Related Experiment Video
Updated: Jan 29, 2026
Influence of Step-Width Manipulation on Running Biomechanics
Published on: February 28, 2025
Ventilatory Demand During Stepping and Running: Implications for Exercise-Induced Bronchoconstriction in Children
Jessyca P Selman1, Fernanda C Lanza1, Gustavo F Wandalsen2
1Postgraduate Program in Rehabilitation Sciences, Universidade Nove de Julho, São Paulo, Brazil.
Insights
Single-step tests may not fully diagnose exercise-induced bronchoconstriction (EIB) in children with asthma. While convenient, a negative stepping test result should be confirmed with a treadmill running test for accurate diagnosis.
Area of Science:
- Pediatric Pulmonology
- Exercise Physiology
- Diagnostic Testing
Background:
- Single-step tests are proposed for diagnosing exercise-induced bronchoconstriction (EIB) in children due to their simplicity and low cost.
- However, the lower work and ventilation demands of stepping compared to running may reduce diagnostic accuracy.
Purpose of the Study:
- To compare the diagnostic yield of incremental stepping, constant stepping, and treadmill running tests for EIB in children with asthma.
- To investigate the relationship between test modality, ventilatory demands, and EIB diagnosis.
Main Methods:
- A cross-sectional study involving 53 children (age 6-18) with asthma and exercise-related symptoms.
- Participants completed incremental stepping, constant stepping, and treadmill running tests on separate occasions.
Main Results:
- Stepping tests exhibited lower metabolic, ventilatory, and cardiovascular demands than the treadmill test (P < .05).
- Agreement in EIB diagnosis between tests was poor (kappa 0.217-0.361).
- Treadmill running showed higher EIB prevalence (60%) than constant (53%) and incremental (47%) stepping, though 7 subjects had EIB only with stepping.
Conclusions:
- Lower EIB prevalence in stepping tests is not solely due to reduced ventilation demand.
- Stepping tests can serve as a portable, low-cost screening tool for EIB.
- A negative result from a stepping test in symptomatic children warrants confirmation with a running-based test.
Background:
Single-step tests have been proposed as simple and inexpensive challenges to diagnose exercise-induced bronchoconstriction (EIB) in the pediatric population. Work performed and the resulting ventilation, however, might be substantially lower in stepping than running. This might decrease the diagnostic yield of step-based challenges.
Methods:
In a cross-sectional study, 53 children with asthma with exercise-related symptoms (34 boys, age 6-18 y) underwent an incremental stepping test, a 6-min constant stepping test, and a treadmill running test on different days.
Results:
Constant and incremental stepping tests presented with lower metabolic demands (V̇O 1.42 ± 0.48 and 1.34 ± 0.55 L/min, respectively), ventilatory demands (V̇O 45 ± 14 and 43 ± 16 L/min, respectively), and cardiovascular demands (160 ± 20 and 161 ± 19 beats/min, respectively) than the treadmill running test (1.65 ± 0.60 L/min, 54 ± 17 L/min, and 172 ± 7 beats/min, respectively) (P < .05). Between-test agreement in diagnosing EIB was poor (kappa 0.217-0.361). Although EIB prevalence was higher after the treadmill running test (60%) compared to constant (53%) and incremental (47%) stepping tests, 7 subjects developed EIB only in stepping. Clinical and resting functional characteristics did not differ in discordant subjects (ie, EIB negative in a given test but positive in another) versus concordant subjects (ie, EIB negative or positive in both tests). EIB was not related to individual test ability in eliciting high to very-high ventilation (≥ 40% or ≥ 60% maximum voluntary ventilation, respectively). Moreover, a negative stepping test but a positive treadmill test (and vice versa) was not associated with greater ventilatory demands.
Conclusions:
Lower prevalence of EIB in stepping compared to treadmill running is not related to less ventilation demand in the former modality. Although stepping might be useful as a screening EIB test due its portability and low cost, a negative test should be confirmed with a running-based test in symptomatic children.
Related Concept Videos
01:14Ventilatory Modes
There are three ventilatory modes: full support, partial support, and spontaneous. These are described below.
Full Support Modes
Full support modes include controlled mechanical ventilation, continuous mandatory...
01:17Wald-Wolfowitz Runs Test II
For binary data, runs are identified using symbols such as + and −, or equivalently, 1s and 0s. In...
01:17Wald-Wolfowitz Runs Test I
The test works...
01:26Exercise Stress Test
Exercise stress testing, commonly known as a treadmill test, is a noninvasive procedure used to evaluate cardiovascular function and diagnose heart conditions.
Definition
An exercise stress test measures the heart's response to exertion using a treadmill or stationary bicycle. Chest electrodes record the heart's electrical activity through an ECG, and blood pressure is monitored regularly.
Purposes
01:27Exercise and Muscle Performance
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...
01:17Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be...