It has been repeatedly demonstrated that increasing the variety of available food and purchasing options reliably increases eating and consumer spending behavior, respectively. However, the potential probehavioral effect of increasing the variety of exercise equipment options on the amount of exercise individuals perform is very limited. The purpose of this investigation was to compare the amount, enjoyment (liking), and effort perception of resistance training exercise vs. sedentary alternatives during a high-variety (HV) resistance-exercise equipment condition (10 choices) vs. a low-variety (LV) equipment condition (2 choices). During each condition (HV) and (LV), children (8-12 years), young adults (18-26 years), and older adults (≥60 years) had free-choice access to both resistance-exercise equipment and sedentary activities for a total of 20 minutes. The amount of time allocated to resistance exercise, the total number of repetitions performed, and session liking were measured during each condition. The participants significantly (p ≤ 0.05 for all) increased: repetitions performed (126.4 ± 71.7 vs. 88.0 ± 48.8), the amount of time allocated for exercise (14.3 ± 6.3 vs. 12.1 ± 6.5 minutes) and liking (8.1 ± 1.5 vs. 7.1 ± 2.1 cm) during the HV condition relative to the LV condition. The rating of perceived exertion was not significantly (p = 0.13) different from HV (4.2 ± 2.4) to LV (3.8 ± 2.3). Increasing the variety of exercise equipment available to children, young and older adults increased their exercise participation and enjoyment of that exercise without altering their perceived exertion. The practical application from this research is that increasing the variety of exercise equipment available to one's clients may increase their exercise adherence.

The current study showed that ULTRA using a seven-site methodology did not agree with DXA in measuring %BF. Thus, this investigational ULTRA methodology might not be appropriate in estimating %BF in this population.

There was statistical agreement between US and ADP for FM and FFM but lack of agreement for US and ADP when compared to DXA. However, the large limits of agreement between methods warrant caution in generalizing these findings.

The Pollock 3-site method estimates body fat percentage with comparable accuracy to JP7 using ULTRA.

Providing greater autonomy through choice of a greater number of physically active options increased young children's physical activity participation by 20.5%.