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Gubler C.1, Boyd Z.1, Thibodeaux K.1, Haskins R.1
1University of South Alabama, Physical Therapy, Mobile, United States
Background: Aerobic training produces cardioprotective and cardiopulmonary fitness benefits that are better than resistance training alone. There are also many psychological benefits. In recent years, high-intensity interval training (HIIT) has become known for its health benefits and been shown to be more effective in reducing cardiovascular disease risk than moderate-intensity continuous exercise. CrossFit is a training program that uses components of HIIT and other techniques like high and low speed resistance training. There is little research comparing CrossFit to other exercise groups such as traditional recreational runners and the cardiopulmonary and psychological benefits of experienced CrossFitters have not been well studied.
Purpose: To compare the cardiopulmonary fitness and psychological health of experienced CrossFit athletes to runners.
Methods: Inclusion criteria required participants to be continuously training for 6 months or more. The CrossFit group (CF) was recruited from local area CrossFit gyms. The runners (RG) were recruited from local running clubs by flyers and word of mouth. Informed consent, short form-12 (SF-12), resting vital signs were completed. A VO2max treadmill test was performed with heart rate and oxygen consumption recorded at each stage and heart rate recovery (HRR) measured 2 minutes after completion. A MANOVA was run in SPSS to determine differences between groups.
Results: Twenty-eight subjects (14 CF and 14 RG) completed all testing. Maximum oxygen consumption averaged 49.8 ml/kg/min for RC and 44.4 ml/kg/min for CF. The HRR of RG was 71 bpm which was significantly greater (p = 0.002) than the HRR of CF at 57 bpm. There were no significant differences between the CF and RG groups for VO2 peak (p = 0.052), SF-12 scores (p = 0.178), resting systolic blood pressure (p = 0.480), resting diastolic blood pressure (p = 0.500), and resting heart rate (p = 0.495).
Conclusion(s): Overall, RG had a superior level of fitness as indicated by mean values of HRR. However, CF acquired similar aerobic, cardioprotective and psychological benefits as the RG as indicated by resting vital signs, VO2peak and SF-12 results. The HRR value of 22 bpm taken after two minutes is a strong predictor of mortality. Both the CrossFit and aerobic groups were markedly above 22 bpm with averages of 57 bpm and 71 bpm respectively. Runners exhibited better HRR, which may be due to specificity of training in aerobic running while CrossFit training uses a combination of anaerobic and aerobic training principles more characteristic of HIIT.
Implications: As the physical therapy profession moves towards a more active role in health promotion, it is important to educate patients on exercise options and their benefits. The results of this study demonstrated that CrossFit may be appropriate to recommend for cardioprotective and psychological benefits. Future studies should look at other components of CrossFit to better define the health benefits of this program.
Funding acknowledgements: none
Topic: Cardiorespiratory
Ethics approval: This study was approved by the University of South Alabama IRB.
All authors, affiliations and abstracts have been published as submitted.
