Factors in maximal power production and in exercise endurance relative to maximal power

1990 ◽  
Vol 60 (3) ◽  
pp. 222-227 ◽  
Author(s):  
J. F. Patton ◽  
W. J. Kraemer ◽  
H. G. Knuttgen ◽  
E. A. Harman
Keyword(s):  
Power Production ◽  
Maximal Power ◽  
Exercise Endurance

Exercise endurance time as a function of percent maximal power production

1987 ◽  
Vol 19 (5) ◽  
pp. 480???485 ◽  
Author(s):  
EVERETT A. HARMAN ◽  
HOWARD G. KNUTTGEN ◽  
PETER N. FRYKMAN ◽  
JOHN F. PATTON
Keyword(s):  
Power Production ◽  
Maximal Power ◽  
Endurance Time ◽  
Exercise Endurance

scholarly journals Topology optimized thermoelectric generator: a parametric study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
John Mativo ◽  
Kevin Hallinan ◽  
Uduak George ◽  
Greg Reich ◽  
Robin Steininger
Keyword(s):  
Topology Optimization ◽  
Thermoelectric Generator ◽  
Volume Fraction ◽  
Power Conversion ◽  
Power Production ◽  
Power Reduction ◽  
Void Volume Fraction ◽  
Thermoelectric Generators ◽  
Maximal Power ◽  
Design Yield

Abstract Typical thermoelectric generator legs are brittle which limits their application in vibratory and shear environments. Research is conducted to develop compliant thermoelectric generators (TEGs) capable of converting thermal loads to power, while also supporting shear and vibratory loads. Mathematical structural, thermal, and power conversion models are developed. Topology optimization is employed to tailor the TEG design yield maximal power production while sustaining the applied shear and vibratory loads. As a specific example, results are presented for optimized TEG legs with a void volume fraction of 0.2 that achieve compliance shear displacement of 0.0636 (from a range of 0.0504 to 0.6079). In order to achieve the necessary compliance to support the load, the power reduction is reduced by 20% relative to similarly sized void free TEG legs.

Age- and Activity-Related Differences in the Mechanisms Underlying Maximal Power Production in Young and Older Adults

2014 ◽  
Vol 30 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Thomas Korff ◽  
Ann H. Newstead ◽  
Renate van Zandwijk ◽  
Jody L. Jensen
Keyword(s):  
Older Adults ◽  
Knee Flexion ◽  
Power Production ◽  
Activity Level ◽  
Maximum Power ◽  
Maximal Power ◽  
Joint Power ◽  
Age Related ◽  
Peak Knee ◽  
Active Adults

The purpose of this study was to examine the interactions between aging, activity levels and maximal power production during cycling. Participants were divided into younger adults (YA), older active adults (OA,) and older sedentary adults (OS). Absolute maximum power was significantly greater in YA compared with OS and OA; no differences were found between OA and OS. The age-related difference in maximum power was accompanied by greater absolute peak knee extension and knee flexion powers. Relative joint power contributions revealed both age- and activity-related differences. YA produced less relative hip extension power than older adults, regardless of activity level. The OS participants produced less relative knee flexion power than active adults, regardless of age. The results show the age-related decline in muscular power production is joint specific and that activity level can be a modifier of intersegmental coordination, which has implications for designing interventions for the aging population.

Optimal shortening velocities for in situ power production of rat soleus and plantaris muscles

1997 ◽  
Vol 273 (3) ◽  
pp. C1057-C1063 ◽  
Author(s):  
S. J. Swoap ◽  
V. J. Caiozzo ◽  
K. M. Baldwin
Keyword(s):  
Power Production ◽  
Sprague Dawley ◽  
Maximal Power ◽  
Cycle Frequency ◽  
Optimal Velocity ◽  
Velocity Of Shortening ◽  
Loop Technique ◽  
Length Changes ◽  
Work Loop

Force-velocity (FV) relationships have been used previously to calculate maximal power production and to identify an optimal velocity of shortening (V(opt)-fv) to produce such power in skeletal muscle. The cyclical nature of muscle position during locomotion for muscles such as the soleus and plantaris is such that either constant force or velocity is rarely attained. In the present study, the work loop technique, a technique developed to measure maximal attainable power output from muscles undergoing cyclic length changes, was undertaken to determine whether simulating in vivo function alters the power-velocity relationship of the soleus and plantaris and, in particular, the velocity of shortening that produces maximal power (V(opt)-wl). FV relationships were determined for both soleus (n = 4) and plantaris (n = 4) muscles in situ from adult female Sprague-Dawley rats by measuring shortening velocities during afterloaded isotonic contractions. The velocity that produced maximal power using FV relationships, V(opt)-fv, was 54.6 +/- 0.7 mm/s for the plantaris vs. 20.2 +/- 1.2 mm/s for the soleus. Then, the work loop technique was employed to measure net power from these same muscles at multiple cycling frequencies (1.5 to 4.0 Hz for the soleus; 4.0 to 8.0 Hz for the plantaris). Multiple power-velocity curves were generated (one at each cycle frequency) by varying the strain (1-8 mm). Thus, at each cycle frequency, V(opt)-wl could be identified. For both the plantaris and soleus, V(opt)-wl at each cycle frequency was not different from their respective V(opt)-fv value. Thus both fast and slow skeletal muscles have inherent optimal shortening velocities, identifiable with FV relationships, that dictate their respective maximal attainable mechanical power production using the work loop technique.

