Feasibility of Physiological Assessments for Long-Distance Swimming Safety in Open Water Using Virtual Reality Settings

Approximately 240,000 people drown annually worldwide. The benefits of programs of long-distance swimming in the sea are important for children. However, due to safety concerns, fewer schools are implementing the programs. A better system for monitoring heart rate that enables the detection of physiological abnormalities and improves the safety of long-distance swimming is needed. In this feasibility study, a system was developed for an open-water setting. Furthermore, we explored acute stress responses using Virtual Reality (VR) as a potential screening tool.

40 healthy subjects (28 males, 12 females; age: 18 ± 0.4 years) were timed in the 400m breaststroke, and their peak oxygen uptake (peak VO₂) was measured; heart rate was monitored during long-distance swimming in the sea. Furthermore, cardiac autonomic nerve activity was measured during swimming VR exposure.

A significant correlation was observed between heart rate during long-distance swimming in the sea and the 400m breaststroke time (r = 0.46, p < 0.01), but not at peak VO₂ (r = -0.10, n.s.). A rapid increase in a subject's heart rate was observed immediately before fitting the buoyancy device. Sympathetic activity after VR exposure was significantly higher than before exposure (p < 0.05).

Heart rate during long-distance swimming depends on swimming ability, not maximum aerobic fitness. Monitoring early heart rate spikes could assist in detecting physiological abnormalities. Furthermore, acute stress responses during VR exposure offer a safe screening method for collecting near-miss data in simulated environments.

Real-time heart rate monitoring showed a relationship between swimming ability and heart rate in the sea. The swimming VR exposure demonstrated potential as an exploratory method for safe risk assessment, though its clinical value requires further validation.