Alternative Methods To Quantify Baroreflex Sensitivity Following Resistance Exercise
Bibliographic record
Abstract
Most studies assess baroflex sensitivity (BRS) assuming a linear relationship between R-R inteval (RRI) and systolic blood pressure (SBP). However, exponential models may be more appropriate and provide timings of baroreflex responses. PURPOSE: Resistance exercise induces substantial BRS alterations, and was used here to examine the utility of exponential modelling. METHODS: Eight healthy participants completed a resistance exercise bout lasting 1 hour that involved 8 exercises (3 sets, 10 repetitions to failure). BRS was determined from continuous arterial blood pressure, and ECG during phase II and phase IV of a series of 6-10 Valsalva maneuvers (VM) completed before, immediately after, and 1 hour after the bout. We determined traditional BRS as the slope of the linear regression between RRI and SBP during phase II and phase IV, and we modelled the phase IV RRI response. The time delay (TD) and time constant (tau) quantified the baroreflex response latency. Response magnitude was determined as the gain and normalized gain (gain/deltaSBP). Time comparisons were made using 1-way repeated measures ANOVA. RESULTS: Phase II traditional BRS decreased significantly immediately following exercise (Post: 4.9 ± 2.6 vs. Pre: 12.5 ± 6.0 ms/mmHg p < 0.01) but returned to baseline by 1H (p = 0.43). Whilst the phase IV BRS tended to decrease (p = 0.09). Gain was significantly increased immediately following (Post: 361 ± 195 vs. Pre: 269 ± 132 ms p < 0.01) and remained elevated but not significantly at 1H (p = 0.07). The deltaSBP followed this same response (Post: 41 ± 22 vs. Pre: 23 ± 12 mmHg p = <0.01) but remained elevated at 1H (28 ± 12 mmHg, p = 0.03). The normalized gain tended to decrease immediately after the bout (p = 0.09). Exponential modelling was less sensitive to the bout of resistance exercise with tau, and TD, not significantly altered (p > 0.05). CONCLUSION: Our finding of a reduced PII BRS is novel and not previously reported. Whereas, both the normalized gain and the traditional PIV BRS showed a similar decreasing trend suggesting high methodological similarity. Gain increased after the exercise bout indicating a more pronounced heart rate response to VMs but the latency and kinetics of the baroreflex response were not altered. Supported by the Canada Foundation for Innovation John R Evans Leaders Fund.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.006 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".