Creatine for Recovery and Thinking in Mothers

Postpartum women frequently experience changes in physical performance, recovery, cognition, sleep quality, and mood. Creatine supplementation may enhance energy availability in skeletal muscle and brain tissue, potentially improving exercise performance, recovery, and cognitive function. This study will enroll 40 postpartum women and randomly assign participants in a 1:1 ratio to receive either 5 g/day or 10 g/day of creatine monohydrate for four weeks in a double-blind fashion. Assessments will be conducted before and after supplementation and will include repeated sprint ability testing, skeletal muscle oxygen recovery, and cognitive testing. A subsample of 20 participants will undergo magnetic resonance spectroscopy to assess brain creatine stores.

• Creatine Monohdyrate (Dietary supplement): Creatine monohydrate taken daily mixed with 6-8 oz of water.

Primary outcomes

• Repeated Sprint Ability Peak Power [Change from baseline to 4 weeks post-supplementation.]: Peak power (Watts) measured during a repeated sprint ability cycling test.
• Fatigue Index [Change from baseline to 4 weeks post-supplementation.]: Fatigue index (%) calculated from repeated sprint ability testing.

Secondary outcomes

• Skeletal Muscle Oxygen Recovery [Change from baseline to 4 weeks post-supplementation]: Recovery rate constant of skeletal muscle oxygen consumption following exercise measured by near-infrared spectroscopy and arterial occlusion procedures.
• Executive Function [Change from baseline to 4 weeks post-supplementation]: Executive function measured using the NIH Toolbox Flanker Inhibitory Control and Attention Test.
• Working Memory [Change in baseline to 4 weeks post-supplementation.]: Working memory measured using the NIH Toolbox List Sorting Working Memory Test.
• Brain Creatine Concentration [Change from baseline to 4 weeks post-supplementation]: Brain phosphocreatine and related bioenergetic metabolites assessed using phosphorus magnetic resonance spectroscopy (³¹P-MRS) in the imaging subsample

Sex: Female, ages: 18 Years to 45 Years

Inclusion Criteria:

* 6 weeks -12 months postpartum
* Body mass index of 18.5-34.9 kg/m2
* Cleared to resume physical activity

Exclusion Criteria:

* Experienced a musculoskeletal injury, excluding a Cesarean delivery,within the past three months that inhibits participation in the study.
* Has chronic kidney disease, liver disease, chronic obstructive pulmonary disease, or cancer
* Currently using medications that may directly impact the primary outcomes including: diuretics and corticosteroids).
* Has uncontrolled hypertension or diabetes, or has recently started medication, without a stable dose for 3 consecutive months.
* Currently using creatine monohydrate or other performance-enhancing supplements
* Has a self-identified or clinically diagnosed eating disorder
* Taking or having supplemented with creatine monohydrate in the last 28-days
* Medical contradictions for physical exercise
* Has participated in another clinical trial within 4-weeks prior to enrollment that in the opinion of the PI would influence the results.
* Has severely impaired hearing or speech or inability to speak English.
* Unwilling or unable to comply with the study protocol, including abstaining from caffeine, tobacco, alcohol, and physical activity before testing days.
* Is currently pregnant.
* Has a known allergy to the transducer gel used for the ultrasound
* Has a known allergy to creatine monohydrate

• Abbie Smith-Ryan, PhD, Principal investigator, University of North Carolina, Chapel Hill