Physiologic responses to running with a jogging stroller

Energetic Cost and Kinematics of Pushing a Stroller on Flat and Uphill Terrain

During early parenthood, walking and/or running while pushing a stroller is a common form of endurance exercise among both recreationally active individuals and athletes. Here, we investigate how pushing a stroller influences the energetic cost, gross efficiency (GE), and kinematic behavior of well-trained men and women while walking or running on flat and uphill incline. Eight men and nine women, all recreationally active, performed three 5-min submaximal tests of walking or running during four different testing sessions, in randomized order: with and without pushing a 24.3-kg stroller on a flat (1%; 6, 8/9, and 11/12 km/h for women/men) and uphill (10%; 5, 6.5/7.5, and 7.5/8.5 km/h for women/men) incline. Respiratory parameters, heart rate (HR), blood lactate concentration, and rating of perceived exertion (RPE) were determined and video-based kinematic analysis was performed in connection with all these tests. Except while walking on the flat incline, pushing a stroller increased the energetic cost of walking/running under all conditions (all p < 0.05). This was associated with shorter and more rapid strides on both inclines (all p < 0.05); however, GE was higher when pushing the stroller (p < 0.05). The increase in energetic cost of pushing the stroller was approximately threefold higher uphill than on the flat incline, and women were influenced more than men when running uphill at the highest speed (all p < 0.05). Here, we provide novel insights on the energetic cost and kinematic behavior of pushing a stroller while walking or running on flat and uphill inclines. The energetic cost of pushing a stroller was clearly higher than for unloaded exercise, coincided by shorter and more rapid strides, and especially pronounced on uphill terrain where also women were more influenced than men.

Mediators of a 12-month change in physical activity in ethnically diverse sample of postpartum women

Purpose

Understanding theoretically derived social and behavioral mediators of long-term increases in physical activity (PA) in a vulnerable population at risk for being underactive is needed to inform future research, clinical applications, and public health efforts. This is an analysis of potential mediators of an intervention that increased long-term (12-month) moderate-to-vigorous physical activity (MVPA) in postpartum (2-12months) women in a randomized trial, using a longitudinal analysis.

Methods

Healthy, underactive (i.e., not meeting national guidelines for MVPA) women (n = 311; mean age = 32 ± 5.6 years, 85% minorities) with infants (mean age: 5.7 ± 2.8 months) were randomly assigned to either a tailored eHealth condition consisting of personalized telephone counseling plus access to a website tailored to new mothers' MVPA issues or to a standard MVPA materials-only website. MVPA was assessed via surveys completed at baseline, then 6 and 12 months later. Theoretically derived mediators included social support for MVPA, self-efficacy to increase MVPA, barriers to increasing MVPA, and benefits of increasing MVPA.

Results

All mediators, except benefits, improved over the 12 months in the tailored eHealth condition. The tailored condition's effect on increasing MVPA from 6 months to 12 months was mediated by an increase in social support from baseline to six months. No other hypothesized mediators were significant.

Conclusion

Our results demonstrated that learning strategies to increase social support for MVPA was instrumental in new mothers' increase in MVPA over a 12 month intervention. During this brief but impactful life-stage, where the focus can understandably be on her baby, being able to elicit support from friends and family may facilitate women's efforts to focus on their own needs with respect to MVPA.

Trial Registration

ClinicalTrials.gov number.

Stroller running: Energetic and kinematic changes across pushing methods

OBJECTIVE

Running with a stroller provides an opportunity for parents to exercise near their child and counteract health declines experienced during early parenthood. Understanding biomechanical and physiological changes that occur when stroller running is needed to evaluate its health impact, yet the effects of stroller running have not been clearly presented. Here, three commonly used stroller pushing methods were investigated to detect potential changes in energetic cost and lower-limb kinematics.

METHODS

Sixteen individuals (M/F: 10/6) ran at self-selected speeds for 800m under three stroller conditions (2-Hands, 1-Hand, and Push/Chase) and an independent running control.

RESULTS

A significant decrease in speed (p = 0.001) and stride length (p<0.001) was observed between the control and stroller conditions, however no significant change in energetic cost (p = 0.080) or heart rate (p = 0.393) was observed. Additionally, pushing method had a significant effect on speed (p = 0.001) and stride length (p<0.001).

CONCLUSIONS

These findings suggest that pushing technique influences stroller running speed and kinematics. These findings suggest specific fitness effects may be achieved through the implementation of different pushing methods.

The postpartum triathlete

The postpartum period in a woman's life is filled with numerous changes, including physical changes, changes in sleep habits, and learning how to best care for a newborn. A common goal among postpartum women is to either begin or resume an active lifestyle, which often includes physical activity such as running, biking and swimming. The postpartum athlete may discover barriers that prevent her from returning to or beginning an exercise routine. These obstacles include muscle weakness, fatigue, depression and physical changes that require exercise modification. The physical therapist is well-suited to properly assess, treat and manage the care of the postpartum athlete. Postpartum athletes wishing to begin or resume training for triathlons require special consideration, as the triathlete must balance training to compete in three different sports. The purpose of the paper is to identify the unique physical and physiological changes that occur to the female during the postpartum period. In addition, injuries that are more commonly seen during the postpartum period will be discussed. Recommendations for beginning or resuming an exercise program will be reviewed. Lastly, sport-specific training for the postpartum triathlete, including challenges presented with each triathlon component, will be discussed.

Run kinematics with and without a jogging stroller

BACKGROUND

Jogging strollers have become increasingly popular as they allow a parent the freedom to run without having to leave their children. Few studies have examined the effects of running with a stroller and no study to date has examined the effects on joint kinematics. The aim of this study was to compare lower limb and trunk kinematics while running with and without a jogging stroller.

METHODS

Participants (N=15) ran on a 16-metre indoor runway, with and without a stroller, at their self-selected comfortable training speed. Three-dimensional trunk and lower limb kinematics were assessed using the CODA cx1 active marker system.

FINDINGS

The jogging stroller led to reduced movement of the trunk in both the transverse [mean difference -11.4°, 95% confidence interval (CI) (-14.8°, -8.2°), p<0.001] and coronal [-2.9°, 95% CI (-0.8°, -4.9°), p=0.009] planes most likely due to fixing of the upper limbs. There was also a 6.7° [95% CI (-9°, -4.6°), p<0.001] increase in forward trunk lean, 2.8° [95% CI (-4.2°, -1.7°), p<0.001] increase in anterior pelvic tilt and a 3° [95% CI (-4.4°, -1.5°), p=0.001] decrease in hip extension. There were no significant changes in knee or ankle kinematics and no changes in stride length, cadence or stance time.

INTERPRETATION

Our data suggest that jogging strollers lead to minor changes in trunk, pelvis and hip kinematics with no significant changes at the knee and ankle. Due to the changes in kinematics we suggest that flexibility work for the spine, pelvis and hips may be recommended.