Mothers in both the CBI and HBI groups were similar on all sociodemographic characteristics (see Table 2). On average, participants were 32 years of age (SD = 5.62, range = 25–46 years of age), had three children (SD = 1.47, range = 1–8 children), and had a body mass index of 32 (SD = 6.74, range = 20.47–50.32). A majority were English speakers (60%), Latina (59%), married or living with their partner (73%), were unemployed (72%), and had a total annual family income of less than $20,000 (57%). In terms of education, 43% had a high school education or less.
Study feasibility and progression criteria
The Consolidated Standards of Reporting Trials (CONSORT) diagram of study recruitment, enrollment, and retention is provided in Fig. 2. Of 140 mothers recruited for the study, 50 were ineligible (40% not available to attend the PA classes, 34% not medically cleared to participate, 26% exercising more than 90 min/week), and 15 were no longer interested in participating or lost to contact. Of the remaining 75 mothers, 45 were not randomized (67% did not complete their baseline assessments and therefore were no longer eligible for the study, 24% were no longer available for the study/moved from the area, 5% were no longer medically cleared, and 4% were no longer interested in participating or lost to contact). The remaining 30 mothers were randomized to either a 3-month CBI (n = 20) or HBI (n = 10) PA program (a priori target goal was 52 mothers).
Follow-up assessments were also conducted for mothers randomized to the CBI and HBI groups with participant retention rates of 70%, 63%, and 70% for 1-month, 2-month, and 3-month study time points, respectively (a priori target goal was ≥ 60% retention). Retention rates by randomization group were similar across all time points (see Fig. 2). On average, CBI participants attended 7 out of 12 classes (58%), with 55% (n = 11) attending at least half of the classes (range = 1–12 classes). Of participants randomized to the HBI, 50% completed their PA logs at all four time points. A total of 4 of the 10 mothers in the HBI group (40%) and 14 of 20 mothers in the CBI group (70%) participated in the 3-month post-intervention focus group. No adverse events were reported for mothers in either the CBI or HBI groups throughout their study participation (a priori target goal was 0%).
Change in PA and fitness over time
Approximately 69% (n = 20) of mothers met ACSM PA recommendations to engage in 30 min or more of moderate physical activity per day (based on self-reported PA) at 3 months post-intervention regardless of group assignment. All mothers, controlling for baseline fitness levels, showed a significant increase in objective PA [Fitbit; F(1, 21) = 4.91, p = . 038, ηp2 = 0.19 (linear pattern)], cardiorespiratory fitness [VO2max; F(1, 25) = 7.84, p = 0.010, ηp2 = 0.29 (linear pattern)], and flexibility [Sit & Reach; F(1, 25) = 4.28, p = . 049, ηp2 = . 15 (linear pattern)] from baseline to 3 months post-intervention (see Fig. 3a–e). There were no significant changes in self-reported PA [CALQ; F(2.02, 48.52) = 0.95; p = . 394, ηp2 = . 04] or muscular endurance and strength [Push-ups; F(3, 75) = 1.40; p = 0.248, ηp2 = 0.05] over time.
Group differences in PA and fitness over time
Mothers in the CBI group had higher objective PA levels throughout all time points compared to mothers in the HBI group [Fitbit; F(1, 21) = 4.30, p = 0.051, ηp2 = 0.17 (cubic pattern); see Fig. 3b]. There was also a marginally significant trend in which mothers in the HBI group had greater muscular endurance and strength at 3 months post-intervention compared to mothers in the CBI group [Push-ups; F(1, 25) = 3.36, p = 0.079, ηp2 = 0.12 (quadratic pattern); see Fig. 3d]. There were no significant group differences in self-reported PA [CALQ; F(2.02, 48.52) = 1.67, p = 0.199, ηp2 = 0.07], cardiorespiratory fitness [VO2max; F(2.32, 57.94) = 0.48, p = 0.650, ηp2 = 0.02], or flexibility [Sit & Reach; F(2.13, 53.25) = 0.17; p = 0.855, ηp2 = 0.01] over time.
