Increasing physical activity

A research article described an investigation to determine factors that led to increased physical activity. The participants were overweight middle-aged men with impaired glucose regulation, and one group Nordic walked, another group took up resistance training, and the third group didn't do anything different (control group). The control group acted as the part of population that doesn't do anything different from what they normally do.

All the groups started the study at similar levels of total physical activity. Total physical activity in the study consisted of:

• Occupational (or other daytime) physical activity (OPA): What you do at work.
• Commuting (or transition) physical activity (CPA): What you do to get to work.
• Leisure-time physical activity (LTPA): What you do for fun.
• Miscellaneous home physical activity (MHPA): The household chores you do.
• Structured physical exercise activity (SPEA = Nordic walking or resistance training activities): What you do when you set aside time to work out.
• Sleep: What you do when your eyes are closed.

In structured physical activity (workout sessions), intensity was higher in the Nordic walking group than in the resistance training group. Increasing intensity was seen as more beneficial to fitness than increasing the amount of exercise. We need to understand a key point, however.

Intensity was measured by metabolic equivalent of task (MET). It's a multiple of your energy expended at rest. If you do an activity where the MET is rated as 5, you're expending 5 times the energy expended at rest. Then you multiply the minutes you do that activity to get a final result. If you perform that MET 5 activity for 50 minutes, your total intensity is 5 X 50 = 250. MET provides a way to compare different activities.

Note: MET looks like it's really more of an aerobic measure, so I'm not sure how resistance exercise can really be compared. Weight lifters have to manage their sessions closely because the lifts break down muscle and require recovery time. Nordic walkers can go longer and more frequently.

Overall physical activity didn't increase, but, in comparison to the control group, the researchers reported the Nordic walking group increased their leisure-time physical activity significantly but not in the resistance training group. However, as leisure-time physical activity increased, other kinds of physical activity decreased to compensate. The researchers stopped short of reflecting on why the increase happened. I think the low impact of Nordic walking and how Nordic walkers don't feel like they're working harder even if they really are is a factor in encouraging people to step up their activity.

Tools for research

Something researchers use to study movement like Nordic walking.

Nordic walking and insulin resistance

I came across a research article that tested the effect of Nordic walking on insulin resistance in elderly women. Insulin resistance is related to Type 2 diabetes and other disorders. In this particular case, the participants Nordic walked under instructor supervision two hours per week.

What the researchers found:

The participants improved their walking distance (walked as far as they could in six minutes) and positive improvement in insulin resistance.

• Improvement:
• BMI [body mass index]
• Waist circumference
• SBP [systolic blood pressure]
• Diastolic blood pressure (DBP)
• HDL-C [high-density lipoprotein: good cholesterol]
• hsCRP [high sensitivity C-reactive protein: caused by infections and long term diseases]
• Hemoglobin
• IRI [immunoreactive insulin]
• Unchanged:
• TG [triglycerides]
• LDL-C [low-density lipoprotein: bad cholesterol]
• GGT [serum gamma-glutamyl transferase; detect disorders of liver and bile ducts]
• Uric acid
• HbA1c [hemoglobin A1c]
• FPG [fasting plasma glucose: after overnight fast; 126 mg/dl or higher means a person has diabetes]

Regarding HbA1c, the standard by which glucose in the blood is measured, it's not surprising it was largely unchanged (5.7 before and 5.6 after). It's a measure over a period of time, so HbA1c is really more affected by diet. I saw a similar result in another research article I blogged about. That's why the Nordic Walking Guy tells you, "Don’t' eat like a teenager."