How is 1RM calculated according to the described method?

• A. Start with a single rep at 100% and add 5% each attempt until you fail.
• B. Use a fixed weight for 3 sets of 10 reps, tracking only reps, not weight.
• C. After warming up with 10x60% and 10x40%, try 4x60% = 10 lbs. Increase by 10 lbs until the last weight the athlete can lift for four reps.
• D. Warm up with light cardio for 20 minutes, then attempt a single max lift.

Answer: (C)

Estimating a one-repetition maximum here uses a four-repetition max as the basis. After a careful warm-up, you start with a weight you can lift for four reps and, if you complete all four, you increase the load by a fixed amount (10 pounds) and repeat. You keep building until you can no longer complete four reps. The heaviest weight you successfully lifted for four repetitions is then used to estimate the 1RM (typically with a standard conversion). This approach prioritizes a controlled, repeatable rep-max test over a single all-out attempt, which helps reduce risk and provides a data-driven way to predict the 1RM. The other methods described either test different goals (endurance with sets of ten), rely on a single maximal effort, or skip the structured four-rep progression.