Group differences in self-efficacy over time
Collectively, mothers showed no significant changes in self-efficacy for PA over time [F(1, 18) = 1.91, p = 0.184, ηp2 = 0.10]. However, there were significant differences in self-efficacy by randomization group over time. Specifically, mothers in the CBI group had higher self-efficacy for PA at 3 months post-intervention than mothers in the HBI group [F(1, 18) = 6.28, p = 0.022, ηp2 = 0.26 (linear pattern)], who showed decreased self-efficacy over time (see Fig. 4a).
Furthermore, mothers showed no significant changes in self-efficacy for fitness over time [F(2.09, 31.39) = 2.40, p = 0.105, ηp2 = 0.14]. However, there were significant differences by randomization group. Specifically, mothers in the CBI group demonstrated steady increases in their self-efficacy for fitness over time compared to mothers in the HBI group who showed no changes over time [F(1, 15) = 4.57, p = 0.049, ηp2 = 0.23 (quadratic pattern); see Fig. 4b].
Group differences in social support over time
All mothers showed significant changes in social support from family over time [F(1, 15) = 8.85, p = 0.009, ηp2 = 0.37 (quadratic pattern)]. Specifically, social support from family increased from baseline to 1 month, then decreased from 1 to 3 months post-intervention (see Fig. 4c). Similarly, all mothers showed a marginally significant change in social support from friends over time such that social support increased from baseline to 1 month, then decreased from 1 to 3 months post-intervention [F(1, 15) = 4.35, p = 0.055, ηp2 = 0.23 (cubic pattern); see Fig. 4d]. No significant randomization group differences in social support from family [F(3, 45) = 0.98, p = 0.410, ηp2 = 0.06] or friends [F(1.73, 25.91) = 0.29, p = 0.718, ηp2 = 0.02] were found over time.
Qualitative data from five focus groups with 18 mothers (14 CBI, 4 HBI) resulted in four main themes: barriers to PA (3 subthemes), facilitators to PA (2 subthemes), program benefits (0 subthemes), and future program suggestions (2 subthemes). The definition of each main theme and subtheme, as well as the number of instances in which the theme/subtheme was discussed by mothers are presented in Table 3.
Barriers to PA
Mothers in the CBI, but not the HBI, discussed various barriers to PA while participating in their program, including relationships with others, self-doubt, and household chores. For “relationship with others,” children were described as a barrier to PA. An association of guilt seemed to overcome the mothers who felt they could not allot time to exercise because of their child wanting to spend time with them.
“I could lock myself in the room and workout in there. But I can’t even work out comfortable because my daughter’s knocking at the door and crying ‘come out, come out’. It’s like ‘oh my God am I going to work out and hear you crying?’…It’s a huge guilt factor…cuz [my daughter] wants you there all the time because you’re home.”
Mothers in the CBI also expressed having self-doubt in their ability to engage in PA due to a fear of engaging in PA alone and feelings of being easily discouraged.
“Before this program we [moms] were, especially me I was discouraged…If one day I exercised, the next day I was like, “Okay, I don’t know if this is going to work out.”
Facilitators to physical activity
Mothers discussed the importance of social support from family and friends, along with program materials, as facilitators to PA. Specifically, seven mothers in the CBI group, compared to one mother in the HBI group, discussed the imperative role that their husbands played in supporting their exercise goals by taking over childcare duties, which allowed mothers to set aside time to exercise. CBI mothers also described their husbands as being encouraging and even joining them in walking as a form of social support.
“He’s helping more with the kids and my husband is taking care of them while I go to the gym if I’m gonna do Active Moms…and he’s actually encouraging it.” “My husband has always motivated me and now he supports me. He takes me to the park and he tells me come on go and walk with him and the kids.”
One mother from the HBI discussed the improvement in the relationship with her husband as he saw her engage in PA.
“Yes, because when you’re motivated, for example in my case when my husband sees me happy, he sees me active that I do things and he too is happy, and oh you finished early and let’s go I’ll invite you to dinner or something and there’s a better relationship of course.”
Mothers in both groups also discussed their children as inspiration and motivation to engage in exercise. Mothers pursued a healthier lifestyle through PA to engage in more recreational activities with their children, serve as a healthy role model for them, and live longer for their children. Increased participation in recreational activities was also reported to have subsequently improved their relationship with their children. One mother from the HBI group discussed the motivation her children instilled in her when they engaged in PA together.
