Pregnant and postpartum women have reported a number of barriers that prevent them from being sufficiently physically active. Overcoming these barriers is critical to ensure the health benefits of physical activity to both mother and fetus. The primary focus of this review centers on the potential impact social support may have in overcoming each of the primary barriers to physical activity experienced during pregnancy and the postpartum period. A reasonable body of research exists regarding the relationships between social support and these barriers; however, few investigations have specifically attempted to mitigate the effects of these barriers via social support interventions. Within this review, the enabling influence of social support as it pertains to pregnant and postpartum women's physical activity is discussed. Recommendations are suggested for the application of social support in future research investigations involving physical activity during pregnancy and postpartum.
Overcoming Barriers to Physical Activity During Pregnancy and the Postpartum Period: The Potential Impact of Social Support
Christopher P. Connolly, Deborah L. Feltz, and James M. Pivarnik
Physical Activity Monitor Accuracy for Overground Walking and Free-Living Conditions Among Pregnant Women
Christopher P. Connolly, Jordana Dahmen, Robert D. Catena, Nigel Campbell, and Alexander H.K. Montoye
Purpose: We aimed to determine the step-count validity of commonly used physical activity monitors for pregnancy overground walking and during free-living conditions. Methods: Participants (n = 39, 12–38 weeks gestational age) completed six 100-step overground walking trials (three self-selected “normal pace”, three “brisk pace”) while wearing five physical activity monitors: Omron HJ-720 (OM), New Lifestyles 2000 (NL), Fitbit Flex (FF), ActiGraph Link (AG), and Modus StepWatch (SW). For each walking trial, monitor-recorded steps and criterion-measured steps were assessed. Participants also wore all activity monitors for an extended free-living period (72 hours), with the SW used as the criterion device. Mean absolute percent error (MAPE) was calculated for overground walking and free-living protocols and compared across monitors. Results: For overground walking, the OM, NL, and SW performed well (<5% MAPE) for normal and brisk pace walking trials, and also when trials were analyzed by actual speeds. The AG and FF had significantly greater MAPE for overground walking trials (11.9–14.7%). Trimester did affect device accuracy to some degree for the AG, FF, and SW, with error being lower in the third trimester compared to the second. For the free-living period, the OM, NL, AG, and FF significantly underestimated (>32% MAPE) actual steps taken per day as measured by the criterion SW (M [SD] = 9,350 [3,910]). MAPE for the OM was particularly high (45.3%). Conclusion: The OM, NL, and SW monitors are valid measures for overground step-counting during pregnancy walking. However, the OM and NL significantly underestimate steps by second and third trimester pregnant women in free-living conditions.
Accuracy of Physical Activity Monitors for Steps and Calorie Measurement During Pregnancy Walking
Alexander H.K. Montoye, Jordana Dahmen, Nigel Campbell, and Christopher P. Connolly
Purpose: This purpose of this study was to validate consumer-based and research-grade PA monitors for step counting and Calorie expenditure during treadmill walking. Methods: Participants (n = 40, 24 in second trimester and 16 in third trimester) completed five 2-minute walking activities (1.5–3.5 miles/hour in 0.5 mile/hour increments) while wearing five PA monitors (right hip: ActiGraph Link [AG]; left hip: Omron HJ-720 [OM]; left front pants pocket: New Lifestyles NL 2000 [NL]; non-dominant wrist: Fitbit Flex [FF]; right ankle: StepWatch [SW]). Mean absolute percent error (MAPE) was used to determine device accuracy for step counting (all monitors) and Calorie expenditure (AG with Freedson equations and FF) compared to criterion measures (hand tally for steps, indirect Calorimetry for Calories). Results: For step counting, the SW had MAPE ≤ 10% at all walking speeds, and the OM and NL had MAPE ≤ 10% for all speeds but 1.5 miles/hour. The AG had MAPE ≤ 10% for only 3.0–3.5 miles/hour speeds, and the FF had high MAPE for all speeds. For Calories, the FF and AG had MAPE > 10% for all speeds, with the FF overestimating Calories expended. Trimester did not affect PA monitor accuracy for step counting but did affect accuracy for Calorie expenditure. Conclusion: The ankle-worn SW and hip-worn OM had high accuracy for measuring step counts at all treadmill walking speeds, whereas the NL had high accuracy for speeds ≥2.0 miles/hour. Conversely, the monitors tested for Calorie expenditure have poor accuracy and should be interpreted cautiously for walking behavior.
Can Pregnancy be an Ergogenic Aid to Athletic Performance?: A Review
James M. Pivarnik, Christopher P. Connolly, Mallory R. Marshall, and Rebecca A. Schlaff
Previous research clearly indicates that exercise training decreases during pregnancy, even among the fittest of women. Despite this, women are typically able to resume their prepregnancy exercise routines soon after delivery, and in some instances, their postpartum performances are better than previously experienced. While anecdotal reports are common, there does not appear to be significant research data to explain this phenomenon. In this review, we explore possible physiologic explanations for heightened postpartum exercise performance, such as pregnancy related changes in aerobic fitness, lactate threshold, flexibility, and musculoskeletal fitness. At this time, limited data do not appear to support an ergogenic role for these variables. Another consideration is a positive change in a woman’s psyche or perceptions toward her athletic abilities as a result of her pregnancy and delivery. While this concept is theoretically possible and may have scientific merit, data are sparse. What is clear is that an increasing number of women are maintaining their physical activity and exercise routines during pregnancy, with many able to return to competition soon after delivery. Well-designed studies are needed to further explore the relationships among physiologic and psychological variables and postpartum exercise performance. Ideally, these studies should be prospective (studying women prepregnancy through the postpartum period) and include diverse samples of women with regard to activity type and fitness level.
