Relative aerobic and anaerobic energy contribution in race fit endurance and Thoroughbred racehorses during strenuous exercise
Bibliographic record
Abstract
The objective was to compare fit Arabian endurance and Thoroughbred racehorses’ responses to a maximal intensity standardised incremental treadmill test (MaxSIT) with respect to: (1) their relative aerobic contributions during maximal exercise; and (2) selected physiological parameters related to performance. Six high-level endurance Arabians and six race-ready Thoroughbreds performed a MaxSIT starting at 8 m/s and increasing by 1 m/s increments 60 s until maximum oxygen consumption (V̇O 2max ) was reached. Heart rate (HR), blood lactate concentration (BLac), haematocrit (Hct), minute ventilation (V̇E) and oxygen consumption (V̇O 2 ) were measured. V̇O 2max , the speeds at which the HR were 200 and 160 bpm, respectively (V 200 , V 160 ), the speed at which the BLac reached 4 mmol/l (VLa 4 ) and lactate at HR 200 (BLa 200 ) were calculated. The relative aerobic energy input was determined using ΔBLac Peak-Resting increase as previously described. Data were expressed as median with interquartile range and analysed with a Wilcoxon rank sum test ( P <0.05). Endurance horses had greater V̇O 2max (202.5 ml/(kg.min) (190.3-211) vs 152.7 ml/(kg.min) (140.5-158.3); P <0.001) and had a greater aerobic energy contribution to total exercise effort (89.9% (87.0-96) vs 82.8% (81.1-84.1); P =0.009) than Thoroughbreds. Endurance horses reached HR>200 bpm on the treadmill, but had a lower HR max (210 bpm (205-217) vs 226 bpm (219-228); P =0.008), BLa 200 (3.8 mmol/l (2.7-5.5) vs 4.8 mmol/l (3.6-5.2); P <0.001) and Hct max (56.4% (54.9-57.5) vs 61.5% (59-64); P =0.002). Endurance horses median VLa4 was 11.6 m/s (11.0-13.0); V 200 =11.9 m/s (10.9-12.3) and V 160 =8.5 m/s (7.2-8.6). Because of the HR and speed characteristics of modern endurance races, we proposed BLa 200 as a new calculated parameter with which to assess endurance horses. Trained endurance horses accumulate less lactate, have a greater V̇O 2max and relative aerobic contribution to their energy requirements at maximal intensity exercise despite a lower blood haematocrit.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".