Cagematch! Kettlebells vs. Treadmill

http://www.ncbi.nlm.nih.gov/pubmed/22395274

J Strength Cond Res. 2012 Mar 3. [Epub ahead of print]
Comparison of Kettlebell Swings and Treadmill Running at Equivalent RPE Values.
Husley CR, Soto DT, Koch AJ, Mayhew JL.
Source
1Human Performance Laboratory, Truman State University, Kirksville, Missouri, 2Health and Exercise Science Program, Lenoir-Rhyne University, Hickory, North Carolina; 3Physiology Department, A.T. Still University of Health Sciences, Kirksville, Missouri.

Abstract
The purpose of this study was to compare metabolic demand of a kettlebell (KB) swing routine to treadmill (TM) running at equivalent rating of perceived exertion (RPE). Thirteen subjects (11 M, 2 F, age = 21.4 ± 2.1 y, weight = 73.0 ± 9.2 kg) completed a 10-min KB swing routine consisting of 35-s swing intervals followed by 25-s rest intervals. Men used a 16-kg KB, and women used an 8-kg KB. Following 48 hrs rest, subjects completed a 10-min TM run at equivalent RPEs as measured during the swing workout. Metabolic data were monitored each minute during each exercise using an automated cart, with the final 7 minutes used for analysis. RPE and heart rate (HR) recorded at minutes 5, 7, 9, and 10 increased by 2-3% and 7-9%, respectively, for each exercise, producing a significantly increasing pattern but no significant difference between exercises. Average HR and RPE were not significantly different between KB and TM and averaged 90% and 89%, respectively, of age-predicted HRmax. Oxygen consumption, METS, pulmonary ventilation, and calorie expenditure were significantly higher for TM (25-39%) than for KB. Respiratory exchange ratio (TM = 0.94 ± 0.04, KB = 0.95 ± 0.05) and respiratory rate (TM = 38 ± 7, KB = 36 ± 4 bpm) were not significantly different between the exercises at any time point. During TM and KB exercises matched for RPE, subjects are likely to have higher oxygen consumption, work at a higher MET level, and burn more Kcal/min during TM running than during KB swings. However, according to ACSM standards, this KB drill could provide sufficient exercise stress to produce gains in aerobic capacity.