Related Experiment Video
Updated: Aug 7, 2025
07:53
Assessment of Neuromuscular Function Using Percutaneous Electrical Nerve Stimulation
Published on: September 13, 2015
22.0K
Variable Resistance-An Efficient Method to Generate Muscle Potentiation: A Systematic Review and Meta-Analysis
Álvaro Huerta Ojeda1, Claudio Cifuentes Zapata1,2, Guillermo Barahona-Fuentes1
1Núcleo de Investigación en Salud, Actividad Física y Deporte ISAFYD, Universidad de Las Américas, Viña del Mar 2531098, Chile.
Summary
Variable resistance (VR) effectively triggers post-activation performance enhancement (PAPE) in athletes. This review found VR improves sprint times and jump height, with minimal impact on throwing performance.
Area of Science:
- Sports Science
- Exercise Physiology
- Biomechanics
Background:
- Variable resistance (VR) training is recognized for enhancing muscular strength and power.
- Limited recent research exists on VR's efficacy in inducing post-activation performance enhancement (PAPE).
- This study addresses the gap by examining VR's role in PAPE within power-dominant sports.
Approach:
- A systematic review and meta-analysis of studies published between 2012 and 2022.
- Searches conducted across major scientific databases (WOS, Scopus, PubMed, etc.) following PRISMA guidelines.
- Methodological quality assessed using the Cochrane Collaboration tool; effect sizes calculated via Hedges' g test.
Key Points:
- Analyzed 22 studies for review and 10 for meta-analysis, focusing on throwing speed, sprint times, and jump height.
- Found a moderate effect of VR on jump height (SMD = 0.55) and a small effect on sprint times (SMD = -0.37).
- Observed a trivial effect for throwing speed (SMD = 0.06), indicating VR's varied impact across different power outcomes.
Conclusions:
- Variable resistance activation effectively induces post-activation performance enhancement.
- VR demonstrates significant benefits for explosive movements like jumping and sprinting.
- While VR shows potential, its effectiveness in enhancing throwing velocity and distance requires further investigation.
Related Concept Videos
01:27Exercise and Muscle Performance
1.5K
Exercise induces a range of adaptations in muscle tissue, depending on the type and duration of activity. Such physical training can be broadly categorized into two types: endurance exercises and resistance exercises.
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
1.5K
01:20Motor Unit Stimulation
1.7K
When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
1.7K
01:22Muscle Stimulation Frequency
2.3K
The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
2.3K
01:14Design Example: Frog Muscle Response
270
A student is tasked to work on an intriguing experiment involving an RL (Resistor-Inductor) circuit to study the muscle response of a frog's leg to electrical stimulation. The RL circuit plays a crucial role in this experiment, providing the means to control and measure the electrical impulses that trigger muscle contraction.
When the switch connecting the RL circuit is closed, a brief muscle contraction is observed. This is because, at a steady state, the inductor acts like a short...
When the switch connecting the RL circuit is closed, a brief muscle contraction is observed. This is because, at a steady state, the inductor acts like a short...
270
01:15Muscle Contraction
91.2K
91.2K
01:35Long-term Potentiation
55.5K
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
55.5K