Health Wearables and College Student Health

Evaluated with YMCA 3-minute step test (Golding, Meyers, \& Sinning, 1998). Participants will step up and down for three minutes on a 12-inch riser to a metronome beep set at 96 beats per minute (each beep corresponding to one movement of the leg, with 4 beeps representing one "up-down" cycle). Participants' heart rate will be assessed immediately for one minute following the conclusion of the test by the researcher via palpation of the carotid/radial artery. The step test will be performed at baseline and 12 weeks to assess changes in cardiovascular fitness over time.

Determined via bioelectrical impedance performed with the Tanita BC-558 IRONMAN® Segmental Body Composition Monitor (Tanita, Tokyo, Japan). Bioelectrical impedance sends a small electrical pulsatile wave through the body. Muscle is more conducive to electrical current transmission due to its higher water content versus fat meaning individuals with higher lean mass (i.e., lower body fat mass) will not impede the current to the degree of individuals with higher fat mass and therefore register lower body fat percentage values. Bioelectrical impedance has proven a valid measure of body composition in young adults enrolling in the military (Aandstad, Holtberget, Hageberg, Holme, \& Anderssen, 2014). Notably, to decrease variability in these body composition measurements, individuals will be asked to come in for testing at approximately the same time of day and having eaten/drank similar foods/beverages the night before as they did prior to previous session(s).

Body Weight will be assessed using a calibrated weight scale: the Tanita BC-558 IRONMAN® Segmental Body Composition Monitor (Tanita, Tokyo, Japan).

Self-efficacy will be measured by a nine-question measure developed by Rodgers, Wilson, Hall, Fraser, and Murray (2008) wherein participants will rate how confident they feel in certain exercise situations (e.g., …"exercise when you feel discomfort" or "…exercise when you lack energy") on a percentage scale (0%: not confident at all to 100%: extremely confident in 10% increments).

Social support will be assessed using a five-question measure adapted from the Patient-Centered Assessment and Counseling for Exercise questionnaire, with participants rating on a five-point Likert-type scale (1: almost never to 5: almost always) how often significant others support/encourage them to be physically activity (Carlson et al., 2012).

A 5-question measure developed by Harter et al. (1978) quantified PA enjoyment as college students noted agreement with statements such as "Engaging in physical activity is the thing I like to do best" on a 5-point Likert-type scale (1: strongly disagree to 5: strongly agree).

A 14-question measure will evaluate participants' physical activity barriers, with participants asked to rate agreement between hypothetical barriers and their own barriers on a four-point Likert-type scale (1: strongly disagree to 4: strongly agree) (Sechrist, Walker, \& Pender, 1987).

Outcome expectancy will be assessed with a nine-question measure developed by Trost et al. (1997) using a five-point Likert-type scale (1: strongly disagree to 5: strongly agree) to evaluate participants' agreement with responses originating from the stem "If I was to exercise on most days it would…". Sample responses are "give me more energy" and "help to control my weight".

Will be evaluated using the interest/enjoyment subscale of the Intrinsic Motivation Inventory (McAuley, Duncan, \& Tammen, 1987). This seven-question subscale requires participants to determent how true certain statements such as "I enjoyed this activity very much" and "I would describe this activity as interesting" are to them on a seven-point Likert-type scale (1: not at all true to 7: very true). The Intrinsic Motivation Inventory has demonstrated good validity in the assessment of intrinsic motivation during exercise (Deci, Eghrari, Patrick, \& Leone, 1994).

To assess participant eating behaviors, the National Cancer Institute's Automated Self-Administered (ASA) 24-hour Dietary Recall will be used requiring participants to recall all foods consumed within the past 24 hours. The ASA 24-hour Dietary Recall has been validated in previous research (Kipnis et al., 2003; Moshfegh et al., 2008). Participants will receive unique login information allowing them to access and complete the recall after which the researcher will be able to download and analyze the results. The ASA 24-hour Dietary recall will be administered three times on random dates during the seven days following baseline and post-intervention testing at 12 weeks, with participants notified during these testing sessions that they will be asked to complete this questionnaire. Concentration will be placed on examining changes in participants' fruit and vegetable consumption in addition to the participants' intake of fast food and sugar-sweetened beverages.

Regardless of group allocation, adherence to the social media-delivered health intervention previously outlined will be tracked. Briefly, the researcher will determine whether the participants have checked the Facebook health tips twice weekly in two manners following the alert each participant will receive when a new post goes live on each groups' Facebook page. First, Facebook now has a "Seen By" function that automatically indicates and lists everyone who has interacted with a new posting within a private Facebook group. Second, the researcher will also ask participants to "Like" each of the postings they read. In this way, the researcher will keep a running tally of whether each participant checked the posting by reviewing the "Seen By" function and whether the individual "Liked" the posting. Only individuals listed both within the "Seen By" function and as having "Liked" the posting will be counted as having seen the health tips.