Kettlebell training in clinical practice: a scoping review

Enhancing Athletic Performance: A Comprehensive Review on Kettlebell Training

A kettlebell is a weight made of cast iron shaped like a ball with a handle. Commercial kettlebells are offered in capacities that vary from 3 pounds to 100 pounds (or more). The kettlebell has a variety of possible clinical applications, including dynamic flexibility exercises and power training. Players' efficacy during the game can be improved by developing their strongest potential prior to exercising and efficiently converting that strength to power as the event draws near. Strengthening has been recommended as an effective means to avoid injuries, build muscle strength, and enhance one's health in relation to performance in the game. This type of training focuses on the hip, thigh, core, and abdominal muscles to help with appropriate lower-limb alignment and the recruitment of muscle patterns. Kettlebell training is a flexible and useful strategy for improving players' performance in a variety of sports. It adds value to athlete training programs by enhancing strength, power, endurance, explosive power, and postural coordination.

Electromyographic analysis of shoulder-complex muscles performing overhead presses with dumbbell, kettlebell, and bottom-up kettlebell

INTRODUCTION

Kettlebell exercises, specifically the bottom-up grip, have become increasingly popular in training programs. The purpose of this research was to determine if a bottom-up kettlebell grip favorably alters the electromyography (EMG), activity in the medial deltoid (MD), serratus anterior (SA), and lower trapezius (LT), muscles compared to using a dumbbell or traditional kettlebell grip during overhead shoulder presses.

METHODS

Twenty-eight healthy, male, Division III collegiate baseball players (mean age = 19.8 ± 1.28 years) performed five overhead presses of equal weight, 11.34 kg (25 lbs), using a dumbbell (DB), kettlebell w/traditional grip (KB), and kettlebell held with a bottom-up grip (KBU).

RESULTS

For the MD, there was significantly greater EMG activity using the DB compared to KBU, but no significant differences between the DB and KB, or KB and KBU. For the SA, greater EMG activity was noted using the KBU compared to KB, and KBU compared to DB, but no differences between KB and DB. For the LT, greater EMG activity was noted using the DB compared to KB, but no differences between DB and KBU, or KB and KBU.

CONCLUSION

The KBU press only elicited greater EMG activity in the SA. The DB elicited greater EMG activity in both the MD and LT. Shoulder-complex EMG activity varies with different types of overhead presses using equivalent loads.

Effects of 56-Kilogram Kettlebell Swing Endpoint on Total Body Mechanics

ABSTRACT

Ross, JA, Keogh, JWL, Lorenzen, C, and Lake, J. Effects of 56-kilogram kettlebell swing endpoint on total body mechanics. J Strength Cond Res 37(12): 2333-2338, 2023-In the past 2 decades, kettlebell training popularity has increased and the range of kettlebells has expanded to 2-92 kg. However, commercially available kettlebells above 56 kg have 12 kg increments, so alternatives to load are required to provide a suitable way of increasing training stimulus until the athlete is strong enough for a load increase. This study aimed to determine the differences in the force plate-derived biomechanical characteristics of heavy kettlebell swings to 3 different heights, as altering the height of the kettlebell swing may be one way to alter the mechanical demands with the same kettlebell mass. Fifteen resistance-trained men performed the kettlebell swing to acromion process height (AH), acromion process height + 20% (AH+20), and acromion process height-20% (AH-20). Swing height significantly affected vertical braking and propulsion phase net impulse and displacement, vertical braking velocity, and braking and propulsion work but not braking and propulsion duration. Altering kettlebell swing trajectory endpoint is a method to regress/progress the demands of kettlebell training. Coaches may be able to alter the acute demands and likely chronic adaptations of kettlebell training by prescribing different swing heights and kettlebell masses to their athletes.

Body Composition and Strength Symmetry of Kettlebell Sport Athletes

Kettlebell sport (KBs) is increasingly popular, but very few studies have been focused on this discipline. This research aims to investigate the effects of KBs on body composition, strength symmetry, and segmental body composition symmetry in a sample of Italian elite athletes. Data were collected from a sample of 16 athletes of both sexes (11 men and 5 women; 34.5 ± 9.0 years of age). Anthropometric (height, weight, arm, thigh, calf, and waist circumferences), hand grip strength, and total and segmental bioelectrical variables were taken. Body composition was analysed by using specific bioelectrical impedance vector analysis (BIVA). Paired t-tests and confidence ellipses were applied to analyse bilateral differences. Elite athletes of both sexes showed high values of phase angle, indicative of high body cell mass and quality and proxy of muscle mass. Hand grip strength and body composition were symmetrical, with the only exception of a higher %FM in the right leg (Zsp: t = 3.556; p = 0.003). In conclusion, this study suggests that KBs contributes to muscle mass improvement, body composition, and strength symmetry, especially in the upper body.

