Stand with your feet shoulder-width apart, holding a dumbbell vertically in front of your chest (the ‘goblet’ position), with both hands gripping the top of the dumbbell; keep your chest up and your core engaged. Bend your knees and hips simultaneously, lowering yourself in a controlled manner (elbows pointing towards the floor, heels staying on the floor), ideally until your thighs are at least parallel to the floor. Push yourself back up through your heels, straightening your hips and knees at the same time.
Attention:
Keep your back neutral and upright; lift your chest proudly; let your knees follow the tips of your feet; distribute your weight evenly across the whole foot; keep your core engaged; keep your elbows close to your body; lower yourself only as far as your back remains stable.
Common mistakes: Hunching in the lower back; heels lifting off the floor; knees collapsing inwards; leaning the upper body forward too much; holding the dumbbell too far away from the body; not going deep enough despite sufficient flexibility; losing core tension.
Lighten:
Use a lighter dumbbell or no weight at all; reduce the range of motion; perform a box squat; raise your heels slightly (e.g. by placing small discs under them).
Harden:
Use heavier dumbbells; perform a slow eccentric phase (lowering); pause at the bottom position (pause squat).