scholarly journals Great power comes at a high (locomotor) cost: the role of muscle fascicle length in the power versus economy performance trade-off

2021 ◽  
Author(s):  
Amanda N. Cooper ◽  
William J. McDermott ◽  
James C. Martin ◽  
Shea O. Dulaney ◽  
David R. Carrier
Keyword(s):  
Muscle Fiber ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Power Production ◽  
Muscle Fiber Type ◽  
Maximal Power ◽  
Fascicle Length ◽  
Cost Of Transport ◽  
Trade Off ◽  
Muscle Fascicle

Muscle design constraints preclude simultaneous specialization of the vertebrate locomotor system for explosive and economical force generation. The resulting performance trade-off between power and economy has been attributed primarily to individual differences in muscle fiber type composition. While certainly crucial for performance specialization, fiber type likely interacts with muscle architectural parameters, such as fascicle length, to produce this trade-off. Longer fascicles composed of more serial sarcomeres can achieve faster shortening velocities, allowing for greater power production. Long fascicles likely reduce economy, however, because more energy-consuming contractile units are activated for a given force production. We hypothesized that longer fascicles are associated with both increased power production and locomotor cost. In a set of 11 power- and 13 endurance-trained recreational athletes, we measured 1) muscle fascicle length via ultrasound in gastrocnemius lateralis, gastrocnemius medialis, and vastus lateralis, 2) maximal power during cycling and countermovement jumps, and 3) running cost of transport. We estimated muscle fiber type noninvasively based on the pedaling rate at which maximal cycling power occurred. As predicted, longer gastrocnemius muscle fascicles were correlated with greater lower-body power production and cost of transport. Multiple regression analyses revealed that variability in maximal power was explained by fiber type (48% for cycling; 25% for jumping) and average fascicle length (18% for cycling; 12% for jumping), while average fascicle length accounted for 15% of the variation in cost of transport. These results suggest that, at least for certain muscles, fascicle length plays an important role in the power versus economy performance trade-off.

Maximal power production as a function of sex and training status

2019 ◽  
Vol 36 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Ryan M. Miller ◽  
Eduardo D. Freitas ◽  
Aaron D. Heishman ◽  
Japneet Kaur ◽  
Karolina J. Koziol ◽  
...  
Keyword(s):  
Power Production ◽  
Training Status ◽  
Maximal Power ◽  
And Training

Effect of Varying Light Intensity on Maximal Power Production and Selected Metabolic Variables

2001 ◽  
Vol 109 (5) ◽  
pp. 430-434 ◽  
Author(s):  
T. Ohkuwa ◽  
H. Itoh ◽  
T. Yamamoto ◽  
H. Yanagi ◽  
Y. Yamazaki ◽  
...  
Keyword(s):  
Light Intensity ◽  
Power Production ◽  
Maximal Power ◽  
Metabolic Variables

The Optimal Load for Maximal Power Production During Lower-Body Resistance Exercises: A Meta-Analysis

2015 ◽  
Vol 45 (8) ◽  
pp. 1191-1205 ◽  
Author(s):  
Marco A. Soriano ◽  
Pedro Jiménez-Reyes ◽  
Matthew R. Rhea ◽  
Pedro J. Marín
Keyword(s):  
Meta Analysis ◽  
Power Production ◽  
Lower Body ◽  
Maximal Power ◽  
Optimal Load ◽  
Resistance Exercises ◽  
Body Resistance

The Optimal Load for Maximal Power Production During Upper-Body Resistance Exercises: A Meta-Analysis

2016 ◽  
Vol 47 (4) ◽  
pp. 757-768 ◽  
Author(s):  
Marco Antonio Soriano ◽  
Timothy J. Suchomel ◽  
Pedro J. Marín
Keyword(s):  
Meta Analysis ◽  
Power Production ◽  
Upper Body ◽  
Maximal Power ◽  
Optimal Load ◽  
Resistance Exercises ◽  
Body Resistance
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