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The peloton of the Tour de France 2026 rides into another mountain stage, and a soigneur from UAE Team Emirates-XRG hands Tadej Pogačar a bottle with something new in it. It doesn’t only contain glucose and fructose. It also contains lactate, a compound athletes were taught for decades to avoid, and which is now being sold as fuel.

This isn’t a forum rumour. Enervit and its rival From Lab to Field have officially confirmed testing lactate gels and drinks during this year’s Tour. It’s the question every amateur triathlete asks: does this actually make sense for them, or is it another fad that will vanish from the shelves as fast as it appeared?

What lactate actually is as fuel

Forget what you were taught in PE class. Lactate, lactic acid in its dissociated form, is not waste that “acidifies” muscles and needs to be “flushed out” with a jog. This is established physiology, confirmed for decades: the lactate shuttle theory, developed by Prof. George A. Brooks of UC Berkeley, shows that muscles, the heart and the brain use lactate as an energy source in real time, during exercise. This isn’t speculation, it’s textbook exercise physiology.

The novelty isn’t the knowledge about lactate itself. It’s the attempt to deliver it externally, in a form the body can actually use without triggering a stomach disaster. A standard carbohydrate gel has a natural ceiling: glucose enters the bloodstream through a single intestinal transporter, and above 60g/h it stops giving any extra benefit. Adding fructose, which uses a different transporter, raises that ceiling to 90-120g/h, and that’s the basis of today’s carbohydrate gels. Lactate manufacturers claim it enters through a third, independent pathway, so in theory it could push that energy limit even higher. In theory, and that word does all the work here.

Who’s testing it, and what’s actually in it

Two specific products are circulating at the Tour, not one.

ExoLactate is the result of seven years of work by Aitor Viribay, a doctor of exercise physiology and former head physiologist at Ineos Grenadiers, now working in performance at Salomon. Enervit, meanwhile, doesn’t use its product routinely on every stage. UAE Team Emirates-XRG’s nutritionist, Gorka Prieto-Bellver, told Cyclingnews plainly: “we use it when it’s needed, not always… on stages where energy expenditure is high.” That sounds reasonable enough, since the team itself admits it’s still testing rather than running a proven protocol.

What the research confirms, and what is marketing

This is where physiology needs to be separated from sales.

Prof. Brooks, whose years of research Enervit built this product on, called C2:1PRO “a breakthrough that starts a new era in sports nutrition.” That’s a quote repeated in the manufacturer’s promotional material, not a conclusion from an independent clinical trial. Worth keeping those two things apart.

The actual research says little, and what exists is mixed. A randomised, double-blind crossover study from 2024 (Ewell et al., published in Nutrients) was not conducted on professionals: it involved 15 recreationally active people with an average age of 24, and the authors note that none belonged to the elite. Calcium and magnesium lactate supplementation didn’t change VO2peak, lactate threshold or ventilatory threshold. It recorded a 4 percent increase in average power over a 20-minute time trial, with no change in heart rate or perceived exertion. That’s a signal, but from a small pilot sample of amateurs, not proof for a professional.

A second 2024 study (Bordoli et al.) went the other way and involved 16 trained cyclists, at a higher dose of about 120mg/kg of body weight, roughly 8g for a 70kg (154lb) rider. Across five repeated blocks with 1km and 4km trials, it showed no time benefit at all, even though it raised blood bicarbonate levels and lowered perceived exertion. A 2025 study from the University of Tokyo (Seike, Takahashi, Hatta) confirmed that the body metabolically uses orally administered lactate, but it also found no breakthrough in performance.

The shared conclusion from these three studies: exogenous lactate works mostly as a mild acid-base buffer, similar to the already familiar sodium bicarbonate. It reduces perceived exertion and changes blood chemistry, but doesn’t reliably produce a measurable time advantage. Olav Bu, head of performance at Uno-X Mobility, is even more reserved in comments to Cyclist magazine: lactate delivers less energy than glucose for a similar absorption cost, and his team’s own research hasn’t yet found a “hard ceiling” for exogenous carbohydrate oxidation. Until that ceiling is established, lactate remains a less efficient fuel than what’s already known.

Gut tolerance: promising, but not independently confirmed

Manufacturers and some riders report that the new formulations, in ExoLactate’s case at a dose of 15-25g of lactate per hour, cause less gastrointestinal irritation than earlier, prototype versions of lactate supplements. That matters, because previous attempts at oral lactate had exactly this problem: it was hard to absorb a meaningful dose without stomach pain during exercise.

It’s worth being precise here, though: these are reports from the manufacturer and athletes at the race, not the result of a controlled study on gut tolerance under race conditions. No such study exists for this specific formulation. Lactate is, however, a substance the body produces naturally, so these products aren’t on the prohibited substances list. That’s one of the few things here that can be stated without qualification.

What this means for you as an amateur

Neither of these products is available for normal purchase yet. ExoLactate will reach the market after the Tour de France 2026 ends, Enervit C2:1PRO after the Vuelta a España, in September. Neither manufacturer has released a retail price yet, so there isn’t one here either. Don’t guess at it based on comparisons to gels like Maurten.

Before you trade a proven carbohydrate gel for something with lactate, it’s worth remembering: the strategy of 90-120g of carbohydrate per hour in a glucose-fructose mix has decades of research and years of race testing behind it. Lactate has three small, contradictory studies behind it and an enthusiastic quote from a press kit. That doesn’t mean the topic is meaningless, since Aitor Viribay spent seven years on this and UAE Team Emirates-XRG wouldn’t be testing it without reason on cycling’s biggest stage. It means that, for now, this is an elite experiment, not a protocol ready to copy for your next half-distance race.

