{"publication_id":"a0900cba-0a00-4208-88a9-1b1711cbdbd3","traces":[{"claim_id":"claim_1","claim":"Two 1991 caffeine studies appear to disagree when bundled together: a 60-minute submaximal metabolism trial showed no measurable effect, while an elite distance runner time-to-exhaustion trial at the same approximate era showed longer run distance with caffeine. The receipts support treating this as a boundary-condition tension, not a contradiction on the same metric.","candidate_sources":[{"study":"Failure of caffeine to affect metabolism during 60 min submaximal exercise.","doi":"10.1080/02640419108729851","url":"https://doi.org/10.1080/02640419108729851"},{"study":"Caffeine ingestion during exercise to exhaustion in elite distance runners. Revision.","doi":null,"url":""}]},{"claim_id":"claim_2","claim":"For elite endurance, where time-to-exhaustion is the operationally relevant endpoint, the positive-signal receipt suggests caffeine ingested just prior to exercise can extend work capacity. For submaximal steady-state work under the null-signal receipt's design, the metabolic readout does not change. The actionable read is that caffeine's lever may depend on the proximity to exhaustion rather than on average metabolism.","candidate_sources":[{"study":"Failure of caffeine to affect metabolism during 60 min submaximal exercise.","doi":"10.1080/02640419108729851","url":"https://doi.org/10.1080/02640419108729851"},{"study":"Caffeine ingestion during exercise to exhaustion in elite distance runners. Revision.","doi":null,"url":""}]},{"claim_id":"claim_3","claim":"A within-subject crossover in elite distance runners that pairs time-to-exhaustion with continuous metabolic sampling (RER, FFA, lactate) across the same 10 mg·kg⁻¹ dose would resolve whether the metabolism null is real or a sensitivity-floor artifact of the 1991 submaximal design.","candidate_sources":[{"study":"Failure of caffeine to affect metabolism during 60 min submaximal exercise.","doi":"10.1080/02640419108729851","url":"https://doi.org/10.1080/02640419108729851"},{"study":"Caffeine ingestion during exercise to exhaustion in elite distance runners. Revision.","doi":null,"url":""}]},{"claim_id":"claim_4","claim":"10.1080/02640419108729851 — null_signal: 200 mg caffeine, 60 min pre-exercise, 5 males, 60% MHR, no significant metabolic differences.","candidate_sources":[{"study":"Failure of caffeine to affect metabolism during 60 min submaximal exercise.","doi":"10.1080/02640419108729851","url":"https://doi.org/10.1080/02640419108729851"},{"study":"Caffeine ingestion during exercise to exhaustion in elite distance runners. Revision.","doi":null,"url":""}]}]}