I moved to Canada at a time when I had just read The Way To Live by George Hackenscmidt and The Text-book of Weightlifting by Arthur Saxon. Both books contained the quote, “Train outside as much as possible, in as little clothes as possible.” There is a lot of research on the effects of sun exposure and fresh, clean air. There is really good coverage of a lot of that research in the book The Healing Sun: Sunlight and Health in the 21st Century, by Richard Hobday. Well, to make a long story short, when I moved to Canada I decided to do my own lifting outside. My gym consists of kettlebells, dumbbells, a pull up bar, a sledgehammer, fat gripz, chains, and a large rope. A few years ago, I spoke to a local strength coach who asked me about my own training.
“I do a lot of kettlebell lifting,” I said.
“What kind of kettlebell exercises do you use with the athletes you work with?” was his next question.
“I have rarely used kettlebell exercises with the athletes that I have worked with,” I said.
He was baffled that I did not use the exercises that I personally liked with the athletes I trained. The principle of not having any emotional attachments to any exercises or equipment is a key principle in The Flexible Periodization Method. It took several years, including a few incidents, from hearing the principle for the first time, until I truly felt that I was embracing it in practice. Working with this principle means that at a given point in time, for a given athlete, we use our knowledge about the athlete, about physiology, biomechanics, etc., to choose the exercises that to the highest degree possible will help the athlete towards the accomplishment of the stated goal.
If another strength coach looked at ten of your programs, made for different types of athletes, he should not be able to see what kind of background you have or what courses you have taken. The programs should be different from each other, therefore a total fit for the individual athlete and only recognizable by the results they produce. The reason that I have rarely used kettlebell exercises with the athletes that I have worked with is simply that in most cases it has been my estimate, based on the knowledge available, that kettlebell exercise were not the best choices in that particular situation. That does not mean that I don’t think kettlebell exercises are effective, in fact there is quite a bit of research on the kettlebell swing that indicate some interesting effects.
In the rest of this column as well as the next, we will review some of this research and include take away messages. The third column will show in more detail how this information might be applied to training programs created with The Flexible Periodization Method.
Study #1:
Five healthy males with some kettlebell (KB) training experience performed various KB exercises including single-arm swings and single-arm snatches with 16 kilos. The study was motivated by lifters reporting both decreased and increased back pain with KB swings. Electromyography activity and forces on the spine were analyzed during the concentric phase of the first repetition.
Results
Low to moderate compressive forces, significant L4-L5 posterior shear forces (L4 moving backwards in relation to L5). Single-arm swings with the right hand creates a rotational torque towards the left that must be stabilized. Swings of increased height with a KB of the same load results in higher electromyographic activity in agonist muscles. (1)
Discussion
Possibly to do the significant horizontal displacement of the KB the ratio of shear (both anterior and posterior) in relation to compression is much higher in the KB swing compared to, for example, deadlifts. The posterior shear seen in this study is explained by the action of the lumbar portions of the longissimus and iliocostalis group (McGill, S – personal communication). The author’s emphasize that the ability to handle this shear is critical to the safe performance of swings.
Take away message
Most athletes will soon reach a level of strength where they would have to use a higher load than 16 kilos in order to stimulate a training response. An increased training stimulus can be accomplished by swinging the weight higher. However, one might avoid the vertical position as the KB could flip over the hand. It could be speculated that if the training with swings is initiated conservatively, the ability to stabilize the mentioned shear forces is built gradually and the swings will have a back stabilizing effect. The single arm swings could be used as an anti-rotational exercise.
The video below shows a progression of partial swings to hip height, waist height, and ribcage height that can be used to build the ability to stabilize against the mentioned shear forces.
Study #2
Ten recreationally active, college-aged males with minimal KB experience performed a V02max test on a treadmill. The participants received instruction in the two-handed KB swing and on a separate occasion they performed “as many swings as possible” in 12 minutes.
Results
During the 12 minutes of KB swings the heart rate reached an average of 87 percent of the maximal heart rate.
Discussion
It was concluded that two-handed KB swing can provide a training stimulus sufficient to increase V02max.(2) The subjects were not trained runners, thus their V02max could have been underestimated during the treadmill test. If the VO2max was underestimated, the relative intensity during KB swings would be overestimated. The average heart rate would be expected to change with the frequency of swings as well as the load used.
Take away message
Two-handed KB swings could provide a strong enough cardio respiratory stimulus to improve VO2max. If you are a strength coach and want to use two-handed KB swings to improve VO2max for your athletes, you should confirm, with heart rate measurements, that your athletes are in the proper HR zone for the necessary amount of time.
