A vape before football training or a gym session might feel harmless if your breathing seems fine. But new research measuring performance at matched exercise intensity has found that vaping quietly saps physical capacity by roughly 15%, and the damage is happening in the blood vessels, not the airways.
Researchers at Manchester Metropolitan University put 75 people aged 18 to 30 through rigorous exercise testing, splitting them into three even groups: those who had never smoked or vaped, established smokers, and vapers with around three years of regular use who had never touched tobacco. The study examined 75 people aged 18-30, a third had never smoked or vaped, a third were smokers but had never used vapes, and a third were vapers for approximately 3 years but had never smoked. Every participant had normal lung function going into the test. That detail matters enormously, because it rules out the obvious suspect before the results even come in.
Key takeaways
- Young vapers perform 15% worse during intense exercise, matching smokers—even though their lungs appear completely normal
- The damage happens in blood vessel walls, not airways: they become stiffer and less able to deliver oxygen when muscles need it most
- Adolescent hearts and arteries may be uniquely vulnerable during these formative years, potentially setting a lower fitness ceiling for life
The numbers behind the 15% drop
Published in ERJ Open Research, the findings were unambiguous. Young people who vape or smoke cigarettes have reduced blood vessel functionality, breathing efficiency and exercise capacity compared to those who have never smoked or vaped, according to a study published today in ERJ Open Research. Dr. Azmy Faisal, the lead author of the study from the Manchester Metropolitan University, United Kingdom, explains: “In active, healthy young adults with normal lungs, both vapes and tobacco smoking led to worsened exercise capacity, shortness of breath, and intense leg fatigue. The overall fitness gap was striking: vaping can lead to harmful changes to the blood vessels, lung efficiency during exercise and approximately a 15% reduction in fitness compared to those who have never smoked or vaped.
This wasn’t the team’s first pass at the question. An earlier phase of the same research programme, presented at the European Respiratory Society Congress in Vienna in 2024, tested 60 people in their twenties on a static bike, pushing them to their absolute limit. On average, the group of young vapers had lower ‘peak exercise capacity’ (186 watts) than the group who did not vape or smoke (226 watts) but similar capacity to the group of smokers (182 watts). This is a measure of the maximum amount of physical exertion that a person can achieve. Watch that gap for a second: vapers were producing barely more power than people who smoke actual cigarettes, despite never having lit one themselves. That’s not a rounding error. That’s a meaningful hit to how hard someone can push during a run, a match, or a spin class.
Why the lungs get the blame, wrongly
Here’s where the story gets genuinely surprising. Everyone in these studies had lungs that looked completely normal on paper. Faisal’s team conducted a study that included 60 people in their 20s with normal lung function as assessed by spirometry testing. Yet at the same workload, vapers were gasping harder, their legs were giving out sooner, and their blood chemistry showed they were struggling more than it should. The vapers and smokers were “more out of breath, experienced intense leg fatigue and had higher levels of lactate in their blood, a sign of muscle fatigue, even before they reached their maximum level of exercise.”
The real culprit turned out to be sitting in the arteries. Using ultrasound scans to measure how well blood vessels dilate and respond, researchers found a clear deficit in vapers compared with people who had never smoked or vaped. On ultrasound, vapers and smokers had lower flow-mediated dilatation (FMD%) of the brachial artery compared with their nonsmoking counterparts (5.4% vs. 7.9%). Flow-mediated dilatation is essentially a measure of how flexible and responsive your blood vessels are when they need to deliver more oxygen quickly, exactly what happens the moment you start sprinting or lifting. When that responsiveness is blunted, muscles get short-changed on oxygen and fuel, fatigue sets in faster, and lactate builds up sooner. Dr Faisal, senior lecturer in cardiorespiratory physiology at Manchester Metropolitan University, put it plainly: “In this study, we looked at a group of young people with no apparent signs of lung damage. Among the people who had been vaping or smoking for at least two years, we saw important differences in how well they coped with exercise.”
Why this should worry parents of teenagers specifically
None of these participants were schoolchildren, they were young adults aged 18 to 30. But the implications for teenagers are sharper, not softer. The American Heart Association issued a scientific statement warning that adolescent cardiovascular systems may be particularly vulnerable to the chemical cocktail inhaled through e-cigarettes. The report from the AHA states that young e-cigarette users are at risk for developing increased arterial stiffness and higher blood pressure, along with elevated oxidative stress and inflammation. One of the statement’s authors was blunt about the disconnect between how vaping feels and what it’s actually doing: “While adolescents who use e-cigarettes may not feel that vaping is affecting them at the moment, it is increasingly clear that the chemicals contained within e-cigarette aerosols are harming cardiovascular cells.”
That’s precisely the trap of the quick vape before training. There’s no cough, no wheeze, nothing that flags a problem in the moment. The arteries are quietly getting stiffer and less responsive while the teenager laces up their trainers feeling perfectly normal. And because adolescence is when aerobic capacity and cardiovascular fitness are still being built, a repeated vascular hit during these formative years could set a lower ceiling for fitness that follows someone into adulthood, though researchers are honest that longer-term, dedicated adolescent studies are still needed to confirm exactly how far this extends.
What actually helps
If a teenager is vaping regularly and training seriously, the smartest single move isn’t switching flavours or cutting down to “just before matches”, it’s stopping altogether, ideally with support from a GP or a stop-smoking service designed for young people. Coaches and PE teachers might also want to rethink assumptions: a player who’s suddenly gassed earlier than usual, or whose recovery between sprints has slowed, isn’t necessarily unfit or undertrained. Faisal’s team is now planning MRI studies to look directly inside the heart, lungs and muscles of vapers, which should finally reveal exactly how these vascular changes take hold and whether they reverse once someone quits. Until then, the practical takeaway for anyone reaching for a vape before a session is straightforward: the lungs might pass every test you throw at them, but the pipes carrying oxygen to working muscles are already paying the price. As always, if you’re concerned about a teenager’s vaping habits or fitness changes, a conversation with your GP is the sensible next step.
Sources : newsroom.heart.org | ersnet.org