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

Efficiency of The Carnot Cycle01:16

Efficiency of The Carnot Cycle

3.2K
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...
3.2K
Exercise and Cardiovascular Response01:20

Exercise and Cardiovascular Response

3.6K
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...
3.6K
The Carnot Cycle01:30

The Carnot Cycle

3.6K
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...
3.6K
Factors Influencing Heart Rate01:30

Factors Influencing Heart Rate

5.7K
The heart rate, or pulse rate, is a vital indicator of cardiovascular health. It reflects the number of times the heart beats per minute. Various physiological and environmental factors influence heart rate, increasing or decreasing cardiac output. Understanding these factors is crucial for assessing heart function and identifying potential health issues.
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
5.7K
Cyclic Processes And Isolated Systems01:19

Cyclic Processes And Isolated Systems

3.2K
A thermodynamic system with zero heat exchange and work is an isolated system. For these systems, the internal energy remains constant.
In the case of a non-isolated system, the change in the internal energy is zero only if the process is cyclic. A thermodynamic process is considered cyclic if the system undergoes a series of changes and returns to its initial state. 
Consider a cyclic process that returns to its initial state, undergoing a four-step process. The heat transfer along each...
3.2K
Cardiac Output I:Effect of Heart Rate on Cardiac Output01:19

Cardiac Output I:Effect of Heart Rate on Cardiac Output

1.9K
Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart...
1.9K

You might also read

Related Articles

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

Sort by
Same author

Evolution of Methods for Exercise Evaluation and Prescription.

International journal of sports physiology and performance·2026
Same author

The Role of Y Balance Test Execution Time in Detecting Chronic Ankle Instability.

Journal of strength and conditioning research·2026
Same author

Take-Off Velocity and Trunk Inclination Enhance Countermovement Jump Assessment in Older Women.

Journal of strength and conditioning research·2026
Same author

Comparable blood pressure reductions after indoor and outdoor walking exercise.

Biology of sport·2026
Same author

Rethinking Warm-Up in Overhead Exercise: Acute Shoulder Responses to a Strength- and Mobility-Oriented Protocol in Youth Athletes.

Sports (Basel, Switzerland)·2026
Same author

Greatest of All Time: Development of a Ranking System to Determine the Most Successful Olympic and World Championship Runners Since 1896.

Sports medicine (Auckland, N.Z.)·2026

Related Experiment Video

Updated: Nov 19, 2025

Determining the Contribution of the Energy Systems During Exercise
11:15

Determining the Contribution of the Energy Systems During Exercise

Published on: March 20, 2012

42.1K

Indoor Cycling Energy Expenditure: Does Sequence Matter?

Cristina Cortis1, Andrea Fusco1, Mitchell Cook2

  • 1Department of Human Sciences, Society and Health, University of Cassino and Lazio Meridionale, 03043 Cassino, Italy.

International Journal of Environmental Research and Public Health
|January 27, 2021
PubMed
Summary

Cycling intensity order does not impact overall energy expenditure or physiological responses. However, descending intervals showed slightly lower energy expenditure during the recovery phase.

Keywords:
high intensity interval trainingintensity sequencingperceptual responsesphysiological markerssRPE

More Related Videos

Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training
07:40

Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training

Published on: October 10, 2019

7.6K
Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury
08:07

Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury

Published on: February 1, 2018

13.0K

Related Experiment Videos

Last Updated: Nov 19, 2025

Determining the Contribution of the Energy Systems During Exercise
11:15

Determining the Contribution of the Energy Systems During Exercise

Published on: March 20, 2012

42.1K
Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training
07:40

Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training

Published on: October 10, 2019

7.6K
Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury
08:07

Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury

Published on: February 1, 2018

13.0K

Area of Science:

  • Exercise Physiology
  • Sports Science
  • Cardiovascular Health

Background:

  • Cycling class intensity can be adjusted by altering interval sequencing.
  • The impact of interval intensity order on physiological and perceptual responses remains unclear.

Purpose of the Study:

  • To investigate the effects of different interval intensity sequencing protocols on energy expenditure (EE), physiological markers, and perceptual responses during indoor cycling.

Main Methods:

  • Healthy male and female volunteers completed three randomized interval cycling protocols: mixed pyramid (MP), ascending intervals (AI), and descending intervals (DI).
  • Work intervals were set at 50%, 75%, and 100% of peak power output (PPO), with recovery intervals at 25% PPO.
  • Physiological measures included heart rate (HR) and oxygen consumption (VO2), expressed as percentages of maximal values (%HRmax, %VO2max). Energy expenditure (EE), Session Rating of Perceived Exertion (sRPE), and Exercise Enjoyment Scale (EES) were also recorded.

Main Results:

  • No significant differences were observed across the protocols for %HRmax, %VO2max, overall EE, EES, or sRPE.
  • Energy expenditure during the recovery phase was significantly lower following the descending intervals (DI) protocol compared to mixed pyramid (MP) and ascending intervals (AI) protocols.
  • Despite lower recovery EE in DI, overall physiological and perceptual responses were not significantly altered by interval intensity sequencing.

Conclusions:

  • Interval intensity sequencing in indoor cycling does not substantially affect overall energy expenditure, physiological responses, or perceived exertion.
  • While descending interval protocols may lead to slightly reduced energy expenditure during recovery, this difference does not impact the overall training outcome.
  • Exercise intensity and duration are key determinants of physiological adaptation, rather than the specific order of intensity intervals.