Last updated: June 2026 — Alex Turner, NASM-CPT
Why most people get the measurement part completely backwards
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Here’s what usually happens. Someone decides to work on their core. They start doing crunches or a 30-day ab challenge they found online. Four weeks later they feel like they’ve done something, but they have no idea if anything actually changed — because they never measured where they started.
This matters more than it sounds. Without a baseline, you’re training blind. You might be getting stronger and not know it. Or you might be plateaued and not know that either. Both are demoralizing in different ways.
The good news: measuring core strength doesn’t require equipment, a lab, or a personal trainer standing over you with a clipboard. Three tests. A timer on your phone. Ten minutes.
“You can’t fix what you haven’t tested. And you can’t stay motivated if you have no idea whether anything is actually changing.”
The 3-test core baseline you do before you train anything
Do these in order. Rest 90 seconds between each one. Write the numbers down somewhere you won’t lose them — your notes app, a sticky note on the fridge, wherever. You’ll retest every 14 days.
The 30-60 day plan — week by week, no vague “increase intensity” nonsense
This is 4 days a week. Not 7. Not 6. Four. The reason everyone burns out on core programs is they try to train it every single day like it’s a different kind of muscle. It’s not. It recovers like every other muscle. It needs rest days.
Do this Monday, Tuesday, Thursday, Friday. Or any 4 days with at least one rest day mid-week. Sessions run 20-25 minutes.
WEEKS 1-2 — Build the pattern (not the burn)
- Dead bug holds — 4 sets of 20 seconds, 30-second rest between sets
- Forearm plank — 3 sets, hold to 80% of your baseline number (so if you hit 50 seconds on day one, hold 40 seconds here)
- Bird dog — 3 sets of 8 reps per side, 3-second hold at extension
- Side plank — 3 sets of 20 seconds per side
- Glute bridge with 2-second hold at top — 3 sets of 12
That’s it for weeks 1-2. I know it feels like not enough. It’s not supposed to feel like enough. The goal here is teaching your nervous system the movement patterns, not destroying yourself.
WEEKS 3-4 — Add load, add range
- Dead bug — now with arm and leg extension, 4 sets of 6 reps per side (slow, 4-count descent)
- Ab wheel rollout — from knees, 3 sets of 6-8 reps (this is where an Ab Roller Abdominal Muscle Wheel earns its place — nothing else hits the anterior core through that full range of motion, and it’s brutally honest about whether your brace is actually working)
- Forearm plank — increase hold to 110% of your baseline number
- Side plank with hip dip — 3 sets of 8 dips per side
- Pallof press (with resistance band) — 3 sets of 10 per side, 2-second pause at extension
Retest your baseline at the end of week 4. Write the numbers down next to your week 1 numbers. Most people see a 15-25 second improvement on their plank by this point. Some people see more. A few people see barely anything yet — and that’s genuinely okay, because weeks 5-8 is usually when those people suddenly jump.
WEEKS 5-8 — This is where it gets real
- Ab wheel rollout — progress to 3 sets of 10, add 1-2 reps per week
- Dead bug — add a light resistance band around feet for added tension, 4 sets of 8 per side
- Plank to push-up — 3 sets of 8 transitions, controlled
- Copenhagen plank (inside of bottom knee on bench) — 3 sets of 20 seconds per side
- Hollow body hold — 4 sets of 25 seconds, lower back pressed completely flat
- Retest all 3 baseline tests at end of week 6 and again at end of week 8
Realistic expectation by day 60: plank hold up to 90-120 seconds, dead bug hold up to 55-70 seconds, side plank gap under 8 seconds. Those aren’t made-up numbers. They’re averages I’ve tracked across clients doing this exact progression.
What actually changes — and when
Week 1 is uncomfortable. Not dramatic movie-training uncomfortable — just the specific low-grade soreness of waking up muscles that have been decorative for a while. Your obliques will remind you they exist in about 36 hours.
Week 2 the soreness stops. This is where most people panic and think it stopped working. It didn’t. Your body is adapting. Keep going.
Weeks 3-4 you’ll notice something weird: you’re holding yourself differently when you sit. You’re bracing automatically when you pick things up. That’s the actual goal. That’s functional core strength.
Weeks 5-8 the numbers jump. I don’t know exactly why the adaptation curve is shaped this way — steeper at the back half — but it consistently is. The clients I’ve trained who stuck through the boring middle weeks are always a little shocked at how much their retest numbers moved.
The thing nobody tells you about weeks 2-3
It’s gonna feel terrible. Not physically terrible — the physical part gets easier fast. Mentally terrible, because nothing looks different yet and the novelty has worn off and you’re just doing planks in your living room at 7am like a weirdo.
I grew up the kid who got picked last in gym class. Every single time. Not once, not sometimes — every time. So I understand viscerally what it feels like to do physical work and see nothing happen and wonder why you’re bothering. The answer, which nobody gave me as a kid and which I now say to every client in week 2: your body is changing before your brain can perceive it. The nervous system is learning. The muscle fibers are adapting. The mirror and the scale are the last things to update, not the first.
The numbers — your plank time, your dead bug hold, your side plank gap — those update first. Which is exactly why you wrote them down on day one. Check them at day 14. Something will have moved.
- ✓ Test first — 3 exercises, write down your time in seconds, retest every 14 days
- ✓ Train 4 days a week, not 7 — the rest days are doing actual work
- ✓ By day 60, expect plank to reach 90-120 seconds and side plank gap under 8 seconds
- ✓ Replace 70% of crunch-based work with anti-extension and anti-rotation movements
- NOWDo all 3 baseline tests right now — dead bug hold, plank, side plank both sides — write the seconds in your phone notes app
- THIS WEEKComplete the Week 1-2 circuit 4 times — 20-25 minutes each session, no skipping the rest intervals
- 30 DAYSRetest at day 14 and day 30 — you should see at least 12-20 seconds added to your plank and a noticeably smaller gap between your side plank sides
You can find the ab wheel and other simple tools at Aura Heaven if you want to add week 3-4 equipment without making it complicated.
Questions I get all the time
How long until I can actually see my core muscles?
Honest answer: that’s a body fat question more than a strength question. You can have an extremely strong core that isn’t visible. Visibility requires a caloric deficit. Strength requires progressive training. Those are two different projects and you don’t have to do both at once — but if you’re asking about seeing abs, know that you’re asking about nutrition as much as training.
Is my lower back pain a sign my core is weak?
Sometimes. But back pain has about fifteen different causes and weak core is one of them. If your pain is new, sharp, or radiating down your leg, see a doctor before training anything. If it’s the dull chronic kind that’s been there for years and gets worse when you sit all day, core stability work (specifically anti-extension, like dead bugs and planks) often helps. McGill’s research is clear on this — it’s not crunches that help back pain, it’s the bracing-pattern exercises.
Can I do core training every day?
You can. You probably shouldn’t. Your core is skeletal muscle. It needs 48 hours to recover from real training, same as your biceps or your quads. If you want to do something daily, do 5-minute brace-practice sessions — standing, sitting, during walks. That’s building the habit without frying the tissue.
Why does my plank time vary so much day to day?
Sleep, hydration, and whether you ate
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8 Years Experience Β· Home Fitness Expert
Alex is a NASM-certified personal trainer who has helped thousands of beginners build lasting fitness habits at home β no gym required. His no-fluff approach focuses on what actually works for real people with busy lives. Find his recommended gear at Aura Heaven.
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