In this blog I will cover a number of areas that make up work capacity and its importance to kettlebell sport. Each of these individual areas are quite large, therefore I’ll only cover them briefly in this blog. Kettlebell sport is renowned for requiring huge volumes of work to be performed. It’s not uncommon to have tonnage for a single set of over 3-4 tonnes, and even over 10 tonnes within a single training session. But of course building up to this volume of work can be quite a lengthy process. Remaining injury free while being able to perform a large amount of work in both training and competition are of paramount importance to kettlebell sport. In this post I’ll look at five things that can and will affect work capacity. These include energy systems, strength, training history, movement variability and a model of fatigue that is applicable to GS.

Energy systems are a key factor within kettlebell sport and below we will take a look at a very simple breakdown of aerobic and anaerobic energy systems:

Aerobic

During a GS set you want as much energy as possible to come from the aerobic system. The aerobic system uses oxygen and can be sustained long term. During a GS set if you hold a steady pace you will most likely sit on an intensity known as your ‘lactate steady state’ for that given exercise (provided that your strength and technique aren’t issues). At your lactate steady state you are able to sustain this pace because you are able to use and clear the by-products of the anaerobic system at the same rate in combination with the aerobic system. So if we were to think about the intensity lactate curve we want to shift it to the right (to increase the workload of the aerobic system before it calls upon the anaerobic system). This would increase the intensity before you were required to call upon the anaerobic energy system, (see figure 1). Additionally, the aerobic system is needed to recover from fatiguing efforts involving the anaerobic system, making it key for biathlon and increasing training density.

Figure 1, of the lactate intensity curve. This is taken from ‘Physiological Tests for Elite Athletes’.

Anaerobic

The anaerobic system can rapidly produce energy without oxygen, however it can quickly cause fatigue. The key benefit of training this system is to increase the amount of lactate/by-products we can produce and buffer/clear. This can be more easily trained than Vo2max and help both your overall pace (threshold) and your ability to sprint within the last minute of a set. In a previous post, I wrote about a modified anaerobic speed reserve (think 10 minute pace vs 1 minute pace), by having a larger anaerobic speed reserve. This may allow you to get out a few extra reps within the last minute. Energy systems are key to any GS competition from 5 minutes to an hour long event. They will also allow you to perform more work within a session and promote recovery between sessions.

Strength

Strength is another key component (or bio-motor ability) that is needed for kettlebell sport. Kettlebell sport is often referred to as a strength/power endurance sport. Increasing your maximal strength will often increase your 20RM (a 20RM is a common test of strength endurance). Within kettlebell sport we try to pace ourselves to avoid fatigue and prolong strength. I have found strength/strength endurance to be extremely useful for building up to 60 reps. Also, strength training will have a number of helpful effects within the muscles. Firstly, there is some plasticity within type two muscle fibres. Type two fibres are also called fast twitch fibres as they are most powerful and have less endurance compared to the slow twitch fibres. Simply, within the type two fibres there are two main fibre types, B (fastest) and A (relatively slower with more endurance). Strength training that simulates type two B fibres causes them to become type two A. Type two A muscle fibres are more fatigue resistant and have greater aerobic capacity then type two B. Strength training will also affect the motor unit behaviour (a motor unit is made up of the nerve and the muscle fibres it controls). Maximal strength training and strength speed training can promote motor unit synchronization. When muscles are synchronized, this means that they work together. Being stronger will lower the percentage of your 1RM relative to the weight of the kettlebell. This means that each rep will be less demanding, which will increase your work capacity. Additionally, strength training can increase musculotendinous stiffness and increase reactive strength. All these factors are very useful, particularly for increasing leg speed within the jerk, thus increasing efficiency.

Training history

Training history is a term used to summarise your training life, the last month and last week can all affect your work capacity. Your training age refers to the cumulative total of years you have been training over your life, and generally the greater your training age, the more resistant to injury you will be. Chronic training load (compared to acute training load) can be a very useful measure for preventing injuries. Training load can be measured a number of ways, session RPE (rate of perceived exertion) is a common way to do this. Chronic training load refers to the average of the previous four weeks training, whilst the acute training load refers to the current weeks training. Large jumps within an acute training load may increase an individual’s risk of injury.

