If you rely on a pre-workout coffee or a caffeinated supplement before training, there's a detail about your cardiovascular health you should know. Caffeine raises arterial stiffness, a well-established marker of cardiovascular risk. New research suggests that pairing it with beetroot, or more precisely with the nitrates it contains, may significantly blunt that effect.
That's a meaningful finding for athletes, recreational gym-goers, and anyone who treats caffeine as a non-negotiable part of their performance routine. Here's what the science actually says, and what you can reasonably do with it.
Caffeine and Arterial Stiffness: The Problem Worth Taking Seriously
Arterial stiffness refers to a loss of elasticity in the walls of your arteries. Flexible arteries expand and contract with each heartbeat, absorbing pressure. When they stiffen, the heart has to work harder, blood pressure spikes more sharply with each beat, and the risk of cardiovascular events increases over time.
Caffeine is known to acutely increase arterial stiffness. Studies measuring pulse wave velocity, the standard clinical tool for quantifying stiffness, consistently show that caffeine consumption raises this metric within 30 to 60 minutes of ingestion. For most healthy people, the effect is temporary. But for those consuming caffeine multiple times daily, or at doses common in pre-workout supplements (often 200 to 400 mg per serving), that repeated stress on the arterial walls becomes a legitimate concern.
The effect is dose-dependent and more pronounced in people who are not regular caffeine consumers. Habitual users develop some tolerance, but the stiffening response doesn't disappear entirely, even with long-term use.
Where Beetroot Enters the Picture
Beetroot is one of the richest dietary sources of inorganic nitrates. When you eat it, your body converts those nitrates into nitric oxide through a bacterial pathway in your saliva and gut. Nitric oxide is a vasodilator. It signals the smooth muscle lining your blood vessels to relax, which widens the vessels and lowers vascular resistance.
This is not fringe science. The nitrate-nitrite-nitric oxide pathway is well-documented, and beetroot juice has been used in exercise physiology research for over a decade. It improves oxygen efficiency during endurance exercise, lowers resting blood pressure, and, crucially here, reduces arterial stiffness.
The new research directly tested whether beetroot nitrates could counteract caffeine's stiffening effect. Participants who consumed beetroot alongside caffeine showed significantly attenuated increases in pulse wave velocity compared to those who took caffeine alone. In practical terms, the combination produced arterial stiffness readings closer to baseline than caffeine by itself did.
That's a striking result. It suggests the vasodilatory action of nitric oxide may be strong enough to offset the vasoconstrictive and stiffening effects that caffeine triggers through adenosine receptor blockade and increased sympathetic nervous system activity.
What This Means for Pre-Workout Stacking
The pre-workout supplement market is built heavily on caffeine. A standard commercial pre-workout product delivers anywhere from 150 mg to 400 mg of caffeine per serving, often alongside creatine, beta-alanine, and various amino acids. Beetroot extract or nitrate compounds are already appearing in some formulations, but typically for performance reasons rather than cardiovascular protection.
This research reframes that combination. If you're already taking a high-caffeine pre-workout, adding a nitrate source may not just improve your performance metrics. It may reduce one of caffeine's more underappreciated physiological downsides.
For context, a standard 250 ml serving of commercial beetroot juice contains roughly 300 to 500 mg of nitrates. Research protocols that show arterial benefits typically use doses in the 400 to 500 mg range. That's achievable through food without needing a separate supplement. Two medium-sized beetroots, consumed raw or juiced, will generally land you in that range.
If you're looking to optimize your training while managing recovery and cardiovascular load, combining these inputs is worth considering alongside other evidence-backed strategies. How long you rest between sets is another variable that directly affects cardiovascular strain during sessions, and it's one most people underestimate.
Whole Food vs. Supplement: Which Route Is Smarter?
You have options here, and the choice depends on convenience, cost, and what you're trying to optimize.
Whole beetroot is the most affordable and least processed option. You can roast it, eat it raw, or blend it into a pre-workout smoothie. It's widely available, costs a few dollars per week, and delivers fiber alongside the nitrates.
Beetroot juice is more concentrated and faster to consume. Commercial options are available in most grocery stores for roughly $3 to $6 per 250 ml bottle. The nitrate content varies by brand, so look for products that list nitrate concentration explicitly or opt for cold-pressed, unpasteurized versions, which tend to retain more active compounds.
