Viagra, Beta-Blockers, and Benzodiazepines in Freediving

Buckle up — what's ahead is a long read. I've been sitting on the idea of two articles that, between them, would more or less exhaust the topic of doping in sport. You're reading the first one now: it covers the current state of play and the doping scandals we've already lived through. I promise it'll be a wild ride and that everyone will walk away knowing something they didn't before. So you don't get spooked by the wall of text, here's the abstract upfront, so it's clear what we're chewing on today:

Vlad Masterskikh AIDA pool champion

• Supplements, sports pharmacology, doping. What's the difference? And where does Viagra fit in?
• Malina, Čolak, and Žanki — disqualified for doping (beta-blockers), but Petrović is the one to blame (Malina drops Undisputed Truth).
• Klovar and Maričić visit Trubridge. The Viagra scandal that ended with CMAS putting it on the list.
• A deep dive into what Viagra actually is, how it works, whether it does anything for freediving, and the demolition of an enormous pile of myths.

So, friends — stripping away the romance, what's the goal of elite sport? Right: faster, higher, stronger (longer, farther, deeper) — and by any means necessary. Athletes give their entire lives to it and use every available tool to get there. Training, recovery, top-shelf gear, nutrition, sports supplements, sports pharmacology, and outright doping. The line between the last three is more or less arbitrary. The aim is the same — boost performance and recovery — only the efficacy, legality, and health consequences differ. Supplements are easy enough to peel off from the rest: you can buy them at any sports nutrition store, they aren't classified as PEDs, they're always non-synthetic compounds that you could in principle obtain from ordinary food. Their efficacy varies wildly, but every athlete needs to dial in a personal supplementation protocol, and they do. Take creatine — the most thoroughly studied and undeniably effective ergogenic aid out there. It's present in red meat, but to get the equivalent of 5 g of daily creatine monohydrate, you'd need to put down more than a kilo of beef every day. It boosts strength roughly 10% on a one-rep max (a massive effect), is safe and arguably beneficial for general health, and will never be banned — and yet it is taken purely to enhance performance (which already runs counter to the WADA "code", that hypocritical bedtime story for children). Supplements that meaningfully move the needle on your performance are few and far between; in general, the effect size tends to be modest at best.

Sports pharmacology is synthetic agents that aren't on the WADA prohibited list. I'm not even going to try to dress this up — what isn't banned is permitted. They're used for the same goals as supplements: better recovery, better bloodwork, better physiological output. And Viagra is the perfect case study for us. Sildenafil isn't on the WADA list, but CMAS, by virtue of its own additional bylaws, has banned phosphodiesterase type 5 (PDE5) inhibitors (which is the class Viagra belongs to) along with benzodiazepines. And here we run into a delicious paradox: you fly to the AIDA World Championships, take these compounds without a second thought, and you're a clean athlete; fly to a CMAS event with the same molecule in your system and suddenly you're a doper.

And finally, the third bucket — doping in the strict sense. The use of compounds you know damn well are prohibited in order to enhance performance: anabolic-androgenic steroids (AAS), testosterone esters, recombinant human growth hormone (rhGH), exogenous insulin, and so on. Used wholesale across Olympic and non-Olympic disciplines, the supposedly draconian anti-doping enforcement notwithstanding. That's a separate, much longer conversation — not the subject of this article.

Beta-Blockers and the Disqualification of Malina & Co.

One of the loud scandals from a few years back — there isn't a lot of information left about it on the internet. The gist is this: at a doping control, Malina, Čolak, and Žanki were caught using beta-blockers and disqualified from sport (I don't remember the exact term, but something like three years). Beta-blockers are a cardiology workhorse — indicated for arterial hypertension, ischemic heart disease, tachyarrhythmias, and chronic heart failure. The pharmacodynamic effect is a reduction in heart rate and a decrease in myocardial oxygen demand — and as you can guess, that's exactly what athletes are chasing. The legal status of beta-blockers under WADA is as follows: they are prohibited in specific disciplines (shooting, darts, billiards, motorsport, and our beloved freediving) — i.e., wherever they confer a tangible competitive edge (in shooting, you have to fire between heartbeats so your hand doesn't drift, and at a heart rate of 120 that's borderline impossible). If you decide that in a non-restricted sport they'd give you an edge and you start taking them, you've now drifted into the sports-pharmacology bucket. Their duration of action depends on the specific molecule but runs roughly 24 hours, and the urinary detection window exceeds the elimination half-life by a multiple, sitting at several days. This category of doping isn't really a threat to sport — if doping control (DC) is conducted, the compound will be detected, full stop. A separate conversation altogether is Russian domestic events — I genuinely can't recall the last time anyone was tested there — feel free to load up on whatever you want.

