There has probably never been a more confusing time to be an endurance athlete interested in sports nutrition.
A decade ago, the supplement conversation was relatively straightforward. Caffeine worked, sodium bicarbonate was effective but notoriously difficult to tolerate, and carbohydrates remained the boring but indispensable foundation of endurance performance.
Today, things look different. Elite athletes are consuming carbohydrates at rates that would have seemed extreme not long ago. Bicarbonate has been repackaged into sophisticated hydrogel systems. Ketone shots promise another energy source for the brain and body. Concentrated compounds from cruciferous vegetables are being investigated for their effects on the lactate response to exercise. And perhaps strangest of all, companies are now selling lactate itself as fuel.
The physiology behind many of these ideas is genuinely fascinating. But the problem is that a supplement can change physiology without improving performance. That distinction—between changing a biomarker, improving a lab exercise test, and improving actual race performance—may be the most useful lens for viewing the modern supplement boom.
Here’s how I’ve been thinking about it, and my take on a few of the hottest supplements at the moment.
The Real Revolution Isn’t a New Supplement — It’s Fueling More
The explosion of performance products can make it seem as though sports science has suddenly discovered a collection of new molecules. In reality, many of the compounds attracting the most attention are old.
Sodium bicarbonate is baking soda. Nitrate is abundant in vegetables. Creatine has been investigated for decades. The human body has always generated and consumed lactate. What has changed is our ability to deliver these compounds more strategically—and our willingness to push sports nutrition harder.
Carbohydrate fueling is perhaps the clearest example.
Older endurance practices often clustered around roughly 30 to 60 grams of carbohydrate per hour. Using multiple transportable carbohydrates such as glucose and fructose helped athletes move toward higher intake rates, and contemporary endurance athletes now routinely experiment with around 90 grams per hour and, increasingly, above 100 grams per hour.
A particularly interesting experiment published in the Journal of Applied Physiology studied eight highly trained or elite male marathoners while they ran for two hours consuming 60, 90, or 120 grams of carbohydrate per hour.1Ravikanti, S., Silang, K. G., Martyn, H. J., Johnson, K. O., Louis, J. B., Bampouras, T. M., Owens, D. J., Jones, A. M., Morton, J. P., & Pugh, J. N. (2025). 13 C-labelled glucose-fructose show greater exogenous and whole-body CHO oxidation and lower O 2 cost of running at 120 versus 60 and 90 g·h −1 in elite male marathoners. Journal of Applied Physiology, 139(6), 1581–1595. https://doi.org/10.1152/japplphysiol.00665.2025 During the second hour, exogenous carbohydrate oxidation averaged 0.89 g/min at 60 g/h, 1.31 g/min at 90 g/h, and 1.68 g/min at 120 g/h. The investigators also reported a lower oxygen cost at 120 g/h than at 60 g/h.
The study highlights an important shift. We are no longer asking whether athletes can consume a certain number of carbohydrates, but rather how much they can absorb, tolerate, and actually “burn” while racing.
And that may be more representative of the modern sports-nutrition revolution than any exotic new supplement. Fueling is increasingly being treated like training: something you can progressively practice and individualize rather than improvise on race morning (please, for your own sake, do not attempt 120 grams of carbs per hour for the first time on race day).
Lactate Is Not The Enemy
Few molecules have undergone a greater public-relations transformation than lactate.
For decades, we were taught some version of the same story: exercise intensity rises, oxygen becomes insufficient, “lactic acid” accumulates, and lactate causes the burning sensation and fatigue that eventually force us to slow down.
That explanation is badly outdated.
Lactate is produced continuously, including under aerobic conditions. Muscles and the heart can use it as fuel, convert it back into glucose, transport it between cells and organs, and use it in cellular signaling. George Brooks’s lactate-shuttle work helped drive this major shift in how exercise physiologists think about the molecule.2Brooks, G. A. (2018). The science and translation of lactate shuttle theory. Cell Metabolism, 27(4), 757–785. https://doi.org/10.1016/j.cmet.2018.03.008
One useful way to think about blood lactate is as a bathtub.