“For my children, if they see me go out to walk, they put on tennis shoes…it makes me happy that they say, ‘oh we’re going to walk with my mom’ and my daughter says, ‘oh you’re gonna do Active Moms.’ It also gives me motivation that they [children] are also involved, that they know what I do and why I do it [exercise].”
One mother from the CBI group discussed her children’s role in her PA maintenance.
“For me I thought, ’Oh no, how am I going to do it.’ But so far it has worked out and I like it. It’s a good thing because I’m getting older, so it’s good that I’m getting it now and it’s going to continue because I have to stick around for my kids.”
A total of 16 out of 18 mothers (89%) reported experiencing health benefits as a result of their program participation. Three prominent topics emerged, including stress management, self-confidence, and prioritizing self-care. Mothers in the CBI discussed how their stress levels decreased, which improved their sleep and mood. They also discussed an increase in their overall self-confidence to engage in PA that was also noticed by their family members and friends.
“Now [after the intervention] it’s like I’m more active, less stressed. I hang out with her [my daughter]. I play with her a lot. I have a lot of energy. I started taking care of myself, liking myself, and telling myself that it’s not impossible.”
One mother from the HBI group discussed the effects of PA on her overall well-being and outlook on life.
“When you are good, you feel good and you reflect well. Sometimes when you are at home you think a lot of dumb things but when you go out to walk your mind clears… You analyze the bad and the good and the good is how when you’re exercising you are generating good health for your body and your emotional health too.”
Mothers from both groups discussed the importance of self-care and prioritizing themselves more after participating in their program. Specifically, one mother from the HBI group recalled her ability to bypass her husband’s discouraging comments regarding her weight and her decision to continue to engage in PA because of the changes she saw in herself.
“I did notice that my husband would tell me why do you do that if you’re not losing weight and I would think ‘yes that’s true, I’m not noticing anything in my physical appearance’. But after I began to analyze [and think], it’s more of making a habit and as the habit is made, one moderates their lifestyle. And I said, well maybe physically I’m not looking different, but I am feeling different.”
Furthermore, a mother from the CBI group explained the importance of setting aside time from other priorities, such as chores, to engage in PA to live a healthier lifestyle.
“I think this is an excellent program and, you know, moms should start thinking about themselves because chores are always going to wait, and if you don’t think about yourself then nobody else is. I think this has helped me a lot. I’m really thankful for coming here and meeting the other moms.”
Future program suggestions
Mothers provided suggestions for future PA programs related to family participation and program structure. For family participation, most mothers in the CBI indicated that the program worked best without including their spouses because it offered them alone time that they otherwise would not normally have.
“I feel that when I come here or when I go to the gym or I go for a walk I could join in with my family but there are times that you want that one hour to yourself where you’re not, ‘oh what are you going to cook,’ ‘oh you need to do this,’ ‘oh, you know mommy…’ You know, all the multi-tasking and for one hour you get to break free.”
Mothers in the CBI and HBI also advocated for graduates of the program to return to serve as group facilitators for future classes and discussed the various benefits of having other “successful” mothers lead the class, including maintaining their own PA gains.
“I think [bringing graduates of the program] would be a good thing. When we [mothers] share here, we all have to know everybody’s obstacles and challenges. I think sometimes when you hear somebody’s story, it might encourage you.” “Even if we helped the next cohort, they probably could help us for accountability…cuz they can help us as much as we’re helping them.”
Additionally, mothers from the CBI discussed the need to increase the length of the program and to transition from the group-based format to the home-based format at a slower pace with more group instruction days.
“I would suggest two things, that it would be longer and more days. Three months is not a lot because one needs more time. That there would be more days because two [days per week] were not enough, if it could be all week up to 6 months is good.”
Finally, two mothers from the HBI discussed their preference for group-based PA.
“In my case, I would have liked to be in the group with the other people more than being alone because when someone has little willpower, being with other people motivate[s] you a lot. A while back I was in another program to lose weight and it was very important to be with other people because you learn directly from other people, what they think and how they make things work, so I do think being with other people helps you a lot.”