Return to exercise after delivery is recommended but it should be gradual and should not involve high impact exercise too quickly. It is advised to wait until at least 6weeks after your delivery to ensure healing and vaginal discharge (lochia) have stopped.
Remember that the hormonal changes that begun in pregnancy can still affect your ligaments and joints for 6months or more postnatally. Ensure that you have comfortable supportive clothes and bra when exercising and are well hydrated, especially if you are breastfeeding.
If you have any concerns regarding urinary or faecal leakage (incontinence), a division or gap in your tummy muscle (diastasis recti) or ongoing low back or pelvic pain. It is advised that you seek help and support from your GP or local women’s health specialist physiotherapist prior to starting exercise.
For guidance as to when to return to running refer to:
Groom, Tom; Donnelly, Grainne and Brockwell, Emma (2019).
https://www.researchgate.net/publication/335928424_Returning_to_running_postnatal_-_guidelines_for_medical_health_and_fitness_professionals_managing_this_population