Abstract TU200: Greater Peak Oxygen Uptake Is Linked to Higher Early Recovery Systolic Pressure, While Respiratory Exchange Ratio and Lactate Are Not

Abstract

Introduction: Cardiovascular fitness is a key determinant of hemodynamic response following maximal exercise. This study investigated whether blood lactate (BLa) and respiratory exchange ratio (RER) were associated with central systolic (cSBP) and systemic systolic blood pressure (SBP) measurements following maximal graded exercise testing (GXT). Hypothesis: Based on evidence that cardiovascular fitness (peak oxygen consumption; VO 2peak ) influences recovery hemodynamics, we hypothesized that markers of anabolic stress (peak blood lactate; BLa peak and peak RER; RER peak ) may also be associated with hemodynamic recovery. Methods: In a repeated measures design, eight adults (n=8; 21±1 years) completed maximal GXTs on three separate days. Metabolic gas and BLa were collected at volitional fatigue and central systolic blood pressure (cSBP) and standard systolic blood pressure (SBP) were measured 5, 10, 20, and 30 minutes into post-exercise supine recovery. Linear mixed-effects models tested associations of VO 2peak , RER peak , and BLa peak with cSBP and SBP and their interactions with recovery duration. Results: In recovery, cSBP was elevated at 5 minutes (105.3±17.2 mmHg) compared to 10, 20 and 30 (97.5±13.5, 96.8±14.4, and 96.3±13.5 mmHg, respectively; p<0.05). SBP was also elevated at 5 minutes (131.0±16.2 mmHg) compared to 10, 20 and 30 (117.8±11.1, 116.0±13.2, and 114.0±15.2 mmHg, respectively; p<0.05). Each 5 mL/kg/min higher VO 2peak corresponded to ~6.0 mmHg higher cSBP (p=0.003) and ~5.3 mmHg higher SBP (p=0.025) during 5–30 minutes of recovery. However, there was no observed interaction between VO 2peak and recovery duration for cSBP (p=0.39) or SBP (p=0.40). There was no association between RER peak and either cSBP (p=0.94) or SBP (p=0.87) and no observed interaction between RER peak and recovery duration for cSBP (p=0.63) or SBP (p=0.87). There was no association between BLa peak and cSBP (p=0.91) or SBP (p=0.88) and no observed interaction between BLa peak and recovery duration for cSBP (p=0.35) or SBP (p=0.12). Conclusion: During the first 30 minutes of recovery from maximal exercise, individuals with higher aerobic capacity exhibited slightly higher systolic pressures, whereas peak metabolic stress markers (RER and BLa) were not related to cSBP or SBP. These data suggest fitness level rather than peak metabolic strain aligns with the hemodynamic profile from 5–30 minutes post-exercise.