Pilates in the Second and Third Trimester: What Changes and Why

Somewhere around week 14, most people notice their Pilates practice needs to shift — not because Pilates suddenly becomes riskier, but because your body genuinely is different from one trimester to the next. Here's what changes, and the physiology behind why.

Second trimester (weeks 14–26): the "sweet spot" with new limits

For many, energy and nausea improve in the second trimester, which makes it tempting to push harder. At the same time, your body is releasing more relaxin, the hormone that loosens ligaments and joints to prepare for birth — which means stability work matters more, and certain exercises might need to be adapted, covered in detail in Pilates Moves to Avoid During Pregnancy. The focus shifts to controlled strength and mobility: pressure management, glutes, upper back, and pelvic floor.

Third trimester (weeks 27–40): preparing for labour, not just "staying active"

By the third trimester, your centre of gravity has shifted noticeably, and comfort — not just safety — starts driving what feels good. The emphasis moves toward posture to support the weight of the baby, breathwork that mirrors labour breathing, and pelvic floor conditioning that supports both birth and recovery.

Why it changes: the physiology in brief

Two things drive almost all of these adjustments. First, relaxin loosens ligaments throughout pregnancy, which is why some ranges of movement may feel uncomfortable. Second, from roughly the second trimester onward, lying flat on your back for any length of time can compress a major blood vessel, which is why supine positions are swapped for side-lying or inclined alternatives. Neither of these is about pregnancy making you "fragile" — it's your body doing exactly what it's supposed to, and Pilates adapting alongside it.

How a trimester-matched programme handles this for you

This is the exact reasoning built into Grace's Second Trimester Programme and Third Trimester Programme — each trimester's classes are built around what's appropriate for that stage, so you're not left adapting exercises on the fly. If you'd rather have access to the full journey from week 14 through birth in one place, the Complete Pregnancy Pilates Programme covers all 27 classes and 8 tutorials across both trimesters.

If you're still in the first trimester, start with Is Pilates Safe in the First Trimester? or the full overview, Is Pilates Safe During Pregnancy? A Trimester-by-Trimester Guide.

This article is for general information and isn't a substitute for personalised medical advice. Always check with your doctor or midwife before starting or continuing exercise in pregnancy, especially if you have any pregnancy complications.