Start with a free account for 3 free CME credits. Already a subscriber? Sign in.

Sitting, Walking, Running

Robert Pepper, MD and Andrew Buelt, DO
00:00
22:19

No me gusta!

The flash player was unable to start. If you have a flash blocker then try unblocking the flash content - it should be visible below.

A discussion on the health benefits of walking and running with specific recommendations for patients.

PEARLS:

  • The data is clear that a sedentary lifestyle contributes to excess cardiovascular and overall mortality.

  • Running is a more efficient than walking in reaching the exercise goals that result in health benefits.

  • A 5 minute run (even at a slower 10-12 minute per mile pace) generates the same benefits as a 15 minute walk.  

 

  • Several recent studies have suggested that sedentary behavior may be as much a health hazard as cigarette smoking.  

    • An Australian study published in 2014 showed that inactivity or office-type jobs (where one sits for 6-8 hours a day) inferred the same mortality and morbidity risks as tobacco use.  

    • In the 1950s in the UK, it was noted that London bus drivers had an increased risk of heart attacks and early death as compared to conductors.

    • Another 2014 paper said that working out after sitting for 8 hours does not undo the damage due to being sedentary.

    • A German study published in 2014 showed that sedentary behavior and television viewing time were associated with increased risk of certain types of cancer.

      • Schmid D, et al. Television viewing and time spent sedentary in
        relation to cancer risk: a meta-analysis. J Natl Cancer Inst. 2014 Jun 16;106(7). PMID: 24935969

    • A Swedish study found that reducing sitting time increased telomere length, which is associated with increased longevity.  Even on the molecular level, getting up and moving around seems to be beneficial.

      • Sjögren P, et al. Stand up for health--avoiding sedentary behaviour might lengthen your telomeres: secondary outcomes from a physical activity RCT in older people. Br J Sports Med. 2014 Oct;48(19):1407-9. PMID: 25185586

  • What are some of the weaknesses of studies which examine the health effects of exercise?

    • The vast majority of exercise studies are observational, as it is hard to do a randomized controlled trial where the non-exercisers are blinded.

    • Some studies are also hampered by small sample sizes.  This is particularly true of the cardiotoxicity studies which showed that too much exercise is dangerous.  

    • Retrospective studies (such as surveys) can be unreliable due to the fact that people tend not to accurately recall how much they exercise.

    • The issue of variation poses challenges for exercise studies.  Since exercise is a broad term, studies must specify the exact type of exercise being done.  Walking and running constitute the majority of studies because they’re the most reproducible and least affected by conditions of the environment or equipment being used.  In contrast, a study looking at outdoor cycling would have trouble controlling for the many variables which affect this form of activity (e.g. wheel size, wind, grade of the road, the bicycle, the weight of the rider.)  

  • What is the goal exertion level which yields the greatest health benefits?  About 9-10 METs.

    • The Bruce protocol allows measurement of exercise in METs and is a standardized way of measuring escalating exertion while exercising on a treadmill.  A MET is a metabolic equivalent task which allows the comparison of effort.  Sitting is equal to 1 MET, walking briskly is about 4 METs, and jogging is 9-10 METs.  

    • The goal is to exercise at about 9-10 METs; this is associated with the best cardiovascular and overall mortality benefit.  Unfortunately, this requires walking at a 5 mile/hour pace (or 12 minute mile) which is difficult for most people to do.  It is a fast clip and an unnatural pace.  For most, it is a slow jog.  

    • The absolute minimum number of METs associated with improvement in cardiovascular and overall mortality is 5, which is about a 4 mile/hour pace.  

    • People exercising on a treadmill set at 3 miles/hour are not likely getting the benefit they hope for.  They need to either increase their speed or their incline.

  • The United States guidelines recommend 150 minutes per week of moderate exercise (5 miles/hour).  This is more time than many patients (or physicians) have for daily exercise.  If people choose to run instead of briskly walk, can they get the same benefit for a shorter duration of weekly exercise?  Yes.   

    • Only 3-5% of people in the US actually meet the US  guidelines.  Exercising at a moderate level for approximately 20 minutes/day is unrealistic for most people.

    • Fortunately, there is excellent data that a much lower dose of running confers the same amount of benefit.  Running is a much more efficient form of exercise; the ratio of running to walking is probably on the magnitude of 3-4:1.  In other words,  5 minutes of running is equivalent to about 15 minutes of walking and instead of briskly walking 20 minutes per day, people can run 7-8 minutes.

