This pilot randomized crossover study will evaluate the acute effects of immersive virtual reality (IVR) on respiratory effort during submaximal exercise in healthy adults. Dyspnea and increased respiratory effort are influenced not only by mechanical and metabolic factors, but also by emotional and central neural inputs. IVR has shown potential to reduce anxiety, promote relaxation, and modulate physiological responses, but its direct effect on respiratory effort has not been adequately studied.

Healthy adults will complete two experimental exercise sessions: one session with IVR and one session without IVR, in randomized order. In both conditions, participants will perform a 6-minute constant-load cycling test at a submaximal workload individualized from a prior incremental exercise test. Respiratory effort will be assessed continuously using esophageal pressure monitoring. Additional measurements will include ventilatory variables, perceived dyspnea, acute state anxiety, heart rate, oxygen saturation, and heart rate variability.

The primary aim is to determine whether IVR reduces respiratory effort compared with the control condition. This pilot study is intended to provide physiological evidence on the potential role of IVR as a non-pharmacological strategy to modulate respiratory effort and dyspnea, and to inform future research in clinical populations.

Dyspnea is a complex and multidimensional symptom defined as a subjective experience of breathing discomfort that arises from interactions among physiological, psychological, and environmental factors. It is highly prevalent, affecting approximately 10% of the general adult population and up to half of hospitalized patients. The sensation of dyspnea can emerge when there is a mismatch between central respiratory drive and the effective ventilatory response, a condition known as neuromechanical dissociation. In this context, efferent motor signals to the respiratory muscles are accompanied by afferent signals to sensory cortical areas (corollary discharge), which contribute to the conscious perception of respiratory effort and breathing discomfort.

Respiratory effort is influenced not only by mechanical and metabolic factors but also by emotional and cognitive processes. Increasing evidence suggests that cortical and limbic networks involved in emotion, attention, and anxiety may modulate the perception of breathing effort. Therefore, interventions capable of modifying emotional or cognitive states may influence respiratory perception and the physiological response to exercise.

Immersive virtual reality (IVR) is an emerging technology capable of inducing a strong sense of presence within a simulated environment through visual and auditory immersion. IVR has demonstrated beneficial effects in several clinical contexts, including anxiety reduction, stress modulation, and pain control. By altering sensory input and attentional focus, IVR may also influence physiological responses mediated by central neural mechanisms. However, the potential effect of IVR on respiratory effort and ventilatory control during exercise has not been well characterized.

The present study aims to explore the acute physiological effects of IVR on respiratory effort during submaximal exercise in healthy adults. This pilot study uses a randomized crossover design in which participants perform two experimental conditions: exercise with immersive virtual reality and exercise without virtual reality (control condition). Each participant serves as their own control.

Participants will complete an initial incremental cardiopulmonary exercise test to determine individual exercise capacity and identify the respiratory compensation point. Based on these results, a constant-load cycling protocol will be prescribed at a submaximal intensity corresponding to a fixed proportion of this threshold. During the experimental sessions, participants will perform a six-minute constant-load cycling test under each condition, separated by at least one week.

Respiratory effort will be continuously assessed using esophageal pressure monitoring, allowing calculation of indices such as inspiratory effort and pressure-time product. Additional physiological and perceptual variables will also be collected, including ventilatory parameters, tidal volume, respiratory rate, inspiratory time, heart rate, oxygen saturation, heart rate variability, perceived dyspnea using the Borg scale, and acute state anxiety measured through a validated questionnaire.

The primary objective of this pilot study is to evaluate whether immersive virtual reality reduces respiratory effort during submaximal exercise compared with the control condition. Secondary objectives include exploring the effects of IVR on ventilatory responses, perceived dyspnea, and anxiety. The findings are intended to provide preliminary physiological evidence regarding the potential role of immersive virtual reality as a non-pharmacological strategy to modulate respiratory perception and respiratory effort, and to inform the design of future studies in clinical populations experiencing dyspnea.

Inclusion Criteria:

• Healthy adults aged 18-40 years
• Ability to perform cycle ergometer exercise testing
• No known history of cardiovascular, pulmonary, neurological, or metabolic disease

Exclusion Criteria:

• Current respiratory symptoms or acute illness
• Known cardiovascular, pulmonary, neurological, or metabolic disease
• Use of medications that may affect respiratory or cardiovascular responses to exercise
• Contraindications to exercise testing according to standard clinical guidelines
• Pregnancy
• Inability to tolerate placement of an esophageal balloon catheter
• Susceptibility to motion sickness or discomfort with immersive virtual reality devices

Nos applicable