The water level depends on both the faucet and the drain. Similarly, blood lactate concentration reflects the balance between lactate appearance and lactate removal. An elevated concentration therefore does not simply tell us that muscles are suddenly “producing too much lactate.” Production, transport, oxidation, and clearance are all occurring simultaneously.
This becomes especially important once supplements enter the conversation.
A supplement-induced reduction in blood lactate may look impressive. But unless that change is accompanied by better performance, greater sustainable power, improved recovery, or another meaningful endpoint, the biomarker itself doesn’t tell us whether the athlete improved.
Conversely, higher lactate is not necessarily bad.
Sodium bicarbonate provides a perfect example…
Sodium Bicarbonate: An Old Trick With a Better Delivery System
Sodium bicarbonate may be one of the best examples of how better delivery can revive an old ergogenic aid.
There is nothing novel about the molecule itself. Athletes have been experimenting with baking soda for decades.
Its primary role is extracellular buffering. Ingesting a sufficiently large dose increases blood bicarbonate and blood pH, improving the body’s ability to handle the acid-base disturbances associated with very intense exercise. That is importantly different from “clearing lactate.”
In fact, bicarbonate can allow an athlete to sustain greater glycolytic flux and export more lactate and hydrogen ions from working muscle. Blood lactate may therefore be higher during successful bicarbonate supplementation, not lower.
The evidence is strongest for high-intensity efforts, traditionally in the range of roughly one to ten minutes, although newer studies suggest the useful window may extend further. A 2024 study gave 14 trained male cyclists 0.3 g/kg of sodium bicarbonate delivered as mini-tablets within a carbohydrate hydrogel.3Shannon, E. S., Regnier, A., Dobson, B., Yang, X., Sparks, S. A., & Mc, R. (2024). The effect of sodium bicarbonate mini-tablets ingested in a carbohydrate hydrogel system on 40 km cycling time trial performance and metabolism in trained male cyclists. European Journal of Applied Physiology, 124. https://doi.org/10.1007/s00421-024-05567-3 In a 40-kilometer cycling time trial, bicarbonate improved finishing time by an average of 54 seconds, equivalent to approximately 1.42%, compared with placebo.
That is meaningful, but it does not demonstrate that bicarbonate improves marathon running. Forty-kilometer cycling at high intensity is physiologically different from running 42.2 kilometers, and we should resist extending a result beyond what the experiment allows.
The practical challenge is also substantial. A dose of 0.3 g/kg means that a 70-kilogram athlete is consuming 21 grams of sodium bicarbonate. Traditional protocols are notorious for producing nausea, bloating, abdominal pain, diarrhea, and sometimes vomiting.
That is why delivery systems matter. In the same 2024 study, gastrointestinal symptoms did not differ significantly between the hydrogel bicarbonate condition and placebo—one reason the result attracted so much interest.
Broccoli and Kale Sprouts: Early and Interesting, Not Yet Proven
One of the more interesting emerging ideas comes from glucosinolate-rich vegetables and the isothiocyanates they produce.
These compounds are abundant in cruciferous vegetables such as broccoli and kale and interact with cellular stress-response systems, including pathways involving Nrf2, a transcription factor that regulates numerous antioxidant and cell-protective proteins.
That biology has led to the hypothesis that concentrated glucosinolate or isothiocyanate preparations might alter metabolic responses to exercise.
The human evidence is intriguing, but very early. A 2023 randomized double-blind crossover experiment involved just nine participants completing seven days of intense exercise training while consuming glucosinolate-rich broccoli sprouts or placebo.4Flockhart, M., Nilsson, L. C., Tillqvist, E. N., Vinge, F., Millbert, F., Lännerström, J., Nilsson, P. H., Samyn, D., Apró, W., Sundqvist, M. L., & Larsen, F. J. (2023). Glucosinolate-rich broccoli sprouts protect against oxidative stress and improve adaptations to intense exercise training. Redox Biology, 67, 102873. The sprout intervention was associated with lower submaximal lactate and changes in oxidative-stress-related outcomes during training.
