Original Project Aims/Objectives: The focus of the project is to use recently documented motivation gains in task groups (dyads in particular) to heighten the exercise experience for astronauts and help keep them motivated to exercise at levels necessary to mitigate reductions in aerobic fitness and muscle loss over long space missions. A secondary focus is to determine the most effective features in exercise partners for enhancing, enjoyment, confidence, and social connectedness. Specific aims: (1) Develop software to create Software Generated (SG) exercise partners and interface with exercise equipment (cycle ergometer) similar to equipment available on the International Space Station; (2) Test various design features of an SG partner within designed exercise video games to determine the most effective features for enhancing motivation to exercise, enjoyment, confidence, and connectedness; and (3) Test whether exercising with an SG partner over a 24-weeks, compared to exercising alone, leads to better aerobic capacity and muscle strength, adherence to exercise regimen, enhanced exercise enjoyment, self-efficacy, and sense of social connectedness. Key Findings since last report: In Year 3, we continued work on Aims 2 and 3. Aim 2 was a short-term study (6 days) to determine the most effective partners to enhance exercise intensity. In Aim 2, we tested an SG partner in one of three modes against an individual control condition: (a) coacting mode, where the subject cycled with the SG partner but whose performance was independent of the partner (i.e., they were not teammates), (b) conjunctive-teammate mode, where scores were based on the slower performer, and (c) choice mode where subject could choose coacting mode or conjunctive teammate mode for all trials. The experiment used activity routines developed by Ploutz-Snyder that consist of (a) 30 min. of continuous aerobic exercise on a cycle ergometer at or above 75% of maximum heart rate (HR max) and (b) high-intensity interval training involving 4 repetitions of 4 min. at or above 90% HR max. In Aim 2 (Year 3), we tested an additional 38 chronic exercisers (22 female). Subjects (N = 82, 47 female; M age = 44.89, 9.45) were allowed to adjust the power output (watts) during workouts. The main outcome variable was average watts cycled above target prescribed watts. Results showed no condition main effects from baseline; however, during the 4 min. interval sessions conjunctive (Mdiff = 5.23 watts) trended toward greater exercise effort than control (Mdiff = 4.45 watts) and coactive conditions (3.46 watts). The 4 min. intervals probably represent the most motivationally demanding workout at 90% HR max. Increases in effort above target watts positively correlated with Enjoyment (r = .44), Self-efficacy (r = .51), and Team perceptions (r = .21) during the 4 min. intervals. No relationships were found with less intense continuous exercise. Although this pilot study did not find significant between group increases in performance effort, participants significantly increased their effort with our exercise video game (i.e., simulated bike paths). In Aim 3, long-term study, we tested an SG exercise partner in one of two modes: (a) conjunctive-teammate mode and (b) conjunctive teammate who is not always superior (NAS) and is sometimes surpassed by the subject (~15% of the time), plus (c) individual control condition. We finished both cohorts of subjects (Cohort 1 = 23; 11 female; Cohort 2 = 18; 7 female). Subjects (N = 41; M age = 45.53 8.12) exercised 6 days/week for 24 weeks, using the following aerobic routines developed by Ploutz-Snyder: (a) 30 min. of continuous aerobic exercise on a stationary cycle at or above 75% HR max, (b) 4x4 min. intervals at or above 90% HR max with 3 min. active rest, (c) 6x2 min. intervals at varying intensities with 2 min. active rest, and (d) 30 sec. sprint intervals at maximal effort with 20 sec. active rest. We first tested whether the Conjunctive or NAS groups adhered more to the protocol than Controls. Conjunctive (M = 122.67) and NAS (M = 123.69) conditions averaged 15 more days completing the protocol than the Control (M = 107.00). However, group differences were not statistically different. In terms of our primary dependent measure, effort (watt increases above one's target), analyses are based on the continuous and 4-min. interval sessions. Subjects were not allowed to increase their intensity on the 2-min. intervals. Similarly, the dependent measure for the 30 sec. sprints was number of intervals completed, which all subjects completed. During Week 20 (last week with >80% of subjects remaining), NAS subjects increased their effort more (M = 8.9 watts) compared to Controls (M = 1.5 watts; d = 0.37) and Conjunctive subjects (M = 3.9 watts) on the 4-min. interval workout. Throughout the duration of the study, NAS subjects always outperformed Controls on the 4-min. intervals. All groups had large significant increases in VO2max from baseline (M = 34) to midpoint (M = 39), then values leveled off from midpoint to final (M = 38). Social connectedness rose significantly from midpoint (M = 2.96) to final (M = 3.48), and those with an SG partner increased their teams' perceptions from midpoint (M = 3.39) to final (M = 4.22). Subjects in NAS (M = 7.85) and Conjunctive conditions (M = 7.26) had higher self-efficacy beliefs than Controls (M = 6.86 2.83) after 1 week with the SG partner. Enjoyment remained stable, above response scale midpoint, across 24 weeks. Impact of Key Findings: Aim 3: The findings in Aim 3 suggest that having an SG partner, where the subject can intermittently be superior (~15% of time in NAS condition) is most motivating in the most demanding 4-min interval workouts. Proposed Research Plan for Coming Year: We will prepare manuscripts to submit to journals and present results at professional conferences.