Table 4. Alternative Test-Based Risk Stratification in Cardiac Rehabilitation Patients without Cardiopulmonary Exercise Testing. Reproduced from Komici et al. (2026), Front Sports Act Living, under CC BY license [41].

Test Red flag (Defer exercise/Urgent evaluation) Yellow flag (Modify exercise/Close monitoring) Green flag (Safe to proceed/progress)
6MWT Distance <150 m (severe impairment)Unable to complete test (stops due to symptoms)Significant desaturation (O2 sat < 88% on room air)Severe dyspnea/chest pain during test Distance 150–300 m (moderate impairment)Completed but with symptoms (dyspnea, leg pain)Oxygen saturation 88–92%No improvement or decline > 30 m (MCID) from baseline after 4–12 weeks of exercise Distance > 300 m (mild impairment or normal)Completed without significant symptomsO2 sat > 92% throughoutImprovement ≥ 30 m (MCID) after exercise program indicates meaningful benefit
Handgrip strength < 16 kg (women) or < 27 kg (men) and declining over timeSevere sarcopenia with functional impairmentCombined with very low SPPB (< 4) 16–20 kg (women) or 27–32 kg (men) - borderline sarcopeniaNo improvement or decline > 5–6 kg (MCID) after resistance training program ≥ 20 kg (women) or ≥ 32 kg (men) – normalImprovement ≥ 5–6 kg (MCID) after resistance training indicates meaningful strength gainSafe to progress resistance training
Timed Up and Go > 20 s (very high fall risk)Unable to complete without assistanceNear-fall or loss of balance during testCombined with history of recent falls 13.5–20 s (moderate-high fall risk)Completed but slow, unsteadyNo improvement or decline > 3.5 s (substantial change) after balance training < 13.5 s (low fall risk)Completed smoothly, steadyImprovement ≥ 3.5 s (substantial change) or ≥ 2.5 s (MCID) after balance training indicates meaningful fall risk reduction
SPPB score 0–3 points (high risk-severe functional impairment, very high fall/disability risk)Score declining over time 4–6 points (moderate risk-moderate functional impairment)No improvement or decline > 1 point (MCID) after exercise 7–12 points (low risk-mild or no impairment)Improvement ≥ 1 point (MCID) or ≥ 2 points (substantial change) after exercise indicates meaningful functional gain
6MWT: 6 minute walk test, MCID: minimal clinically important difference, SPPB: short physical performance battery