What's interesting here is some of the granular detail of this scandal and the psychology of the athletes involved. A bit later, Malina published a sprawling piece called Undisputed Truth in which he accused Branko Petrović of riding beta-blockers. He later took the article down and I can no longer dig it up, but the gist was that Branko was setting all his records at meets without doping control, and on tested events his performance cratered. Now here's the interesting case study in how athletes drift into doping. He and Čolak were both competing at the FAZZA static apnea events in Dubai — no anti-doping testing, and seriously fat commercial purses (some years, if memory serves, the sheikhs were handing out cars — Nissan Patrols, Range Rover Sports). Malina is talented, trains his ass off, and is no fool. He understands exactly why Branko is outholding him, can't prove it, and the meet is untested anyway — so what are his options? Either don't compete, or join in. Small spoiler for the next article: this is how weightlifting (and track and field, and cycling) operates. No matter how genetically gifted you are, if you don't dope you will never be world champion — those numbers are simply not achievable on natural training. Either quit the sport or play the game.

Klovar and Maričić at Vertical Blue

Now we get to "doping" scandal No. 2 and the reason most of you are here. Vertical Blue 2023. The organizer is William Trubridge — the bloke who, breaststroking through Blue Hole in Speedos in a video I still consider one of the most legendary pieces of footage in freediving, and the then-current CNF world record holder. Up close, he turned out to be a deeply envious character who, unable to reproduce or improve on his own record, was furiously trying to defend it through every other available avenue. Everyone knew Klovar was poised to take it down — and he subsequently did. Nevertheless, the meet rules forbade not just taking prohibited substances but possessing or transporting them. During a covertly audio-recorded search of their luggage, Klovar and Maričić were found with sildenafil, furosemide, and diazepam. Of those, only furosemide is prohibited — a loop diuretic (almost all diuretics are on the list as masking agents used to dilute or accelerate clearance of doping metabolites). Diazepam is an anxiolytic, and its effect in freediving is dubious at best, arguably negative; it was banned by the meet rules. Whether Viagra was additionally banned by the meet rules, I don't know. That said, no actual finding of doping was ever established, and Klovar and Maričić weren't disqualified from competing in other events. As fallout, CMAS added PDE5 inhibitors and benzodiazepines to their prohibited list, and you cannot take them while competing under the CMAS banner. AIDA still defers solely to the standard WADA list, which contains neither — so there, you can take them freely.

Now let's bulldoze a few myths

Myth 1: "Slip somebody a Viagra and they'll walk around all day with a hard-on"

Libido and sexual desire are governed primarily by testosterone and luteinizing hormone (LH). Tadalafil is not a hormonal agent; it has no effect on libido. Only when ordinary psychological and physical erotic stimuli are present does it help produce a higher-quality and more sustained erection. If a man's erectile dysfunction is hormonally driven and rooted in low libido, tadalafil isn't going to fix anything.

Myth 2: "Athletes on Viagra lie there with a hard-on, then sprint at the end of the dive because of it"

Same flavor of nonsense as the first. There's no way to clinically detect tadalafil use unless the side effects show up — headache, hypotension, nasal congestion. Tadalafil simply makes the physiological cascade underlying erection — which is fundamentally a vascular event — more pronounced and more durable. It does not initiate it.

Myth 3: "Viagra raises nitric oxide and that's why it works for breath-hold"

I get that this is a lot, but we have to dismantle one more entrenched athlete misconception. The myth that Viagra will improve your performance arose from the belief that it raises nitric oxide (NO) levels. Side note: among supplements with documented NO-elevating effects — concentrated beetroot juice (dietary nitrate), L-citrulline, and L-arginine — you can take any of them in any federation without restriction. Let's look at what NO actually does:

Mitochondria

• modulates the respiratory chain
• affects oxygen utilization

Nervous system

• acts as a neurotransmitter
• participates in signal transduction

Sounds promising, except — first, don't forget that NO is a vasodilator, while the diving response is fundamentally a vasoconstrictive reflex, which means the net effect on a breath-hold is highly ambiguous and may well be net-negative. And, more importantly: tadalafil doesn't act on nitric oxide at all. It inhibits the enzyme that degrades cGMP (cyclic guanosine monophosphate), and cGMP, downstream, no longer carries the broader effects of NO — it's most potent specifically in penile vasculature, where it relaxes the trabecular smooth muscle and improves blood flow.

