A little Kettlebell history…
Looking akin to the handbag of a hollywood celebrity or a cannonball with a handle stuck on top, the humble kettlebell is probably the earliest piece of weight training equipment (apart from the rocks and logs used by early cave people of course).
Kettlebells have their origins in Russia or Scotland (depending on who you want to believe) and while they were popular ‘historical’ training tools this popularity waned with the invention of dumbbells, barbells and weight machines. Over the past decade however kettlebells and a specific type of ‘kettlebell training’ have been undergoing a rejuvenation, as personal trainers, and equipment manufacturers and retailers’ embrace ‘functional’ training with free weights as opposed to machine based training.
Are Kettlebells a ‘functional’ training tool?
What is it about kettlebells that makes them popular with the advocates of functional training? Why would you, as a personal trainer use a kettlebell as opposed to an ordinary dumbbell or weight machine with your clients?
By having the handle on top of the weight, the centre of mass of the Kettlebell is extended beyond the hand when it is held. This makes it much easier to complete the explosive, multi joint, swinging type movements that characterise kettlebell training and many other forms of ‘functional’ training for that matter.
Now we have a series of articles discussing ‘functional’ training at ptdirect.com so we’re not going to go over this ambiguous term in detail here, suffice to say that what actually makes training ‘functional’ for a client is that it is ‘fit for the clients purpose’, namely that the training will achieve the individual clients goals in the most efficient and enjoyable way for them.
So regardless of the structural advantages kettlebells have for certain types of training, they will only be a ‘functional’ tool for clients that want to benefit from that type of training and are able to perform that type of training safely and effectively
What is ‘Kettlebell Training?’
Now kettlebells can be used just like dumbbells to add weight to conventional exercises such as squats, deadlifts, lunges and bent over rows. In fact any conventional weight training exercise that you’d use a dumbbell for could be performed with a kettlebell.
‘Kettlebell training’ however is quite different to simply performing conventional exercises with kettlebells as opposed to dumbbells. Kettlebell training is a specific form of training that:
1. Is focused on explosive, power oriented swinging movements. These movements utilise more fast twitch muscle fibres and these fibres have a greater capacity for developing size, strength and power
2. Incorporates the Olympic lifts – the clean, the clean and jerk, and the snatch. These large, multi joint exercises use virtually every muscle in the body and as such can be great for burning lots of calories and stimulating lots of muscle in a short period of time
Is Kettlebell Training Safe for your Personal Training Clients?
Ultimately any type of resistance training has the potential to be dangerous, just like crossing the road has the potential to be dangerous. As a personal trainer you minimise the inherent dangers for your clients by only selecting exercises that suit their capabilities, and you instruct your clients on how to perform those exercises safely. That being said, as kettlebell training exercises are complex, multi-joint, power oriented exercises then kettlebell training does carry more ‘risk’ than many other forms of resistance training.
To understand why there is a greater risk of injury with kettlebell training we need to have a brief review of biomechanics and the human energy systems…
Basic Biomechanics Recap
Highlighted on the adjacent diagram is the base of support (shown by the red line underneath the skeletons feet), the centre of mass (the red dot at the top of the pelvis), and the line of force (the yellow line passing through the body).
The base of support is simply wherever the body touches the ground – so in any standing position the base of support includes the feet and the area between the feet. The centre of mass is simply the middle of an abject where there is the same amount of mass above as there is below, and the same amount of mass in front of, as there is behind, the centre point. The line of force is simply the direction that a load acts in. As this skeleton is not holding a load the line of force reflects gravity which always pushes straight down.
As soon as a persons centre of mass moves outside their base of support their ability to balance is significantly impaired. If their centre of mass moves forward of their base of support they’ll likely fall forward, and if it moves behind their base of support they’ll fall backwards.
This is why ‘good’ biomechanics for exercises like squats as shown here, rely on having the weight placed directly over the client’s base of support, and ensuring that during the movement the client’s centre of mass remains directly above their base of support. If the weight was positioned high on the clients’ neck in this image of the squat the clients centre of mass would move to the front of their base of support making them vulnerable to tipping forward (as well as having far too much load on a vulnerable part of the spine!)
One of the guiding principles for safe resistance training with standing exercises is to keep the centre of mass directly over the base of support. This becomes even more important as the loads that are being lifted get heavier and are performed in an explosive manner.
Kettlebells do offer a significant advantage for some of the lifts used in kettlebell training, namely the high pull, and the Olympic lifts – the snatch, the clean and the clean and jerk. The advantage is that the kettlebell can be lowered between the legs thus keeping the centre of mass well positioned directly above the base of support. The disadvantage of using bars is that they have to be pulled from the ground up and over the protruding knees which does bring the centre of mass slightly forward, thus requiring a very sound, well refined technique to keep the client balanced and ensure their safety during the lift.
