The Cooper Institute
 

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH

 
 

The 10 Minutes of Aerobic Exercise Rule: Does it Still Apply?

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Wednesday, Jul 11, 2018

 It is well-known that regular physical activity is strongly associated with a reduced risk of many chronic health conditions, including but not limited to cardiovascular disease, some cancers, and type 2 diabetes.

Back in 2008, the Physical Activity Guidelines for Americans recommended that adults get a minimum of 150 minutes each week of moderate to vigorous physical activity (MVPA) to enjoy substantial health benefits. The guidelines also stated that MVPA should be performed in increments of at least 10 minutes or more. For example, you could choose to walk for 30 minutes a day all at once or break it up into three 10 minute walks. The health benefits of both are virtually the same, placing greater emphasis on accumulating MVPA minutes throughout the day.

But is 10 the magic number? The 10-minute rule was intended to give people options on how they achieved their MVPA, but there was little evidence to support the notion that each bout had to be at least 10 minutes in duration in order to achieve health benefits and a reduction in mortality risk. In other words, the benefits using bouts of less than 10 minutes were unknown.





With this idea in mind, researchers from the
National Cancer Institute carefully examined data from the National Health and Nutrition Examination Survey (NHANES). A representative sample of 4840 adult men and women ages 40 and older were examined during 2003-2006.


Most studies on physical activity rely on self-reported answers from questionnaires. This method is not always accurate, since the right questions may not be asked, and some people tend to overestimate their level of MVPA. A particular strength of this study was that MVPA was objectively measured using a sophisticated wearable device called an accelerometer. Subjects wore the accelerometer for up to 7 days.


Total minutes per day of MVPA were determined by using 3 different measures:
1) total minutes with no bout duration restriction, 2) accumulated in bouts of at least 5 minutes each, 3) accumulated in bouts of at least 10 minutes each. The sample was followed for an average of 6.6 years, during which time 700 deaths occurred.   

Study Results:

Researchers divided the sample into four groups (quartiles) based on the amount of daily MVPA performed. For example, quartile 1 had the least amount of MVPA (<40 minutes per day), while quartile 4 had the greatest amount (>123 minutes per day). Regardless of which of the 3 MVPA measures were used, a greater amount of MVPA was associated with substantially lower all-cause mortality risk. Let’s look at the Figures below to show what we mean. 



In Figure 1, the risk of all-cause mortality is shown across the 4 MVPA groups using the 10 minute rule. In other words, this data shows the results for individuals who accumulated their MVPA in bouts of at least 10 minutes each. The greater the amount of MVPA, the lower the risk of death during the follow-up. As an example, those in quartile 4 had a 65% lower risk of all-cause mortality than those in quartile 1.  


In Figure 2, the risk of mortality is shown across the 4 MVPA groups using the 5 minute rule. In other words, this data shows the results for individuals who accumulated their MVPA in bouts of at least 5 minutes each. Just as we saw in Figure 1, the greater the amount of MVPA, the lower the risk of death during the follow-up.  


Finally in Figure 3, the risk of mortality is shown across the 4 MVPA groups using no restrictions on the length of each bout. In other words, this data shows the results for individuals who accumulated their MVPA many different ways. Some accumulated their daily MVPA all at once, while others used the 5 minute rule, 10 minute rule, or no rule at all (sporadic activity throughout the day). Just as we saw in Figures 1 and 2, the greater the amount of MVPA the lower the risk of death during the follow-up (the reduced risks seen in quartiles 3 and 4 were not significantly different from each other).  

Conclusion:

The 10-minute rule is not set in stone. You can get your activity minutes in throughout the day at any level. These findings dispel the notion that MVPA must be accumulated in bouts of at least 10 minutes in duration. Results were similar when bouts of at least 5 minutes in duration were used, and were still similar when there was no restriction on the length of each bout.



Say for example that you want to get 90 minutes of brisk walking in each day. Now you have more options because your minutes can include walking to and from the car in the parking lot,
walking while shopping or at work, walking from room to room at home, as well as deliberate walking for exercise, etc. Just remember that the activity must be moderate or vigorous to count.


You can try any of the following and still get the same reduced mortality risk benefit:

  • MVPA for 90 minutes all at once (probably not realistic for most people)
  • MVPA for 30 minutes 3 times a day  
  • MVPA for 15 minutes 6 times a day
  • MVPA for 10 minutes 9 times a day    
  • MVPA sporadically throughout the day to accumulate 90 total minutes (much more realistic if you build up to this slowly)

In summary, the benefit of reduced mortality risk will be virtually identical regardless of which of these types of approaches that you choose to use when performing MVPA. It’s all about how much MVPA is accumulated throughout the day. How you get there is your choice.  

Reference

Saint-Maurice, P., Trojano, R., Matthews, C., Kraus, W. Moderate-to-vigorous physical activity and all-cause mortality: do bouts matter? (2018). Journal of the American Heart Association, 7(6). DOI: 10. 1161/JAHA. 117.007678