Beetroot powder or extract capsules offer convenience but vary significantly in quality. Some products use heat-treated or heavily processed beet, which degrades nitrate content. If you go this route, look for standardized nitrate content on the label. Products in this category typically run $25 to $50 for a month's supply.
One important caveat: avoid using antibacterial mouthwash immediately before or after consuming beetroot. The nitrate-to-nitric oxide conversion depends on oral bacteria. Killing those bacteria with antiseptic mouthwash can reduce nitric oxide production by up to 90%, effectively neutralizing the benefit. This is a genuine, research-supported interaction that most people aren't aware of.
Timing: When to Take Each
Timing matters more than most people realize when combining these two inputs.
Beetroot nitrates take longer to peak than caffeine. Nitric oxide levels from a beetroot dose typically peak around 2 to 3 hours post-ingestion, though some studies show meaningful effects as early as 60 to 90 minutes in. Caffeine, by contrast, peaks in plasma at roughly 30 to 60 minutes after consumption.
That gap matters. To get the protective overlap you're looking for, beetroot should ideally be consumed 90 to 120 minutes before training, with caffeine taken closer to 30 to 45 minutes pre-workout. This ensures both compounds are active simultaneously during your session.
For athletes already using structured pre-workout protocols, fitting beetroot into this window isn't complicated. A small glass of beetroot juice two hours before training, followed by your usual caffeinated pre-workout 30 to 45 minutes out, covers the timing requirements without disrupting your existing routine.
Who Should Pay the Most Attention to This
Not everyone faces the same level of risk from caffeine-induced arterial stiffness. But several groups have more reason to act on this research.
- High-dose caffeine users. If your pre-workout or daily coffee habit puts you above 400 mg of caffeine per day, the cumulative arterial stiffening effect is more significant. The nitrate buffer is correspondingly more valuable.
- Older athletes. Arterial stiffness increases naturally with age. Adding caffeine-related stiffening on top of age-related decline is a compounding risk, not just an isolated acute effect.
- People with elevated blood pressure. Caffeine causes acute spikes in blood pressure partly through arterial stiffening. If your resting blood pressure is already at the higher end of normal, or if you have a diagnosed hypertensive condition, this interaction is clinically relevant.
- Endurance athletes. Those who rely heavily on caffeine for sustained output during long events are often consuming it at higher doses and for longer durations than gym-based athletes. The combination of exercise-induced cardiovascular demand and caffeine effects on vasculature is worth managing proactively.
For strength-focused athletes, this connects to broader conversations about how training load interacts with recovery and cardiovascular adaptation. Research into how just seven strength sessions can begin to shift metabolic markers shows that even modest training frequency produces measurable physiological changes. What you stack on top of that training, nutritionally and supplementally, shapes the outcome.
The Bigger Picture: Food-First Performance Nutrition
This research is a useful reminder that performance nutrition doesn't always mean adding more supplements. Sometimes it means using whole foods strategically to offset the downsides of compounds you're already using.
Beetroot is inexpensive, widely available, and backed by a substantial body of research. Its performance benefits, lower oxygen cost during exercise, reduced blood pressure, and now potential cardiovascular protection against caffeine, make it one of the better-supported functional foods in sports nutrition. It doesn't require a subscription, a sophisticated supplement stack, or significant financial outlay.
That said, this is a single study with a specific population and protocol. The magnitude of the protective effect may differ based on your individual nitric oxide responsiveness, your habitual caffeine intake, your fitness level, and your baseline arterial health. It's not a license to drink unlimited espresso on the assumption that a beet will fix everything.
What it does offer is a practical, low-risk addition to a pre-workout protocol that may make a real difference to your cardiovascular health over time. If you're already paying close attention to your training inputs, and you're looking at how diet, recovery, and supplementation interact, then understanding how different lifestyle factors stack together to influence cardiovascular and metabolic health is the right frame for evaluating this evidence.
Caffeine isn't going anywhere in performance nutrition. But if beetroot can take the edge off its cardiovascular cost, there's very little reason not to add it to the protocol. Start simple: a glass of beetroot juice before your next hard session, timed correctly, and see how your body responds.