# Muscle oxygenation levels in smokers and non-smokers during exercise: insights from a university-based study

## TL;DR

This study shows that smoking reduces muscle oxygenation during exercise, with effects worsening as smoking increases.

## Contribution

The study links smoking levels directly to measurable changes in muscle oxygenation during physical activity.

## Key findings

- Smokers had significantly lower muscle oxygenation levels during a six-minute walking test compared to non-smokers.
- Smoking levels and exhaled CO were strongly correlated with reduced oxygenation and increased oxygen depletion.
- These findings suggest smoking may contribute to future health complications through impaired oxygen delivery.

## Abstract

Today, as the age of smoking is decreasing, awareness of the harms of tobacco is still not at a sufficient level among young people. In our study, we aimed to compare the muscle oxygenation levels between students who smoke and those who do not smoke after the training on the harms of tobacco products.

A total of 40 smokers and 30 non-smokers, aged 23 and studying at our university, participated between November 2024 and December 2024. Vastus lateralis muscle oxygenation was measured during the six-minute walking test (6MWT).

In smokers, exhaled CO, pulse at the beginning and end of 6MWT, Borg dyspnea, and fatigue scores were significantly higher than in non-smokers (p < 0.001). Maximum and minimum SmO2 levels measured at the beginning and end of 6MWT were lower in smokers (p < 0.001), while changes in SmO2 were greater in smokers (p < 0.001). Smoking level negatively correlated with maximum and minimum SmO2 and positively with ΔSmO2 (R = − 0.82, p < 0.001; R = 0.83, p < 0.001; R = 0.79, p < 0.001). Similarly, exhaled CO negatively correlated with maximum and minimum SmO2 and positively with ΔSmO2 (R = − 0.83, p < 0.001; R = 0.84, p < 0.001; R = 0.78, p < 0.001).

Smoking causes a decrease in muscle oxygenation depending on the amount smoked. We believe that this cumulative burden may be a precursor to comorbidities that develop in later ages.