Moderate Vs. Vigorous Intensity Training


When training for athletic performance or simply trying to improve fitness, intensity of activity helps signal how hard the body is working. Moderate intensity training examples are walking briskly or gardening, for example. Vigorous intensity examples are jogging or jumping rope. Several methods can be used to determine whether training is moderate or vigorous (high) intensity. Numerous health organizations endorse levels and time of training intensity for athletes and others.


Exercise prescription is founded upon the F.I.T.T. principle; this acronym stands for exercise frequency, intensity, time, and type. The most critical component of the exercise prescription model typically is exercise intensity. If a person fails to meet minimal threshold values, the result can be little to no training effect, and too high an exercise intensity can lead to overtraining and even injury. Moderate- and vigorous-intensity exercise stress body systems differently; training should vary depending on the type of exercise intensity being performed. The goals of an exercise program should include target exercise intensity—moderate, vigorous, or a combination of both. High-intensity interval training involves periods of vigorous intensity exercise for 30 seconds to 3 minutes alternated with periods of slower movement to recover.


In 2013, about one-half (50.2%) of American adults met current physical activity recommendations, yet in 2014, nearly 24% reported they participated in no leisure-time activity. More men than women engage in moderate- and vigorous-intensity physical activity. Older men and women are less active in terms of either moderate- or vigorous-physical activity compared to their younger counterparts.


To help people remain fit or train for athletic competition, various organizations have set recommended guidelines for moderate and vigorous activity. The 2015 to 2020 Physical Activity Guidelines for Americans recommend either 150 minutes of moderate-intensity aerobic activity a week or 75 minutes of vigorous-intensity activity as a minimum each week. In healthy adults 18–65 years of age, moderate-intensity aerobic activity commonly equates to a brisk walk and should noticeably increase heart rate. Comparatively, in adults age 65 years and older as well as adults age 50–64 years with clinically significant chronic conditions and/or functional limitations, moderate-intensity aerobic activity corresponds to a 5 or 6 on a 10-point scale, where 0 equates to sitting and 10 equates to an all-out physical effort. The signs associated with 5 or 6 (i.e., moderate-intensity exercise) include a modest, but noticeable, increase in heart rate and breathing. In healthy adults, vigorous-intensity aerobic activity generally includes activities such as jogging and should cause noticeable increases in heart rate and rapid breathing. By comparison, for older adults, vigorous-intensity activity corresponds to a 7 or 8 on a 10-point scale. Vigorous-intensity activities in the older segment of the population produce large increases in breathing and heart rate.

Target ranges for moderate- and vigorous-intensity exercise can be established using several methods. Athletes, trainers, and researchers might use methods such as percentage of maximal heart rate (HRmax), percentage of heart rate reserve, metabolic equivalents, rating of perceived exertion, and percentage of maximal oxygen uptake reserve (VO2R). The ranges for the different classifications of moderate-intensity exercise are:

Cardiovascular-disease risk factors—
Factors that place one at an increased risk for developing cardiovascular disease. The specific risk factors used for risk stratification by the American College of Sports Medicine include age, family history of heart disease, high cholesterol, hypertension, obesity, physical inactivity, prediabetes, and smoking.
The presence of one or more disorders or diseases in addition to the primary disease; for instance an individual with cardiovascular disease, along with obesity and Parkinson's disease.
Cool down—
Five- to ten-minutes of low-intensity activity following the conditioning phase.
Energy expenditure—
The collective energy cost for maintaining constant conditions in the human body plus the amount of energy required to support daily physical activities.
F.I.T.T. principle—
An acronym that represents exercise frequency, intensity, time, and type.
Heart rate reserve (HRR)—
The difference between maximal heart rate and resting heart rate.
Insulin resistance—
A condition in which normal concentrations of insulin become insufficient at lowering and maintaining normal blood sugar levels.
Maximal heart rate (HRmax)—
The maximal heart rate reached during intense exercise or exertion. This value can either be estimated or directly measured from a maximal exercise test.
Maximal oxygen uptake reserve (VO2R)—
The difference between maximum oxygen uptake and resting oxygen uptake.
Metabolic equivalents (METs)—
A single MET equals the amount of energy expenditure during one minute of seated rest. In terms of oxygen uptake, 1 MET equates to 3.5 mL/kg/min.
Myocardial infarction—
A heart attack. Refers to changes to the heart tissue, with tissue death the principal one, due to sudden disruptions in oxygenated blood flow.
Rating of perceived exertion (RPE)—
A subjective rating of an individual's perception of exercise intensity.
Risk stratification—
A pre-exercise screening process by which individuals at increased risk for an acute cardiac event are identified and subsequently referred for additional medical screening prior to starting an exercise program.
Sympathetic drive—
The influence of increased impulses from the sympathetic nervous system.
Sudden cardiac death—
Abrupt and unexpected death due to cardiac causes; usually death occurs within one hour of the onset of symptoms.
The formation or presence of a blood clot in the blood vessels.
Vagal tone—
The impulses from the vagus nerve that contributes to a reduced heartbeat.
A five- to ten-minute period of lowintensity activity preceding the conditioning phase.

Common activities that are usually classified as moderate-intensity include bicycling on even terrain at 10 mph (16 km/h), walking at 3.0 mph (4.8 km/h), carrying/stacking wood, mowing the lawn with a push mower, and golf, if walking and carrying the clubs.

