Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Energy Supply for Muscle Contraction01:25

Energy Supply for Muscle Contraction

Skeletal muscle fibers have the unique ability to switch between rest and contraction states, using different sources of ATP for energy. The contraction cycle and Ca2+ transport back into the sarcoplasmic reticulum for relaxation require significant ATP. However, the ATP reserves in muscle fibers are limited and can only sustain contractions for a few seconds. Additional ATP production becomes necessary for prolonged contractions. As a result, muscle fibers generate ATP through various sources,...
Muscle Recovery and Fatigue01:24

Muscle Recovery and Fatigue

Muscle fatigue refers to the decline in a muscle's ability to maintain the force of contraction after prolonged activity. It primarily stems from changes within muscle fibers. Even before experiencing muscle fatigue, one may feel tired and have the urge to stop the activity. This response, known as central fatigue, occurs due to changes in the central nervous system, namely the brain and spinal cord. While there is no single mechanism that induces fatigue, it may serve as a protective response...
Exercise and Muscle Performance01:27

Exercise and Muscle Performance

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...
Exercise and Cardiovascular Response01:20

Exercise and Cardiovascular Response

Exercise significantly impacts cardiovascular response, which is crucial for understanding patient health and designing effective treatment plans.
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
Motor Unit Stimulation01:20

Motor Unit Stimulation

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...
Muscle Stimulation Frequency01:22

Muscle Stimulation Frequency

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...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Effects of normobaric hypoxia and hyperthermia on ventilatory responses to high-intensity interval training bouts.

European journal of applied physiology·2026
Same author

Effects of exercise training on bone health in elderly people with type 2 diabetes without osteoporosis: A randomised clinical trial.

Diabetes research and clinical practice·2026
Same author

The Association Between National Aeronautics and Space Administration Task Load Index Subscales, Training-Induced Fatigue, and Physiological Responses in Endurance Athletes.

International journal of sports physiology and performance·2026
Same author

Ageing does not impair motor neuron adaptations: comparable motor unit responses to strength training in young and older adults.

The Journal of physiology·2026
Same author

Effect of a 1-year supervised exercise intervention on long-term mortality in people with type 2 diabetes.

Acta diabetologica·2026
Same author

Caffeine as an Ergogenic Aid for Neuromuscular Performance: Mechanisms of Action from Brain to Motor Units.

Nutrients·2026
Same journal

Join AANEM.

Muscle & nerve·2026
Same journal

Targeted Muscle Reinnervation for Management and Prevention of Symptomatic Neuroma.

Muscle & nerve·2026
Same journal

AANEM News & Insights.

Muscle & nerve·2026
Same journal

Fat-Fraction Quantification Using Three-Point Dixon Technique in Duchenne Muscular Dystrophy and Its Correlation With Clinical Progression and Genotypic Characteristics: A Single Centre One-Year Prospective Study.

Muscle & nerve·2026
Same journal

Characterizing Combined Central and Peripheral Demyelination-Insights From a Multimodal Comparison With Chronic Inflammatory Demyelinating Polyneuropathy and Multiple Sclerosis.

Muscle & nerve·2026
Same journal

Electrical Modalities in the Rehabilitation of Peripheral Nerve Injuries: State of the Literature and Current Clinical Applications.

Muscle & nerve·2026
See all related articles

Related Experiment Video

Updated: Jun 2, 2026

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy
09:04

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy

Published on: February 20, 2018

Caffeine improves neuromuscular function during maximal dynamic exercise.

Ilenia Bazzucchi1, Francesco Felici, Marco Montini

  • 1Department of Human Movement and Sport Sciences, Università degli Studi di Roma Foro Italico, Piazza Lauro De Bosis 6, Roma 00135, Italy. ilenia.bazzucchi@uniroma4.it

Muscle & Nerve
|April 14, 2011
PubMed
Summary
This summary is machine-generated.

Caffeine supplementation enhances muscle performance during short, maximal dynamic contractions. This improvement in muscle force and conduction velocity suggests caffeine positively impacts motor unit recruitment.

More Related Videos

Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice
10:00

Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice

Published on: March 15, 2019

Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
14:02

Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles

Published on: November 1, 2012

Related Experiment Videos

Last Updated: Jun 2, 2026

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy
09:04

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy

Published on: February 20, 2018

Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice
10:00

Supramaximal Intensity Hypoxic Exercise and Vascular Function Assessment in Mice

Published on: March 15, 2019

Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
14:02

Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles

Published on: November 1, 2012

Area of Science:

  • Exercise Physiology
  • Nutritional Science
  • Sports Medicine

Background:

  • Neuromuscular function is critical for physical performance and has clinical implications.
  • Caffeine is a widely used ergogenic aid with potential benefits for muscle function.

Purpose of the Study:

  • To investigate the effects of caffeine supplementation on neuromuscular function.
  • To determine if caffeine improves muscle force production and muscle fiber characteristics.

Main Methods:

  • A double-blind, repeated-measures study involving 14 male subjects.
  • Administration of placebo (PLA) or caffeine (CAFF) at 6 mg/kg.
  • Assessment of maximal voluntary isometric contractions (MVCs), evoked twitch, and isokinetic contractions during elbow flexion.
  • Measurement of mechanical and electromyographic (EMG) signals from the biceps brachii muscle.
  • Calculation of muscle fiber conduction velocity (CV) to assess force-velocity relationship and muscle fiber recruitment.

Main Results:

  • Caffeine supplementation enhanced the torque-angular velocity curve during dynamic contractions.
  • A significant increase in muscle fiber conduction velocity (CV) was observed following caffeine intake (8.7% higher).

Conclusions:

  • Caffeine supplementation demonstrably improves muscle performance in short-duration, maximal dynamic contractions.
  • The observed increase in mean fiber CV supports the hypothesis that caffeine influences motor unit recruitment and enhances neuromuscular transmission.