The potential benefits of engaging individuals to adopt healthier lifestyles remains largely unrealized due to a lack of information, a shortage of health professionals, and potential costs. To assess the impact of the MyHealthCheckup web-based wellness program on cardio-metabolic risk factors and mental health indicators among Canadian Forces Base (CFB) personnel. Study Design: Military personnel at CFB Halifax were invited to participate in multiple 4-12 week, web-based physical activity and healthy weight challenges. They also completed pre- and post-health risk assessments that measured cardio-metabolic risk factors, mental stress, sleep quality, and physical fatigue. During the challenge they tracked daily steps/physical activities and/or food intake and compared their progress to other participants or teams on a virtual course summarized on a google map. Of the1506 participants in the program (26% of eligible participants), there were 592 who had their health risk assessed at one of our 13 risk screening days, 1403 who registered on the website, and 859 doing at least 1 challenge. The average user accessed the website 42 times. Among participants who completed both pre- and post assessments (n=274), improvements were observed for a variety of health measures including sedentary behaviour (weekly METs < 720 dropped from 35% to 11%; p<0.0001), systolic and diastolic blood pressure (124/79 to 122/77 mmHg; p<0.05), weight (88.9 to 88.7 kg; p<0.05), poor sleep (Insomnia Severity Index ≥ 8 dropped from 35% to 25%; p<0.01), stress (Perceived Stress Score decreased from 11.4 to 10.1; p<0.0001), and fatigue (Multidimentional Fatigue Inventory ≥ 16 dropped from 11% to 1%; p<0.01). A dose response was observed between the number of website visits and improvement in stress scores (p<0.001) and sleep scores (p<0.01). An evaluation survey was completed by 241 participants to rate the various website components on a scale of 1-5 (5=best). Average scores included the usefulness of the screening event (4.0), the educational modules (3.7), and the challenges (3.8 to 4.0), as well as, ease of use (3.8) and fun factor (3.8). The overall experience was considered positive or very positive by 74% of participants and 73% of participants found the program to be better or much better than other health initiatives held on the base. The MyHealthCheckup with CFB Halifax effectively increased daily physical activity levels while improving blood pressure, weight, sleep, stress, and fatigue. It also had high user ratings and proved to be engaging.