  • The Aerobics Center Longitudinal Study showed that people who exercise at very low levels and low frequencies had the same benefits as the intense exercisers.

    • Low level and intensity was defined as about 52-56 minutes per week at an average pace of 10-12 minute miles (or 5 miles/hour).

    • Participants who exercised at low level and intensity had the same cardiovascular benefits as people who did much higher levels of exercise.  According to the authors, the "maximal benefits of running occur at quite modest jogging doses.”

    • Consistency is always better than intensity.  People need to make exercise a habit.  

    • While 150 minutes per week of moderate exercise is intimidating to most people, exercising at a low level for only 56 minutes (however they want to divide it up -- around 10 minutes a day, 26 minutes twice weekly, or 56 minutes all at once) is much more doable.

    • The cardiovascular and overall mortality benefits of running are significant:

      • Compared with non-runners, runners had a 30% reduction in all-cause mortality and a 45% reduction in cardiovascular mortality.

      • Runners had an average increase in survival of 3 years for all-cause mortality and 4.1 years for cardiovascular survival.

    • Lavie CJ, et al.  Effects of Running on Chronic Diseases and Cardiovascular and All-Cause Mortality. Mayo Clin Proc. 2015 Nov;90(11):1541-52. PubMed PMID: 26362561

  • While there is evidence to support the notion that running is more efficient than walking at achieving the health benefits of exercise, some data suggests that at the highest intensities, running can be as detrimental to health as being sedentary.

    • Studies have shown a loss of benefit in the highest dose runners.  A problem with the data, however, is that the number of people in these high intensity groups is very small.  The data is cloudy.

    • The Aerobics Center and Longitudinal Study found that there was no increase in mortality but, rather, a declining trend in benefit in all-cause and cardiovascular mortality at the highest dose compared with non-runners.  While they found no remarkable increase in mortality risk compared with non-runners, they also showed no mortality benefit in excessive running.

  • What additional health benefits does running provide?

    • Running decreases the risk of type 2 diabetes, obesity, certain cancers, osteoarthritis, and the need for hip replacement.

    • While many believe that running increases the risk of knee damage, MRI studies show that runners actually have increased cartilage density.

  • How can we encourage an inactive individual to start exercising?  Get them to walk before you suggest that they run!

    • Have patients start with 10, 15, or 20 minutes of walking.

    • Then progress to a walk/run program, gradually increasing the amount of time running spent running and decreasing the walking component.

    • For patients with knee osteoarthritis, Dr. Pepper suggests the AlterG treadmill which de-weights the patient using air inflation.  An alternative is pool running.

  • Is running safe for the elderly population?  Absolutely!

    • A study of 538 members of a nationwide runners club and 423 controls showed that running has multiple benefits in the elderly.  

      • The participants were all older than 50 when they entered the trial and were followed until they died.  284 runners and 186 controls completed the 21-year follow-up.

      • At about two years, the mortality curves between the two groups started to split.

      • At 19 years, 15% of the runners had died, compared with 35% of the controls.  

      • The disability scores were even more dramatic.  A disability index score was used which showed that runners gained about 16 years on the non-runners.  This means that the physical condition of the non-runners was 16 years older than the runners of the same age.  

      • Many runners in their 80s and 90s remained fully functional, much more so than their compatriots who chose not to run.

Chakravarty EF, et al. Reduced disability and mortality among aging runners: a 21-year longitudinal study. Arch Intern Med. 2008 Aug 11;168(15):1638-46. PMID: 18695077

To join the conversation, you need to subscribe.

Sign up today for full access to all episodes and to join the conversation.

To download files, you need to subscribe.

Sign up today for full access to all episodes.
Best Weight, Best Exercise! Full episode audio for MD edition 195:42 min - 92 MB - M4AHippo Peds RAP September 2016 Summary 705 KB - PDF

To earn CME for this chapter, you need to subscribe.

Sign up today for full access to all episodes and earn CME.

0.25 Free AMA PRA Category 1 Credits™ certified by Hippo Education or 0.25 Free prescribed credits by the American Academy of Family Physicians

  1. Complete Quiz
  2. Complete Evaluation
  3. Print Certificate

3.25 AMA PRA Category 1 Credits™ certified by Hippo Education or 3.25 prescribed credits by the American Academy of Family Physicians

  1. Complete Quiz
  2. Complete Evaluation
  3. Print Certificate