To help your athletes achieve “as many swings as possible” within a certain time-frame, you might consider to teach them to actively PULL the KB down and back instead of simply letting gravity do the job.
Study #3
Thirteen moderately trained participants (11 males + 2 females) with no KB swing experience performed 10 sets of 35 seconds, two-handed swings in a “steady rhythm.” They were given 25 seconds of rest between each set. The men used a 16 kg KB and the females used an 8 kilo KB. On a separate day the subjects completed a 10-minute treadmill run, where the speed was adjusted to create a rate of perceived exertion similar to the KB swings.
Results
The average heart rate was 89-90 percent of age predicted max respectively, but oxygen consumption and caloric expenditure were significantly higher during the treadmill run.
Discussion
The authors emphasize that the comparison could have looked differently with different training protocols.(3)
Take away message
Yet another study indicating that two-handed KB swings can be a strong enough stimulus on the cardiorespiratory system to improve VO2max. The 35 seconds on to 25 seconds off follows standard guidelines for work to rest ratios for aerobic training. Most likely ten sets would be in the low end with respect to volume. A guideline for intensities around 90 perecent of maximal heart rate is 15-20 minutes (or more) at the target heart rate, in this case equating to approximately 20-30 sets. However, applying efficient program design would use a circuit which would reduce the total time needed to have the heart rate in the 90 percent range for a total of 15-20 minutes.
Study #4
Twenty-four men, active in university sport and a minimum of three months resistance training experience, were taught two-handed KB swings. All subjects were tested for their 1RM half squat and vertical jump both before and after the training. Each participant was assigned to a KB training group or a jump squat training group. Each group trained twice per week for six weeks. The KB training consisted of 12 rounds of 30 seconds of swings (12-16 kilos depending on body mass) with 30 seconds of rest in between. The subjects were instructed to perform “as many swings as possible” during the 30 seconds. In the jump squat group, each person trained with the load that maximized peak mechanical power. Within the jump squat group peak mechanical power was maximized with 0, 20, 40 or 60 percent of the 1RM half squat. The set/rep combination differed depending on the load that maximized peak mechanical power output: 0-8 x 6, 20% - 6 x 6, 40% - 6 x 3, 60% - 4 x 3. During jump squat training the participants were encouraged to maximize the velocity of the bar.
Results
Both groups significantly improved their 1RM half squat, but the improvements in the kettlebell group were larger. Both groups also significantly improved their vertical jump, but in this case the jump squat group showed larger improvements.(5)
Discussion
The authors explain the effect of the KB swings on strength might be due to a unique strengthening of the trunk as well as the posterior chain muscles. Due to the horizontal component of the two-handed KB swing the authors speculate that KB swing may have a stronger effect on standing broad jump and potentially sprinting ability.
Take away message
Again, the results of the comparison depend on many factors, including fitness level and program design. What is particularly interesting here is that the two-handed KB swing can have a positive effect on the vertical jump, at least for low to moderately trained individuals. Thus, two-handed swings could be a possibility to develop the power needed to jump but at the same time minimize impact forces. Even more interesting is that the KB protocol used is similar to Study #2 and Study #3 that both resulted in a cardiorespiratory stimulus. Taken together, training with KB swings may simultaneously stimulate cardiorespiratory fitness and peak mechanical power—not a bad combo!
If you are using KB swings as a means to improve vertical jump ability and power, you might want to progress on load or on the height of the swing (see video below). Make sure that the athletes have normal range of motion in shoulder-flexion before applying this swing variation.
This column reviewed four research papers on kettlebell exercise and training with an emphasis on providing specific take away messages to immediately apply in program design.
The next column will continue this review with additional studies before showing how this information can be put together in the design of a training program with The Flexible Periodization Method.
References
- McGill S, Marshall LW. Kettlebell Swing, Snatch, and Bottoms Up Carry: Back and Hip Muscle Activation, Motion, and Low Back Loads. J Strength Cond Res. 26(1): 16-27. 2012
- Farrar RE, Mayhew JL, Koch AJ. Oxygen Cost of Kettlebell Swings. J Strength Cond Res 24(4): 1034-1036. 2010
- Hulsey CR, Soto DT, Koch AJ, Mayhew JL. Comparison of Kettlebell Swings and Treadmill Running At Equivalent Rating of Perceived Exertion Values. J Strength Cond Res 26(5): 1203-1207. 2012
- Jensen K. Block # 1 – Isolation – Stability- Structure. The Flexible Periodization Method. Chapter 2, p 146. The Write Fit. 2010.
- Lake JP, Lauder MA. Kettlebell Swing Training Improves Maximal and Explosive Strength. J Strength Cond Res 26(8): 2228-2233. 2012
