Workout Intensity Calculator: Target Heart Rate & Calories

Find your target heart rate for light, moderate or vigorous exercise with the Karvonen method, plus calories burned and a warm-up plan.

Quick 1-Click Workout Intensity Presets

Physiological Biometrics & Workout Parameters

Target Heart Rate
145bpm
Karvonen Formula (moderate)
Calories Burned
276kcal
At 5 METs (70 kg)
Heart Rate Reserve
130bpm
Max 190 bpm - Rest 60 bpm
Max Output Cap
190bpm
Tanaka Model: 187 bpm

Cardiovascular Training Zones (Karvonen)

Upper ceiling for each training zone based on your resting pulse and age.

Periodized 45-Minute Session Plan

Warm-Up (Dynamic)
Easy mobility
125 bpm
5 min
Main Working Block
Moderate Aerobic (65% HRR)
145 bpm
35 min
Cool-Down (Recovery)
Gentle flush
112 bpm
5 min
Clinical Safety Notice: Target heart rate formulas are population estimates. If taking beta-blockers or antihypertensive drugs, consult your cardiologist.

Worked Example: 30-Year-Old Exercising at Moderate Intensity (45 Minutes, 70 kg)

Step-by-step Karvonen Heart Rate Reserve calculation and caloric expenditure:

User Profile
Age: 30 years | Resting HR: 60 bpm | Weight: 70 kg
Session Duration
45 minutes
Target Intensity
Moderate Intensity (65% Heart Rate Reserve)
Estimated Energy MET
5.0 METs (Moderate aerobic effort)
Step-by-Step Exercise Physiology Calculations:
•1. Maximum Heart Rate (Fox Formula): HR_max = 220 - age = 220 - 30 = 190 bpm (Tanaka alternate: 208 - 0.7 × 30 = 187 bpm).
•2. Heart Rate Reserve (HRR): HRR = HR_max - HR_rest = 190 - 60 = 130 bpm.
•3. Target Heart Rate (Karvonen): Target = HR_rest + (HRR × 0.65) = 60 + (130 × 0.65) = 60 + 84.5 = 145 bpm (144.5 rounded).
•4. Calorie Burn Estimation: Calories = (duration × MET × 3.5 × weight_kg) / 200 = (45 × 5.0 × 3.5 × 70) / 200 = 55,125 / 200 = 275.6 kcal.
•5. Periodized Workout Phases: Warm-up: 5 min at 125 bpm (50% HRR); Main Set: 35 min at 145 bpm (65% HRR); Cool-down: 5 min at 112 bpm (40% HRR). Total session = 45 min.

💡 Exercise Physiologist Verdict: Exercising at a steady 145 bpm maintains optimal aerobic zone conditioning, burning ~276 kcal without triggering premature lactic acid accumulation.

Frequently Asked Questions

Authoritative Cardiovascular & Exercise Science References

American College of Sports Medicine (ACSM) - Guidelines for Exercise Testing

Authoritative clinical exercise physiology protocols for aerobic intensity, target heart rate calculation, and safety thresholds.

American Heart Association (AHA) - Target Heart Rates Chart

Official cardiovascular health guidance for moderate versus vigorous exercise zones and resting heart rate benchmarks.

CDC - Target Heart Rate and Estimated Maximum Heart Rate

Public health guidelines on the talk test, perceived exertion, and weekly aerobic duration recommendations.

Tanaka et al. - Age-predicted maximal heart rate revisited (JACC)

Seminal 2001 study establishing the validated 208 - 0.7 × age linear regression formula across diverse adult demographics.

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