Categorical Analysis of the Impact of Aerobic and Resistance Exercise Training, Alone and in Combination, on Cardiorespiratory Fitness Levels in Patients With Type 2 Diabetes: Results from the HART-D study

OBJECTIVE: Low cardiorespiratory fitness (CRF) is an independent risk factor for cardiovascular disease (CVD), especially in individuals with type 2 diabetes. Age-predicted, sex-stratified, and maximal MET cut points have been developed to determine the risk of CVD events and mortality in low CRF categories. We examined the proportion of Health Benefits of Aerobic and Resistance Training in Individuals With Type 2 Diabetes (HART-D) participants above these cut points before and after 9 months of aerobic training (AT), resistance training (RT), or a combination of both (ATRT). RESEARCH DESIGN AND METHODS: Participants from the HART-D study (n = 196) who were randomly assigned to exercise training (AT, RT, or ATRT) or to a nonexercise control group between April 2007 and August 2009 were used in this ancillary study. Cut points were previously established for age-predicted METs (>100% and >85%, mean and increased CVD risk, respectively), age- and sex-stratified METs (Aerobic Center Longitudinal Study), and clinically discernible METs (men >8.0, women >6.5). RESULTS: Baseline prevalence of participants above these cut points was similar for all intervention groups (P > 0.50) and ranged from 11.9% (>100% age predicted) to 55.1% (>85% age predicted). Baseline prevalence and age-, sex-, and race/ethnic group–adjusted percentage of participants above each cut point increased significantly after AT and ATRT (P < 0.05 for all). CONCLUSIONS: Structured exercise training, especially the AT component, was associated with a greater number of participants moving above established cut points indicative of low CRF. These results have public health and clinical implications for the growing number of patients with type 2 diabetes at high risk for CVD.