If this topic intrigues you, watch what appears after September, and don’t try anything new for the first time on race day. That rule applies to lactate even more than to an ordinary gel, since there’s far less data on its tolerance under race conditions.

You would think a triathlete, someone who spends long hours outdoors on a bike or in running shoes, would be the last person to worry about vitamin D.

The research says otherwise. Deficiency shows up in endurance athletes surprisingly often, including well-tanned ones. The reason is geographic and biological, and it applies directly to anyone training and living in countries with less sun.

Sun caught during a session is not enough on its own. Here is why, and how the theory translates into watts and faster recovery.

1. Why sunlight is not always enough for a triathlete

Skin only produces vitamin D when the sun sits high enough in the sky. From October to March the angle of UVB radiation is too low for any synthesis to happen in the skin, even on a training run in full sun with no shirt on.

That is not the whole story. Even in summer, when sunlight is theoretically plentiful, triathlon habits themselves get in the way:

• UV filters (SPF 30/50): sensible sun protection against burns and melanoma during a five-hour ride is the right call. But an SPF 15 sunscreen blocks vitamin D synthesis by more than 95%, and SPF 30 blocks it almost completely.
• Training hours: to fit sport around work and avoid summer heat, most training happens early morning or late afternoon, when the sun’s angle rules out skin synthesis.
• Technical clothing: fitted cycling and running kit covers most of the body.

The result is a season spent covering thousands of kilometres, a cyclist’s tan lined up perfectly with shorts and jersey, and an autumn that starts with an empty vitamin D reserve.

2. What vitamin D does for muscles and bones

For an athlete this is not just an “immunity” vitamin. It behaves as a hormone with a strong anabolic and metabolic role.

Faster type II muscle fibres

Vitamin D receptors sit directly in muscle tissue. A deficiency leads to fatty degeneration of type II fibres, the fast-twitch fibres responsible for a finishing kick, power on climbs, and sudden force output on the bike.

Protection against stress fractures

Without vitamin D, calcium absorption in the gut drops sharply, by as much as 50 to 80%. You can drink litres of isotonic drinks and eat a dairy-rich diet, but with low vitamin D your bones will still lose density. Combined with a high running volume, that is a straight path to stress fractures that can end a season for months.

Faster recovery and lower inflammation

An optimal vitamin D level suppresses pro-inflammatory cytokines and speeds up repair of muscle micro-damage after hard sessions. Research also shows a clear correlation between high blood levels of 25(OH)D and a higher VO2max in endurance athletes.

The enzymes that activate vitamin D in the liver and kidneys need magnesium to work. If you train hard, sweat heavily and run low on magnesium, even high doses of vitamin D may raise your blood level poorly. Keep the two in balance.

3. Target levels for athletes: Polish 2023 guidelines

Vitamin D status is measured through the blood metabolite 25(OH)D. Under the latest official guidelines for Central Europe (Płudowski et al., 2023), your supply status breaks down as follows:

While a level of 30 ng/ml is enough for an inactive person, endurance athletes aim to hold a stable level between 40 and 50 ng/ml.

4. How much to supplement: prevention versus treatment

Dosing should match your current blood result and the time of year.

Prevention, for healthy adults

If between May and September you train in full sun, arms and legs uncovered, no SPF, for at least 30 to 45 minutes between 10:00 and 15:00, you can skip supplementation over summer. Otherwise, and as standard from October to April:

• At a normal body weight: 1,000 to 2,000 IU a day (cholecalciferol).
• With overweight or obesity, BMI over 30: double the dose, 2,000 to 4,000 IU a day, year-round.

Treating a confirmed deficiency, 20 ng/ml or below

If testing shows a deep deficiency, a preventive 2,000 IU will not be enough. A treatment protocol is then run under a doctor’s or dietitian’s supervision:

• Therapeutic doses: typically 4,000 to 10,000 IU a day for one to three months, depending on the severity of the deficiency and body weight.
• Bundled dosing: current guidelines allow safely bundling doses, for example once a week at 20,000 to 30,000 IU instead of small daily amounts, a useful option for anyone who forgets a daily pill.
• Follow-up: after 8 to 12 weeks of treatment, retest, and once the target level is reached, above 30 to 40 ng/ml, switch to a maintenance dose.

A note of caution: current guidelines advise against single, high-dose “mega” boosts, for example 100,000 IU at once, in Poland without a clear clinical indication, because of the load on the kidneys. Steady daily or weekly supplementation is considerably safer.

5. How, when and for how much to test vitamin D

For a triathlete, the rule is simple: test first, then dose. Vitamin D is fat-soluble and accumulates in the body, so it should not be taken blind in very large amounts.

• Cost: a private 25(OH)D test at a lab typically runs about $20 to $60 – depending on country. Look for “packages for runners” or “active people”, which often bundle a blood count, iron and ferritin with the vitamin D test at a better combined price.
• When to test: March or April, at the end of winter, is when levels are at their lowest, a true test of whether winter supplementation worked. October, at the end of the season, shows how well natural summer sun protected you into autumn.
• Preparation: you do not need to fast, unless other parameters are being tested too. Stop vitamin D supplementation 3 to 5 days before the blood draw, so the result reflects your real stored reserve rather than a recently taken capsule.
• Take vitamin D with a meal that contains some fat, for example with scrambled eggs, a meal with olive oil, avocado or peanut butter. Taken on an empty stomach it absorbs poorly.

Vitamin D is one of the cheapest, and most underrated, performance factors in endurance sport. Get tested, plan supplementation around the result, and do not let one small blood parameter cost you power on the day that matters most.