scholarly journals Within- and between-session reliability of a pedal force system for power output and pedal force effectiveness measurements

2020 ◽  
Vol 21 (4) ◽  
pp. 69-78
Author(s):  
Rodrigo Bini ◽  
Patria Hume
Keyword(s):  
Power Output ◽  
Force System ◽  
Pedal Force

scholarly journals Differences in Pedaling Technique in Cycling: A Cluster Analysis

2016 ◽  
Vol 11 (7) ◽  
pp. 959-964
Author(s):  
Fábio J. Lanferdini ◽  
Rodrigo R. Bini ◽  
Pedro Figueiredo ◽  
Fernando Diefenthaeler ◽  
Carlos B. Mota ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Power Output ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Unit Length ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Fascicle Length ◽  
Pedal Force ◽  
Cluster 2

Purpose:To employ cluster analysis to assess if cyclists would opt for different strategies in terms of neuromuscular patterns when pedaling at the power output of their second ventilatory threshold (POVT2) compared with cycling at their maximal power output (POMAX).Methods:Twenty athletes performed an incremental cycling test to determine their power output (POMAX and POVT2; first session), and pedal forces, muscle activation, muscle–tendon unit length, and vastus lateralis architecture (fascicle length, pennation angle, and muscle thickness) were recorded (second session) in POMAX and POVT2. Athletes were assigned to 2 clusters based on the behavior of outcome variables at POVT2 and POMAX using cluster analysis.Results:Clusters 1 (n = 14) and 2 (n = 6) showed similar power output and oxygen uptake. Cluster 1 presented larger increases in pedal force and knee power than cluster 2, without differences for the index of effectiveness. Cluster 1 presented less variation in knee angle, muscle–tendon unit length, pennation angle, and tendon length than cluster 2. However, clusters 1 and 2 showed similar muscle thickness, fascicle length, and muscle activation. When cycling at POVT2 vs POMAX, cyclists could opt for keeping a constant knee power and pedal-force production, associated with an increase in tendon excursion and a constant fascicle length.Conclusions:Increases in power output lead to greater variations in knee angle, muscle–tendon unit length, tendon length, and pennation angle of vastus lateralis for a similar knee-extensor activation and smaller pedal-force changes in cyclists from cluster 2 than in cluster 1.

Individuals With Knee Osteoarthritis Demonstrate Interlimb Asymmetry in Pedaling Power During Stationary Cycling

2018 ◽  
Vol 34 (4) ◽  
pp. 306-311 ◽  
Author(s):  
Harsh H. Buddhadev ◽  
Daniel L. Crisafulli ◽  
David N. Suprak ◽  
Jun G. San Juan
Keyword(s):  
Knee Osteoarthritis ◽  
Power Output ◽  
Physical Rehabilitation ◽  
Healthy Controls ◽  
Knee Oa ◽  
Pedal Force ◽  
Therapeutic Benefits ◽  
Higher Power ◽  
Effective Component

Cycling is commonly prescribed for physical rehabilitation of individuals with knee osteoarthritis (OA). Despite the known therapeutic benefits, no research has examined interlimb symmetry of power output during cycling in these individuals. We investigated the effects of external workload and cadence on interlimb symmetry of crank power output in individuals with knee OA versus healthy controls. A total of 12 older participants with knee OA and 12 healthy sex- and age-matched controls were recruited. Participants performed 2-minute bouts of stationary cycling at 4 workload-cadence conditions (75 W at 60 rpm, 75 W at 90 rpm, 100 W at 60 rpm, and 100 W at 90 rpm). Power output contribution of each limb toward total crank power output was computed over 60 crank cycles from the effective component of pedal force, which was perpendicular to the crank arm. Across the workload-cadence conditions, the knee OA group generated significantly higher power output with the severely affected leg compared with the less affected leg (10% difference; P = .02). Healthy controls did not show interlimb asymmetry in power output (0.1% difference; P > .99). For both groups, interlimb asymmetry was unaffected by external workload and cadence. Our results indicate that individuals with knee OA demonstrate interlimb asymmetry in crank power output during stationary cycling.

Caffeine supplementation for 4-day, followed by acute ingestion, did not impact triathlete output power after submaximal intensity exercise

2019 ◽  
Vol 18 (3) ◽  
pp. 118
Author(s):  
Anderson Pontes Morales ◽  
Felipe Sampaio-Jorge ◽  
Thiago Barth ◽  
Alessandra Alegre De Matos ◽  
Luiz Felipe Da Cruz Rangel ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Output Power ◽  
Body Mass ◽  
Effect Size ◽  
Power Output ◽  
Anaerobic Power ◽  
Lactate Concentration ◽  
Wingate Test ◽  
Large Effect Size ◽  
Acute Ingestion

Introduction: The aim of this study was to test the hypothesis that caffeine supplementation (6 mg·kg-1 body mass) for 4-days, followed by acute intake, would impact five male triathletes output power after performed submaximal intensity exercise. Methods: This was a randomized, double-blind, placebo-controlled crossover study, placebo (4-day) - placebo (acute) PP, placebo (4-days) -caffeine (acute) PC, and caffeine (4-day) - caffeine (acute) CC. Participants abstained from dietary caffeine sources for 4 days and ingested capsules containing either placebo or caffeine (6 mg.kg-1 body mass day in one absorption). The acute trials the capsules containing placebo or caffeine (6 mg.kg-1 body mass day in one absorption) were ingested 60min before completing exercise in a treadmill for 40min (80% VO2max) and to perform the Wingate test. Results: Blood lactate was determined before, 60min after ingestion, and immediately after the exercise on the treadmill, the Wingate test, and after the recovery (10-min). CC and PC trials did not change the cardiopulmonary variables (P>0.05) and the anaerobic power variables (peak/mean power output and fatigue index) (P>0.05). The PC trial compared with PP promoted improvements in the curve power output in 2 sec by 31.19% (large effect-size d = 1.08; P<0.05) and 3 sec by 20% (large effect-size d = 1.19; P<0.05). A 10min recovery was not sufficient to reduce blood lactate concentration in the PC trial compared with PP (PC, 13.73±2.66 vs. PP, 10.26±1.60 mmol.L-1; P<0.05, respectively) (P<0.05). Conclusion: In conclusion, these results indicate that caffeine supplementation (6 mg·kg-1 body mass) for 4 days, followed by acute ingestion, did not impact the triathletes output power after performed submaximal intensity exercise. Nutritional interventions may help researchers and athletes to adapt strategies for manipulating caffeine use.Key-words: caffeine metabolism, Wingate test, blood lactate, performance.

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