The McGill Big 3 are three simple exercises designed to build a strong, resilient back and help ease low back pain. Developed by spine researcher Professor Stuart McGill, they focus on core endurance and control rather than crunches or heavy twisting, which makes them a safe, effective place to start.
In this guide we walk through all three exercises, plus a couple of progressions, with videos for each of these core exercises. Done consistently, the Big 3 build the core strength and endurance that protect your spine. If you have significant or worsening back pain, check with a physiotherapist before starting.
What Is the McGill Big 3?
The Big 3 are three core exercises: the bird dog, the side plank and the curl-up, sometimes called the core sit. Together they train the muscles that stabilise your spine from the front, sides and back, without loading it in ways that tend to aggravate back pain. The emphasis is on endurance and control, holding good positions rather than chasing reps, which is exactly what a resilient back needs.
How the Big 3 Build Core Strength
Rather than isolated crunches, the Big 3 build core strength and endurance across the whole trunk. Good core strength gives your spine steady support during everyday movements, which is a big part of why these exercises help with back pain. Because they are low-risk and scalable, they suit most people, from those recovering from back pain to anyone wanting a stronger, more durable back. Because the focus is on endurance and spine-sparing positions rather than maximal effort, they are gentle enough for most people to start at home, yet scalable enough to keep challenging you as you get stronger. That combination is a big part of why they have become a staple of back rehabilitation.
The Three Exercises Explained
Here is what each of the Big 3 involves before you watch them below. The bird dog builds control through your back and deep core: on all fours, extend one arm and the opposite leg in line with your body, keeping your spine still and hips level, then return with control. The side plank targets the muscles along the sides of your trunk; propped on your forearm, lift your hips so your body forms a straight line and hold, dropping to your knees if needed. The curl-up, or core sit, trains the front of your core without heavy spinal flexion: lie on your back with one knee bent, hands under your lower back, and lift your head and shoulders slightly, holding briefly. These three core exercises are the heart of the Big 3.
The Progressions
Once the basics feel comfortable, two progressions add more challenge. The bird dog row adds a rowing motion with the extended arm while you keep your trunk rock-steady, building extra core strength and anti-rotation control. The side plank with rotation reaches the top arm under and through, raising the demand on your obliques and deep core. Progress to these only once your basic holds are solid. Watch each exercise and progression demonstrated in the videos below.
How to Program the McGill Big 3
For the Big 3, endurance beats intensity. A common approach is a descending pyramid, holding each position for about ten seconds and doing sets of, say, six, then four, then two reps per side. Keep the holds strict and stop well before your form breaks. As you improve, you can add a set or hold the positions a little longer, but there is rarely any need to push to failure; quality and consistency matter far more. Most people do well practising them most days, since little and often builds the endurance a healthy back relies on.
Common Questions About the McGill Big 3
What are the Big 3 exercises?
The Big 3 are the bird dog, the side plank and the curl-up, or core sit. Together these core exercises build the endurance and control that support a healthy spine.
Do the McGill Big 3 help low back pain?
For many people, yes. The Big 3 are widely used to help manage and prevent low back pain by building core endurance, though they work best as part of a broader plan and should be tailored if your pain is significant.
How often should I do core exercises for my back?
Most people benefit from doing core exercises like the Big 3 most days. Consistency matters more than long sessions; a few focused minutes daily builds lasting core strength and endurance.
How BeFit Can Help With Low Back Pain
At BeFit Training Physiotherapy, we use exercises like the Big 3 as part of a complete approach to low back pain. Our lower back pain physiotherapy team assesses what is driving your symptoms and builds a plan around you, and evidence-based strength and conditioning takes your core strength further when you are ready. For a broader movement check, our sports physiotherapy team can help. Initial consultations run for 45 minutes, one-on-one.
Our team at Edgecliff and Coogee would be glad to help you build a stronger, more comfortable back. No referral is required, and HICAPS is available on-site for immediate health fund claiming.
Book an appointment at BeFit Training Physiotherapy — no referral needed.
Edgecliff: (02) 9327 7749 | Coogee: (02) 7205 2805 | befittrainingphysio.com/book-now
Related Services at BeFit
Learn more about how our team can help:
Lower Back Pain Physiotherapy
Strength & Conditioning
Sports Physiotherapy
Further Reading
How to Get Rid of Low Back Pain for Good
The Truth About Trunk Core Stability and Low Back Pain
How to Treat Low Back Pain With Evidence-Based Physiotherapy in Sydney
How to Train Through Low Back Pain as an Athlete
How to Know if Bad Posture Is Causing Your Back Pain
How to Ease Winter Back Pain and Neck Pain
References
McGill SM, Childs A, Liebenson C. Endurance times for low back stabilization exercises: clinical targets for testing and training from a normal database. Arch Phys Med Rehabil. 1999.
Smith BE, et al. An update of stabilisation exercises for low back pain: a systematic review with meta-analysis. BMC Musculoskelet Disord. 2014.
Stevens VK, et al. Trunk muscle activity in healthy subjects during bridging stabilization exercises. BMC Musculoskelet Disord. 2006.
Australian Physiotherapy Association. Clinical guidelines. physiotherapy.asn.au.
