Unilateral training: single leg and single arm work

Why it is worth doing

• Balance and stability: standing on one leg forces the muscles around the hip, knee and ankle to control the joint, particularly the glute muscles on the outside of the hip.
• Less load on the spine: a split squat can challenge your legs as hard as a heavy back squat with a fraction of the weight on your back. Useful for people with back issues or anyone wanting leg work without extra spinal fatigue.
• Each side works independently: the stronger side cannot quietly take over, so weaknesses show up and get trained.
• Transfer to running and sport: single leg strength matters for every stride and change of direction.
• Rehab and return from injury: loads can be controlled precisely for each side, which is why single leg work is a staple of rehab.

Unilateral exercises are also brilliant when equipment is limited. A pair of dumbbells or a kettlebell and a bench are enough for a genuinely demanding lower body session, which makes them ideal for home training or a crowded gym.

They can also flag problems early. If one knee always drifts inwards on step-ups, or one hip always drops during single leg work, that is useful information for you, your coach or a physio.

The best unilateral exercises

For the lower body:

• Bulgarian split squat: rear foot on a bench, very demanding on the front quad and glute.
• Reverse lunge: easier on the knees than forward lunges and great for learning control.
• Step-up: simple, scalable and very transferable to stairs, hills and hiking.
• Single leg Romanian deadlift: hamstrings, glutes and a real balance challenge.
• Walking lunges and sandbag lunges: endurance and coordination, and a HYROX staple.

For the upper body:

• Single arm dumbbell row: back strength plus anti-rotation work for the trunk.
• Single arm dumbbell press, flat or overhead: each shoulder has to stabilise itself.
• Landmine press: an angled press that suits many people who struggle to press straight overhead.
• Suitcase carry: a one-sided carry that challenges grip and the side of the trunk.

Choose two or three that suit your equipment and goals rather than trying them all. A beginner might start with reverse lunges, step-ups and single arm rows, then add Bulgarian split squats and single leg Romanian deadlifts once balance and control improve.

What about imbalances?

Most people have some difference between sides, and small differences are completely normal. Your dominant leg may be a bit stronger; your non-dominant arm may be a bit less coordinated. There is no strong evidence that small asymmetries cause injury in healthy people.

Larger differences are worth addressing, particularly after an injury. After an ankle sprain, knee injury or surgery, the injured side can stay weaker for a long time, even once it feels fine. Physios often compare single leg strength and hop tests between sides when deciding whether someone is ready to return to sport.

The practical rule is simple. Always start with the weaker side, then do the same number of reps on the stronger side, rather than letting the strong side run away with extra reps.

How to programme it

Most people do well putting one bilateral lift first in a session, then one or two unilateral exercises afterwards. A lower body day might be back squat, then Bulgarian split squats, then single leg Romanian deadlifts. Two to four sets of 6 to 12 reps per side covers most goals.

Unilateral work takes longer, because each side is done separately, so alternate sides without resting between them and rest after both. It is also more tiring for the heart and lungs than people expect, especially walking lunges and step-ups, so allow for that if conditioning follows.

Progress them like any lift: add reps, then load. Dumbbells held at your sides are the easiest to balance, while a goblet hold or a barbell on your back changes the challenge. Increasing the range, such as step-ups onto a higher box or reverse lunges from a low platform, is another way to progress.

For some people, unilateral lifts can become the main lower body exercise: those with back problems, those training at home, or older lifters who find heavy barbell squats uncomfortable. The legs can get very strong this way.

Unilateral training for HYROX

HYROX includes 100 metres of sandbag lunges, 80 metres of burpee broad jumps and eight kilometres of running, all of which demand single leg strength and endurance under fatigue. Regular split squats, step-ups and lunges build both the strength and the tolerance to repeated single leg loading that the race needs. Our guide to sandbag lunge technique covers the station itself.

If you want to build this kind of strength in a group, Lycan Strength runs Lower classes on Thursday morning and evening and Full Body classes on Mondays, and every class is scaled to the person. The class timetable has the full week.