For most strength and conditioning experts, the answer is yes, but there is another point of view worth understanding. The purpose of all strength training for athletes is to improve athletic performance and building lower body and core strength is key for almost all athletes. Conventional practice is that the barbell back squat is THE way to develop lower body strength.
However, if you think about it a second athletes do very little with both feet evenly spaced out beneath them. All running is about landing and pushing off on one leg and most jumping happens off one foot not both feet. One of the few exceptions is the sport of rowing where you always push off with both feet evenly spaced.
According to Mike Boyle, one of the best sport conditioning experts in the world, the back squat is an exercise that does not translate well to sport, carries a high risk of injury (particularly for the low back), and is hard for many athletes to perform properly based on the length of their torsos, lower leg, and upper leg.
So, what does he recommend? Split squats with rear foot elevated aka Bulgarian split squats. Boyle feels they translate better to athletic performance and are also much safer than back squats. He points out that muscular failure occurs because of lower body muscle fatigue instead of low back strength being the limiting factor like the back squat.
Critics of Boyle maintain that the loads utilized in split squats are too low for athletes to gain the strength they need, but is that true? Boyle’s answer is that you can lift MORE weight with split squats, and he has the evidence to prove it. If you work at Split Squats and increase load over time as you become stronger you will find that if you add the loads you are capable of using on each side together the combination is usually significantly higher than what you can barbell back squat!
In addition, when you train one side of the body the other side is also stimulated. Indirect stimulation of the non-working side of the body via working the opposite side improves strength in the injured area. This is called cross-education of muscles and is a neural event. The brain pathways that are used for the primary unilateral exercise stimulate the same muscles on the opposite side of the body.
Split squats have several other key advantages:
They require higher levels of core stabilization because of the unbalanced loading
They require better balance.
They allow a greater range of motion at the hip with higher levels of hip flexion and extension.
They provide a great emphasis on the eccentric strength both in hip extensors AND hip flexors.