The Role of Kettlebells in Strength and Conditioning: A Review of the Literature Chris Beardsley, MA (Hons)1 and Bret Contreras, MA2 1Strength and Conditioning Research Limited, Loughborough, Leicestershire, United Kingdom; and 2School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand ABSTRACT and power, and whether they are useful measured by the half squat and counter- for improving aerobic fitness. Addition- movement jump. The subjects performed STUDIES SUPPORT THE USE OF ally, researchers have been interested in Pavel Tsatsouline’s Program Minimum KETTLEBELLS FOR IMPROVING several biomechanical factors (muscle protocol with 16-kg kettlebells for men POWER, ALTHOUGH EVIDENCE activity, ground reaction forces, lumbar over 70 kg of body weight and 12-kg FOR USING THEM TO IMPROVE motion, and spinal loading) associated kettlebells for men under 70 kg of body STRENGTH AND AEROBIC FITNESS with various kettlebell movements, with weight (see Tsatsouline (20)). It was IS STILL EQUIVOCAL. STUDIES the kettlebell swing being the most com- found that both programs improved INVESTIGATING THE BIOMECHANI- monly researched exercise. maximum and explosivestrengthsignifi- CAL PROPERTIES OF KETTLEBELL cantly and to the same extent. It is pos- TRAINING HAVE BEEN FRUITFUL, sible that the positive results observed by CHRONIC EFFECTS OF AND IT MAY BE USEFUL FOR KETTLEBELL TRAINING ON the program implemented by Lake and DEVELOPING SPRINT RUNNING STRENGTH AND POWER Lauder (10) arose as a result of the PERFORMANCE AND FOR INJURY Several investigations have looked at heavier weights used, which may have PREVENTION. HOWEVER, WE STILL strength and power changes with resulted in a greater training stimulus DO NOT KNOW THE OPTIMAL chronic kettlebell training. Jay et al. and therefore more significant adapta- LOADS FOR MAXIMIZING SYSTEM (8) investigated the effects of kettlebell tions. Similarly, Otto et al. (16) compared AND JOINT POWER PRODUCTION, training on postural coordination and the effects of a 6-week, 2 days per week, HOW THE MECHANICS, JOINT countermovement jump height in weightlifting or kettlebell program on MOMENTS, AND ELECTROMYO- untrained subjects. They implemented maximum strength (as measured by the GRAPHIC ACTIVITY CHANGES AS a standard 8-week kettlebell training back squat) and explosive strength (as LOADS INCREASE DURING KET- program involving progressions from measured by the vertical jump and power TLEBELL SWINGS, NOR WHETHER the unweighted swing to the kettlebell clean) in resistance-trained subjects. The kettlebell group performed kettlebell KETTLEBELL TRAINING TRANSFERS deadlift, to the 2-handed kettlebell swings, accelerated swings, and goblet TO SPORTS PERFORMANCE. swing, and finally to the 1-handed kettlebellswing.Malesubjectsuseda squats with a 16-kg kettlebell, whereas 12-kg kettlebell, and female subjects the Olympic-style weightlifting group INTRODUCTION used an 8-kg kettlebell. The program performed back squats and Olympic- he use of kettlebells in the did not significantly improve counter- style pull variations. Although both United States is a recent phe- movement jump height in comparison groups improved vertical jump similarly, T nomenon. As a result, research- with a control group. In contrast, Lake ers have just started to investigate the and Lauder (10) compared the effects of KEY WORDS: utility of kettlebells in strength and con- a 6-week program of kettlebell swing kettlebell swing exercise; sprint running; ditioning programs over the last few training with a similar program of jump horizontal jumping; hamstrings; gluteus years. Of primary interest is whether ket- squats in resistance-trained athletes on maximus; hip extensors tlebells can be used to develop strength maximum and explosive strength, as 64 VOLUME 36 | NUMBER 3 | JUNE 2014 Copyright Ó National Strength and Conditioning Association and both groups improved strength strength measures. Two of the studies a maximum kettlebell 5-minute snatch measures, the group that performed compared kettlebell exercises with test, a maximum treadmill test, and weightlifting improved back squat and more traditional methods. One of these heart rate response and energy cost power clean by a greater amount than found that kettlebells produced similar during a less intense 20-minute kettle- the kettlebell group. This seems to sug- results, and the other found that kettle- bell workout. They found that tread- ̇ 21 21 gest that weightlifting leads to superior bells produced inferior results. Three of mill VO2max was 38.9 mL$kg $min , ̇ improvements in vertical sports-specific the 4 studies investigating power trans- whereas the kettlebell VO2max was 2 2 performance than kettlebell training. fer found that kettlebells improved 31.6 mL$kg 1$min 1, which was ̇ However, the weightlifting group per- measures of power. Two of these stud- 81.2% of the treadmill VO2max. During formed a greater volume of work and ies compared kettlebells with more