How To Lose Baby Weight Safely by Avoiding Post-Natal Exercise Risks

Safe return to exercise after childbirth

Safe return to exercise after childbirth

Although pregnancy, labor, and postpartum aren’t athletic events, they have been compared to athletic events (CrossFit Journal Sep 2011). Many women who enjoyed sports before their pregnancy want to get back into it soon after birth to lose the baby weight. This is particularly true for women who were used to high impact high intensity training such as Crossfit and running.

Whether or not you are ready to return to sport or exercise depends on individual factors and type of birth. A Cesarean section requires more recovery time than natural birth. As a general rule, new mums are advised to wait between 4-6 weeks after birth before resuming exercise. Keep reading as I share with you some considerations to lose the baby weight by avoiding post-natal exercise risks for a safe return to sport after childbirth.

Physiological Changes after Childbirth and Potential Exercise Risks

After birth, your body continues to experience physiological changes for a period of time. These changes create the potential for injuries in post-natal women. In case of doubt, always err on the side of caution and check with your doctor or woman’s physio. However, by considering a few of the most common risks created by these changes, you can return to sport, safely, and get the results you desire.


During pregnancy and after childbirth, your body produces a hormone called Relaxin, which relaxes the muscles, joints and ligaments to help the pelvis prepare for birth. However, Relaxin affects every joint in your body, which makes your body more susceptible to injury. The hormone can stay in your system for up to 6 months after birth and even longer if you’re breastfeeding.

Considerations: Because all your major joints aren’t as stable as they once were, be extra careful with impact-based exercise, heavy weights, and quick changes of direction.

Guidelines: Low impact activities, such as swimming, walking your baby, or light body weight exercises will challenge your cardiovascular fitness. Should you feel the urge to go for a run or engage in other high impact activities, go easy and go short (15-20 min). Listen to your body. Wear comfortable shoes and a supporting bra.

Pelvic Floor Muscles

Your pelvic floor is made up of layers of muscle and other tissues that support your bladder, womb (uterus) and bowel (colon). Think of a hammock that stretches from the tailbone at the back, to the pubic bone in front. Returning to sport or high intensity exercise without having worked those muscles throughout pregnancy can cause severe problems, such as hemorrhage, prolapse, and leakage of urine.

pelvic floor

Considerations: High impact movements and lifting heavy weight place constant and excessive downward pressure on the pelvic floor.

Guidelines: Exercising your pelvic floor muscles every day is a must.  Here is a good explanation on how to train those muscles properly. In addition, a woman’s physio will be able to assess your pelvic floor and develop an individualised pelvic floor muscle training program for you.

Abdominals Separation or Diastasis

A separation of the abdominal muscles also occurs during pregnancy to allow for the baby to grow. The TVA is attached infront of, and behind, the rectus muscles, are the ones that have split. The muscles can stay separated postnatally, due to the influence of relaxin. This is called Diastasis recti. Pregnant and post-natal women with Diastasis will see their TVA (Transverse Abdominis) ‘peak’ or a bulge during an abdominal contraction.

Considerations: Lifting weights, including your baby, and abdominal exercises should aim to minimise the impact on the linea alba. This is the connective tissue between the rectus muscles.

Guidelines: Engage your Pelvic floor muscles first, then TVA. Working the TVA correctly will reduce the diastasis (gap) and keep the muscles in place.

Pelvic Girdle Pain (PGP) or Symphysis Pubis Dysfunction (SPD)

PGP or SPD is pain, felt across the front or back of the pelvis, and can range from mild discomfort to severe pain. When the body is experiencing pain, muscles tighten and compensate, causing asymmetry and misalignment of joints. If pain persists, it is important that you receive treatment from a physiotherapist, chiropractor or osteopath.

Considerations: Exercise cannot realign joints or tighten ligaments affected by the hormone Relaxin. However, strengthening core muscles can improve stability of the joints.

Guidelines: You should visit a Physiotherapist, chiro or ostheo, who can prescribe correct treatment for realigning your pelvis, and exercises to help stabilise the joints.


Studies have shown that moderate exercise does not compromise breast milk supply, (Department of Nutrition and Program in International Nutrition, University of California, 1994), composition, or a baby’s growth (Lovelady C 2011). Although, not much research has been done on intense exercise and breastfeeding, a few studies show that high-intensity exercise has no negative effects on breast milk.

Considerations: While lactic acid can increase in breast milk following intense exercise, no evidence indicates that breast milk with increased lactic acid harms the baby in any way or makes the baby refuse the breast after exercise.

Guidelines: Breastfeeding will not affect breast milk supply, as long as you’re staying adequately hydrated, eating enough, and avoiding calorie restriction diets. For your comfort, make sure you breastfeed before you exercise and wear a supportive bra.

heavy lifting is high intensity

High intensity training: heavy weight lifting

Your post-natal fitness program should focus on safety, strengthening the pelvic floor, and listening to your body. You may well find that the simple act of picking up and carrying your baby everyday is a great workout after all. If you desire to return to sport, do so safely and avoid injury.

Please comment below if you have any favorite post-partum exercises, or want to provide feedback on the article.


Exercise and Breast Milk Volume:

Dewy K, Lovelady C, Nommsen–Rivers L, McCrory M, Lonnerdal B 1994, A randomised study of the effects of aerobic exercise by lactating women on breast-milk volume and composition. New Engl J Med 330: 449–453.

Lovelady C 2011, Balancing exercise and food intake with lactation to promote post-partum weight loss (Review). Proc Nutr Soc 70(2):181–4.

High Intensity Exercise and Breast milk:

Concentration of lactic acid in breast milk following maximal exercise:

Amorim AR, Linne YM, Lourenco PMC 2008, Diet or exercise or both for weight reduction in women after childbirth. Cochrane Database Systematic Reviews, Issue 3.

Infant acceptance of breast milk after maternal exercise:

Pediatrics. 2002 Apr;109(4):585-9.Wright KS, Quinn TJ, Carey GB.  These data support the hypothesis that moderate or even high-intensity exercise during lactation does not impede infant acceptance of breast milk consumed 1 hour post-exercise.

Department of Animal and Nutritional Sciences University of New Hampshire, Durham, New Hampshire 03824, USA.