in β3-isoform, also result in depression in maximal catalytic activity.

Determination of Phosphorus and Potassium in Commercial Inorganic Fertilizers by Inductively Coupled Plasma-Optical Emission Spectrometry: Single-Laboratory Validation

2014 ◽  
Vol 97 (3) ◽  
pp. 687-699 ◽  
Author(s):  
James M Bartos ◽  
Barton L Boggs ◽  
J Harold Falls ◽  
Sanford A Siegel
Keyword(s):  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Optical Emission Spectrometry ◽  
Ammonium Citrate ◽  
Emission Spectrometry ◽  
Icp Oes ◽  
Inductively Coupled ◽  
Plasma Optical Emission Spectrometry ◽  
Single Laboratory

Abstract A two-part single-laboratory validation study was conducted for determination of the P and K content in commercial fertilizer materials by inductively coupled plasma-optical emission spectrometry (ICP- OES). While several methods exist for determination of P and K in fertilizer products, the main focus of this study was on ICP-OES determination, which offers several unique advantages. Fertilizer samples with consensus P and K values from the Magruder and Association of Fertilizer and Phosphate Chemists (AFPC) check sample programs were selected for this study. Validation materials ranging from 4.4 to 52.4% P2O5 (1.7 to 22.7% P) and 3 to 62% K2O (2.5 to 51.5% K) were utilized. Because all P and K compounds contained in fertilizer materials are not "available" for plants to use, this study was conducted in two parts. Part A focused on ammonium citrate–disodium EDTA as the extraction solvent, as it estimates the pool of fertilizer P and K that is considered available to plants. Part B focused on hydrochloric acid as the digestion solvent, as it estimates the total P and K content of the fertilizer product. Selectivity studies indicated that this method can have a high bias for fertilizer products containing sources of phosphite or organic P compared to gravimetric or colorimetric methods that measure just orthophosphate. Provided the analytical challenges outlined in this study are addressed, this method offers the potential for a quick, accurate, and safe alternative for determining the P and K content of commercial inorganic fertilizer materials.

Sign in / Sign up

Export Citation Format

Share Document