REF-497 · Page, Jeffries & Waldron, 2019 — taurine (cross-study synthesis: endurance + thermoregulation in cycling) · European Journal of Sport Science, · Paper
Conditionally essential sulfur amino acid; primary application is thermoregulation in heat
What it is
Sulfur-containing amino acid; conditionally essential.
Free molecule (NOT incorporated into proteins), most abundant free AA in skeletal muscle.
Concentrations reported higher in Type I (slow oxidative) fibres than Type II (cited study; not checked against its abstract).
Dietary sources: meat and seafood; essentially none in plants (vegan/vegetarian baseline lower).
Pharmacokinetics (cited study; not checked against its abstract): plasma rises within minutes, peaks around 1 h and returns to baseline within several hours → acute pre-exercise dosing is physiologically plausible; Page 2019 dosed 2 h before exercise.
Mechanisms (4)
1
Calcium handling — sarcoplasmic-reticulum Ca²⁺ cycling; underpins excitation-contraction coupling. Plausibly preserved efficiency during prolonged work; supports the high Type I concentration.
2
Antioxidant / mitochondrial protection — stabilises mitochondrial matrix pH; reduces lipid peroxidation. Zhang 2004: 6 g/day × 7 days ↓ DNA strand breakage, ↑ VO₂max, ↑ exercise capacity in young men (cited study; not checked against its abstract).
3
Fat oxidation — 1.66 g acute → +16% fat ox over 90 min cycling, no change in CHO oxidation (cited study; not checked against its abstract); no consistent performance translation.
4
Thermoregulation — primary practical mechanism for cyclists. Page 2019 measured higher end sweat rate and lower late-exercise core temperature; the hypothalamic set-point explanation is the authors' proposed mechanism (Inference, not tested in the trial).
Protocol
Primary trial (Page 2019): double-blind, randomised crossover in 11 healthy males (from the abstract).
Riders cycled to exhaustion in the heat (35°C, 40% RH) at their ventilatory-threshold power, starting 2 h after taking taurine (50 mg/kg) or a placebo (3 mg/kg maltodextrin).
Measures: core and mean skin temperature, mean sweat rate, heart rate, RPE, thermal comfort and thermal sensation during exercise; blood lactate after exercise.
Key Findings — Key endurance / heat findings
| Study | Cohort | Protocol | Result |
|---|---|---|---|
| Page 2019 (primary cycling-in-heat; abstract verified) | n=11 healthy males | 50 mg/kg taurine vs 3 mg/kg maltodextrin placebo, 2 h pre-exercise, TTE at ventilatory-threshold power in 35 °C / 40 % RH, double-blind randomised crossover | TTE +10 % (25.16 vs 22.43 min, p = 0.040) · end sweat rate +12.7 % (687 vs 600 nL/min, p = 0.034) · post-exercise lactate −16.5 % (5.75 vs 6.85 mmol/L, p = 0.033) · core temperature in the final 10 % of TTE 38.1 vs 38.5 °C (p = 0.049; −0.4 °C by arithmetic) · lower RPE late in exercise |
| Multi-day protocol (8 days) (cited study; not checked against its abstract) | Cited in the 2026 Rothschild review | Daily taurine | Whole-body sweat loss +26-27 % · local sweat rate +8-15 % · sweat-gland count +22-32 % · evaporative heat loss +27 % · net heat storage −72 % |
| Temperate-condition cycling (cited study; not checked against its abstract) | Trained cyclists | 1.66 g, 90-min TT after steady-state | +16 % fat ox · no TT improvement |
| Meta-analysis (Waldron 2018) (cited study; not checked against its abstract) | 10 endurance trials, 1-6 g | Acute or up to 2 wk | Small but significant TTE/endurance improvement; no dose or duration moderation within range |
| Recent broader meta, 2024 (endurance + strength + power) (cited study; not checked against its abstract) | Mixed | Mixed | Smaller overall effect; certainty low to very low (small samples, varying protocols) |
| Caffeine + Taurine in heat (2025) (cited study; not checked against its abstract) | Cycling TTE @ 35 °C | Caffeine 5 mg/kg + taurine 50 mg/kg vs placebo | NO improvement in TTE · ↑VO₂, ↑VE, ↑metabolic heat production. Combined dose attenuated the thermoregulatory benefit. |
Practical Application — protocols
Page, Jeffries & Waldron 2019 (n=11 healthy men, double-blind crossover): 50 mg/kg taurine 2 h before cycling at ventilatory-threshold power in 35 °C extended time to exhaustion by 10% (25.16 vs 22.43 min), raised end sweat rate 12.7% and kept late-exercise core temperature 0.4 °C lower. For a hot race, a single pre-event dose is the evidence-backed use; the authors themselves recommend a single dose 2 h before training or competition in the heat.
