What this trial measures

• Average Total Activity Counts (TAC) per day over 7 days7 days pre-intervention, 7 days post-intervention

  Physical activity habits around the time of testing will be assessed with a tri-axial accelerometer for 7 days outside of the laboratory, in part by measuring the TAC per day. TAC is the total number of filtered, full-wave rectified, integrated accelerations (all directions). These will then be averaged/day based on the total number of valid wear days for each participant.

• Physical Activity Measured by Average Steps per day over 7 days7 days pre-intervention, 7 days post-intervention

  Physical activity habits around the time of testing will be assessed with a tri-axial accelerometer for 7 days outside of the laboratory, in part by measuring mean steps per day. This will be quantified as reported by the Ametris (formerly ActiGraph) accelerometer and CentrePoint analysis software. The Algorithm used by Ametris is not publicly available, but Ametris/ActiGraph accelerometers are frequently used in research quantifying physical activity.

• Mean Duration per day of Moderate-Vigorous Physical Activity (MVPA) over 7 days: tri-axial counts7 days pre-intervention, 7 days post-intervention

  Physical activity habits around the time of testing will be assessed with a tri-axial accelerometer for 7 days outside of the laboratory, in part by measuring mean duration per day of MVPA. Intensity of physical activity assessed using tri-axial counts (per the accelerometer software) are as follows: Light physical activity is between 200 and 2690 counts/min, moderate intensity between 2690-6166 counts/min, and vigorous intensity is ≥ 6167 counts/min. MVPA is ≥2690.

• Mean Duration per day of Moderate-Vigorous Physical Activity (MVPA) over 7 days: vertical counts7 days pre-intervention, 7 days post-intervention

  Physical activity habits around the time of testing will be assessed with a tri-axial accelerometer for 7 days outside of the laboratory, in part by measuring mean duration per day of MVPA. Intensity of physical activity assessed using vertical counts (per the accelerometer software) are as follows: Light physical activity is between 100 and 759 counts/min, moderate intensity is 760-5999 counts/min, and vigorous intensity is ≥ 6000 counts/min (MVPA is \> 760 counts/min).

• Average Minutes per Day of Activity in at least 5-minute bouts7 days pre-intervention, 7 days post-intervention

  Physical activity habits around the time of testing will be assessed with a tri-axial accelerometer for 7 days outside of the laboratory, in part by measuring mean duration per day of all activity. Average minutes per day of activity within each of the following categories: light = 25.8 mg - 100.5 mg; moderate = 100.6 mg - 428.7 mg; vigorous = \> 428.8 mg (mg is the vector magnitude of acceleration calculated in gravities using Euclidean Norm minus 1 metric)

• Average Minutes per Day of Activity in at least 10-minute bouts7 days pre-intervention, 7 days post-intervention

  Physical activity habits around the time of testing will be assessed with a tri-axial accelerometer for 7 days outside of the laboratory, in part by measuring mean duration per day of all activity. Average minutes per day of activity within each of the following categories: light = 25.8 mg - 100.5 mg; moderate = 100.6 mg - 428.7 mg; vigorous = \> 428.8 mg. (mg is the vector magnitude of acceleration calculated in gravities using Euclidean Norm minus 1 metric)

• Physical activity levels via self-reported questionnairesOnce-a-week for the 8-week intervention period

  Participants will complete the International Physical Activity Questionnaire (IPAQ) short-form. The IPAQ short-form quantifies physical activity (PA) over the previous week in 2 categories: low, moderate, or high activity; or metabolic equivalents (MET) minutes per week. High PA is categorized as (1)vigorous PA on at least 3 days/week with a combined minimum of at least 1500 MET minutes/week or (2) 7 days of cumulative PA of any intensity that sums to a minimum total of at least 3000 MET minutes/week. Moderate PA is categorized as (1) 3+ days of at least 30 minutes of vigorous PA, (2) 5+ days of moderate PA or walking at least 30 minutes/day, or (3) 5+ days of any level of PA that sums to a minimum of 600 MET minutes/week. Low physical activity is categorized as activity that does not meet the criteria for medium or high activity.

