The goal of this prospective observational study is to investigate the acute effects of mask use on walking distance and vital signs in healthy individuals aged 18-24 years. The main questions it aims to answer are:

Does wearing a mask affect walking distance during the Incremental Shuttle Walk Test (ISWT)? How does mask use influence heart rate, oxygen saturation, blood pressure, and respiratory rate during the test? Researchers will compare participants performing the ISWT with a mask to those performing it without a mask to determine any differences in walking distance and vital signs.

Participants will:

Complete the ISWT twice: once with a mask and once without a mask, on separate days.

Have their heart rate, oxygen saturation, respiratory rate, blood pressure, and dyspnea perception measured before and after each test.

The incremental shuttle walk test (ISWT) is an exercise test used to evaluate maximum exercise capacity in different chronic diseases. ISWT consists of 12 levels, each lasting 1 minute, where the participant walks back and forth along a 10-meter course. The test involves progressively increasing the pace as the individual moves between two cones placed 9 meters apart. The speed of walking is controlled by an audio signal. Initially, the speed is set at 0.50 m/s and is incremented by 0.17 m/s every minute until reaching a final speed of 2.37 m/s at level 12. The test concludes when the participant is hindered by shortness of breath or reaches a heart rate of 85% of their predicted maximum, or if they cannot sustain the required speed and fail to complete a shuttle for two consecutive attempts. The main result is determined by the distance traveled, which is calculated based on the number of shuttles completed.

The coronavirus pandemic has altered the manner in which routine tests are conducted. Since the beginning of the pandemic, wearing masks in public places has been mandatory, necessitating the use of masks during clinical tests.

There are a limited number of studies on the effects of mask use on the results of exercise tests. In a study investigating the effects of mask use on the results of the 6-minute walk test, no significant difference was found in terms of walking distance, while no significant difference was found in terms of dyspnea perception between the two groups. Similar results were found in another study on this subject.

To the best of our knowledge, there is no study in the literature examining the effect of mask use on the results of the ISWT. The aim of this study is to determine whether there are differences in walking distance, maximal heart rate, oxygen saturation, perception of dyspnea, and respiratory rate between healthy individuals undergoing the ISWT with and without masks.

Individuals aged 18-24 years with a body mass index of less than 30 kg/m² and no known diseases will be included in the study. Individuals who self-report a history of chronic or acute disease/dysfunction that contraindicates or limits participation in exercise testing, those taking prescription medications other than oral contraception, those with known pregnancy status, those using drugs, cigarettes, or alcohol, and those with blood pressure greater than or equal to 160/100 mmHg will be excluded from the study.

Participants will be recommended to wear comfortable clothing and appropriate shoes for the test. To minimize variability, each participant will perform the Incremental Shuttle Walk Test (ISWT) twice, once with a mask and once without a mask, at the same time of day on separate days. Walking distance, respiratory frequency, heart rate, dyspnea perception, and blood pressure will be measured at rest, immediately after the test, and one minute after the test.

Heart rate will be evaluated using a heart rate monitor (Polar FT 100), oxygen saturation will be measured with a portable pulse oximeter, blood pressure will be taken with a sphygmomanometer, respiratory frequency will be measured by counting the number of breaths per minute, and dyspnea perception will be assessed using the Modified Borg Scale.

The Modified Borg Scale is frequently used to evaluate the severity of dyspnea on exertion and at rest. It is a 10-point scale that defines the severity of dyspnea and is known to be a reliable scale for determining dyspnea severity and is related to respiratory function tests.

Statistical analysis will be performed using IBM Statistics SPSS v21.0 (IBM Corp., Armonk, NY, USA). Variables will be assessed using histograms and the Shapiro-Wilk test. For the primary and secondary outcomes, changes in ISWT with and without a mask, the Mann-Whitney U test will be used. Significance will be set at p < 0.05.

Inclusion Criteria:

• Individuals aged 18-24 years.
• Body mass index of less than 30 kg/m².
• No known diseases

Exclusion Criteria:

• Individuals with a self-reported history of chronic or acute disease/dysfunction that contraindicates or limits participation in exercise testing.
• Individuals taking prescription medications other than oral contraception.
• Those with known pregnancy status.
• Individuals who use drugs, cigarettes, or alcohol.
• Individuals with blood pressure greater than ≥160/100 mmHg.

The study population consists of healthy volunteers, aged between 18 and 24 years, with a body mass index (BMI) of less than 30 kg/m². All participants are free from any known chronic or acute diseases, do not take prescription medications (except for oral contraception), and have no history of drug, alcohol, or cigarette use. Additionally, participants with blood pressure greater than 160/100 mmHg or those with known pregnancy status are excluded from the study.