More recently, a 2026 randomized trial tested an acute dose of glucosinolate-rich red kale sprouts in 15 healthy participants. Three hours after consuming either 37.5 grams, 75 grams, or a placebo beverage, subjects completed submaximal cycling. At the highest workload, the 37.5-gram condition produced blood lactate concentrations approximately 0.4 mmol/L lower than placebo. That is a real physiological effect. But it is not yet a performance result. The researchers did not show that athletes raced faster because their lactate was lower. Nor does a lower lactate concentration tell us exactly whether production fell, clearance increased, or substrate metabolism shifted in some other way.
That distinction matters because products built around this concept can easily be marketed as though “lower lactate” is synonymous with “better endurance.” It is not.
Beetroot and Nitrate: The Best-Supported Bet on This List
Beetroot has already survived an entire hype cycle.
It became especially visible around the 2012 London Olympics, when concentrated beetroot shots appeared throughout elite sport.
The important molecule is not the red beet pigment. It is nitrate.
Dietary nitrate is converted to nitrite, with oral bacteria playing an important role in that step. Nitrite can subsequently contribute to nitric oxide formation. Nitric oxide influences vascular tone, skeletal muscle function, and several aspects of exercise energetics.
So does that translate into better performance? Sometimes.
A major 2025 review brought together 20 systematic reviews and meta-analyses representing 180 studies and 2,672 participants. Nitrate supplementation improved several outcomes, including time-to-exhaustion performance, muscular endurance, total distance covered, and peak power.
Nitrate is one of the better-supported nutritional ergogenic aids, but the size and consistency of the benefit depends on the athlete, dose, training status, and performance task. The fitter you are, the less it appears to work. But that doesn’t mean it’s not worth a shot (pun intended).
Lactate as Fuel? The Strangest New Idea in Sports Nutrition
Perhaps the strangest development in endurance nutrition is the shift from treating lactate as metabolic trash to deliberately consuming it.
Lactate is an oxidizable fuel. Working tissues continuously produce, exchange, and consume it. The intriguing hypothesis is that ingested lactate might provide usable substrate through transport pathways that are at least partly distinct from the intestinal transport systems relied on by glucose and fructose. This becomes particularly interesting when endurance athletes already push carbohydrate intake toward 100 to 120 grams per hour.
Could lactate provide another route for getting fuel into the system?
A 2024 study gave 15 recreational exercisers either placebo or an oral lactate supplement before cycling.5Ewell, T. R., Bomar, M. C., Brown, D. M., Brown, R. L., Kwarteng, B. S., Thomson, D. P., & Bell, C. (2024). The Influence of Acute Oral Lactate Supplementation on Responses to Cycle Ergometer Exercise: A Randomized, Crossover Pilot Clinical Trial. In Nutrients (Vol. 16, Issue 16, p. 2624). PubMed. https://doi.org/10.3390/nu16162624 Lactate supplementation did not significantly alter VO₂peak, ventilatory threshold, or the workload associated with lactate threshold. But during a 20-minute cycling time trial, average power was 204 watts with lactate versus 197 watts with placebo, an improvement of roughly 4%.
This is exactly the sort of area where I would rather say “watch this space” than declare a breakthrough. We already know lactate can be fuel. What we do not yet know is whether intentionally adding it to endurance nutrition reliably makes trained athletes faster.
Ketones: Great Theory, Underwhelming Results
Ketones may be the perfect example of a supplement whose theoretical appeal outpaced its performance evidence.
Ketone bodies such as beta-hydroxybutyrate are normally produced by the liver during periods of low carbohydrate availability, including fasting and ketogenic dieting.
Exogenous ketone products allow blood ketone concentrations to rise without requiring an athlete to deplete glycogen or eliminate carbohydrate.
Carbohydrates are fuel. Ketones are fuel. Why not provide both?
Because metabolism is rarely that simple.
A meta-analysis of 13 randomized trials found no significant overall improvement in exercise performance with acute ketone supplementation. The pooled effect for overall performance was essentially zero, and separate analyses of endurance time trials also found no significant advantage.6Valenzuela, P. L., Morales, J. S., Castillo-García, A., & Lucia, A. (2020). Acute Ketone Supplementation and Exercise Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. International Journal of Sports Physiology and Performance, 15(3), 298–308. https://doi.org/10.1123/ijspp.2019-0918
A broader systematic review similarly found a mixture of positive, null, and negative outcomes: among 16 performance outcomes, three favored ketones, ten were null, and three were negative.
