Postpartum Abdominal Strengthening: When Can You Safely Start Crunches?

For many years, postpartum women were told to avoid crunches and abdominal flexion due to concerns they may worsen diastasis recti (abdominal separation). However, as research evolves, so does our understanding. We now know the abdominal wall - including the linea alba - is not something that needs to be protected through avoidance, but rather something that benefits from gradual, progressive loading to restore strength, tension, and function.

That said, the current evidence is more nuanced than simply “start crunches early.” While recent systematic reviews show that abdominal exercise can reduce inter-rectus distance (IRD) and improve function postpartum, most of this research has been conducted from around 6-12 weeks postpartum onwards, not in the immediate early phase. Studies have also shown that movement-based abdominal exercises (such as curl-ups) are not harmful when performed appropriately, and may even increase tension through the linea alba during contraction. This represents a clear shift away from older beliefs that abdominal loading would worsen separation.

In the early postpartum period, the focus should still be on recovery foundations - breathing, pelvic floor activation, and gentle deep core engagement. From around 2-6 weeks, some women may begin introducing very low-load abdominal work, such as head lifts or supported curl-up patterns, depending on symptoms and individual recovery. From 6 weeks and beyond, many women can progressively build toward more traditional abdominal strengthening, including curl-ups, crunch-type movements, reformer-based exercises, and functional core loading. Importantly, there is no single “right time” that applies to everyone - progression should always be guided by individual presentation, including pelvic floor symptoms, severity of separation, delivery type, and overall load tolerance.

The key shift in understanding is this: the linea alba is load-responsive connective tissue. Like muscle, it adapts to tension. Avoiding load altogether may actually reduce its capacity and delay recovery, whereas appropriate, progressive loading can help improve stiffness, strength, and force transfer across the abdominal wall. This is why crunches are no longer considered inherently “bad”- they are simply a later-stage progression that needs to be introduced at the right time, with the right control.

For those attending pre and postnatal Pilates, this aligns perfectly with the principles we already use - controlled movement, breath awareness, alignment, and gradual progression. Rather than avoiding abdominal work altogether, we now reintroduce it in stages, moving from gentle activation through to more dynamic and loaded core exercises as the body becomes ready.

A simple way to understand it:

We used to avoid crunches after pregnancy, but newer research shows the abdominal wall actually needs gradual loading to recover well. The key isn’t avoiding these movements—it’s introducing them at the right time, with the right control, and progressing them properly.

At our clinic, we offer postpartum physiotherapy and Pilates in Rockhampton, helping women rebuild their core safely through evidence-based rehabilitation, reformer Pilates, and individualised care.

References (Recent Evidence)

• Beamish et al., 2025 – Systematic review: abdominal training reduces IRD and improves function

• de Oliveira et al., 2025 – Abdominal exercises effective in reducing diastasis recti postpartum

• Rehman et al., 2025 – Abdominal exercise more effective than no intervention for DRA

• Celenay et al., 2024 – Curl-ups improve abdominal strength without worsening IRD and may increase linea alba tension

• Recent meta-analyses (2024–2026) – Support structured, progressive exercise for DRA management