How one rep max (1RM) is estimated without maxing out, the different heart rate training zones, and how to use both numbers to structure strength and cardio training properly.
One Rep Max is the maximum weight you can lift for a single complete repetition of an exercise with proper form. It's a standard reference point in strength training, commonly used to set training percentages — for example, programming a set at "75% of 1RM" gives a consistent way to scale intensity across different lifters and different exercises.
Actually testing a true 1RM carries real injury risk, particularly for less experienced lifters, since it requires attempting a maximal single lift at the edge of your current strength. Instead, 1RM is commonly estimated using a formula based on a weight you can comfortably lift for multiple reps — typically somewhere between 2 and 10 reps.
| Formula | Calculation |
|---|---|
| Epley | 1RM = weight × (1 + reps ÷ 30) |
| Brzycki | 1RM = weight × (36 ÷ (37 − reps)) |
Estimate your 1RM safely from a multi-rep set, without needing to test a true single max lift.
Open 1RM Calculator →Target heart rate training uses your estimated maximum heart rate to set training intensity zones for cardiovascular exercise. The most common starting formula estimates maximum heart rate as:
For example, a 35-year-old has an estimated maximum heart rate of 220 − 35 = 185 beats per minute. Training zones are then calculated as percentages of this number.
| Zone | % of Max HR | Purpose |
|---|---|---|
| Very light | 50-60% | Warm-up, active recovery |
| Light | 60-70% | Fat-burning, easy aerobic base |
| Moderate | 70-80% | Cardiovascular fitness building |
| Vigorous | 80-90% | Performance and endurance training |
| Maximum | 90-100% | Short, high-intensity efforts only |
Get your personalised heart rate training zones for cardio workouts.
Open Target Heart Rate Calculator →