Table 4.
Intensity thresholds most discriminative of BDNF responses exceeding MDC-UCL
Intensity Measure/BDNF MDC-UCL | AUC [95% CI] | Best Threshold | Sensitivity, % | Specificity, % |
---|---|---|---|---|
Blood lactate mean, mmol/l | ||||
MDC80&85 | 0.88 [0.78, 0.98] | 4.7 | 100 | 77 |
MDC90 | 0.85 [0.74, 0.96] | 4.7 | 100 | 75 |
MDC95 | 0.88 [0.77, 0.99] | 5.3 | 100 | 79 |
Blood lactate T5, mmol/l | ||||
MDC80&85 | 0.87 [0.75, 0.99] | 4.1 | 86 | 84 |
MDC90 | 0.83 [0.70, 0.97] | 4.1 | 83 | 82 |
MDC95 | 0.89 [0.78, 1.00] | 4.1 | 100 | 80 |
Blood lactate T10, mmol/l | ||||
MDC80&85 | 0.90 [0.80, 1.00] | 4.5 | 100 | 76 |
MDC90 | 0.88 [0.76, 0.99] | 4.5 | 100 | 74 |
MDC95 | 0.94 [0.86, 1.00] | 7.3 | 100 | 90 |
Mean V̇o2, %V̇o2peak | ||||
MDC80&85 | 0.92 [0.84, 1.00] | 67 | 100 | 82 |
MDC90 | 0.91 [0.82, 1.00] | 67 | 100 | 80 |
MDC95 | 0.90 [0.80, 0.90] | 72 | 100 | 81 |
Max V̇o2, %V̇o2peak | ||||
MDC80&85 | 0.87 [0.72, 1.00] | 116 | 71 | 97 |
MDC90 | 0.85 [0.68, 1.00] | 117 | 67 | 98 |
MDC95 | 0.89 [0.71, 1.00] | 120 | 75 | 98 |
Minutes 60–85% V̇o2peak | ||||
MDC80&85 | 0.65 [0.46, 0.84] | 6 | 100 | 44 |
MDC90 | 0.66 [0.46, 0.87] | 6 | 100 | 43 |
MDC95 | 0.46 [0.20, 0.71] | 7 | 75 | 55 |
Minutes ≥85% V̇o2peak | ||||
MDC80&85 | 0.89 [0.78, 1.00] | 4 | 86 | 85 |
MDC90 | 0.88 [0.74, 1.00] | 4 | 83 | 83 |
MDC95 | 0.90 [0.80, 1.00] | 4 | 100 | 81 |
Mean HR, %HRpeak | ||||
MDC80&85 | 0.94 [0.87, 1.00] | 84 | 100 | 89 |
MDC90 | 0.95 [0.89, 1.00] | 90 | 100 | 95 |
MDC95 | 0.94 [0.87, 1.00] | 90 | 100 | 90 |
Mean HR, %APmaxHRR | ||||
MDC80&85 | 0.93 [0.85, 1.00] | 74 | 100 | 84 |
MDC90 | 0.91 [0.81, 1.00] | 74 | 100 | 82 |
MDC95 | 0.83 [0.71, 0.96] | 74 | 100 | 78 |
Mean HR, %HRRpeak | ||||
MDC80&85 | 0.94 [0.87, 1.00] | 72 | 100 | 92 |
MDC90 | 0.95 [0.88, 1.00] | 76 | 100 | 92 |
MDC95 | 0.95 [0.88, 1.00] | 80 | 100 | 93 |
Mean HR, %APmaxHRR | ||||
MDC80&85 | 0.92 [0.83, 1.00] | 53 | 100 | 86 |
MDC90 | 0.89 [0.79, 0.99] | 53 | 100 | 84 |
MDC95 | 0.83 [0.71, 0.96] | 53 | 100 | 80 |
Minutes ≥85%HRR | ||||
MDC80&85 | 0.94 [0.86, 1.00] | 6 | 100 | 92 |
MDC90 | 0.93 [0.85, 1.00] | 6 | 100 | 89 |
MDC95 | 0.93 [0.84, 1.00] | 8 | 100 | 88 |
Receiver operating characteristic analysis of intensity variables with significant association to brain-derived neurotrophic factor (BDNF) response (see Table 2). The “best” threshold was the one that maximized (sensitivity + specificity). MDC-UCL, minimal detectable change upper confidence limits; AUC, area under the curve; V̇o2, oxygen consumption rate; HR, heart rate; HRR, heart rate reserve; peak, maximum value reached during symptom-limited, graded exercise test; APmax, age-predicted maximum.