tra- the standard 20-minute workout, they trained with greater specificity to ditional methods and both found that found that heart rate averaged 164 6 these 2 tests. Manocchia et al. (12) kettlebells produced similar results to 15 beats per minute, which equated to investigated the carryover of kettle- traditional methods of power develop- 93 6 4.5% of maximum heart rate. Farrar bell training to strength and endur- ment. Although the evidence is still et al. (3) also measured oxygen cost and ance on traditional lifts compared very sparse, it seems that kettlebell the heart rate response during a com- with a nontraining control group training is more likely to demonstrate monly used 12-minute kettlebell exercise using a 10-week periodized program useful improvements in power than in routine and compared the results with ̇ training twice per week in resistance- strength, however it is noted that in all the VO2max and heart rate response trained subjects. The workouts com- of these studies, very light weights measured during a maximal treadmill prised a wide range of exercises and were used, and it is likely that different test. The researchers found that during included non-kettlebell exercises such results might have been achieved using the kettlebell exercise bout, the oxygen 2 2 as push-ups. The kettlebell group heavier loads. cost was 34.3 6 5.7 mL$kg 1$min 1, improved their bench press 3 repeti- which was 65.3 6 9.8% of the measured ACUTE AND CHRONIC EFFECTS OF ̇ tion maximum (RM) and their clean VO max during the treadmill test. The KETTLEBELL TRAINING ON 2 and jerk 3RM significantly in compar- CARDIOVASCULAR MEASURES measured heart rates were similar to ison with the nontraining control, Several investigations have looked at those reported by Schnettler et al. (19) 6 thereby demonstrating increases in either chronic changes in cardiovascu- at 165 13 beats per minute, which was 6 both strength and power. Finally, lar fitness or the acute physiological 87 6% of maximum heart rate. Husley Jay et al. (7) performed a study com- responses to kettlebell training. Jay et al. (6) examined the oxygen consump- paring the effects of 3 days per week et al. (7) performed a study comparing tion and the heart rate response during of kettlebell interval training over 8 the effects of 3 days per week of kettle- a typical 10-minute kettlebell swing rou- weeks with a control for improving bell interval training over 8 weeks with tine and compared it with a treadmill run measures of back, neck, and shoulder a control for improving measures of at an equivalent rating of perceived exer- pain, as well as back extensor strength back, neck, and shoulder pain, as well tion (RPE). The researchers observed in untrained subjects. The pain inten- as aerobic fitness in untrained subjects. that oxygen consumption was signifi- sity of the lower back and the muscu- They did not notice any change in aer- cantly higher for treadmill running 6 $ 21$ 21 lar strength of the back extensors obic fitness in relation to a control (46.7 7.3 mL kg min )than 6 improved more in the intervention group over the 8-week period. How- for kettlebell swings (34.1 4.7 21 21 groupthaninthecontrolgroup. ever, the workouts used began with pro- mL$kg $min ). In fact, the average In summary, to date, we have found 5 gressions from the unweighted swing to oxygen consumption during the ket- studies that have investigated the the kettlebell deadlift, then to the tlebell workout was 73% of the oxygen effects of kettlebell training on meas- 2-handed kettlebell swing, and finally consumption during the treadmill ures of strength and power (Jay et al. to the 1-handed kettlebell swing. Male workout at the same RPE. In regards (8), Lake and Lauder (10), Otto et al. subjects used a 12-kg kettlebell, and to heart rate response, Husley et al. (6) 6 (16), Manocchia et al. (12), and Jay female subjects used an 8-kg kettlebell. found that heart rate averaged 89 et al. (7)). Four of the studies investi- The use of unloaded progressions to 5.3% of age-predicted maximum for gated the effects on power production begin with and the relatively light loads the kettlebell workout and was similar 6 (Lake and Lauder (10), Otto et al. (16), in comparison with other studies may for both kettlebell (180 12 beats 6 Manocchia et al. (12) and Jay et al. (8)), have resulted in inadequate training per minute) and treadmill (177 11 and 4 of the studies investigated the stimulus to produce any adaptations. beats per minute) workouts. effects on strength (Jay et al. (7), Lake Three studies have investigated the In summary, only 1 study (Jay et al. (7)) and Lauder (10), Otto et al. (16), acute physiological responses to ket- so far has investigated the effect of a ket- Manocchia et al. (12)). All 4 studies tlebell training. Schnettler et al. (19) tlebell program on aerobic fitness and ̇ investigating strength transfer found investigated VO2max, heart rate found that it had no measurable effect.