Acute dose (from the trial): 50 mg/kg, 2 h pre-exercise — about 4 g for an 80 kg athlete (arithmetic).
Not from this paper; the base's own practice: a multi-day loading of ~3 g/day for 5-8 days before a hot target event (rests on the 8-day protocol row above, cited study; not checked against its abstract).
Pair with a deliberate hydration adjustment: sweat rate up → fluid and sodium losses up → match intake (Inference from the trial's sweat-rate result).
Not from this paper; the base's own practice: keep caffeine moderate if both are used — a 2025 study (cited study; not checked against its abstract) found 5 mg/kg caffeine + 50 mg/kg taurine gave no TTE benefit in the heat and raised metabolic heat production. See REF-350 for caffeine dosing.
Not from this paper; the base's own practice: use powdered taurine with water; an energy drink is not a substitute (typical cans carry about 1 g taurine plus caffeine — cited product data; not checked against its abstract).
General endurance application:
Not from this paper; the base's own practice: 1-3 g acute, 1-2 h pre-exercise (rests on the Waldron 2018 meta-analysis row, cited study; not checked against its abstract). Effects modest and certainty low; a reasonable n=1 experiment.
When NOT to use:
Not from this paper; the base's own practice: not during heat-acclimation blocks (e.g. 2-4 weeks of sauna/overdress/heat-room build). Inference, not tested: chronic taurine could blunt the heat-stress signal (HSP72, plasma-volume expansion) that drives adaptation — no trial has tested this. Use it for the target event in heat, not for the build-up.
When sweating is mechanically constrained (impermeable clothing) — the mechanism depends on evaporation working (Inference from the trial's sweat-rate result).
Combined with a very high caffeine dose if thermoregulation is the goal (cited study; not checked against its abstract).
Evidence Quality / Limitations
Heat application: B. Page 2019 is a clean double-blind crossover but n=11 healthy men, one dose, one protocol; the multi-day sweat findings and the 2026 review are cited but not verified here (cited study; not checked against its abstract).
Endurance (temperate): B at best. Meta-analyses positive but with low-very-low certainty, small samples, wide prediction intervals frequently including zero (cited study; not checked against its abstract).
Strength / power: combined caffeine + taurine showed a Wingate benefit in female team-sport athletes while taurine alone did not (cited study; not checked against its abstract).
Chronic effects on heat acclimation: untested. Plausible blunting via attenuated HSP / plasma-volume signalling, but no direct trial.
Safety / tolerability: well tolerated at doses tested in the cited studies (up to 6 g acute; cited study; not checked against its abstract); GI upset rare. Long-term safety at chronic high doses not extensively studied in athletes.
Limitations
From the design as the abstract reports it (Page 2019): an acute, single-dose crossover in 11 healthy males — training status not stated, no women.
One test: time to exhaustion at a fixed intensity (ventilatory-threshold power) in 35°C and 40% RH — not a time trial or race; other doses, temperatures and multi-day use were not tested in this trial.
How this entry was checked and changed
Why this level
regraded 2026-09-27 from B+: the verified evidence is a crossover with n=11; the other cited studies are not verified against their abstracts here
Content correction 2026-09-27
Level B+ (heat A−) -> B: the verified primary trial is a crossover with n=11; secondary sources not verified. Tier "N/A" -> 1-2 (healthy males); Sport "cycling, running" -> cycling.
Page 2019 row corrected to the abstract: "trained males" -> healthy males; placebo 3 mg/kg maltodextrin; exact values (25.16 vs 22.43 min; 687 vs 600 nL/min; 5.75 vs 6.85 mmol/L; 38.1 vs 38.5 °C) with p-values; lower RPE added.
Every number from another cited study (8-day protocol, Waldron 2018, Zhang 2004, 1.66 g fat-oxidation trial, 2025 caffeine study, energy-drink content, 4× Type I concentration, pharmacokinetic times) marked "cited study; not checked against its abstract"; dosing protocols relabelled as the base's own practice; the athlete-personal caffeine remark removed.
2026-09-28: added Journal, Protocol and Limitations for the primary trial from the Europe PMC record and abstract (PMID 30776254).