Crossfit Vs. Circuit-trained Individuals

Abstract

CrossFit (CF) emphasizes constantly varied, high-intensity, functional movement including strength and conditioning exercises, gymnastics, Olympic lifting, and specialty movements. Many workouts are completed as quickly as possible, emphasizing power and speed over strength. In contrast, the purpose of circuit training (CT) programs is to improve strength and cardiovascular health by utilizing the progressive overload principle, high volume, low resistance exercises, similar movements weekly, and specific work-to-rest ratios. To the authors’ knowledge, no empirical research currently exists comparing the effects of CF or CT on individuals after a longitudinal training program. PURPOSE: : To determine if differences exist in body composition (BC) and bone mineral density (BMD) measures in participants who have completed a CF or CT training program. METHODS : Recreationally active females (CF: N=9, age: 29.2 + 8.4 yr; CT: N=14, age: 29.7 + 8.4 yrs) participated in a 10 week exercise intervention. Participants were randomly assigned to the CF or CT group and trained 3 days a week with certified trainers. Investigators examined BC utilizing a 7-site skinfold formula; and BMD of the lumbar spine, hip, and wrist were measured using dual-energy X-ray absorptiometry. Repeated measures ANOVA were used for statistical analyses with an alpha level of < 0.05. RESULTS: There were no differences within or between the groups for body weight (CFpre: 67.3 + 16.08 - CFpost: 67.3 + 17.0 kg; CTpre: 66.5 + 14.0 - CTpost: 68.7 + 16.0 kg), body fat percentage (CFpre: 27.4 + 7.7 - CFpost: 28.0 + 9.8 %; CTpre: 26.0 + 8.5 - CTpost: 26.4 + 8.7 %), or BMD of the lumbar spine (CFpre: 1.1 + .0 - CFpost: 1.1+ .07 g/cm2; CTpre: 1.0 + .11 - CTpost: 1.0 + .11 g/cm2), hip (CFpre: .93 + .12 - CFpost: .93 + .11 g/cm2; CTpre: .94 + .10 - CTpost: .95 + .10 g/cm2), and wrist (CFpre: .54 + .10 - CFpost: .53 + .10 g/cm2; CTpre: .52 + .02 - CTpost: .54 + .10 g/cm2). CONCLUSIONS: Neither CF nor CT was effective in changing body weight, BC, or BMD of the lumbar spine, hip, or wrist. The lack of change in BC may be due to increased appetite resulting from the training volume. Although the changes in BMD did not reach significance, the percentage of change may be clinically relevant. Further research is needed to understand the effects of CF training on BC and BMD compared to traditional training styles.