The Influence of Risk Perceptions and Efficacy Beliefs on Leisure-Time Physical Activity During Pregnancy
Christopher P. Connolly, James M. Pivarnik, Lanay M. Mudd, Deborah L. Feltz, Rebecca A. Schlaff, Mark G. Lewis, Robert M. Silver, and Maria K. Lapinski
Pregnancy risk perceptions and physical activity efficacy beliefs may facilitate or impede pregnancy leisure-time physical activity (LTPA). We examined the separate and joint influence of these variables on LTPA behavior among pregnant women.
Pregnant women (n = 302) completed a survey containing questions on LTPA efficacy beliefs and behavior, as well as pregnancy risk perceptions with respect to the health of the unborn baby. As stipulated by the Risk Perception Attitude (RPA) Framework, 4 attitudinal groups were created: Responsive (High Risk+High Efficacy), Proactive (Low+High), Avoidant (High+Low), and Indifferent (Low+Low). Moderate LTPA and vigorous LTPA were dichotomized for study analyses.
A total of 82 women (27.2%) met the moderate physical activity guideline and 90 women (30.1%) performed any vigorous LTPA. Responsive and proactive pregnant women (those with high efficacy) were most likely to meet the moderate guideline and participate in vigorous LTPA. Hierarchical logistic regression did not reveal an interactive effect of pregnancy risk perceptions and LTPA efficacy beliefs for meeting the moderate guideline (OR = 0.94, 95% CI = 0.66–1.36) or any vigorous LTPA participation (OR = 1.41, 95% CI = 0.86–2.29).
LTPA efficacy beliefs appear important in facilitating greater levels of pregnancy LTPA. Significant interactive effects between pregnancy risk perceptions and LTPA efficacy beliefs were not found.
Validity and Reliability of the Omron HJ-303 Tri-Axial Accelerometer-Based Pedometer
Jeremy A. Steeves, Brian M. Tyo, Christopher P. Connolly, Douglas A. Gregory, Nyle A. Stark, and David R. Bassett
This study compared the validity of a new Omron HJ-303 piezoelectric pedometer and 2 other pedometers (Sportline Traq and Yamax SW200).
To examine the effect of speed, 60 subjects walked on a treadmill at 2, 3, and 4 mph. Twenty subjects also ran at 6, 7, and 8 mph. To test lifestyle activities, 60 subjects performed front-back-side-side stepping, elliptical machine and stair climbing/descending. Twenty others performed ballroom dancing. Sixty participants completed 5 100-step trials while wearing 5 different sets of the devices tested device reliability. Actual steps were determined using a hand tally counter.
Significant differences existed among pedometers (P < .05). For walking, the Omron pedometers were the most valid. The Sportline overestimated and the Yamax underestimated steps (P < .05). Worn on the waist or in the backpack, the Omron device and Sportline were valid for running. The Omron was valid for 3 activities (elliptical machine, ascending and descending stairs). The Sportline overestimated all of these activities, and Yamax was only valid for descending stairs. The Omron and Yamax were both valid and reliable in the 100-step trials.
The Omron HJ-303, worn on the waist, appeared to be the most valid of the 3 pedometers.
Breaking Barriers: Women’s Experiences of CrossFit Training During Pregnancy
Tanya Prewitt-White, Christopher P. Connolly, Yuri Feito, Alexandra Bladek, Sarah Forsythe, Logan Hamel, and Mary Ryan McChesney
CrossFit is a form of resistance training characterized by constantly varied, weight-training, gymnastic, and body weight movements. While resistance training is a popular exercise option among pregnant women, it is not included in current physical activity recommendations for expectant mothers. Additionally, despite negative connotations, there are anecdotal accounts of pregnant women participating in CrossFit training without adverse effects to their pregnancies. Therefore, given the barriers to physical activity during pregnancy and vigorous-intensity exercise, examining the experience of pregnant women participating in CrossFit training is of interest in the present study. Participants in the study included 22 women at least three months post-pregnancy, who had adhered to CrossFit training for at least six months throughout pregnancy and were 18 years of age or older. A semi-structured interview guide was developed and transcripts were analyzed using a thematic content analysis. Researchers searched for themes across the interview data and reached agreement on subsequent themes. Seven themes emerged characterizing the experiences of pregnant women who participated in CrossFit training while pregnant: (1) quitting was not an option, (2) support and community, (3) overcoming judgments and stereotypes, (4) listening to my body and modifying movements, (5) empowerment and pride, (6) easy pregnancy and delivery, and (7) lifestyle and functioning post-baby. Findings offer practical implications for practitioners working with pregnant women hoping to maintain their exercise regimens and demonstrate the barriers and opportunities for pregnant women desiring to maintain healthy lifestyles.