As loads get heavier and exercises are performed in a more explosive manner the risk of injury increases so it is imperative that the body is well balanced and the structures of the body that are more vulnerable to injury are not exposed to undue risk. This is where the safety of some of the swinging kettlebell training exercises becomes questionable.
In this example of the two-handed kettlebell swing the clients centre of mass moves forward of their base of support as the heavy kettlebell moves out in front of her body. In order to stay balanced and keep her centre of mass above her base of support she has to lean backwards to counterbalance the weight in front of her body. This places a lot of extra load on her lower back in particular. If this exercise was performed by an inexperienced client with a muscular system unable to cope with high loading on vulnerable areas such as the lower back then injury is highly likely.
You also need to consider that ‘what goes up must come down’. With kettlebell swings the client is usually instructed to ‘pull’ the kettlebell back down into their body from the top position. Combined with the effects of gravity this results in a lot of momentum being created as the kettlebell returns to the starting position. The client will need to be able to resist this momentum at the bottom point of the exercise to avoid an injury and/or loss of balance.
So when we consider the mechanics of kettlebell training (complex, explosive multi-joint exercises) it should be reasonably obvious that there is a high injury risk for clients with very little resistance training experience. If you’re considering using kettlebell training with any of your clients then adhere to the following guidelines:
- Focus initially on instructing clients how to squat. Only move into kettlebell training exercises once clients can squat safely and effectively (the squat movement is used in most kettlebell training exercises)
- Focus on building strength and endurance in your clients’ core musculature and in particular their ability to hold an abdominal ‘brace’. The abdominal brace locks the lumbar spine safely in neutral and protects it from injury during any type of movement.
- Once clients are able to brace and squat effectively then use light kettlebells initially and focus on instructing safe technique with all kettlebell exercises before adding extra load.
Basic Energy System Recap
If your understanding of the human energy systems is ‘somewhat rusty’ then please refresh your knowledge by visiting the energy systems folder at ptdirect.com where you’ll find all the information you need to understand the human energy systems.
In order to generate explosive power, energy comes almost exclusively from the ATP-PC energy system. After approximately 15 seconds of very high intensity exercise, energy is supplied at a slower rate predominantly from the anaerobic glycolytic system.
When energy is supplied at a slower rate, the body isn’t able to produce maximal or near maximal power. So if you have a client trying to produce explosive power with moderate – heavy loads, after about 10-15 seconds of exercise you’d see their power output start to drop – their repetitions would become slower, and their safe technique might be jeopardized in an attempt to generate more power, or to resist momentum as the kettlebell returns to the start position after each swing.
Often in the fitness world personal trainers push their clients to do more repetitions, to ‘feel the burn’ or to get out of their comfort zone. This mentality (unfortunately seldom challenged) represents a lack of understanding of the human energy systems. You see, any type of training which relies predominately on the ATP-PC system such as kettlebell training will be characterised by short sets, with long rests in between. Where the aim of the training is to generate lots of power then sets should finish as soon as the repetitions start to slow and/or safe technique cannot be maintained (this should correspond with ATP-PC energy system fatiguing at around 10-15 seconds).
If the sets were to last in excess of 15 seconds then it would be important to ensure that the loads being lifted were lighter to ensure that safe technique could be maintained at all times during the set(s).
Who is Kettlebell Training suitable for?
The simple reality is that the complex Olympic style lifts and explosive power oriented exercises that characterise kettlebell training make it much more suited to clients with significant resistance training experience. It may well be that kettlebell training is more suited to you than to any of your clients!
Sure, you can help your clients learn how to squat and brace their core muscles, and start learning kettlebell training with light weights, but you must ask yourself the question – will my clients enjoy this, and will it produce the results they desire quicker than any other types of training?
Try to remember that kettlebells are simply tools and kettlebell training is one of many training options available to you. Great personal trainers will always use the tools that are most suited to each client and the individual goals each client is trying to achieve.
So as traditional kettlebell training is oriented on increasing power then is it suited to the majority of personal training clients who simply want to lose weight and increase muscle tone? Let’s not forget that kettlebell training exercises are multi joint and use most of the large muscle groups in the body. So if your clients are capable of doing kettlebell training safely it could be a very effective means of burning calories and firming muscles.
The vital considerations however come back to whether your clients are capable of performing kettlebell training exercises safely, and are willing to do so. Bear in mind that if the majority of your personal training sessions are made up of you instructing technique then the clients won’t be burning any calories, and will likely be becoming increasingly frustrated at their lack of progress…and it won’t be long before they are ‘former clients’.
So choose your training tools wisely, and always choose exercises with the best interests of your clients in mind! If you determine that your clients are capable of, and would benefit from some kettlebell training (or perhaps you'd like to give it a go) then check out some 'Kettlebell training exercises in action' here.