Exercise: Part II. Translating the exercise prescription

Wearable Device Validity in Measuring Steps, Energy Expenditure, and Heart Rate Across Age, Gender, and Body Mass Index: Data Analysis From a Systematic Review

BACKGROUND

This paper examined whether the criterion validity of step count (SC), energy expenditure (EE), and heart rate (HR) varied across studies depending on the average age, body mass index (BMI), and predominant gender of participants.

METHODS

Data from 1536 studies examining the validity of various wearable devices were used. Separate multilevel regression models examined the associations among age, gender, and BMI with device criterion validity assessed using mean absolute percent error (MAPE) at the study level.

RESULTS

MAPE values were reported in 970 studies for SC, 328 for EE, and 238 for HR, respectively. There were several significant differences in MAPE between age, gender, and BMI categories for SC, EE, and HR. SC MAPE was significantly different for older adults compared with adults. Compared with studies among normal-weight populations, MAPE was greater among studies with overweight samples for SC, HR, and EE. Comparing studies with more women than men, MAPE was significantly greater for EE and HR.

CONCLUSIONS

There are important differences in the criterion validity of commercial wearable devices across studies of varying ages, BMIs, and genders. Few studies have examined differences in error between different age groups, particularly for EE and HR.

Why do we eat?

The urge to eat is the main apparent issue underlying obesity. Although vast information regarding the physiology and psychology of eating behavior has been accumulated, a comprehensive concept is still missing. The model presented suggests that feeding behavior is ultimately controlled by the rate of work performed in the muscle or in an as yet unidentified compartment. It suggests a novel approach of a dynamic set-point weight and explains why diets usually fail to resolve the disorder while physical activity is beneficial in losing excess weight. Obesity is presented as a syndrome of high efficiency of energy conversion resulting in a variety of symptoms of which over-weight is only the more apparent. Other symptoms manifested in the predisposition to a variety of illnesses constitute the main health problem and can prevail in the obese subject even without the excess weight. Therefore, resolution of the disorder requires developing approaches which directly affect the efficiency of energy conversion.

Control of type II diabetes. Reaping the rewards of exercise and weight loss

After a complete physical examination to identify possible complications, patients with non-insulin-dependent (type II) diabetes mellitus should be placed on an exercise program and a weight-control diet. Individualizing these regimens according to patients' health goals and personal interests enhances the chance of success. Exercise guidelines must be followed to ensure the patient's safety. Weight loss, however moderate, should be encouraged, and once a reasonable weight is obtained, a balanced maintenance diet should be recommended. Patience and persistence by physicians and patients can bring success in management of type II diabetes with nonpharmacologic means.