Keto Training in 2025: A Sport‑Specific, Evidence‑Based Fueling Guide (No Ketone Supplements Required)

What changed—and why it matters in November 2025

• UCI guidance for pros: On October 20, 2025, the UCI formally discouraged ketone supplements in pro cycling, citing lack of proven performance or recovery benefits. This mirrors multiple randomized trials and meta‑analyses showing no clear ergogenic effect from ketone esters or salts. Translation: focus your budget and effort on fundamentals that move the needle. ^[2]
• What the broader evidence shows (performance): Meta‑analyses of acute ketone supplementation find no significant improvement in time trials or time‑to‑exhaustion. Individual RCTs show mixed or even impaired performance on certain protocols, with occasional positives under specific conditions (e.g., early efforts with bicarbonate co‑ingestion). Practical takeaway: not reliable enough to plan training around. ^[3]
• What the broader evidence shows (training on keto): A 2025 systematic review/meta‑analysis in adults reports keto can increase fat oxidation without significant losses in muscle mass or strength; endurance outcomes are variable and often favor higher‑carb approaches for peak output. Program design matters. ^[4]

Fueling fundamentals for keto athletes

Macros that match your sport

• Endurance base days (Zone 2/steady aerobic): 65–75% fat, 20–30% protein (~1.6–2.2 g/kg/day), 5–10% net carbs (typically ≤20–50 g/day). This supports fat adaptation and glycogen sparing. Evidence suggests muscle mass/strength can be maintained with adequate protein. ^[6]
• Strength/power days: Keep protein toward the upper end (≈2.0–2.4 g/kg/day in energy deficit; 1.6–2.2 g/kg when weight‑stable) to preserve/build lean mass; hold net carbs low if strict ketosis is a goal. ^[7]
• Competition/quality intervals: If performance (not strict ketone levels) is paramount, some athletes use a targeted carbohydrate strategy (e.g., 10–25 g very near the session) without long‑term loss of fat adaptation. Note: high‑quality RCT data specific to TKD are limited—treat as experimental and monitor glucose/ketones and performance. [Evidence level: limited.]

Hydration and electrolytes (the keto‑specific edge)

Keto lowers insulin and increases natriuresis, raising your need for sodium and fluids around training. Sports nutrition positions and recent reviews converge on practical in‑session targets:

• Fluids: Begin well‑hydrated; for sessions >60–90 minutes, drink to thirst with access to a sodium‑containing beverage. ^[8]
• Sodium: For prolonged/hot training, aim ≈300–600 mg sodium per hour (adjust up for heavy/salty sweaters), delivered in 230–690 mg/L solutions to aid absorption and reduce hyponatremia risk. Individualize via sweat testing when possible. ^[9]

MCT oil: when it helps—and when to skip

• Proven effect: C8 (tricaprylin) and C10 MCTs raise blood β‑hydroxybutyrate in a dose‑dependent manner; emulsified or taken without a mixed meal is more ketogenic. Typical acute rises are modest (often 0.3–1.0 mmol/L). ^[13]
• Lipid caution: A 2021 meta‑analysis of randomized trials found MCT oil did not raise LDL‑C on average versus comparators overall, but triglycerides rose slightly; results varied by comparator fat. For athletes with atherogenic lipid concerns, monitor ApoB and triglycerides after adding MCT. ^[14]
• Performance note: MCTs may provide quick ketones and GI‑tolerable energy for some, but robust performance advantages are unproven; introduce gradually to avoid GI upset. [Evidence level: mixed/limited.]

Should you use exogenous ketone supplements?

• Scientifically proven: Multiple meta‑analyses and controlled trials show no consistent benefit to time‑trial or endurance performance; some protocols show impairment. ^[15]
• Policy update: UCI now advises against their routine use in pro cycling. Not banned, just not recommended. ^[16]
• Anecdotal: Some athletes report steadier energy or appetite control. Treat as n=1; if you trial them, do so in training, not on race day, and track objective outcomes (power, pace, RPE). [Evidence level: anecdotal.]

Build your week: sample keto training templates

Recipes and intra‑workout ideas

Evidence map: proven vs. anecdotal

• Proven (high‑quality): Exogenous ketone supplements don’t consistently improve endurance performance; UCI discourages their use in pros. Strategic sodium during prolonged exercise reduces hyponatremia risk and supports fluid retention. ^[24]
• Promising/conditional: Keto can preserve strength and lean mass with adequate protein; endurance effects vary by protocol and athlete. ^[25]
• Anecdotal/coach‑driven: Targeted 10–25 g pre‑workout carbs while “staying keto,” or MCTs as a pre‑session “feel‑good” aid. Try cautiously and track outcomes. [Limited direct RCT data.]

Common mistakes to avoid

• Under‑salting on keto: Low insulin increases sodium loss; under‑replacing can cause headaches, cramps, and poor splits. ^[26]
• Relying on ketone drinks: They’re expensive and generally don’t boost performance; invest in coaching, protein, and produce instead. ^[27]
• Ignoring lipids: If you add frequent MCTs or raise saturated fat, monitor ApoB and triglycerides; MCTs can nudge TG up. ^[28]

“Athletes should prioritize evidence‑based nutrition—adequate protein, individualized carbohydrate strategies, and fluid‑electrolyte planning—over unproven supplements.”

Actionable summary (save or screenshot) 🥑💪

• Base your plan on macros that fit the session; keep protein high (≥1.6 g/kg/day).
• Hydrate to thirst; include sodium 300–600 mg/h for long/hot sessions (drink sodium 230–690 mg/L). ^[30]
• Use MCTs sparingly (5–15 g C8) if they help you feel steady; monitor lipids over time. ^[31]
• Skip ketone supplements: evidence and UCI guidance don’t support them for performance. ^[32]
• Adjust only one variable at a time and track power/pace, RPE, and recovery.

References

1. UCI guidance discouraging ketone supplement use in pro cycling (October 20, 2025). ^[33]
2. Systematic reviews/meta‑analyses: exogenous ketones and endurance performance—no consistent benefit. ^[34]
3. Mixed RCT findings on ketone esters (examples of impairment and context‑specific effects). ^[35]
4. Ketogenic diet and muscle/strength/endurance outcomes in adults (2025 systematic review/meta‑analysis). ^[36]
5. Hydration/electrolyte guidance and sodium ranges for endurance athletes. ^[37]
6. MCTs raise ketones in a dose‑dependent manner; C8 is especially ketogenic; lipid effects and triglycerides. ^[38]
7. Sports nutrition joint position statement (AND/DC/ACSM). ^[39]

Use this as your 2025 field manual: train hard, salt smart, keep protein high, and let the evidence—not hype—shape your keto performance plan.