Intramuscular determinants of the ability to recover work capacity above critical power

2014 ◽  
Vol 115 (4) ◽  
pp. 703-713 ◽  
Author(s):  
Philip Friere Skiba ◽  
Jonathan Fulford ◽  
David C. Clarke ◽  
Anni Vanhatalo ◽  
Andrew M. Jones
Keyword(s):  
Critical Power ◽  
Work Capacity

Validating an Adjustment to the Intermittent Critical Power Model for Elite Cyclists—Modeling W′ Balance During World Cup Team Pursuit Performances

2021 ◽  
pp. 1-6
Author(s):  
Jason C. Bartram ◽  
Dominic Thewlis ◽  
David T. Martin ◽  
Kevin I. Norton
Keyword(s):  
Confidence Limit ◽  
Critical Power ◽  
Work Capacity ◽  
Error Threshold ◽  
Power Model ◽  
World Cup ◽  
Effective Use ◽  
Exciting Development ◽  
Elite Cyclists ◽  
Intermittent Work

Purpose: Modeling intermittent work capacity is an exciting development to the critical power model with many possible applications across elite sport. With the Skiba 2 model validated using subelite participants, an adjustment to the model’s recovery rate has been proposed for use in elite cyclists (Bartram adjustment). The team pursuit provides an intermittent supramaximal event with which to validate the modeling of W′ in this population. Methods: Team pursuit data of 6 elite cyclists competing for Australia at a Track World Cup were solved for end W′ values using both the Skiba 2 model and the Bartram adjustment. Each model’s success was evaluated by its ability to approximate end W′ values of 0 kJ, as well as a count of races modeled to within a predetermined error threshold of ±1.840 kJ. Results: On average, using the Skiba 2 model found end W′ values different from zero (P = .007; mean ± 95% confidence limit, –2.7 ± 2.0 kJ), with 3 out of 8 cases ending within the predetermined error threshold. Using the Bartram adjustment on average resulted in end W′ values that were not different from zero (P = .626; mean ± 95% confidence limit, 0.5 ± 2.5 kJ), with 4 out of 8 cases falling within the predetermined error threshold. Conclusions: On average, the Bartram adjustment was an improvement to modeling intermittent work capacity in elite cyclists, with the Skiba 2 model underestimating the rate of W′ recovery. In the specific context of modeling team pursuit races, all models were too variable for effective use; hence, individual recovery rates should be explored beyond population-specific rates.

scholarly journals The effect of resting blood flow occlusion on exercise tolerance and W′

2015 ◽  
Vol 309 (6) ◽  
pp. R684-R691 ◽  
Author(s):  
Ryan M. Broxterman ◽  
Jesse C. Craig ◽  
Carl J. Ade ◽  
Samuel L. Wilcox ◽  
Thomas J. Barstow
Keyword(s):  
Blood Flow ◽  
Critical Power ◽  
Work Capacity ◽  
Mechanical Work ◽  
Handgrip Exercise ◽  
Constant Amount ◽  
Severe Intensity ◽  
Anaerobic Work ◽  
Blood Flow Occlusion ◽  
Flow Occlusion

It has previously been postulated that the anaerobic work capacity (W′) may be utilized during resting blood flow occlusion in the absence of mechanical work. We tested the hypothesis that W′ would not be utilized during an initial range of time following the onset of resting blood flow occlusion, after which W′ would be utilized progressively more. Seven men completed blood flow occlusion constant power severe intensity handgrip exercise to task failure following 0, 300, 600, 900, and 1,200 s of resting blood flow occlusion. The work performed above critical power (CP) was not significantly different between the 0-, 300-, and 600-s conditions and was not significantly different from the total W′ available. Significantly less work was performed above CP during the 1,200-s condition than the 900-s condition ( P < 0.05), while both conditions were significantly less than the 0-, 300-, and 600-s conditions ( P < 0.05). The work performed above CP during these conditions was significantly less than the total W′ available ( P < 0.05). The utilization of W′ during resting blood flow occlusion did not begin until 751 ± 118 s, after which time W′ was progressively utilized. The current findings demonstrate that W′ is not utilized during the initial ∼751 s of resting blood flow occlusion, but is progressively utilized thereafter, despite no mechanical work being performed. Thus, the utilization of W′ is not exclusive to exercise, and a constant amount of work that can be performed above CP is not the determining mechanism of W′.