And a 2024 study makes the biomarker-versus-performance distinction especially clear.7Gonzalez, M., Jachino, C., Murphy, B., Heinemann, K., Magrini, M. A., Bredahl, E. C., Eckerson, J. M., & Siedlik, J. A. (2024). The Effect of Acute Ketone Supplementation on Time to Fatigue in NCAA Division I Cross-Country Athletes. Nutraceuticals, 4(2), 232–240. https://doi.org/10.3390/nutraceuticals4020014
Researchers tested a commercial ketone supplement in 12 NCAA Division I cross-country runners. Post-exercise blood lactate was significantly lower with the ketone supplement—by an estimated 4.6 mmol/L—yet time to fatigue did not improve significantly. Athletes actually reached voluntary exhaustion an average of 1.2% sooner in the supplement condition.
Ketones may still prove useful in specific situations such as exercise recovery and enhancing training adaptations. They are scientifically interesting, especially to me, but they just are not reliably ergogenic (performance-enhancing) yet.
Creatine: Built for Power, Not for Endurance
Unlike many newer supplements, creatine is supported by an enormous body of research.
The creatine-phosphocreatine system helps buffer cellular energy demand by rapidly regenerating ATP. That makes creatine especially effective for strength, power, sprinting, and repeated high-intensity work.
But what happens when we look specifically at endurance?
A 2023 systematic review and meta-analysis included 13 placebo-controlled studies in trained individuals and found no significant improvement in endurance performance with creatine.8Fernández-Landa, J., Santibañez-Gutierrez, A., Todorovic, N., Stajer, V., & Ostojic, S. M. (2023). Effects of Creatine Monohydrate on Endurance Performance in a Trained Population: A Systematic Review and Meta-analysis. Sports Medicine, 53(5), 1–11. https://doi.org/10.1007/s40279-023-01823-2
That does not make creatine irrelevant to endurance athletes. Runners lift weights (at least they should). They sprint. They run hills. They perform intervals. They may need to produce a finishing kick after prolonged aerobic exercise. Creatine may support those components of training even if it does not directly improve steady-state endurance performance.
So what is actually worth taking?
I can’t give you a single answer because a supplement’s usefulness depends on the athlete, event, and problem being solved.
For endurance athletes, one of the largest nutritional levers is still getting carbohydrate intake right and training the gut to tolerate it. The recent elite-marathon data show that athletes can oxidize very high intakes, but they also reinforce that tolerability and performance still need to be established individually.
- Dietary nitrate has a substantial evidence base, but its average effects are modest and vary considerably across protocols and performance tests.
- Sodium bicarbonate is a legitimate ergogenic aid, particularly when glycolytic demand is high, but its practical usefulness depends heavily on the event and the athlete’s ability to tolerate the dose.
- Creatine is extremely well supported for strength and repeated high-intensity work, while its direct effect on continuous endurance performance appears minimal. Its emerging cognitive research makes it increasingly interesting for endurance athletes for reasons that extend beyond running economy or VO₂max.
- Ketones remain biologically fascinating but inconsistent as an acute endurance-performance aid.
- Glucosinolate- and isothiocyanate-based strategies have intriguing early human evidence showing altered lactate responses, but we need much more performance data before concluding that they make athletes faster.
- And lactate supplementation might represent a genuinely new frontier, but we are nowhere close to declaring lactate the next essential marathon fuel.
This uncertainty is how sports science is supposed to work.
The mistake is assuming that because a mechanism sounds compelling, the performance outcome has already been settled. The best athletes increasingly use sophisticated fueling and supplementation strategies because they are chasing fractions of a percent. But they are usually doing so after years of training, careful fueling, individualized testing, and deliberate experimentation.
In conclusion: A supplement can be useful without being necessary. And before asking what else to add to your stack, the better question is to ask what performance problem you’re trying to solve. That will ultimately determine whether a supplement is “worth it” or not for you.
References
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