Related Experiment Video
Updated: Jun 23, 2026
07:32
Experimental Protocol of a Three-minute, All-out Arm Crank Exercise Test in Spinal-cord Injured and Able-bodied Individuals
Published on: June 8, 2017
Cycling efficiency and performance following short-term training using uncoupled cranks
Andrew D Williams1, Isaac Selva Raj, Kristie L Stucas
1School of Human Life Sciences, University of Tasmania, Australia.
Summary
Training with uncoupled cycling cranks did not improve physiological measures or cycling performance in well-trained cyclists. This 6-week intervention showed no significant benefits for VO2max, lactate threshold, or efficiency.
Area of Science:
- Sports Science
- Exercise Physiology
- Cycling Biomechanics
Background:
- Uncoupled cycling cranks aim to isolate leg action, potentially enhancing mechanical efficiency.
- Previous research suggests benefits, but evidence in elite cyclists is lacking.
Purpose of the Study:
- To investigate the effects of uncoupled crank training on physiological and performance adaptations in well-trained cyclists.
- To determine if uncoupled crank training improves maximal oxygen uptake, lactate threshold, gross efficiency, or cycling performance.
Main Methods:
- Fourteen well-trained cyclists underwent a 6-week training intervention.
- Participants were randomized to either uncoupled or traditional crank systems.
- Training consisted of 1-hour sessions, 3 times per week, at 70% of peak power output.
Main Results:
- No significant differences were found between groups in changes to VO2max, lactate threshold, or gross efficiency.
- Average power output during a 30-minute time trial remained unchanged in both groups.
Conclusions:
- Six weeks of training with uncoupled cranks does not yield improvements in physiological or performance metrics for well-trained cyclists.
- The use of uncoupled cranks in training does not appear to enhance cycling performance in this population.
Related Concept Videos
01:16Efficiency of The Carnot Cycle
The hypothetical Carnot cycle consists of an ideal gas subjected to two isothermal and two adiabatic processes. Since the internal energy of an ideal gas depends only on its temperature, which is the same before and after the completion of the Carnot cycle, there is no change in its internal energy. Hence, using the first law of thermodynamics, the total heat exchanged by the ideal gas equals the total work done. Thus, we can quantify the efficiency of the Carnot cycle via the heat exchanged...
01:26Carnot Cycle and Efficiency
The Second Law of Thermodynamics asserts that it's impossible for any heat engine to achieve 100% efficiency. While contemplating the maximum possible efficiency, Nicolas Sadi Carnot conceptualized an ideal heat engine. This engine gets its energy from a high-temperature reservoir. It then performs some work and releases the remaining energy into a low-temperature reservoir.The Carnot cycle, named after Sadi Carnot, is fully reversible. The cycle consists of four distinct stages. In the first...
01:21Fatigue
Fatigue occurs when materials rupture under repeated or fluctuating loads, even at stress levels far below their static breaking strength. It typically results in brittle failure, even for ductile materials. It is a critical consideration in designing machines and structural components subjected to repetitive or varying loads. The nature of these loadings can range from fluctuating loads like unbalanced pump impellers causing vibrations to repeatedly bending a thin steel rod wire back and forth...
01:30The Carnot Cycle
Converting work to heat is an irreversible process, and the purpose of a heat engine is to reverse the effect partially. Heat engines aim to increase the efficiency of the reversal, that is, maximize the work retrieved from heat. If the efficiency of a heat engine were 100%, it would imply reversing the process completely without introducing any other effect. Thus, it would violate the second law of thermodynamics.
What could be the theoretical limit to the efficiency of a heat engine? The...
What could be the theoretical limit to the efficiency of a heat engine? The...
01:20Microcracking in Concrete
Microcracking in concrete refers to the tiny cracks that can form within the material even before any external load is applied. These microcracks typically occur at the interface between the coarse aggregate and the hydrated cement paste, often as a result of differential volume changes prompted by variations in stress-strain behavior, as well as thermal and moisture movement. Initially, these microcracks remain stable and do not grow substantially until the concrete is stressed to about 30...
01:22Fatigue Strength of Concrete
Fatigue, in the context of materials science and engineering, refers to the weakening or failure of a material caused by repeatedly applied loads, even if these loads are below the strength limit of the material. Fatigue strength in concrete is a critical property that influences its durability and longevity. Concrete can fail in two ways due to fatigue. Static fatigue or creep rupture occurs under a constant load or one that increases slowly. The other failure mode is due to cyclical or...