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

Exercise and Cardiovascular Response01:20

Exercise and Cardiovascular Response

1.2K
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...
1.2K
Vitamins01:30

Vitamins

1.2K
Vitamins, derived from the Latin word for life, are essential organic substances required in small quantities for optimal growth and overall well-being. Unlike other organic nutrients, vitamins don't act as sources of energy or building materials but rather facilitate these nutrients' utilization by the body. Vitamins are predominantly coenzymes, assisting enzymes in specific chemical actions, like the oxidation of glucose for energy involving B vitamins. Most vitamins are not produced...
1.2K
Antianginal Drugs: Nitrates and β-Blockers01:16

Antianginal Drugs: Nitrates and β-Blockers

855
In cardiovascular health, antianginal drugs combat angina pectoris — a condition marked by chest pain owing to diminished blood flow to the heart.
Organic nitrates,  such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow....
855
Exercise and Muscle Performance01:27

Exercise and Muscle Performance

1.8K
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...
1.8K
Effect of Hepatic Disease on Pharmacokinetics: Dose Adjustments Due to Hepatic Impairment01:08

Effect of Hepatic Disease on Pharmacokinetics: Dose Adjustments Due to Hepatic Impairment

25
Hepatic impairment, characterized by decreased liver function, does not uniformly mandate adjustments in drug dosage. Whether dosage modifications are necessary depends on various factors related to the drug's metabolism and elimination pathways. If a drug is primarily excreted via the kidneys and bypasses significant hepatic processing, if it undergoes minimal metabolic transformation in the liver, or if it is volatile and primarily expelled through the lungs, dose adjustments may not be...
25
Drugs Acting on Autonomic Ganglia: Stimulants01:23

Drugs Acting on Autonomic Ganglia: Stimulants

1.7K

Ganglionic stimulants activate NM nicotinic receptors in autonomic ganglia, falling into two categories: nicotine mimetics [e.g., lobeline, dimethylpiperazine, tetramethylammonium] and muscarinic receptor agonists [e.g., muscarine, methacholine]. The first category's action is rapid and blocked by nicotinic receptor antagonists, while the second category's action is delayed and blocked by atropine-like agents. Nicotine, an alkaloid, affects the heart rate by stimulating...
1.7K

You might also read

Related Articles

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

Sort by
Same author

Contrast Induced Nephropathy in Trauma: A Real Phenomenon?

The American surgeon·2026
Same author

Lack of Follow-Up in a Food-Insecure Population.

American journal of lifestyle medicine·2025
Same author

Maximal Respiratory Pressure Reference Values for Hopi Children Ages 4-13.

Cardiopulmonary physical therapy journal·2022
Same author

Passive static stretching alters the characteristics of the force-velocity curvature differently for fast and slow muscle groups-A practical application of Hill's equation.

Human movement science·2021
Same author

The Effect of Vinegar Supplementation on High-Intensity Cycling Performance within Recreationally Trained Individuals.

Medicina (Kaunas, Lithuania)·2020
Same author

Muscle Sentry® has No Effect on Total Work Performed and Estimated MVO <b></b> after High Intensity Short Duration Resistance Training.

International journal of exercise science·2020
Same journal

Fructooligosaccharide Upregulates Colonic Vitamin D Receptors and Modulates Inflammatory Status in High-Fat Diet-Induced Obese Male C57BL/6 Mice.

International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition·2026
Same journal

Effects of Dietary Peptides From Essence of Chicken on Neuroinflammation and Their Synergism in Neuroprotection.

International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition·2026
Same journal

The Protective Effect of Vitamin C Targeting Oxidative Stress on Renal Function in Patients with Septic Acute Kidney Injury: A Prospective, Randomized Controlled, Pilot Study.

International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition·2026
Same journal

Potential Effects of Chia Seed (<i>Salvia</i> <i>hispanica</i> L.) on Adipose Tissue Gene Expression and Obesity Indicators in Cafeteria Diet-Fed Rats.

International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition·2026
Same journal

Spirulina Supplementation Can Reduce Serum Levels of C-Reactive Protein: A Systematic Review and Meta-Analysis on Randomized Clinical Trials.

