|Move 3 for Every 30
By Len Kravitz, PhD
With most U.S. adults sitting 9-12 hours daily, and the known risks of sedentary behavior being associated to undesirable health effects, the popular press and the scientific community agree, sitting is the new smoking (Diaz et al., 2017). In fact, more evidence than ever is emerging indicating a strong association with sedentary lifestyle and cardiovascular disease and all causes of mortality (Diaz et al). However, one major question has puzzled researchers, up to now. Is the accumulation of sedentary time in several short sessions just as risky as accumulation of sedentary time in long periods? This IFJ Research column provides new research results from two new studies offering evidence-based answers and solutions to this question. As well, 10 novel movement ideas are introduced to get clients moving, utilizing the new research.
Study 1. Diaz, K.M., Howard, V. J., Hutto, V. et al. (2017). Patterns of sedentary behavior and mortality in the U.S. middle-aged and older adults, Annals of Internal Medicine, doi:10.7326/M17-0212
Purpose: The purpose of this study was to examine the association between objectively measured sedentary time and all-cause mortality.
Participants: The participants in this study were 7985 black and white adults approximtely 45 yeas of age. Participants were volunteers in the REGARDS study, which examined regional disparities in stroke in the U.S.
Methods: Cardiovascular risk factor data and other demographics were collected by telephone interview and in-home physician examination at start of the study. Participants were then followed from 2009 to 2013, a period of 5.7 years. The researchers had the participants wear hip-belt accelerometers at different intervals during this period to assess their daily movement. Accelerometers are devices, similar to pedometers, that measure energy expenditure quite accurately.
Results: On average, most of the adults in this study spend 12.3 hours (out of a 16-hour waking day) in a sedentary behavior (primarily sitting). Total sitting time was found to be highly correlated to all causes of mortality. However, those adults whose sedentary time was regularly interrupted with some type of movement every 30 minute (or less) had the lowest risk to all causes of mortality. From these unique findings, the researchers submit that existing physical activity and exercise guidelines need to be amended to include a recommendation stating that optimally, adults should do some type of movement every 30 minutes (of waking behavior) to combat the deleterious effects of sustained sitting. This second study answers two other crucial components to this discovery
how much movement every 30 minutes and what type of movement works.
Study 2: Dempsey, P.A., Larsen, R.N., Sethi, P. et al. (2016). Benefits for type 2 diabetes of interrupting prolonged sitting with brief bouts of light walking or simple resistance activities. Diabetes Care, 39, 964-972.
Purpose: The purpose of this study was to determine whether interrupting prolonged sitting with brief bouts of light intensity walking or simple resistance activities improves postprandial (the period after dinner or lunch) cardiometabolic risk markers in adults.
Participants: Twenty-four inactive, overweight/obese adults (14 men, 10 women; 62 years old; BMI = 33 kg/m2, hemoglobin A1c = 7.2%) diagnosed with Type 2 diabetes volunteered for this study.
Methods: After initial telephone screening, participants attended a medical screening that included a 12-Lead resting EKG, a blood chemistry work-up, resting blood pressure, and a physical exam from a physician. The participants were familiarized with the treadmill walking, and learned the simple resistance training exercises, which included half-squats, heel raises, gluteal contractions and knee raises.
For the study, all participants completed three different 8-hour conditions, which were randomized and separated by 6-14 days. The longer separation was needed to sufficiently 'washout' the influence of insulin, the one variable that could influence other metabolic variables of interest over the course of a few days. The three experimental conditions were as follows:
A. Control: uninterrupted sitting for the 8-hour period.
B. Sitting plus 3-min bouts of treadmill walking 2 miles/hr every 30 minutes (for the 8-hour period).
C. Sitting plus 3-min bouts of resistance training every 30 minutes (for the 8-hour period).
The participants were asked not to do any type of exercise, drink coffee or alcohol for 48 hrs prior to a trial condition testing. In addition, to minimize any diet-induced variability in the study, the diet of all volunteers was standardized prior to each testing condition.