Self-directed kinematic adjustments when learning the kettlebell swing in young adults

The kettlebell swing is a complex exercise shown to provide cardiovascular and strength benefits. However, novice kinematic pattern differences might limit the effectiveness of the kettlebell swing to fully realise those benefits. The purpose of this study was to assess how novices self-directed their learning of the kettlebell swing using only an instructional video. Twelve young adults performed kettlebell swings sets over one week. We captured kinematic data of their first sets without practice, sets within-day following practice, and sets one week later following practice. The subjects received no augmented feedback. Ankle, knee, hip, and shoulder mean and variability kinematics were compared. In addition, the relative timing of peak sagittal plane angular velocity of the hip and shoulder was evaluated to determine whether the hips led to the shoulders. Within-day subjects reduced hip and shoulder peak extension, knee and hip peak flexion, and hip peak flexion velocity. Between-day subjects reduced mean hip peak flexion and range of motion, as well as peak knee flexion. Our results suggest novices prioritised improving consistency early in practice and then adjusted their kinematic pattern over the week. Moreover, most subjects transitioned to the hips leading shoulders, suggesting this is a perceivable coordination pattern by intrinsic feedback.

The Effect of the Weight and Type of Equipment on Shoulder and Back Muscle Activity in Surface Electromyography during the Overhead Press-Preliminary Report

The overhead press is a multi-joint exercise that has the potential to use a high external load due to the cooperation of many muscle groups. The purpose of this study was to compare the activity of shoulder and back muscles during the overhead press with a kettlebell and a dumbbell. Surface electromyography (EMG) for the anterior and posterior deltoid, upper and lower trapezius, serratus anterior, and spinal erectors was analysed for 20 subjects. Participants performed the four trials of pressing kettlebell and dumbbell, weighted at 6 kg, and 70% of one maximum repetition (1RM) in the sitting position. Statistical analysis was performed using a non-parametric Friedman test and a post-hoc test of Dunn Bonferroni. No significant differences were found in the activation of assessed muscles when comparing dumbbell to kettlebell press trials with the same load (6 kg and 70% of 1RM). However, muscle activity of all muscles except the upper trapezius was always higher for kettlebell pressing. Different center of gravity locations in the kettlebell versus the dumbbell can increase shoulder muscle activity during the overhead press. However, more studies are required to confirm these results.

Effects of Kettlebell Load on Joint Kinetics and Global Characteristics during Overhead Swings in Women

This study sought to identify the changes in ankle, knee, and hip joint kinetics with increasing load while performing the kettlebell overhead swing (OHS). Women (n = 18, age: 29.4 ± 5.3 years, 69.7 ± 8.9 kg) with a minimum of 6 months of kettlebell swing training experience performed fifteen repetitions of the kettlebell OHS with three different kettlebell masses (8 kg, 12 kg, 16 kg) in a counterbalanced order. Ankle, knee, and hip joint kinematics were captured within a 12-camera infrared motion capture space, while standing atop two force plates collecting ground reaction force (GRF) data. Post hoc results of statistically significant joint by mass interactions (p < 0.05) of the net joint moment impulse, work, and peak power revealed the hip demonstrating the greatest increase in response to load, followed by the ankle (p < 0.05). The knee joint kinetics changed very little between the masses. Pairwise post hoc comparisons between the joints at each mass level support the kettlebell OHS as being a hip dominant exercise, with the knee making the second largest contribution, despite contributions not changing across kettlebell masses. Collectively, these results provide practitioners with objective evidence regarding the mechanical demands and effects of load changes on the kettlebell OHS.

Reliability of kettlebell swing one and five repetition maximum

Background

Research into the kettlebell swing has increased in the last decade. There has been a paucity of literature assessing an individual's ability to perform the kettlebell swing exercise. The purpose of this study was to determine the test-retest reliability of the one and five repetition maximum (1RM and 5RM) kettlebell swing.