Contributions of Lower-Body Strength Parameters to Critical Power and Anaerobic Work Capacity

2021 ◽  
Vol 35 (1) ◽  
pp. 97-101 ◽  
Author(s):  
M. Travis Byrd ◽  
Brian J. Wallace ◽  
Jody L. Clasey ◽  
Haley C. Bergstrom
Keyword(s):  
Critical Power ◽  
Work Capacity ◽  
Lower Body ◽  
Strength Parameters ◽  
Anaerobic Work Capacity ◽  
Body Strength ◽  
Anaerobic Work ◽  
Lower Body Strength

Accuracy of W′ Recovery Kinetics in High Performance Cyclists—Modeling Intermittent Work Capacity

2018 ◽  
Vol 13 (6) ◽  
pp. 724-728 ◽  
Author(s):  
Jason C. Bartram ◽  
Dominic Thewlis ◽  
David T. Martin ◽  
Kevin I. Norton
Keyword(s):  
Recovery Rate ◽  
High Performance ◽  
Critical Power ◽  
Intermittent Exercise ◽  
Work Capacity ◽  
Confidence Limits ◽  
Volitional Exhaustion ◽  
The Difference ◽  
Effective Use ◽  
Elite Cyclists

Purpose: With knowledge of an individual’s critical power and W′, the SKIBA 2 model provides a framework with which to track W′ balance during intermittent high-intensity work bouts. There are fears that the time constant controlling the recovery rate of W′ (τW′) may require refinement to enable effective use in an elite population. Methods: Four elite endurance cyclists completed an array of intermittent exercise protocols to volitional exhaustion. Each protocol lasted approximately 3.5–6 min and featured a range of recovery intensities, set in relation to the athlete’s critical power (DCP). Using the framework of the SKIBA 2 model, the τW′ values were modified for each protocol to achieve an accurate W′ at volitional exhaustion. Modified τW′ values were compared with equivalent SKIBA 2 τW′ values to assess the difference in recovery rates for this population. Plotting modified τW′ values against DCP showed the adjusted relationship between work rate and recovery rate. Results: Comparing modified τW′ values against the SKIBA 2 τW′ values showed a negative bias of 112 (46) s (mean ± 95% confidence limits), suggesting that athletes recovered W′ faster than predicted by SKIBA 2 (P = .0001). The modified τW′–DCP relationship was best described by a power function: τW′ = 2287.2 × DCP–0.688 (R2 = .433). Conclusions: The current SKIBA 2 model is not appropriate for use in elite cyclists, as it underpredicts the recovery rate of W′. The modified τW′ equation presented will require validation but appears more appropriate for high-performance athletes. Individual τW′ relationships may be necessary to maximize the model’s validity.

The Impact of Elevated Body Core Temperature on Critical Power as Determined by a 3-min All-Out Test

2021 ◽  
Author(s):  
Brendan W. Kaiser ◽  
Ka'eo K. Kruse ◽  
Brandon M. Gibson ◽  
Kelsey J. Santisteban ◽  
Emily A. Larson ◽  
...  
Keyword(s):  
Core Temperature ◽  
Critical Power ◽  
Work Capacity ◽  
Cycle Ergometer ◽  
Body Core Temperature ◽  
Test Power ◽  
Body Core ◽  
Severe Exercise ◽  
Duration Relationship ◽  
The Impact

