Page 58 - Journal of Special Operations Medicine - Winter 2016

When following a traditional PT program, an active-duty Several studies have evaluated the metabolic demands
member typically engages in 30 to 60 minutes of running of continuous KB swings to determine if the level of aer-
or walking 3–5 days per week, followed by muscular obic stimulus meets the ACSM recommendations for
1
strength and endurance training, specifically push-ups and cardiorespiratory exercise, or if KB swings can improve
sit-ups. Although traditional fitness training may be ad- aerobic capacity. 8–13 Farrar et al. reported an average
2
11
equate to meet fitness assessment standards, it has become intensity of 65% of maximum oxygen consumption
increasingly popular for active-duty members to engage in (Vo 2max ) during a 12-minute bout of two-handed KB
more nontraditional forms of training such as powerlift- swings in highly fit college-aged men that falls into the
ing, agility training, or kettlebell (KB) training to improve ACSM range of 60% to 85% of Vo 2max for cardiorespira-
operationally relevant aspects of fitness. Alternate fitness tory fitness.Thomas and colleagues reported that com-
12

training programs may better prepare airmen for military bining 10 minutes of continuous KB swings and sumo
missions and rapid deployment. There is a need to sci- deadlifts elicited similar metabolic demands as graded
entifically evaluate the effectiveness of such programs in treadmill walking. Additionally, Falatic and colleagues
10
military populations for inclusion in formalized PT. 3,4 reported the effects of 4 weeks of high-intensity KB
training on aerobic capacity in female collegiate soccer
It may be advantageous for military PT leaders to learn players. KB snatches were performed 3 days per week
of possible alternative forms of training, such as KB for 20 minutes with 15-second work-to-rest intervals
training. KB training programs, such as the one used in while the control group performed 20 minutes of free-
4
this study, are appealing, in part, because of their sim- weight and body-weight circuit training. After 4 weeks,
plicity. The only equipment used is a traditional steel- aerobic capacity improved by 6% in the KB group, with
like cannonball weight with a handle. KB training takes no changes in the control group. No measurements of
5
less time to perform because the KB exercises are analo- speed, strength, or power were assessed in this study.
gous to Olympic-style lifting, eliciting the recruitment of
multiple muscle groups with one functional movement, The primary aim of this study was to determine if con-
providing both a time-efficient and sufficient exercise tinuous one-arm KB swing training could be a used
stimulus. KB training has been reported to improve to improve USAF fitness assessment scores as well as
muscular strength, muscular endurance, power, and car- operationally relevant aspects of fitness such as speed,
diorespiratory fitness. Additionally, KB training has power, and agility. We hypothesized that KB training
6–8
been reported to elicit an aerobic response while simul- would improve 1.5-mile run times, muscular strength
taneously providing sufficient resistance for strength- and endurance, speed, power, and agility to a greater
ening the musculature of the posterior chain, such as extent than traditional USAF PT.
the biceps femoris, gluteus maximus, and the erector
spinae, which are predominantly used in running. Fur- Methods
9
thermore, it has been suggested that the effects of KB
training programs should be compared with traditional Thirty active-duty members between the ages of 18 and
forms of military PT, especially in regard to run perfor- 40 years were recruited for participation in this study.
mance, muscular strength, and injury prevention. 4 Subjects were asked to complete a medical screening
questionnaire and were cleared by the research medi-
As reviewed previously, Lake and Lauder reported that cal monitor before participation. Only data from the
6
6 weeks of 12-minute KB swing training performed bi- subjects who completed both pretesting and posttest-
weekly (30-second bouts with 30 seconds’ rest) resulted ing were reported. Table 1 lists pretest descriptive data
in a 9.8% improvement in maximal strength and a 19.8% for all three groups. The research protocol was cleared
improvement in explosive strength when compared with through the Wright Site Institutional Review Board for
jump-squat power training to develop maximal strength Human Subjects and subjects were asked to sign an in-
and power. Neither sprinting speed nor cardiorespira- formed consent form before participation.
tory fitness was assessed in this study to determine if the
KB swings improved sprinting speed or aerobic running Each person trained on Monday, Wednesday, and Fri-
performance. Collectively, KB swing training provided an day for 10 weeks. Participants received commander ap-
adequate stimulus that was sufficient to increase explosive proval to replace unit PT with study training sessions
and maximum muscular strength in the study group of 21 and were encouraged to continue to perform normal
healthy men. Furthermore, Hulsey et al. reported average daily activities throughout the study. Additionally, par-
7
heart rate (HR) values greater than 85% of age-predicted ticipants were asked to maintain normal dietary hab-
MHR during 10 minutes of KB swing intervals in mod- its and refrain from starting any new physical activities
erately trained men and women. The high heart-rate re- during the study period. All groups were supervised by a
sponse reported by Hulsey et al. indicates that KB swings trained master’s level exercise physiologist. Participants
7
may elicit an anaerobic response in this population. in all three groups wore a HR monitor and reported

42 Journal of Special Operations Medicine Volume 16, Edition 4/Winter 2016