• Lower extremity strengthBaseline and 7-14 days post-intervention

  A straight leg raise maximal voluntary contraction (MVC) of each lower extremity will be performed in supine before and within 2 minutes of completing the ASLR fatigue task with a custom made load cell instrumented strength testing device. This device consists of a rigid platform on which the study participant will lie supine. At the foot of the device is a tower that houses 2 load cells and is connected to a lightly padded push plate. This push plate can be raised and lowered such that the participant can push up into the plate (contacts the anterior surface of the participant's shin) or push down onto the push plate (contacts the posterior aspect of the participant's heel). Before the ASLR fatigue task, a minimum of 3 MVC trials will be performed on each leg, with a minimum of 1 minute rest between trials; the highest peak force will be considered the MVC. Only 1 MVC trial per leg will be performed following the fatigue task.

• Mean Time to ASLR Fatigue Task FailureBaseline and 7-14 days post-intervention

  The Active Straight Leg Raise Fatigue Task will be administered. Participants are asked to raise one leg to a heel height of 20 cm while lying supine. Participants are encouraged to keep the leg raised as long as possible. Task failure will be defined as a heel height less than or equal to 10 centimeters off the ground.

• Pelvic floor muscle strengthBaseline and 7-14 days post-intervention

  An internal vaginal pelvic floor muscle assessment will be performed at baseline and study completion by a licensed physical therapist with advanced training in pelvic floor muscle examination and treatment. Pelvic floor muscle function will be assessed using the PERFECT scale, which assesses both muscular strength ("P" for "power") and endurance ("E"). Strength is assessed by cueing the participant to perform a maximal voluntary pelvic floor muscle contraction while the examiner has their index finger inserted into the vagina. The modified Oxford scale is used to grade strength on a scale of zero (0) to five (5) with 5 being the strongest.

• Pelvic floor muscle enduranceBaseline and 7-14 days post-intervention

  Pelvic floor muscle endurance is also assessed via the internal vaginal PFM examination. After strength testing is performed, participants are instructed to perform a maximal PFM contraction and hold for as long as possible (maximum of 10 seconds). The examiner counts the length of the contraction, and timing is stopped either when (1) strength of the contraction declines or (2) the maximum of 10 seconds is reached.55 The time in seconds is recorded.

• Mean Pelvic Floor Distress Inventory Short Form (PFDI-20) ScoreBaseline and 7-14 days post-intervention

  The PFDI-20 is composed of 20 items total on three scales (Pelvic Organ Prolapse, Colorectal-Anal Distress, Urinary Distress), each scored on a 5 point likert scale. Mean scores from each scale are calculated and multiplied by 25, then added together for a total possible range of scores from 0-300. Higher scores indicate increased pelvic floor distress.

• Fear of movementBaseline and 7-14 days post-intervention

  Fear of movement (kinesiophobia) will be assessed via the Tampa Scale for Kinesiophobia (TSK). The TSK is a 17-question, self-administered questionnaire that utilizes a 4-point Likert scale (1= strongly agree, 4=strongly disagree). Total scores range from 17-68. A higher score indicates higher levels of kinesiophobia; a score of 17 indicates no/minimal kinesiophobia.

• Overall quality of lifeBaseline and 7-14 days post-intervention

  Participants will complete the SF-20 questionnaire, which measures health in six different domains (physical functioning, role functioning, social functioning, mental health, health perceptions, and pain). Scores range from 0-100%, with 0% being the worst score and 100% being the best.

• Mean Global Pittsburgh Sleep Quality Index (PSQI) ScoreBaseline and 7-14 days post-intervention

  The PSQI assesses seven sleep domains: sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medications, and daytime dysfunction. The seven components scores are then added to yield a global PSQI score in the range of zero to 21. Higher scores indicate worse sleep quality. A global score greater than five is diagnostic of poor sleep quality.

• Inter-recti distanceBaseline and 7-14 days post-intervention

  Ultrasound imaging will be used to measure the distance between the right and left rectus abdominis at 2 locations above the umbilicus and 2 locations below the umbilicus. IRD will be assessed in supine at rest (end exhalation), while lifting the head, and while lifting one leg.