What percentage of 1RM typically defines a heavy load in strength training?

In strength training, a heavy load is generally defined as a percentage of an individual's one-repetition maximum (1RM). The classification of what constitutes a "heavy load" can vary slightly based on different training philosophies, but it is widely accepted that a heavy load falls in the range of 80% of 1RM or higher.

When an athlete lifts at 80% of their 1RM, they are operating at a level that typically allows for a low number of repetitions, usually around 6 or fewer, before fatigue sets in. This level of intensity is essential for building strength, as it challenges the muscle sufficiently to stimulate growth and adaptation.

Lower percentages, such as those in the 60% range, are generally associated with lighter loads more suitable for endurance training or initial learning phases. While 70% can still be considered substantial, it often does not meet the stricter criteria for heavy lifting that is needed for maximal strength gains.

Overall, identifying heavy loads at 80% of 1RM provides a clear and effective guideline for athletes and trainers focused on strength development, allowing for structured programming and progression in training regimens.