Step forward, bend both knees, return to standing: step length, knee line and milestones from bodyweight to dumbbells — honestly explained.
The lunge is a single-leg exercise: you take a step forward, bend both knees until the back knee hovers just above the floor, and push back to standing with the front leg. It shows you immediately whether your left and right leg contribute equally.
The honest answer to "how hard is it?": the movement is understood in one session. Balance and knee line need a few weeks (rule of thumb). The lunge is harder than it looks because you must brake and accelerate on one leg.
A myth first here too: your knees may go over your toes. That is biomechanically normal, and a review found no increased risk from deep bending [1]. What matters is something else: that the knee does not collapse inwards.
Stand on one leg, the other hangs loose. Count to 30 without flailing your arms.
Milestone: 30 seconds per side without putting the foot down.
Take a long split stance, back foot on the ball. Bend both knees straight down and come back up without moving your feet. You feel the position before you move.
Milestone: 3 x 8 per side, torso upright, front knee pointing toward the toes.
Step forward, bend both knees, push back with the front leg. Step length changes which muscles dominate: in a study of 20 young men doing split squats at four step lengths, longer steps activated the hip extensors more, while step length had only a limited effect on the knee extensors [2]. That was a split-squat study; we transfer it as an approximation to the lunge. In practice: a slightly longer step if you want to feel your glutes more.
Milestone: 3 x 8 per side, knees stay over the toes, no caving in the front video.
Take light dumbbells, arms hanging loose. Same sequence. The weight lengthens the path of your centre of mass, so control while lowering is what counts now.
Milestone: 3 x 8 per side with 2 x 8 to 12 kg, same depth every rep.
6 to 12 reps are the best compromise for muscle growth, 1 to 5 build more maximal strength [5]. Muscle growth profits from closeness to failure; the effect flattens out at about two reps in reserve [6]. For technique you never need to go to the limit.
Milestone: you only increase when all reps look the same and two were left in the tank.
Among the basic exercises the lunge is one of the safer ones, because when you get unstable you simply abort the step. Still, injury rates in strength sports are 1 to 4 per 1000 training hours, most often at the lower back, shoulder and knee [4].
Stop at stabbing knee pain. Dull muscle fatigue is wanted, stabbing in the knee is not. With known knee problems, the build-up belongs in professional hands.
This guide explains and motivates, it does not replace supervised training or a coach.
Imagine a line running from your front knee to your second toe. And think outward: "push the floor away from you" instead of "tense the knee". A meta-analysis across 73 studies shows an external focus of attention performs better than an internal one for movement performance [7]. No miracle cure, but a trick that costs nothing.
Your body organises itself better when you give it a goal instead of a muscle instruction.
Step forward, bend both knees straight down until the back knee hovers just above the floor, and push back with the front leg. The torso stays upright, the front knee points toward the toes. Start without weight.
Yes. That is biomechanically normal; a review on deep bending found no increased risk from it [1]. Watch for caving inwards, not for the toe line.
Long enough that the front shin stays nearly vertical and the heel stays down. According to a split-squat study, longer steps load the hip extensors more and have a limited effect on the knee extensors [2]. Try shorter and longer and choose what feels stable.
For muscle growth 6 to 12 reps [5], two to three sets per side. Leave two reps in the tank, since closer to failure adds little [6]. The set volume is a practice value.
Both train the legs, but differently. The lunge exposes side differences and challenges balance, the squat usually lets you move more weight. For beginners they complement each other: squat for the base, lunge for balance.