The ‘repeated bout effect’ offers a protective effect to a specific exercise (or eccentric muscle actions) that has been performed recently. By keeping your exercise selection consistent you will protect against muscle damage during a session and this will in turn be very important in increasing work capacity as muscle damage will reduce the efficiency of exercises. You can use this principle to your advantage at times (i.e. running after a session to make an easy run become harder), however it will reduce the amount and quality of your work. Also, the repeated bout effect is important when switching events, as the new event may not have the full protective effect.

Movement variability

A famous Russian scientist – Nikolai Bernstein, has coined the phrase “repetition without repetition”,. He developed a classic study on movement viability where he looked at working blacksmiths. In this study it was suggested that the blacksmiths (see figure 2) could work for hours on end without suffering overuse injuries, by using slight variations within their motion. However, they had low end point variability, meaning that they would hit precisely where they wanted with their hammer in different ways. Other research has indicated that there may be an optimal amount of variability, I.e. either too little or too much to be negative.

Figure 2. Black smith trajectory of striking an anvil.

With respect to GS, we can think about a few different types of variability; 1 – end point variability (fixation), 2 – working point variability (the trajectory of the kettlebell), 3 – co-ordination (how the body/joints move). Within many different skills or exercises, movement variability follows similar patterns within different stages of learning:

Beginner – lots variability across all three areas (some right, some wrong)

Intermediate – low variability (know fewer ways to perform the skill correctly)

Advanced – increased/optimal co-ordination variability (to a point), with low working and end point variability

Increased co-ordination variability and low end point variability would suggest that there are slight variability’s within the contribution of the different joints, i.e. in the snatch – more torso rotation/less elbow flexion etc. From an endurance standpoint, slightly spreading the stress across different joints will change the amount of work performed by relevant muscles. This in turn may prolong performance, oscillating stresses placed upon different muscle groups.

Using the jerk as an example, we want to use the optimal amount of energy to lock the kettlebells out enough in the second dip. If you apply less power in the first dip will you need a deeper second dip and vice versa. I find that if I use a smaller first dip, I use a greater chest bump, in the hope of sparing my legs. For the most part – we want to use the least amount of energy. However, it may come down to a choice between bigger/smaller, first/second dip. Naturally you will have slight changes in the first and second dips, so over time finding the optimal balance between the two is the goal. Additionally, you may need to increase one or another as fatigue sets in.

I remember the feeling of being ‘stuck’ under the bells for the last minute of a set I was doing, as I felt as though I could not produce enough force to get under them. Now that I have more experience, I would happily keep going whilst modifying my technique to accommodate this by increasing the depth of my second dip. This would suggest that I was in that ‘intermediate’ category, as I could perform the exercise, however I couldn’t modify my technique to continue my performance. Optimal technique may also be specific to the degree of fatigue/minute of your set. The classic example of this is what Arseny Zhernakov termed ‘survival style’. In the snatch, ‘survival style’ is where elite lifters often adopt more of a squat backswing with the bell getting closer to the ground. Additionally, some use a second dip during hand insertion phase, however they can still maintain very good fixation. In contrast, a novice might have very poor fixation and need to stop to avoid injury. My first paper looked at the trajectory and its variability within elite kettlebell sport athletes. As expected, we found the kettlebell to have its lowest variability in fixation, it was particularly low in the vertical plane, to the point that one of the lifters was even within 1 mm for the reps we tested.

Figure 3. From my first paper looking at trajectory of the kettlebell snatch within elite lifters.

Fatigue

There is definitely a mental element to work capacity and GS itself. There are eight different modes of fatigue (I will look at them in another blog, I’m planning to do a new series on load management where I’ll go into greater detail regarding this area.). For now, I will talk about the one most applicable to work capacity, which is the central governor mode of fatigue. Briefly, the central governor mode of fatigue involves both a feed-forward and feed-back component. The feed-forward is the pace setting going off the body’s past experiences, i.e. 10 minute set pace. Feed-back is the body telling the brain what’s going on in real time within the muscle and other systems. The brain might be getting messages from the muscle telling it to slow down, however in competition, people may over run this.

Hopefully, these five points give you some interesting things to think about within your kettlebell sport training.