Critical power (CP) delineates the heavy and severe exercise intensity domains, and sustained work rates above CP result in an inexorable progression of oxygen uptake to a maximal value and, subsequently, the limit of exercise tolerance. The finite work capacity above CP, W′, is defined by the curvature constant of the power-duration relationship. Heavy or severe exercise in a hot environment generates additional challenges related to the rise in body core temperature (Tc) that may impact CP and W′. The purpose of this study was to determine the effect of elevated Tc on CP and W′. CP and W′ were estimated by end-test power (EP; mean of final 30s) and work above end-test power (WEP), respectively, from 3-min "all-out" tests performed on a cycle ergometer. Volunteers (n = 8, 4 female) performed the 3-min tests during a familiarization visit and two experimental visits (Thermoneutral vs Hot, randomized crossover design). Before experimental 3-min tests, subjects were immersed in water (Thermoneutral: 36°C for 30 min; Hot: 40.5°C until Tc was ≥ 38.5°C). Mean Tc was significantly greater in Hot compared to Thermoneutral (38.5±0.0°C vs. 37.4±0.2°C; mean±SD, P<0.01). All 3-min tests were performed in an environmental chamber (Thermoneutral: 18°C, 45% RH; Hot: 38°C, 40% RH). EP was similar between Thermoneutral (239 ± 57W) and Hot (234 ± 66W; P = 0.55). WEP was similar between Thermoneutral (10.9 ± 3.0 kJ) and Hot (9.3 ± 3.6; P = 0.19). These results suggest that elevated Tc has no significant impact on EP or WEP.

Assessment of Child-Specific Aerobic Fitness and Anaerobic Capacity by the Use of the Power-Time Relationships Constants

2010 ◽  
Vol 22 (3) ◽  
pp. 454-466 ◽  
Author(s):  
Erwan Leclair ◽  
Benoit Borel ◽  
Delphine Thevenet ◽  
Georges Baquet ◽  
Patrick Mucci ◽  
...  
Keyword(s):  
Critical Power ◽  
Aerobic Power ◽  
Anaerobic Capacity ◽  
Work Capacity ◽  
Constant Load ◽  
Evaluation Methods ◽  
Oxygen Deficit ◽  
Anaerobic Work Capacity ◽  
Accumulated Oxygen Deficit ◽  
Anaerobic Work

This study first aimed to compare critical power (CP) and anaerobic work capacity (AWC), to laboratory standard evaluation methods such as maximal oxygen uptake (V̇O2max) and maximal accumulated oxygen deficit (MAOD). Secondly, this study compared child and adult CP and AWC values. Subjects performed a maximal graded test to determine V̇O2max and maximal aerobic power (MAP); and four constant load exercises. In children, CP (W.kg−1) was related to V̇O2max (ml.kg−1.min−1; r = .68; p = .004). AWC (J.kg−1) in children was related to MAOD (r = .58; p = .018). Children presented lower AWC (J.kg−1; p = .001) than adults, but similar CP (%MAP) values. CP (%MAP and W.kg−1) and AWC (J.kg−1) were significantly related to laboratory standard evaluation methods but low correlation indicated that they cannot be used interchangeably. CP (%MAP) was similar in children and adults, but AWC (J.kg−1) was significantly lower in children. These conclusions support existing knowledge related to child-adults characteristics.

Estimation of the Parameters of the Relationship Between Power and Time to Exhaustion From a Single Ramp Test

2005 ◽  
Vol 30 (6) ◽  
pp. 735-742 ◽  
Author(s):  
Jean-Pierre Pouilly ◽  
Michel Chatagnon ◽  
Vincent Thomas ◽  
Thierry Busso
Keyword(s):  
Critical Power ◽  
Ventilatory Threshold ◽  
Work Capacity ◽  
Cycle Ergometry ◽  
Time To Exhaustion ◽  
Total Work ◽  
Anaerobic Work Capacity ◽  
Ramp Test ◽  
Anaerobic Work ◽  
The Relationship

This study aimed to estimate the power/time relationship from a single ramp test (RT) assuming critical power (Pc) from ventilatory threshold (VT) and energy reserve (W') from total work during RT. These estimates from single RT were compared to those from a series of 4 constant power exercises (CPT) and from a series of 4 RT. Only W' from CPT was higher than from the series of RT and from single RT using VT (p <  0.05). Key words: exercise testing, critical power, anaerobic work capacity, cycle ergometry

scholarly journals Prior Upper Body Exercise Reduces Cycling Work Capacity but Not Critical Power

2014 ◽  
Vol 46 (4) ◽  
pp. 802-808 ◽  
Author(s):  
Michael A. Johnson ◽  
Dean E. Mills ◽  
Peter I. Brown ◽  
Graham R. Sharpe
Keyword(s):  
Critical Power ◽  
Work Capacity ◽  
Upper Body ◽  
Upper Body Exercise
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