Related Experiment Video
Updated: Jul 5, 2025
09:24
A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers
Published on: January 28, 2020
8.9K
What makes a successful relay start in swimming?
Santiago Veiga1, Claudia Braun2, Xiao Qiu1,2
1Departamento de Deportes, Universidad Politécnica de Madrid, Madrid, Spain.
Sports Biomechanics
|January 12, 2024
Summary
Competitive swimmers can improve relay starts by using longer preparatory movements on the block. Successful relay starts involve specific timing of leg and arm movements and optimized force application for greater impulse.
Area of Science:
- Sports Science
- Biomechanics
- Swimming Performance
Background:
- Competitive swimming starts are crucial for race outcomes.
- Previous research has questioned the benefits of relay start techniques.
- Understanding the biomechanics of successful relay starts is essential.
Purpose of the Study:
- To analyze the kinetic and kinematic parameters of successful swimming relay starts.
- To identify key differences between successful and unsuccessful relay starts.
- To investigate the influence of preparatory movements on relay start performance.
Main Methods:
- Analysis of 145 relay starts performed by 20 elite swimmers.
- Use of an instrumented starting platform (OBS11) to collect data.
- Classification of starts as successful or unsuccessful based on 10-m split times.
Main Results:
- Successful relay starts featured a later leg step onset and hand positioning.
- Lower horizontal force during the leg step and greater maximal forces upon block exit were observed.
- Faster horizontal and resultant velocities were associated with successful starts.
- Preparatory movement duration influenced force application time and impulse.
Conclusions:
- Elite swimmers utilize specific kinematic and kinetic strategies for successful relay starts.
- Longer preparatory movements on the block can enhance impulse and performance.
- Relay start techniques differ from individual track starts, emphasizing preparatory phases.
Related Concept Videos
01:26Overcurrent Relays
86
Overcurrent relays, crucial for circuit protection, are connected to the secondary current of a current transformer. There are two primary types of overcurrent relays: instantaneous and time-delay.
Instantaneous overcurrent relays activate immediately when the input current exceeds a predetermined value, known as the pickup current, instantly energizing the circuit breaker trip coil. This rapid response is vital for addressing severe faults quickly.
Time-delay overcurrent relays, on the other...
Instantaneous overcurrent relays activate immediately when the input current exceeds a predetermined value, known as the pickup current, instantly energizing the circuit breaker trip coil. This rapid response is vital for addressing severe faults quickly.
Time-delay overcurrent relays, on the other...
86
01:04Social Facilitation
32.0K
Not all intergroup interactions lead to negative outcomes. Sometimes, being in a group situation can improve performance. Social facilitation occurs when an individual performs better when an audience is watching than when the individual performs the behavior alone. This typically occurs when people are performing a task for which they are skilled.
32.0K
01:25Directional Relays
113
Directional relays, essential for managing unidirectional fault currents, enhance the safety and efficiency of power systems. On power lines equipped with directional relays, faults downstream (to the right) of the current transformer typically cause the fault current to lag the bus voltage by approximately 90 degrees, known as the forward direction. In contrast, upstream (left-side) faults may result in the fault current leading the bus voltage by nearly 90 degrees, termed the reverse...
113
01:27Line Protection with Impedance Relays
82
Coordinating time-delay overcurrent relays in complex radial systems and directional overcurrent relays in multi-source transmission loops can be challenging. Impedance relays address these issues by responding to the voltage-to-current ratio, specifically measuring the apparent impedance of a line. These relays become more sensitive during faults as current increases and voltage decreases, thereby reducing the apparent impedance.
Under normal conditions, low load currents keep the measured...
Under normal conditions, low load currents keep the measured...
82
01:18Design Example: Designing Water Slide
172
When designing a water slide, controlling the speed of water flow is crucial for rider safety while maintaining an exciting experience. As water flows down the slide, gravity causes it to accelerate, with its speed at the bottom depending on the height from which it starts. The higher the slide, the more potential energy the water has at the top, which is converted into kinetic energy as it descends, increasing its speed.
Bernoulli's principle determines the water's velocity along the...
Bernoulli's principle determines the water's velocity along the...
172
01:20Differential Relays
138
Differential relays are used to protect generators, buses, and transformers by comparing electrical quantities at different points. When a fault occurs, the difference in current between the two points triggers the relay to operate, opening the circuit breaker. Under normal conditions, the current entering (i1) and leaving (i2) a generator are equal. When a fault occurs, however, these currents become unequal, and the difference current flows in the relay operating coil, causing the relay to...
138