Progressive overload is the gradual increase of stress placed upon the body during exercise training.
It was developed by Thomas Delorme, M.D. while he rehabilitated soldiers after World War II. The technique is recognized as a fundamental principle for success in various forms of strength training programs including fitness training, weight lifting, high intensity training and physical therapy programs.
A common goal for strength-training programs is to increase or to maintain one's physical strength or muscle mass. In order to achieve more strength, as opposed to maintaining current strength capacity, muscles (see skeletal muscles) need to be stressed in such a way that triggers the body's natural, adaptive response to new demands placed on it.
Progressive overload not only stimulates muscle hypertrophy, but it also stimulates the development of stronger and denser bones, ligaments, tendons and cartilage. Progressive overload also incrementally increases blood flow to exercised regions of the body and stimulates more responsive nerve connections between the brain and the muscles involved.
Conversely, decreased use of the muscle results in incremental loss of mass and strength, known as muscular atrophy (see atrophy and muscle atrophy). Sedentary people often lose a pound or more of muscle annually.
The loss of 10 pounds of muscle per decade is one consequence of a sedentary lifestyle. The adaptive processes of the human body will only respond if continually called upon to exert greater force to meet higher physiological demands.
In order to minimize injury and maximize results, the novice begins at a comfortable level of muscular intensity and advances towards overload of the muscles over the course of the exercise program. Progressive overload requires a gradual increase in volume, intensity, frequency or time in order to achieve the targeted goal of the user. In this context, volume and intensity are defined as follows:
- Volume is the total number of repetitions multiplied by the resistance used as performed in specific periods of time.
- Intensity is the percent value of maximal functional capacity, or expressed as percent repetition maximum.
This technique results in greater gains in physical strength and muscular growth, but there are limits. An excess of training stimuli can lead to the problem of overtraining. Overtraining is the decline in training performance over the course of a training program, often accompanied by an increased risk of illness or injury or a decreased desire to exercise. To help avoid this problem, the technique of periodization is applied. Periodization in the context of fitness or strength training programs means scheduling for adequate recovery time between training sessions, and for variety over the course of a long-term program. Motivation can be maintained by avoiding the monotony of repeating identical exercise routines.
- Kraemer, William J.; Fleck, Steven J. (2007). "Progressive Overload". Optimizing Strength Training: Designing Nonlinear Periodization Workouts. Human Kinetics. pp. 33–6. ISBN 978-0-7360-6068-4.
- Kraemer WJ, Adams K, Cafarelli E, Dudley GA, Dooly C, Feigenbaum MS, Fleck SJ, Franklin B, Fry AC, Hoffman JR, Newton RU, Potteiger J, Stone MH, Ratamess NA, Triplett-McBride T (2002). "American College of Sports Medicine position stand. Progression models in resistance training for healthy adults". Medicine and Science in Sports and Exercise. 34 (2): 364–80. doi:10.1097/00005768-200202000-00027. PMID 11828249.
- American Academy of Family Physicians; American Academy of Orthopaedic Surgeons; American College of Sports Medicine; American Orthopaedic Society for Sports Medicine; American Osteopathic Academy of Sports Medicine; American Medical Society for Sports Medicine (2001). "The team physician and conditioning of athletes for sports: a consensus statement". Medicine and Science in Sports and Exercise. 33 (10): 1789–93. doi:10.1097/00005768-200110000-00027. PMID 11581568.
- Fry, Andrew C. "Overtraining With Resistance Exercise" (PDF). American College of Sports Medicine. Archived from the original (PDF) on October 30, 2012.
- Hass, Christopher J.; Feigenbaum, Matthew S.; Franklin, Barry A. (2001). "Prescription of Resistance Training for Healthy Populations". Sports Medicine. 31 (14): 953–64. doi:10.2165/00007256-200131140-00001. PMID 11735680.
- Lee, Mi-Joung; Kilbreath, Sharon L.; Singh, Maria Fiatarone; Zeman, Brian; Davis, Glen M. (2010). "Effect of Progressive Resistance Training on Muscle Performance after Chronic Stroke". Medicine & Science in Sports & Exercise. 42 (1): 23–34. doi:10.1249/MSS.0b013e3181b07a31. PMID 20010133.
- Vannucci, Robert C.; Brucklacher, Robert M.; Vannucci, Susan J. (2001). "Intracellular calcium accumulation during the evolution of hypoxic–ischemic brain damage in the immature rat". Developmental Brain Research. 126 (1): 117–20. doi:10.1016/S0165-3806(00)00135-8. PMID 11172893.
- Kraemer, William J.; Ratamess, Nicholas A.; French, Duncan N. (2002). "Resistance training for health and performance". Current Sports Medicine Reports. 1 (3): 165–71. doi:10.1249/00149619-200206000-00007. PMID 12831709.