Materials & Methods

Twenty four recreational resistance-trained participants performed an isometric mid-thigh pull (IMTP) and two familiarization sessions followed by three test sessions for each RM load approximately one week apart, using a custom-built plate-loaded kettlebell. On each test occasion, subjects completed a series of warm-up sets followed by 3-4 progressively heavier kettlebell swings to a standardized height until 1RM or 5RM was reached. Test-retest reliability was calculated using the intra-class correlation (ICC) and typical error was represented as the coefficient of variation (CV%) with 90% confidence limits (90% CL). The smallest worthwhile change (SWC%) representing the smallest change of practical importance, was calculated as 0.2 × between-subject standard deviation. The relationship of kettlebell swing performance and maximum strength was determined by Pearson correlation with ±90% CL between the absolute peak force recorded during IMTP and 1RM or 5RM.

Results

Results demonstrated a high test-retest reliability for both the 1RM (ICC = 0.97, 90% CL [0.95-0.99]; CV = 2.7%, 90% CL [2.2-3.7%]) and 5RM (ICC = 0.98, 90% CL [0.96-0.99]; CV = 2.4%, 90% CL [1.9-3.3%]), respectively. The CV% was lower than the SWC for both the 1RM (SWC = 2.8%, 90% CL [1.9-3.5]) and 5RM (SWC = 2.9%, 90% CL [1.9-3.6]) kettlebell swing. The correlation between IMTP absolute peak force and the 1RM (r = 0.69, 90% CL 0.43-0.83) was large and very large for the 5RM (r = 0.75, 90% CL [0.55-0.87]).

Conclusions

These results demonstrate the stability of 1RM and 5RM kettlebell swing performance after two familiarization sessions. Practitioners can be confident that changes in kettlebell swing 1RM and 5RM performance of >3.6 kg represent a practically important difference, which is the upper limit of the 90% CL.

Effects of supervised high-intensity hardstyle kettlebell training on grip strength and health-related physical fitness in insufficiently active older adults: the BELL pragmatic controlled trial

The Ballistic Exercise of the Lower Limb (BELL) trial examined the efficacy and safety of a pragmatic hardstyle kettlebell training program in older adults. Insufficiently active men and women aged 59–79 years, were recruited to a 6-month repeated measures study, involving 3-months usual activity and 3-months progressive hardstyle kettlebell training. Health-related physical fitness outcomes included: grip strength [GS], 6-min walk distance [6MWD], resting heart rate [HR], stair-climb [SC], leg extensor strength [LES], hip extensor strength [HES], Sit-To-Stand [STS], vertical jump [CMVJ], five-times floor transfer [5xFT], 1RM deadlift, body composition (DXA), attendance, and adverse events. Sixteen males (68.8 ± 4.6 yrs, 176.2 ± 7.8 cm, 90.7 ± 11.0 kg, 29.2 ± 2.6 kg/m²) and sixteen females (68.6 ± 4.7 yrs, 163.9 ± 5.4 cm, 70.4 ± 12.7 kg, 26.3 ± 4.9 kg/m²) were recruited. Compliance with the supervised exercise program was very high (91.5%). Kettlebell training increased GS (R: MD = 7.1 kg 95% CI [4.9, 9.3], L: MD = 6.3 kg 95% CI [4.1, 8.4]), 6MWD (41.7 m, 95% CI [17.9, 65.5]), 1RM (16.2 kg, 95% CI [2.4, 30.0]), 30 s STS (3.3 reps, 95% CI [0.9, 5.7]), LES (R: MD = 61.6 N, 95% CI [4.4, 118.8]), HES (L: MD = 21.0 N,95% CI [4.2,37.8]), appendicular skeletal lean mass (MD = 0.65 kg, 95% CI [0.08, 1.22]), self-reported health change (17.1%, 95% CI [4.4, 29.8]) and decreased SC time (2.7 s, 95% CI [0.2, 5.2]), 5xFT time (6.0 s, 95% CI [2.2, 9.8]) and resting HR (7.4 bpm, 95% CI [0.7, 14.1]). There were four non-serious adverse events. Mean individual training load for group training sessions during the trial was 100,977 ± 9,050 kg. High-intensity hardstyle kettlebell training was well tolerated and improved grip strength and measures of health-related physical fitness in insufficiently active older adults.

Trial registration: Prospectively registered: 20/08/2019, Australian New Zealand Clinical Trials Registry (ACTRN12619001177145).