Background/Objectives: Long COVID (LC) has been linked to fatigue, exercise intolerance, and autonomic dysfunction, but sex-stratified data on cardiovascular responses to maximal exercise—an essential component of personalized medicine—are scarce. This study aimed to examine hemodynamic, autonomic, and functional responses during and up to 24 h after a cardiopulmonary exercise test (CPET) in young adults with and without Long COVID (LC). Methods: In this cross-sectional study, we assessed 38 physically active adults, who were allocated into four subgroups stratified by clinical condition (LC or control) and biological sex: control–female (CON-F; n = 10), LC–female (LC-F; n = 10), control–male (CON-M; n = 10), and LC–male (LC-M; n = 8). Outcomes included systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), cardiac output (CO), total (TPR) and peripheral vascular resistance (PVR), pulse wave velocity (PWV), augmentation index (AIx@75), and heart rate variability (HF, LF, LF/HF), assessed at rest, peak effort, recovery (1, 3, 5, 10, 30, and 60 min), and through 24 h ambulatory blood pressure monitoring (ABPM) after CPET. Results: SBP increase appropriately during exercise, with higher peaks in males (p < 0.01), and returned to baseline within 5 min across all groups. HR recovery was preserved; however, LC-F showed lower values than CON-F at 3, 5, and 10 min (126 vs. 144 bpm, p = 0.020; 119 vs. 136 bpm, p = 0.020; 94 vs. 109 bpm, p = 0.011), though all groups normalized by 60 min. PWV, AIx@75, TPR and PVR exhibited expected sex-related patterns without LC-related impairments. HRV indices showed transient post-exercise shifts (HF↓, LF↑, LF/HF↑). Ambulatory monitoring confirmed preserved circadian modulation, with normal systolic dipping (11–13%) and no abnormal nocturnal patterns. Conclusions: Young physically active adults with LC showed preserved hemodynamic, autonomic, and vascular responses during and after maximal exercise. These findings contribute to personalized medicine by showing that individualized, sex-stratified cardiovascular assessments reveal no clinically relevant impairments in this population, supporting tailored clinical decision making and exercise prescription.