Legs day has become a thing. Whereas Monday is International Chest Day in gyms up and down the country, legs day is any time that men and women can proudly say they didn't neglect their lower half. Quads and hamstrings, glutes and calves, they've had their moment in the spotlight.
Those that do skip legs day are cursed to either a lifetime of wearing jeans on hot days or becoming an internet meme.
However, there are times when skipping legs day is not only excusable, but advisable. Put down that barbell and read on...
1. You're doing it wrong
For every perfect barbell squat performed, someone else is about to become a chiropractor's best friend.
The next time you feel your lower back aching, your knees caving in, or you start walking over to the abductor machine, either corner a personal trainer who knows what they're doing or head home and swat up on your research.
Some of the classic big lifts are encountered on legs day, with a plethora of squat and deadlift variations at the fore. If your lower back is already wincing, it's time to analyse your technique, preferably under the guidance of a personal trainer or strength coach. Time off work, physio and a codeine prescription could cost you more if you choose to go it alone without knowing what you're doing.
Barbell back squats may be one of the great lifts - building mass and torching fat - but it is also the cause of many a gym-goer's lower back problems. From slipped discs to sciatica or just the pain of bystanders watching your partial squats, this is an exercise that warrants proper coaching from a fitness professional.
Legs day can be a playground in the gym. Consider hitting your quads and hamstrings with alternatives such as front squats and smith machine deadlifts to lunges on suspension equipment. Just don't waste your time on ineffective abductor machines, which are just there to play on thigh gap insecurities.
2. You've just run a marathon
Intense cardio and a successful legs workout both run off the same fuel: stored muscle glycogen. Whether it's a 10k run or an indoor cycling session that's your cardio of choice, you can be sure it will deplete the reserves you had earmarked for all those box jumps.
Even if you wait to get on the treadmill until after your main legs workout, elevated lactate levels in the muscles will make it difficult to perform to high intensity. Keep your cardio and legs sessions a few days apart, if possible, and let your limbs enjoy the rest.
Also consider delaying your pursuit of the six pack until after a big legs session. To do some of the compound lifts safely, the core needs to be strong in order to support the spine. If you lack core strength, you can probably kiss goodbye to achieving anything with decent form.
3. Your stomach is empty
Not had time for breakfast? Ran out of protein powder? Trying to curb the calories? Training in a fasted state certainly has its supporters but the jury is out on whether the benefits outweigh the negatives.
A study for the Journal of the International Society of Sports Medicine concluded that, fed or fasted, the real key to fat loss is a controlled diet and exercise.
Fasted training means exercise performed when insulin is at its baseline level and nutrients are no longer being absorbed. As there is no food in the tank to act as fuel, in the fasted state the body turns to its fat stores to power the workout.
Legs day can require a significant amount of fuel. In a fasted state, you can expect to start feeling sluggish - making you prone to injury as technique starts to slump - and unless you replenish quickly post-workout, much needed protein will be stripped from other muscles to help repair your tired limbs. In short, all your efforts could end up cannibalizing those all-important pecs and biceps.
These are three valid reasons for skipping a legs workout. Beyond that, besides broken bones and crushed motivation, legs should always be part of your workout routine. Dedicate a whole session to them or split them with one of your more favoured muscles groups, but don't neglect them.
To not train such a large muscle group, whilst over-training the upper body, inevitably leads to an ill-proportioned physique. It also means missing an opportunity to build muscle and burn fat. Studies have shown that performing squats can also lead to upper body muscle development and, depending on the exercise performed, doing leg exercises for 20 minutes can burn roughly 300 calories.
Assuming you're fed, rested and have spent some time in informed company, there's no reason not to mark legs day in your calendar. Your gym shorts will thank you for it.