Continuous vs. Intermittent Exercise — Does it Matter?

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In a recent blog post, Erin Hugus, MS, CN shared that three 10-minute brisk walks can be just as beneficial for blood sugar levels as one 30-minute walk. A reader asked us for some additional information on the subject, so we decided to devote an entire post on short bout or “intermittent exercise.”

Intermittent exercise throughout the day

The question of continuous vs. intermittent exercise comes up frequently among our patients and clients. Are frequent short bouts of exercise just as beneficial as a single longer bout? What if a longer exercise session doesn’t work for your schedule — is it worthwhile to take several shorter walks? These are great questions. Many studies suggest that for reducing cardiovascular risk — and improving general health and fitness — intermittent exercise may be as effective as continuous exercise:
  • One study showed similar increases in HDL cholesterol (the good type), decreases in triglycerides, total cholesterol and anxiety. Significant increases in fitness were also seen in intermittent exercisers — sometimes to a greater extent than for continuous exercise. There were no changes in total body weight, but body fat percent, waist circumference, and hip circumference were reduced for all subjects.
  • In a study of obese women with and without type 2 diabetes, subjects reported a reduced perceived effort with intermittent vs. continuous exercise. Significant improvements were seen in glycosylated hemoglobin (a marker for long-term blood sugar control). Total body weight, body mass index, heart rate, and walking distance improved in both groups.
  • A 12-week study compared an intermittent (2 x 15 minutes/day) exercise program with a traditional continuous (1 x 30 minutes/day) program. Maximal aerobic capacity — a marker of fitness level — increased by 4.5% for continuous exercisers and by 8.7% in the intermittent group.

So, does it matter?

If reducing your health risks and improving overall health and fitness is your goal, intermittent exercise appears to be effective — and that’s great news if you have a busy schedule, are new to exercise, or easily bored. Break up your cardiovascular exercise session into several shorter bouts throughout the day. One way to do this is to build exercise into your daily routine:
  • Use work breaks to walk for 10-15 minutes at a time
  • Walk briskly for 10 minutes before or after each meal
  • If you live close to work, plan on walking or biking at least part of the way
If you’re looking for lasting weight loss, make physical activity a regular part of your day, whether it’s intermittent or continuous. Keep in mind that while exercise burns calories — and plays a huge role in maintaining your weight loss, you are unlikely to lose a significant amount of weight with exercise alone. Adopting good nutrition habits is essential.

Caveat:

If you’re an endurance athlete — or training for your first 10K— you’ll benefit more from continuous exercise simply because it more closely matches the physical demands of your performance event. Doing short speed intervals can help you get faster, but there’s no substitute for continuous training in preparing you to go the distance. Beth Shepard, MS, ACSM-RCEP, ACE-PT, has a master’s degree in Exercise Physiology from the University of Arizona. Beth is an expert in fitness and health promotion and a certified wellness coach, helping people thrive by adopting sustainable lifestyle changes. She and her family love to hike, bicycle, and try new sports.

References

1. Murphy M, Nevill A, Neville C, Biddle S, Hardman A. Accumulating brisk walking for fitness, cardiovascular risk, and psychological health, Med Sci Sports Exerc. 2002 Sep;34(9):1468-74. http://www.ncbi.nlm.nih.gov/pubmed/12218740 2. J E Donnelly, D J Jacobsen, K Snyder Heelan, R Seip and S Smith. The effects of 18 months of intermittent vs. continuous exercise on aerobic capacity, body weight and composition, and metabolic fitness in previously sedentary, moderately obese females, International Journal of Obesity, May 2000, Volume 24, Number 5, Pages 566-572, http://www.nature.com/ijo/journal/v24/n5/full/0801198a.html 3. Coquart JB, Lemaire C, Dubart AE, Luttembacher DP, Douillard C, Garcin M. Intermittent versus continuous exercise: effects of perceptually lower exercise in obese women, Med Sci Sports Exerc. 2008 Aug;40(8):1546-53. http://www.ncbi.nlm.nih.gov/pubmed/18614934 4. Quinn TJ, Klooster JR, Kenefick RW. Two short, daily activity bouts vs. one long bout: are health and fitness improvements similar over twelve and twenty-four weeks? J Strength Cond Res. 2006 Feb;20(1):130-5. http://www.ncbi.nlm.nih.gov/pubmed/16506860 5. American College of Sports Medicine Position Stand, Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Apparently Healthy Adults: Guidance for Prescribing Exercise, Medicine & Science in Sports and Exercise, 43(7):1334-1359, July 2011. http://www.acsm.org/AM/Template.cfm?Section=ACSM_News_Releases&TEMPLATE=/CM/ContentDisplay.cfm&CONTENTID=16007