Exercise Testing and Prescription

Exercise Testing and Prescription - Get Moving Safely

• Purpose: Diagnose CAD, assess functional capacity ($V\text{O}_2\text{max}$), risk stratify, guide exercise prescription.

• Pre-Test Screening: PAR-Q+; identify contraindications.

• Key Absolute Contraindications: Acute MI (<2 days), unstable angina, uncontrolled symptomatic arrhythmias, severe aortic stenosis.

• Test Termination Criteria: Angina, ↓SBP >10 mmHg with ischemia, ST elevation (≥1mm), sustained VT.

• Exercise Prescription (FITT-VP):

  • Frequency, Intensity, Time, Type, Volume, Progression.
  • Intensity: Target HR using Karvonen: $( (HR_{max} - HR_{rest}) \times % \text{intensity} ) + HR_{rest}$.
  • $HR_{max} \approx 220 - \text{age}$. RPE Borg scale 6-20.
  • 📌 FITT for fitness!

⭐ Target for moderate intensity: 40-59% $HRR$ (Heart Rate Reserve) or $V\text{O}_2R$; RPE 12-13 (Borg Scale).

Exercise Testing and Prescription - Stressing for Success

• Purpose: Evaluate cardiac function, diagnose ischemia, guide safe exercise.
• Key Metrics:
  • $VO_2max$: Max oxygen uptake; gold standard aerobic fitness.
  • METs: 1 MET = $3.5 \text{ mL O}_2\text{/kg/min}$ (resting oxygen uptake).
• Common Protocols:
  • Bruce: ↑ speed & grade q3min; for fit individuals.
  • Naughton: Slower increments; for deconditioned/cardiac.
• Stop Test: Angina, ST depression > 2mm, ↓ SBP > 10mmHg, VTach, severe dyspnea.
• Prescription (📌 FITT-VP):
  • Frequency, Intensity, Time, Type, Volume, Progression.
  • Intensity: Target HR (e.g., Karvonen), RPE.

⭐ Target Heart Rate (THR) calculation is crucial for exercise prescription; the Karvonen formula is a key method.

• Karvonen Formula: $THR = [(HR_{max} - HR_{rest}) \times % \text{intensity}] + HR_{rest}$; $HR_{max} \approx 220 - \text{age}$. oka

Exercise Testing and Prescription - Reading the Rhythms

• ECG Changes:
  • Normal: ↑HR, ↓PR, ↓QT, upsloping ST depression <1mm.
  • Ischemia: ST depression (horizontal/downsloping) ≥1mm; ST elevation (non-Q leads).
  • Arrhythmias: PVCs (common), VT (ominous).
• Hemodynamic Response:
  • BP: SBP ↑ (10±2 mmHg/MET); DBP stable/↓. Hypertensive: SBP >250 / DBP >115. Hypotensive: ↓SBP >10 mmHg + ischemia.
  • HR: ↑ linearly; HRmax ≈ $220 - \text{age}$.
  • RPP ($HR \times SBP$): Peak 25k-40k.
• Prognostic Markers:
  • Duke Score (DTS): $\text{ExTime (min)} - (5 \times \text{STdev (mm)}) - (4 \times \text{Angina Index})$. High risk ≤-11.
  • HR Recovery (HRR): ↓HR 1 min post-ex. Abnormal <12 bpm (supine).
  • Chronotropic Incompetence: <85% APMHR.

⭐ Horizontal or downsloping ST depression ≥1mm, 0.08s post J-point, indicates myocardial ischemia during exercise.

Exercise Testing and Prescription - FITT for Life

• Graded Exercise Test (GXT): Assesses cardiorespiratory fitness (CRF), often measures maximal oxygen uptake ($VO_{2}max$).
• Exercise Prescription (FITT-VP Principle):
  • Frequency: Aerobic: 3-5 days/week; Resistance: 2-3 days/week.
  • Intensity: Moderate (40-59% $VO_{2}R$ or Heart Rate Reserve (HRR), RPE 12-13 on Borg 6-20 scale) or Vigorous (≥60% $VO_{2}R$ or HRR, RPE ≥14).
    • 📌 Karvonen formula (Target HR): $[(HR_{max} - HR_{rest}) \times % ext{intensity}] + HR_{rest}$.
    • $HR_{max} \approx extbf{220} - ext{age}$.
  • Time (Duration): Aerobic: 20-60 min/day. Aim for ≥150 min/week (moderate) or ≥75 min/week (vigorous).
  • Type: Aerobic (e.g., walking, cycling), Resistance (weights), Flexibility, Neuromotor (e.g., balance, tai chi).
  • Volume (Quantity): Target ≥500-1000 MET-min/week.
  • Progression: Gradual increase in F, I, T, or V as tolerated.

⭐ For substantial health benefits, adults should do at least 150 minutes to 300 minutes a week of moderate-intensity, or 75 minutes to 150 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity. (ACSM/CDC Guideline).

High‑Yield Points - ⚡ Biggest Takeaways

• VO2 max: Best objective measure of cardiorespiratory fitness.
• METs: Standard unit for exercise intensity; 1 MET ≈ 3.5 mL O2/kg/min.
• Karvonen formula: Calculates Target Heart Rate (THR) using HRR.
• FITT principle: Core of exercise prescription (Frequency, Intensity, Time, Type).
• Borg RPE Scale (6-20): Measures subjective effort perception.
• Key absolute contraindications: Acute MI, unstable angina, symptomatic severe aortic stenosis.
• Anaerobic Threshold (Lactate Threshold): Onset of anaerobic metabolism, ↑ lactate_._