Author(s): HORTOBAGYI, A., KURUCSAI G. , Institution: DR. KURUCSAI MEDICAL CARE CENTRE, Country: HUNGARY, Abstract-ID: 852

INTRODUCTION:
Public-health recommendations commonly prescribe ≥150 min/week of physical activity, yet weight and metabolic outcomes remain poor in many adults with obesity; in our clinical experience, ~40% remain non-responsive despite “meeting the minutes,” suggesting that time-based targets overlook real-life intensity distribution. We hypothesized that failure is driven less by insufficient volume than by inadequate downshifting to intensities that preserve oxygen availability for efficient substrate utilization.
METHODS:
91 adults with obesity (BMI 29.5–42.7) completed our protocol: a 20-min warm-up (yoga-like), an 8-min slow walk (2-4 km/h, graded incline), individualized gymnastics, all-out bout for anaerobic functioning, a 20-min recovery. Indirect calorimetry quantified free fatty acids vs carbohydrate contribution (FFA/CHO), and blood-based markers captured blood gases. Two pragmatic groups were evaluated: Group 1 (n=45, seniors, 55+) performing self-selected tolerable exercise with GLP-1a treatment; Group 2 (n=46, age 35-55) performing ≥150 min/week training.
RESULTS:
Slow movements elicited the most favorable metabolic profile. Group differences were evident in FFA utilization during slow walking (55.1±9.5% vs 38.1±11.5%, p<0.001), whereas individualized gymnastics showed no between-group advantage (37.5±9.0% vs 34.2±10.0%, NS). The gymnastics phase imposed higher intensity in Group 2 (3.64±0.98 vs 5.67±1.55 METs, p<0.05) without superior fat utilization. Recovery insulin was lower in Group 1 (24.0±4.5 vs 31.0±6.7 mIU/mL, p<0.05) and associated with better by-product clearance. Across both obesity-range groups, lactate showed slow clearance: following the 1-min all-out disruptor bout, lactate was not significantly reduced at 20-min recovery (ns). In contrast, faster regulators (H⁺ and pO₂/pCO₂) exhibited significant stepwise responses across stages; together with insulin kinetics, this pattern highlights distinct physiological signatures of active versus passive recovery (rapid gas/acid–base normalization vs delayed lactate handling).
CONCLUSION:
Life-like, repeatable low-intensity movement appears preferable, whereas higher-intensity work increases by-product load. These findings offer a practical explanation for why “≥150 min/week” may be ineffective in ~40% of patients (including those with physically demanding jobs) in our clinical experience: individuals may not slow down sufficiently for low-intensity oxidative metabolism to dominate. Even when GLP-1a is prescribed, outcomes should be interpreted within the patient’s full 168-hour lifestyle context (daily activity pattern, occupational load, recovery, and timing). Mechanistically, we hypothesize that the slow-movement zone improves oxygen availability, stabilizes hypoxia-sensitive regulation (HIF-1α), supports lactate reutilization via monocarboxylate transport (MCT1), and thereby promotes mitochondrial function through oxidative adaptation pathways (PGC-1α–linked); this hypothesis warrants direct verification in future studies.