Without at least one day a week that’s dedicated to legs, you’ll never build up your lower body strength. Activities such as running and cycling can strengthen your legs to a degree, but only a full leg workout with exercises like the squat, leg press and leg curls will maximise your lower body strength and muscularity.
The danger of neglecting legs over time is that your body will start to look disproportionate if you’ve been training your upper body consistently. This may not be obvious in the early stages of training, but after several years of training your upper body and ignoring your legs, this could make your body look severely disproportionate. (think chicken legs!)
Needless to say, legs that are relatively weak in comparison to back, chest and arms could also be more susceptible to injury and strains, as they will be supporting a disproportionate amount of upper body weight.
Another reason you should never skip leg day is that the squat is one of the best overall mass and strength builders, along with deadlifts and the bench press. You'll often find that while the benches in your gym are frequently taken, especially at busy periods, the squat racks are often empty (unless you go to a gym geared towards bodybuilders) because very few gym goers ever perform them.
Big compound movements like the squats are essential for building big, strong glutes. Research has also shown that strong glutes can help reduce your risk of back and hamstring injuries, and improve your hip mobility.
Strong legs are also vital for improving your performance in many sports such as football and rugby. WIthout leg training, you’ll find it much harder to reach your potential in these games.
Because legs are such a gruelling workout – the kind where sweating is almost inevitable – they burn a lot of calories, especially if you include heavy squats and leg presses into your routine.
If you find cardio really boring, you'll be pleased to know that research has indicated that intense weight-lifting - such as big leg workouts - can help you burn more calories than the equivalent amount of time spent on a treadmill. Why is this? Well, it's not that you'll necessarily burn more calories during the leg workout itself - it's what happens afterwards that really matters.
Studies have found that high-intensity exercises like squats can raise your metabolism for up to 38 hours following the workout. That's because your body also uses calories in order to repair and rebuild your muscles - and this requires a large amount of growth hormone, which also promotes fat loss.
It’s the extra growth hormone stimulated by intense leg exercises that can also help promote muscle recovery and growth in your upper body by keeping it in a metabolic state – as long as you are working your back, chest and arm muscles consistently as well.
Hopefully, this advice will convince you to never skip leg day in the future!