It's ridiculous to think that there are gym-goers out there who are neglecting training their lower body with stellar leg exercises in favour of getting top heavy and massive. But you are out there – we can see you and we're here to address this.

Generally speaking, we have moved on from stacked, triangular Hercules lookalikes who haven't felt a squat in years as most people now know the aesthetic and general health benefits of leg exercises, from increasing muscle to accelerating fat loss and even boosting testosterone.

For those who've been living under a rock, here's why skipping leg day is the biggest mistake you can make – backed up with the best leg exercises to have you feeling like a one-stop fitness machine, courtesy of ultra-marathon swimmer and bestselling author Ross Edgley and GQ's crack team of fitness experts.

Want something more specific? Try out our hamstrings guide. We also have workout guides for every other part of your body if your legs are looking stellar – check out biceps, triceps, chest or back. If you're looking to mix up your equipment game, you can also check out our guides to dumbbells, TRX exercises and more.

What's the big deal about leg day?

1. It spikes muscle-building hormones

Naturally boosting testosterone in men is a good thing for fitness. It helps you increase muscle mass, burn fat and even helps you between the sheets, which is exactly why research published in the European Journal of Applied Physiology and Occupational Physiology suggests every man should become good friends with the squat rack.

The study's investigation into hormonal response during heavy resistance exercise demonstrated that “the most striking changes appear evident in the testosterone response to heavy resistance exercise in physically active young and older men”, noting a dramatic spike.

Put simply: irrespective of your age, squatting will increase your body's testosterone, which in turn increases your muscle-building and fat-loss potential.

2. You'll lose fat

Want to lose fat? Get off the treadmill, put down the slimming shake and squat. That's what a study published in the Journal of Applied Physiology says, which tracked athletes' energy expenditure and metabolism after heavy resistance training. What they discovered was that after 90 minutes of heavy weight training (including squats) an athlete's metabolic rates skyrocketed.

Interestingly, these rates stayed high for hours after athletes had left the gym. Scientists concluded that “strenuous resistive exercise may elevate post-exercise metabolic rates for a prolonged period and may enhance post-exercise lipid oxidation [fat burning].” That's something a brisk walk on the Stairmaster won't do.

3. You can eat what you want afterwards

This'll be music to the ears and stomachs of thousands: after leg day you can pretty much eat what you want. Scientists from the Washington University School of Medicine discovered that heavy weight training increases the efficiency of a protein called GLUT4. This improves our body's insulin sensitivity and the rate at which we absorb and use glucose.

Combine this with teachings from the American Journal of Physiology that say “early post-exercise ingestion enhances accretion of whole body and leg protein” and this means a giant, homemade burger with sweet potato fries no longer seems like a bad idea. It will be absorbed efficiently, won't be stored as fat, and will help the muscles repair and re-grow.

So, never skip leg day: squat, eat and heed the words of Vitruvius and Da Vinci. Do all this and you can't go wrong.

Three steps to the perfect leg day

Eoin Ryan, personal trainer

1. Front squat

One of the best lower-body exercises out there. At the end of a good front squat session you'll feel like your whole body has been worked out, with your abs feeling amazing.

First, find your squat stance – for most, this is just outside shoulder width with toes pointing out at 45 degrees, but don't be afraid to play with your stance. Place the bar on the anterior part of your shoulder while making sure it's supported by your shoulders and upper chest. Keep a full grip while keeping your elbows almost parallel to the floor (if you've got tight shoulders or lats you might need to roll the bar onto your fingertips).

The base of your big toe, small toe and heel should remain in contact with the floor as you pinch the floor with your foot. Squeeze your glutes like you're holding a peanut between your cheeks and make sure your knees stay in line with your toes.

With your ribs down, fill up your diaphragm with air, then brace like someone is going to poke you in the stomach. Unlock at the hips to put the weight onto your glutes/quads/hamstrings, and drop to your optimal squat level (as deep as you want while keeping the pelvis in a neutral position). Finish the movement by driving back to the top and squeezing your glutes.

Top tip: just as you're coming out of the bottom position, drive your elbows up to keep them parallel. This will make the lift easier.

2. Bulgarian split squat

One of my go-to quad and glute exercises, with the added benefit of being amazing for your core and balance.

Place one foot on a bench that's just above knee height with the top of the toes facing the floor. Begin with your knee on the floor. Your back knee should be placed underneath your hip and your front ankle should be below your knee or slightly behind it (this can vary depending on your mobility, but it's a good starting point).