The ranges for the different classifications of vigorous-intensity exercise as measured by athletes or other professionals are:


Participation in either moderate- or vigorous-intensity exercise is relatively safe for most individuals. Nevertheless, older individuals or people who have chronic diseases might be at increased risk for an adverse event during exercise. Incorporating health assessments and medical history questionnaires can help identify conditions, risk factors, signs, and symptoms that increase risk of a cardiac event during exercise. Doctors or fitness professionals can estimate risk of complications, such as a heart attack, by asking about past and present health conditions. The questions might lead to further medical screening and exercise testing before a person engages in vigorous-intensity exercise. The process of risk stratification assigns individuals into one of three risk categories (low, moderate, or high) based on the following factors:

Individuals categorized as low risk have no signs or symptoms of and have not been diagnosed with cardiovascular, pulmonary, and/or metabolic disease. These individuals also possess no more than one cardiovascular disease risk factor. Low-risk-stratified individuals have minimal risk for an acute cardiovascular event during exercise. This population can safely participate in either moderate- or vigorous-intensity exercise.

Individuals categorized as moderate risk are those who have no signs or symptoms of and have not been diagnosed with cardiovascular, pulmonary, and/or metabolic disease, but these individuals possess two or more cardiovascular disease risk factors. People with moderate risk also could be more likely to have a heart attack or other event during exercise. Although it is appropriate for these individuals to begin a moderate-intensity exercise program, before engaging in vigorous-intensity exercise, it is recommended that they first undergo a medical examination and complete a physician-supervised exercise test.

Individuals categorized as high risk are those who have one or more signs or symptoms of or have been diagnosed with cardiovascular, pulmonary, and/or metabolic disease. High-risk-stratified individuals have a substantial risk for an acute cardiovascular event during exercise. It is strongly recommended that before engaging in either a moderate- or vigorous-intensity exercise program these individuals first undergo a medical examination and complete a physician-supervised exercise test.



Despite the fact that regular exercise confers numerous health benefits and protects against various age-related chronic diseases, an increased risk of both cardiac and musculoskeletal complications is associated with vigorous-intensity exercise. It is important to understand the risks connected with exercise and how they can be reduced. The most common exercise-related complication is musculoskeletal injury. The incidence of injury increases with exercise intensity. A minimal risk of musculoskeletal complications is linked to walking and other types of moderate-intensity physical activities. Conversely, risk of injury is elevated during vigorous-intensity activities such as jogging. Similarly, musculoskeletal problems are more pronounced in individuals who participate in competitive sports.


Individuals should participate in either moderate-intensity exercise, vigorous-intensity exercise, or a combination of both to fulfill current physical activity guidelines. It is also important to consider whether participation in vigorous-intensity exercise yields greater benefits than moderate-intensity exercise. To address this issue, the total volume of exercise energy expenditure is controlled when comparing the difference in health outcomes between moderate-and vigorous-intensity exercise training programs. Reports that have examined which is better, after controlling for energy expenditure, conclude that vigorous-intensity exercise is superior at reducing risk for cardiovascular disease and death from all causes. Furthermore, important cardiovascular disease risk factors, including insulin resistance and low cardiorespiratory fitness, respond more favorably to vigorous-intensity aerobic exercise as compared to moderate-intensity aerobic exercise.

It is unclear exactly why vigorous-intensity exercise is more beneficial. The greatest benefit accrued from vigorous-intensity exercise might be the larger improvements in cardiorespiratory fitness. It has been proposed that, for each 1 MET increase in cardiorespiratory fitness, there is an accompanying 8%–17% reduction in death rates from cardiovascular disease and all causes. Several ways in which the body's systems adapt to vigorous exercise positively affect blood pressure, thrombosis, and other heart-related risks.



McArdle, William D., and Frank I. Katch. Essentials of Exercise Physiology, 5th ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins Health, 2015.

Swain, David P., et al., ed. ACSM's Resource Manual for Guidelines for Exercise Testing and Prescription, 7th ed. Philadelphia: Lippincott Williams & Wilkins Health, 2014.


Pugliese, L., et al. “Effects of Manipulating Volume and Intensity Training in Masters Swimmers.” International Journal of Sports Physiology and Performance 10, no. 7 (October 2015): 907–12.


Ainsworth, Barbara E., et al. “The Compendium of Physical Activities Tracking Guide.” Healthy Lifestyles Research Center, College of Nursing & Health Innovation, Arizona State University. (accessed March 1, 2017).

American Heart Association. “Moderate to Vigorous: What Is Your Level of Intensity?” . (accessed March 1, 2017).

Centers for Disease Control and Prevention. “Target Heart Rate and Estimated Maximum Heart Rate.” US Department of Health & Human Services. (accessed March 1, 2017).

Kravitz, Len.“High-Intensity Interval Training.” American College of Sports Medicine. (accessed March 1, 2017).


American College of Sports Medicine (ACSM), 401 W. Michigan St., Indianapolis, IN, 46202-3233, (317) 637-9200, Fax: (317) 634-7817, .

American Heart Association (AHA), 7272 Greenville Ave., Dallas, TX, 75231, (800) 242-8721, .

Centers for Disease Control and Prevention, 1600 Clifton Rd., Atlanta, GA, 30329-4027, (800) 232-4636, .

National Coalition for Promoting Physical Activity, 1150 Connecticut Ave., NW, Ste. 300, Washington, DC, 20036, .

Lance C. Dalleck, BA, MS, PhD
Revised by Teresa G. Odle, BA, ELS

  This information is not a tool for self-diagnosis or a substitute for professional care.