Results: In regards to circulating blood glucose, both activity-break conditions significantly lowered blood glucose as compared to the control group (i.e, a very positive finding meaning the cells are using glucose for fuel needs). In addition, insulin levels were significantly lower in the activity-break conditions as compared to the control group (another positive finding). In respect to C-peptide, a marker protein on insulin production, once again the activity-break conditions had a significantly lower effect as compared to the control group (i.e, positive finding).
Interestingly, blood triglycerides were significantly lower in the resistance training activity-break condition (as compared to the control condition) but this was not seen in the treadmill walking condition. Dempsey et al. (2017) remarked that the participants lifestyle in this study represent a large part of the U.S. population (i.e., older adults with Type 2 diabetes) who do not adhere well to traditional exercise programs. The researchers propose that these individuals (and others with similar health conditions) may find it much more achievable to adhere to the 'for every thirty minutes get your 3 minutes of activity (walking or simple resistance exercises or a combination of both).'
The Practical Application
The rapidly advancing technological innovations in communications, workplaces, transportation and entertainment will surely continue to create home, work and leisure environments conducive to prolonged periods of sedentary behavior (Dempsey et al., 2016). The study by Dempsey and colleagues recommends that 3 minutes of walking or simple body weight resistance exercise movements (at a light to moderate intensity) every 30 minutes of sedentary time may have a very positive influence on metabolic factors directly related to cardiovascular disease and type 2 diabetes. Some clients may wish to do some creative and or different walking styles during their 3-min intermittent bouts of movement. Many clients may choose to just move for the 3-min period. Five walking styles are introduced in this column (see Side Bar 1), all modified and derived from interval training research. Other clients may wish to complete more resistance training moves to break up their sedentary periods. Using the exercises Dempsey incorporated, I have mixed up the movements into 5 different patterns (see Side Bar 2). Encourage clients to complete these activity movement breaks at a light to moderate (somewhat hard) intensity. Please note there are many interval training apps for mobile devices that your clients may choose to time these movement periods.
Side Bar 1. Five Walking Ideas for the 3-Min Activity Movement Breaks
1) 30/30 walking. With 30/30 walking, walk briskly for 30 seconds followed by a comfortable 30-second relief walk. Repeat 3 times and the 3-min bout is achieved.
2) 15/15 walking. With 15/15 walking, walk briskly for 15 seconds followed by a comfortable 15-second relief bout of walking. Repeat 6 times and the 3-min bout is achieved.
3) Fartlek walking. With Fartlek walking, inform your client to just set the timer for 3 minutes. Then, encourage the client to randomly change their speed and distance with this straightforward suggestion: Speed changes range from slow, medium and fast. Distance changes range from short, medium and long. Naturally these will be different for all people, which is precisely what you want.
4) 45/45 walking. With 45/45 walking, walk briskly for 45 seconds followed by a comfortable 45-second recovery walk. Repeat 2 times and the 3-min bout is achieved.
5) 8/12 walking. With 8/12 walking, walk briskly for 8 seconds followed by a comfortable 12-second relief walk. Repeat 9 times and the 3-min bout is achieved.
Side Bar 2. Five Combinations of the Simple Resistance Exercises Movement Breaks
From pilot practice, it appears 2 circuits of 10 movements performed slowly fills the 3-minute period nicely. I've also added the marching in place to replace the gluteal contractions. For the knee raises, I suggest alternating knee raises (i.e., total of 20 alternating knee raise). Also, for the 10 marches have a client alternate 10 marches per leg. Suggest teaching the 1/2 squats in a shoulder width stance.
1) Circuit A: 1/2 squats, knee raises, heel raises, marches
2) Circuit B: Knee raises, marches, 1/2 squats, heel raises
3) Circuit C: Marches, 1/2 squats, heel raises, knee raises
4) Circuit D: Heel raises, marches, knee raises, 1/2 squats
5) Circuit E: Marches, knee raises, 1/2 squats, heel raises
Bio: Len Kravitz, PhD, CSCS is the program coordinator of exercise science and a researcher at the University of New Mexico, where he received the Outstanding Teacher of the Year award. In addition to being a 2016 inductee into the National Fitness Hall of Fame, Len was awarded the 2016 CanFitPro Specialty Presenter Award.