Heavy kettlebell swings will help you to build tremendous hip extension power in a manner that is highly transferable to running, sprinting, and other horizontal jumping/movement variations. Now to be sure, there are a plethora of loaded explosive exercises that are absolutely amazing at building overall lower body power, popular and obvious choices include a whole host of variations of the Olympic lifts as well as numerous loaded jumping variations. The primary difference, however, between most of these exercises and the kettlebell swing, is that the former are all inherently knee dominant exercises, whereas the swing, which is essentially an explosive and dynamic RDL or pull through movement, is inherently a hip dominant exercise.

This is because with most popular exercises that are used for developing power the sole vector acting as a source of resistance during the movement is gravity - straight up and down like 6 o'clock. Naturally, this lends these movements to being dominated by the knee extensors, i.e. the quadz.

The kettlebell swing, on the other hand, gives us a different look. Gravity is still at play, obviously, however by heaving the bell in a forward and backward semi-arcing pattern we are introducing a strong horizontal component to the exercise as well, and horizontal action is where the hip extensors (the glutes and hammies) really get their chance to shine. Now your hips must control the incredible force of a heavy object that is literally swinging its way at full momentum, absorb all of that massive force, and seamlessly reverse and expel it at full power without missing a beat.

This is a stimulus that is hard to replicate with any other exercise. The horizontal component that is present is one that is not found in most other power development exercises, and the hip extension power that this builds makes the gains from the exercise highly transferable to running, sprinting, and other movement based activities and exercises that are heavily reliant on powerful hip extension.

The kettlebell swing is a fantastic means of cultivating the stretch shortening cycle in the hamstrings, which is paramount for athletic development. Due to the rapid eccentric stretch followed immediately by a maximal concentric contraction, swinging is in fact a true plyometric activity. Think about the eccentric action that is going on here. We are deliberately heaving an object forward at full force so that it will, in essence, boomerang back towards us in the exact same manner!

So now you are not just resisting the weight of the implement itself, but also the momentum of it reversing course at full speed as well. And as you move rapidly into hip flexion it is primarily the hamstring muscles and tendons that are called upon to resist and stabilize these tremendous forces. What is unique about the swing is that it may be the only training exercise in existence that produces such a powerful plyometric effect on the hamstrings while they’re in a fully stretched position — unlike most plyometric movements, which tend to emphasize the knees and ankles, but no so much the hips.

In time, a skilled athlete will learn not just to merely absorb these eccentric forces, but also to take advantage of them by utilizing the elastic energy to create a much more powerful concentric contraction than they could have otherwise - to seamlessly turn around these eccentric forces and spit them back out tenfold without a hitch. This is due to developing and mastering the stretch reflex. Running, jumping, cutting, hitting, etc - all of these things require sound command of the stretch shortening cycle and proper utilization of the stretch reflex, and as you become proficient at utilizing this skill with gradually heavier and heavier implements your lower body power development and overall movement capacity will be taken to the next level. Not only this but your hamstrings will become nearly bulletproof as well, which leads me to benefit number 3!

It is well known that most hamstring strains occur due to an overload of eccentric force. During sprinting, for example, one of the most notorious hamstring straining activities, the hamstrings are rapidly stretched and, while in a maximally lengthened position, must “work eccentrically to decelerate the thigh and lower leg during the last half of [the] swing phase” (1). This demands the absorption of tremendous eccentric force at full muscle length — an inherently risky situation if the hamstrings aren’t already well conditioned to handle such stress. And unfortunately, this is exactly how many injuries occur, even among elite-level athletes.

This is where the heavy kettlebell swing offers a unique solution. While it also subjects the hamstrings to large eccentric forces in a stretched position, just like sprinting, it does so in a far more controlled environment. There are no unexpected changes in direction, no reactive decisions, no chaotic variables, and perhaps most importantly of all, the load is precisely chosen and controlled.

Much like the idea behind an immunization, or gradually building up the tolerance of the body, we can start our swing training with a benign and manageable load - one that causes adaptation, but not injury. From there, we can progressively increase the load, thereby increasing the intensity of the dosage as our tolerance to these extreme forces increases along with it.

In the end, the heavy kettlebell swing offers 3 massive, often overlooked benefits: explosive hip extension power, enhanced stretch reflex capability, and increased hamstring resilience. These are results you won’t easily find through other training methods — at least not in the same efficient, powerful package. But unlocking them requires a shift in mindset. You have to stop viewing the swing as just a conditioning tool and start treating it like the high-impact strength and power developer it truly is. Once you make that shift, the rewards speak for themselves. So if you’re ready to get a step ahead of the competition and train like a true athlete then it’s time to start swinging!