The lunge is a classic movement that you should still avoid since there are better and safer options.
At first just associated with toning the butt and legs for women and sessions with little or no equipment, it has gained traction in hardcore circles. On the surface the lunge would seem to have right qualities. It is a free weight compound exercise that seems simple enough. Upon closer inspection, it carries risks to the joints and also limits gains in strength and size.
Walking, forward, reverse, static, laterally, or any other way, it matters not how you choose to lunge as you still need to avoid it.
Reasons
Great things are not accomplished by those who yield to trends and fads and popular opinion.
– Jack Kerouac
- It is a unilateral exercise.
Exercises that use both limbs work best for strength training. They allow stability, which is essential for expressing and building strength. Otherwise, you will find that balance, coordination, and other issues take over as the limiting factors. This prevents as much tension in the muscles to stimulate growth.
- Too much shear affects the rear knee.
The position of the rear leg places shearing force on it. This happens because the knee bends without the hip extending in proportion, which occurs in normal movements. This causes a force that rips apart the knee as if snapping an object in two. Unfortunately to keep your balance, you have to place some weight on this leg and this invite this force.
As you fatigue, you may also bang that knee on the floor.
The knee pain many feel come from these or because of the position for the lead leg.
- Difficult to position front leg just right.
You have less control since the plant for the front leg occurs quickly and less precisely.
The ideal exercise for the lower body balances the front and back forces that affect the knees, hips, and their muscles. If you fail to step far enough, you place shearing forces on the knee. If you lunge too far, the hip bares too much of the load. Striking a balance seems tough due to the lack of exactness in how far you lunge plus the instability.
You may also step with your feet too close together horizontally. This shortens the adductors of the inner thigh and may cause you to lose your balance. With a barbell squat, you keep your stance constant and avoid these problems.
- Tough to load heavily.
Using a barbell on the lunge brings risks since you have nowhere but the floor to dump the weight if you fail on a rep. The load possible through dumbbells is limited by the grip. The instability inherent in the exercise also further limits the weight. A squat or trap bar dead-lift allow more weight and better safety features that protect you when you fail.
- The other picks are far better.
The squat has none of the problems affecting the lunge. The squat is bilateral. It allows a balance for the anterior and posterior forces. It allows stability and can be loaded heavily. The split squat, although not as ideal, works better than the lunge too due to the better stability and prevention of knee stress.
Squat and Ignore Lunges
Some assume the middle position of any argument makes the most sense. Why not just squat and lunge? The sensible route is not always a compromise though. If an exercise feels harmful and a better option exists, it makes no sense to include both. Many do so out of ignorance or for the sake of variety.
Versatility, popularity, and tradition do not justify using them, as only the facts should matter. Even if limited to only your bodyweight, the split squat and one-legged squat both work better. The lunge brings no unique value.
The barbell squat works better on all levels. The only slight edge lunges may have comes from the unilateral effect that works the stabilizers. You hit them with a good interval option though and bracing already occurs to work them during the squat. Avoid lunges and focus on better exercises.