Walking is an effective way for many people to incorporate physical activity into their day. Common recommendations for adults are to accumulate 10,000 steps or 30 minutes of walking each day. More recent guidelines¹ however, have emphasized intensity to see health improvements. The use of pedometers have been widely used in physical activity studies, but daily step counts do not necessarily correspond to time spent in adequate levels of moderate intensity activity. Therefore, researchers were interested in producing step rates per minute that would ensure the desired levels of intensity were attained, resulting in improved cardio-respiratory fitness.

Let’s recall that cardiovascular prescriptions must include minimums of Frequency, Intensity, and Time (F.I.T.) or the “FIT” principal. To meet the new national recommendation for health benefits the following are the guidelines:

Frequency: Five days per week 
Intensity: Moderate = 3 METs (energy expenditure of 3 times that over a resting state)
Time: Duration totaling 30 minutes per day but can be accumulated in 10 minute segments

The step rate corresponding to moderate intensity walking had been investigated in two previous studies^2,3. While separate guidelines were given in both studies to men and women, gender differences did not explain the difference in step rates. Therefore, in this recent study⁴, researchers wanted to look at height difference as the possible cause for different stride rates and more precisely recommend stride rates for varying heights of individuals.  Furthermore, with a more accurate stride rate identified to meet the moderate intensity MET rate of 3 METs, adults could advance to higher energy expenditures for further improvements in aerobic capacity and weight loss.

Strengths of this study included the fact that all trials were walking trials (no running), and trials included treadmill walking and over land walking. The walking trials included randomized speeds of slow, moderate, and fast paces. When the subjects walked on the treadmill, appropriate apparatus was used to measure heart rates and VO2 data (maximum oxygen uptake). Also, a metronome was used to give the subjects the proper step cadence when walking over land and an approved, accurate, pedometer was worn on the waistband above the midline of the right knee. There were 75 total subjects with 38 females and 37 males with an average age of 33.

In the previous studies researchers found that the generic stride rate associated with walking at 3 METs (moderate intensity) was 103 steps per minute.  The researchers suggested a convenient population cut point of 100 steps per minute. This is an attractive recommendation as it is easy to use in calculations of total step targets for fixed durations, e.g. 1000 steps in 10 minutes.  Also, recommendations of 120 steps per minute for 4 METs and 140 steps per minute for 5 METs could be inferred.

In the current study, researchers found that meeting the 3 METs intensity should be adjusted for height. For example, the 3 MET stride rates recommended for adults 60 inches tall and 78 inches tall are different by 23 steps per minutes (113 vs. 90 steps per minute). Furthermore, applying the 100-steps per minute generic guideline to people of all heights would result in a 3 METs walking intensity only for adults 70 inches tall and a 2.3 METs in adults 60 inches tall. In the current study, stride rates of 3 METS were correctly classified 88% of the time, a considerable improvement over both previous studies of just 52% that were correctly classified as 3 METs intensity.

The following table from this research article⁴ can be used to set goals and achieve the energy expenditure and intensities desired for your or your clients' walking bouts. Example: A 5'5" inch person (65 inches) needs to take 107 steps per minute or 3,210 steps in 30 minutes to be walking at 3 METs, or moderate intensity.

Try it! Use a step counter to see how many steps you take during a 30-minute brisk walk. Is it equal to or more than what you need (based on the table below) to be walking at a moderate intensity (3 MET) level?

Table from reference 4 below. For full text article from the Medicine and Science in Sports and Exercise journal, click here.  

References
¹American College of Sports Medicine. ACSM’s Guidelines for Exercise testing and Prescription. 8th ed. Philadelphia (PA): Lippincott Williams & Wilkins; 2010. P. 81.
²Marshall SJ, Levy SS, Tudor-Locke CE, et. al. (2009). Translating physical activity recommendations into a pedometer-based step goal: 3000 steps in 30 minutes. Am J Prev Med. 36(5):410-5.
³Tudor-Locke D, Sisson SB, Collova T, Lee SM, Swan PD. (2005). Pedometer-determined step count guidelines for classifying walking intensity in young ostensibly healthy population. Can J Appl Physiol. 30(6):666-76
⁴Rowe DA, Welk GJ, Heil DP, et al. (2011). Stride rate recommendations for moderate-intensity walking. Medi Sci Sports Exerc. 43(2):312-318.