Network Magazine spring 2015 | Page 40

dynamic bodyweight exercises as part of a continuous circuit program for 20 minutes. The authors reported that the KB group improved their VO2 max by 6 per cent and the circuit group achieved no change. A longer intervention (8 weeks) using kettlebells was used in a randomised control trial (RCT) using 40 middle-aged mostly women cohort by Jay et al. (2011). The intervention group completed ballistic full body KB exercises for three sessions per week to improve musculoskeletal (pain in neck, shoulders, low back) and cardiovascular health. While pain intensity in the key areas reduced in the intervention group, strength and cardiovascular fitness remained unchanged. The reality is that many fitness enthusiasts would be challenged to sustain 12 minutes of continuous KB swings (Farrar et al study) at an average of one swing in every 3 seconds, or 20 minutes (15 sec on and 15 off – Falatic et al. study). Working at 65 per cent of your VO2 max during treadmill running or cycling, however, would be easier to achieve for the same cardiovascular benefit. There is no doubt that the KB swings or snatches provide additional benefits outside of cardiovascular improvement, but trainers should consider this in the context of the fitness of their clients. I can see direct benefit in utilising KB exercises in tandem with traditional cardiovascular training and mixing the two in the form of a circuit or intervals with the KB swings being used as the higher intensity due to increased %HR and the cardio being used as lower intensity in the intervals. While current evidence suggests there is value in KB training towards improving cardiovascular fitness, further research with greater numbers and longer interventions is required for us to better understand the real value of this activity for aerobic fitness. Effect on strength and power There is significant evidence to show the value in using KB to develop both strength and power across a number of different performance measures. Manocchia et al. (2013) compared 23 middle-aged participants with a control group of 14. The KB training intervention was a 10-week program of two sessions per week broken into five blocks of four sessions, each with a different focus. The control group maintained normal daily activity which was not described. Participants were tested for a 3-repetition maximum (3RM) bench press, 3RM clean and jerk, a maximal vertical jump and repeated 45o back extensions to volitional 40 | NETWORK SPRING 2015 fatigue both pre and post the 10-week program. The participant group varied significantly, perhaps reducing the value of this research. For example, the range of weight lifted varied between the intervention and control group for bench press (45-215 to 20-79kg) and clean and jerk (30-145 to 9-59kg) showing a major range difference in training load and hence training experience between the intervention group and control group. The results showed there was no significant change in performance of back extension and vertical jump, but there was for bench press and clean and jerk. A study comparing the effects of weightlifting versus kettlebell training on vertical jump, strength, and body composition by Otto et al. (2012) showed that traditional weight lifting training was more effective at improving strength than KB training. The 10-week study comprised two sessions per week for six weeks. The KB group still showed positive changes for vertical jump, back squat and power clean. However, changes achieved from traditional weightlifting were greater for back squat than for the KB group. Lake and Lauder (2012) compared the changes in half squat 1RM and vertical jump between two different protocols, jump squat training and KB training, over six weeks with two sessions completed each week using 12 male college-aged participants matched for half squat 1RM in each group. The KB group performed 12 rounds of 30-second swing exercise alternated with 30 seconds of rest, and the jump squat group performed at least three sets of three jump squats (depending on load) with the load that maximised peak mechanical power applied to the centre of mass (CM). Results showed that half squat 1RM increased by nearly 10 per cent and vertical jump power increased by nearly 20 per cent, yet there was no difference between the two different training groups, showing similar changes in performances. There is plenty of evidence now to show that KB