The actual mechanism, in plain terms

So, to sum up: tadalafil does not produce an erection. It blocks the enzyme that breaks down cyclic GMP, the second messenger responsible for vasodilation and smooth-muscle relaxation. Cyclic GMP is itself synthesized in response to NO release. The PDE5 isoenzyme is concentrated predominantly in penile vasculature — hence the headline effect — but it's expressed throughout the body, with notably elevated concentrations in the pulmonary artery. That, and only that, is the basis on which freedivers cling to any hope of an ergogenic benefit. Meanwhile, the same mild vasodilatory effect can manifest in peripheral vasculature, which would increase peripheral blood flow — and that's bad for us, because the more pronounced the blood shift, the better.

There is not a single study showing that PDE5 inhibitors meaningfully improve aerobic threshold, anaerobic threshold, time-to-exhaustion at maximal load, or VO₂max. Which is precisely why they're not banned in sport. Tadalafil can be brutally effective for its on-label indication, but no further. Common adverse effects include cephalgia and a drop in blood pressure, so when you weigh the net effect on freediving, it ranges from zero to mildly positive or mildly negative. Categorically not "+15 m." You can run the experiment yourself: urinary metabolites are detectable for at most ~5 days, so you'd need to washout for at least a week before any doping control if you're competing in CMAS — and out-of-competition use isn't prohibited, since the drug only works in the moment of administration and there's no functional substitute for patients who clinically need it. Take 5 mg of tadalafil and head into a training session. The result will sit comfortably within your normal day-to-day variance (remember, your max is always going to be modulated by sleep, recovery, mental state, and so on). One day you might swim 200, two days later 215 with nothing on board; but if you take tadalafil and your second attempt happens to come up 215, you'll be tempted to falsely attribute it to the drug. That there will be no statistically meaningful gain — I can practically guarantee. Your wife, on the other hand, may well enjoy the evening.

What about women?

Final question — what about a woman taking it? Same story. Same mechanism — vasodilator. In the context of arousal, there's some probability of improved blood flow to the clitoris and vaginal walls and better lubrication, but the data are mixed. As for peripheral vasculature and the pulmonary artery, the effect profile is identical.

Bottom line — the bullet-form summary

That was a lot of information. I hope you held up through the physiology section, but I'm now confident my readers are among the most pharmacologically literate people in the entire freediving community on this question. Let's wrap it up in bullet form to pull it all together:

• Tadalafil is permitted under AIDA and prohibited under CMAS.
• It does not raise NO and does not produce an erection on its own.
• The principal effect is relaxation of smooth muscle and vasculature in the male genital region; mild systemic vasodilation across the body (likely a net negative for breath-hold performance), and in the pulmonary artery (likely a net positive). The net effect on apnea performance is comparable to placebo.
• To raise NO: concentrated beetroot juice, L-arginine, L-citrulline (1.5–3 g/day), and physical exercise. The effect is vasodilatory — also a negative. May improve mitochondrial function, but excess NO is, on balance, deleterious. Overall, supplementing for NO will produce roughly nothing in freediving terms, and NO's effect on breath-hold itself is equivocal.

That's it for today. On the whole, tadalafil, beta-blockers, and benzodiazepines are doping for kindergartners — and the entire saga so far really only demonstrates that there are essentially no people or physicians who actually understand the pharmacology in freediving (which, frankly, is a good thing). Somebody started taking it, the rest reasoned "well, if he's on it, I'd better be too," CMAS looked over and decided "well, they're taking something — that must be why they dive so deep, let's ban it" — and that's roughly the level of logic and evidence at play. Share the article, drop your thoughts in the comments. If the format and my take on these questions land for you, one of these days I'll publish the second article — about the real doping that's worth being afraid of in freediving, about the illusion of clean sport, about whether steroids and exogenous testosterone are confined to the strength disciplines or whether cyclists and marathoners are on them too, about the anti-doping control system and why it doesn't work, and a lot more.

P.S. And a small disclaimer. Prohibited substance lists change constantly — please verify against the primary source (WADA Prohibited List). The author of this article bears no responsibility for any substances you choose to take or for any violations of competition rules.