International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition·2026
Same journal

Short-Term Turkish Coffee Consumption Elevates Cardiovascular Risk Markers, Decreases Leptin Levels, and Impairs Sleep Quality in Healthy Young Women: A Pilot Randomized Controlled Trial.

International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition·2026
See all related articles

Related Experiment Video

Updated: Oct 15, 2025

Using Near-Infrared Spectroscopy Wearable Devices to Identify Central Versus Peripheral Limitations During Exercise
09:33

Using Near-Infrared Spectroscopy Wearable Devices to Identify Central Versus Peripheral Limitations During Exercise

Published on: December 19, 2024

1.1K

Niacin supplementation impairs exercise performance.

Greggory R Davis1, Arnold G Nelson2

  • 1University of Louisiana at Lafayette, LA, USA.

International Journal for Vitamin and Nutrition Research. Internationale Zeitschrift Fur Vitamin- Und Ernahrungsforschung. Journal International De Vitaminologie Et De Nutrition
|October 26, 2021
PubMed
Summary
This summary is machine-generated.

Niacin (NI) as a pre-workout supplement elevated respiratory exchange ratio and reduced exercise time to exhaustion compared to caffeine (CA). This suggests niacin may impair exercise performance by limiting lipid availability.

Keywords:
Substrateaerobic exerciseperformancerespiratory exchange ratio

More Related Videos

Author Spotlight: Unveiling Mitochondrial Function and Cellular Metabolic Adaptation in Metabolic Diseases
08:12

Author Spotlight: Unveiling Mitochondrial Function and Cellular Metabolic Adaptation in Metabolic Diseases

Published on: October 4, 2024

2.0K
In Ovo Feeding of Commercial Broiler Eggs: An Accurate and Reproducible Method to Affect Muscle Development and Growth
06:38

In Ovo Feeding of Commercial Broiler Eggs: An Accurate and Reproducible Method to Affect Muscle Development and Growth

Published on: September 20, 2021

2.6K

Related Experiment Videos

Last Updated: Oct 15, 2025

Using Near-Infrared Spectroscopy Wearable Devices to Identify Central Versus Peripheral Limitations During Exercise
09:33

Using Near-Infrared Spectroscopy Wearable Devices to Identify Central Versus Peripheral Limitations During Exercise

Published on: December 19, 2024

1.1K
Author Spotlight: Unveiling Mitochondrial Function and Cellular Metabolic Adaptation in Metabolic Diseases
08:12

Author Spotlight: Unveiling Mitochondrial Function and Cellular Metabolic Adaptation in Metabolic Diseases

Published on: October 4, 2024

2.0K
In Ovo Feeding of Commercial Broiler Eggs: An Accurate and Reproducible Method to Affect Muscle Development and Growth
06:38

In Ovo Feeding of Commercial Broiler Eggs: An Accurate and Reproducible Method to Affect Muscle Development and Growth

Published on: September 20, 2021

2.6K

Area of Science:

  • Exercise Physiology
  • Nutritional Biochemistry

Background:

  • Niacin is a common ingredient in pre-workout supplements.
  • The effects of niacin on exercise performance are not well understood.
  • Understanding niacin's impact is crucial for athletes and supplement users.

Purpose of the Study:

  • To investigate the performance effects of niacin compared to caffeine as a pre-workout supplement.
  • To determine if niacin impacts key exercise physiology markers.

Main Methods:

  • Twenty-five untrained males participated in three randomized trials.
  • Participants received caffeine (5 mg/kg), 1000 mg niacin, or placebo before cycling exercise.
  • Ramped aerobic cycling to exhaustion was used to measure performance.

Main Results:

  • Niacin treatment significantly increased respiratory exchange ratio (RER) compared to caffeine.
  • Exercise time to exhaustion was significantly lower with niacin compared to caffeine.
  • Habitual exercise or caffeine intake did not significantly alter these results.

Conclusions:

  • Niacin supplementation may impair exercise performance.
  • Elevated RER with niacin suggests altered substrate utilization (limited lipid availability).
  • Niacin's role as a pre-workout supplement warrants further investigation due to potential negative effects.