Drive up to a standing position. Before you return to the floor, brace your stomach again and try to keep your knee in line with your toes (it's going to want to cave in).

Top tip: lean your chest slightly forward to prevent your back from hyperextending.

3. Romanian deadlift (RDL)

One of my favourite go-to exercises for hamstring and lower-back strength while once again being fantastic for stability.

Start with feet shoulder-width apart with the barbell above the middle of your foot and create your foot tripod (see above). Hinge – imagine someone is pulling your hips back and you should feel your hamstrings engage – and grab the bar just outside your knees.

Keep your back flat, squeeze your armpits like someone is going to tickle you from behind, and tuck your chin. Use your glutes and hamstrings to initiate the movement to the top. Now you're here, you can start an RDL.

Fill your stomach with air and brace. Move your hips back while squeezing your armpits and keeping your back flat, and keep the bar in contact with your quads and then your shins as you move down.

Your end range is just before the point where you can't keep your back flat and you lose the engagement of your lats (when you can’t squeeze your armpits tight any more). Finish the movement by squeezing your glutes at the top.

Top tip: keep squeezing your armpits as you lower the bar down your body.

Single-leg exercises

Duncan Leighton, head trainer at Apex Rides

Our focus here is mainly on single-leg exercises, as this will help support activities such as running while adding an essential balance component. Because of this, start with bodyweight only and progress to weight when you are confident with control throughout all stages.

For exercises one to four, work around three sets of between eight and 12 reps. By the end of the third set, the exercise should be difficult but still manageable without losing form. If three sets of 12 reps aren’t challenging, add weight or increase difficulty as detailed below.

1. Banded squats

We are aiming to engage and strengthen the gluteus medius (the lateral aspect of your butt cheeks), which will support and promote good knee and foot movement.

Grab a looped resistance band and put it around both legs, just below your knees. Stand with feet hips' width apart or slightly further. Ensure you feel tension from the band against the outside of your knees.

With a chair or bench behind you, squat as though you are going to sit down. Tap your bum gently on the chair without sitting and return to standing, squeezing your glutes as you do.

While squatting, tension from the band will try to pull your knees towards each other. Resist this movement, ensuring that your knees are heading in the direction of your middle toes. If you’re unable to resist, tie the band slightly looser. If the movement is easy, tie it slightly tighter or find a band with higher resistance.

2. Reverse lunges

I prefer these to forward lunges, which often run the risk of over-flexion of the knee. They can also put pressure on the patella tendon under the kneecap, which isn’t fun for anyone.

With feet hips' width distance apart, step backwards and slowly lower yourself until your front knee is at around 90 degrees, ensuring your front knee is heading in the direction of your middle toes as it bends.

Your back knee does not need to touch the floor here. Keep your chest up, eyeline forwards and try to split your weight evenly between both feet, ideally aiming for around 90 degrees of flexion in the front ankle. This will help ensure an even split.

Drive through the front foot, return to starting position and repeat with the same leg. Your motion back up to this position can be swifter than the controlled lower, as long as you can maintain balance. For extra difficulty, add weight via dumbbells or a weighted backpack, or add a small sofa cushion or thick folded towel underneath your front foot.

3. Single leg sit to stand

Sitting on the edge of an exercise bench or dining chair, simply stand up on one foot. As before, focus on your knee direction heading towards your middle toes and not dipping in towards the midline of the body. Squeeze the glutes at the top of the movement and slowly control back down to seated.

To reduce difficulty, your non-working foot can be placed further forward than the foot you will stand on, in a staggered stance, aiming to put the majority of weight through the foot closest to you. The wider your feet are staggered, the more difficult the exercise will be. Progress this until you can manage with the front (supporting) leg completely straight, using only the heel of that foot to support, and then eventually progress onto one leg.

4. Single leg calf raise

Off the back of a step, slowly lower and raise your heel in a controlled and slow motion. If balance is an issue, support yourself using the wall. Aim to use your ring finger only to balance as this will prevent you offloading weight onto the wall.

5. Single leg balance on cushion

This is a very important exercise to build ankle control that can be done as part of your routine or separately during the day – great if you have a standing desk.

Simply stand on a folded pillow or fluffy towel and try to balance on one foot. Aim to build up to one minute on each foot with no support. When this is possible, start using the cushion for dynamic movements, such as the reverse lunges as explained above.

If on a hard floor, be careful the cushion doesn’t slide out from underneath you as you use it.

[Via GQ UK]