Principle of Progression (Progressive Resistance)

Progressive resistance is described as the single most important principle of strength training. To improve muscle strength, the training stimulus must be increased gradually. The practical guideline given for bodybuilding exercises: begin with a resistance you can properly perform for at least 8 repetitions and use it until you can complete 12 repetitions. When you can do 12 reps, increase the resistance by approximately 5%. Work at that new resistance until you can again complete 12 reps, then add another 5%.

This is a deliberately slow method, but it ensures gradual increases and few setbacks. Doing too much too soon is a common problem among exercisers, and the consequences can be severe, so the rule is to increase resistance only when you can.

A parallel idea appears in the cardiorespiratory context as the rate of progression: the body's ability to adapt to the stresses imposed on it (the training effect) allows individuals to gradually increase total work over time. In continuous exercise, work can be increased by raising intensity, duration, or some combination. The most significant conditioning effects are typically seen during the first 6 to 8 weeks of a program, and the prescription is normally adjusted as these effects occur — the extent of adjustment depending on the individual, assessment feedback, and exercise performance during sessions.

• Progressive resistance = the single most important principle of strength training.
• Bodybuilding guideline: start at a load good for ≥8 reps, use until 12 reps achievable, then +~5%; repeat (add another 5%).
• Slow method → gradual gains, few setbacks; "too much too soon" is a common, sometimes severe, error.
• Training effect: the body adapts to imposed stress, allowing total work to rise over time.
• Most significant conditioning effects occur in the first 6 to 8 weeks.
• Progress (in continuous exercise) via increased intensity, duration, or both.