Recent guidelines on exercise for weight loss and weight maintenance include resistance training as part of the exercise prescription. Yet few studies have compared the effects of similar amounts of aerobic and resistance training on body mass and fat mass in overweight adults. STRRIDE AT/RT, a randomized trial, compared aerobic training, resistance training, and a combination of the two to determine the optimal mode of exercise for obesity reduction. Participants were 119 sedentary, overweight or obese adults who were randomized to one of three 8-mo exercise protocols: 1) RT: resistance training, 2) AT: aerobic training, and 3) AT/RT: aerobic and resistance training (combination of AT and RT). Primary outcomes included total body mass, fat mass, and lean body mass. The AT and AT/RT groups reduced total body mass and fat mass more than RT (P < 0.05), but they were not different from each other. RT and AT/RT increased lean body mass more than AT (P < 0.05). While requiring double the time commitment, a program of combined AT and RT did not result in significantly more fat mass or body mass reductions over AT alone. Balancing time commitments against health benefits, it appears that AT is the optimal mode of exercise for reducing fat mass and body mass, while a program including RT is needed for increasing lean mass in middle-aged, overweight/obese individuals.

Aerobic training (AT) improves the metabolic syndrome (MS) and its component risk factors; however, to our knowledge, no randomized clinical studies have addressed whether resistance training (RT) improves the MS when performed alone or combined with AT. Sedentary, overweight dyslipidemic men and women, aged 18 to 70 years completed a 4-month inactive run-in period and were randomized to 1 of 3 eight-month exercise programs (n = 196). The exercise programs were (1) RT (3 days/week, 3 sets/day of 8 to 12 repetitions of 8 different exercises targeting all major muscle groups); (2) AT (~120 minutes/week at 75% of the maximum oxygen uptake), and (3) AT and RT combined (AT/RT) (exact combination of AT and RT). Of the 196 randomized patients, 144 completed 1 of the 3 exercise programs. The 86 participants with complete data for all 5 MS criteria were used in the present analysis, and a continuous MS z score was calculated. Eight months of RT did not change the MS score. AT improved the MS score (p <0.07) and showed a trend toward significance compared to RT (p <0.10). AT/RT significantly decreased the MS score and was significantly different from RT alone. In conclusion, RT was not effective at improving the MS score; however, AT was effective. Combined AT and RT was similarly effective but not different from AT alone. When weighing the time commitment versus health benefit, the data suggest that AT alone was the most efficient mode of exercise for improving cardiometabolic health.

While the benefits of exercise are clear, many unresolved issues surround the optimal exercise prescription. Many organizations recommend aerobic training (AT) and resistance training (RT), yet few studies have compared their effects alone or in combination. The purpose of this study, part of Studies Targeting Risk Reduction Interventions Through Defined Exercise-Aerobic Training and/or Resistance Training (STRRIDE/ AT/RT), was to compare the effects of AT, RT, and the full combination (AT/RT) on central ectopic fat, liver enzymes, and fasting insulin resistance [homeostatic model assessment (HOMA)]. In a randomized trial, 249 subjects [18 -70 yr old, overweight, sedentary, with moderate dyslipidemia (LDL cholesterol 130 -190 mg/dl or HDL cholesterol Յ40 mg/dl for men or Յ45 mg/dl for women)] performed an initial 4-mo run-in period. Of these, 196 finished the run-in and were randomized into one of the following 8-mo exercise-training groups: 1) RT, which comprised 3 days/wk, 8 exercises, 3 sets/ exercise, 8 -12 repetitions/set, 2) AT, which was equivalent to ϳ19.2 km/wk (12 miles/wk) at 75% peak O2 uptake, and 3) full AT ϩ full RT (AT/RT), with 155 subjects completing the intervention. The primary outcome variables were as follows: visceral and liver fat via CT, plasma liver enzymes, and HOMA. AT led to significant reductions in liver fat, visceral fat, alanine aminotransferase, HOMA, and total and subcutaneous abdominal fat (all P Ͻ 0.05). RT resulted in a decrease in subcutaneous abdominal fat (P Ͻ 0.05) but did not significantly improve the other variables. AT was more effective than RT at improving visceral fat, liver-to-spleen ratio, and total abdominal fat (all P Ͻ 0.05) and trended toward a greater reduction in liver fat score (P Ͻ 0.10). The effects of AT/RT were statistically indistinguishable from the effects of AT. These data show that, for overweight and obese individuals who want to reduce measures of visceral fat and fatty liver infiltration and improve HOMA and alanine aminotransferase, a moderate amount of aerobic exercise is the most time-efficient and effective exercise mode. aerobic training; liver fat; resistance training; weight lifting; homeostasis model assessment WHILE THE BENEFITS OF BEING physically active are clear, many unresolved issues surround the optimal exercise prescription for these benefits. Many organizations recommend both aerobic training (AT) and resistance training (RT) for all adults. However, these recommendations are mainly based on the evaluation of each modality separately, as few studies have investigated the effects of combined AT and RT regimens compared with each modality individually. Furthermore, adherence to exercise recommendations of physicians is notoriously poor, and many patients cite lack of time as a reason for noncompliance. Understanding the effects of AT and RT is of critical importance if we are to apply evidence-based approaches to exercise recommendations to a wide population.Visceral fat and liver fat are associated with type 2 diabetes, metaboli...

BackgroundRheumatoid arthritis (RA) is a chronic inflammatory disease in which adults have significant joint issues leading to poor health. Poor health is compounded by many factors, including exercise avoidance and increased risk of opportunistic infection. Exercise training can improve the health of patients with RA and potentially improve immune function; however, information on the effects of high-intensity interval training (HIIT) in RA is limited. We sought to determine whether 10 weeks of a walking-based HIIT program would be associated with health improvements as measured by disease activity and aerobic fitness. Further, we assessed whether HIIT was associated with improved immune function, specifically antimicrobial/bacterial functions of neutrophils and monocytes.MethodsTwelve physically inactive adults aged 64 ± 7 years with either seropositive or radiographically proven (bone erosions) RA completed 10 weeks of high-intensity interval walking. Training consisted of 3 × 30-minute sessions/week of ten ≥ 60-second intervals of high intensity (80–90% VO2reserve) separated by similar bouts of lower-intensity intervals (50–60% VO2reserve). Pre- and postintervention assessments included aerobic and physical function; disease activity as measured by Disease Activity score in 28 joints (DAS28), self-perceived health, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR); plasma interleukin (IL)-1β, IL-6, chemokine (C-X-C motif) ligand (CXCL)-8, IL-10, and tumor necrosis factor (TNF)-α concentrations; and neutrophil and monocyte phenotypes and functions.ResultsDespite minimal body composition change, cardiorespiratory fitness increased by 9% (change in both relative and absolute aerobic capacity; p < 0.001), and resting blood pressure and heart rate were both reduced (both p < 0.05). Postintervention disease activity was reduced by 38% (DAS28; p = 0.001) with significant reductions in ESR and swollen joints as well as improved self-perceived health. Neutrophil migration toward CXCL-8 (p = 0.003), phagocytosis of Escherichia coli (p = 0.03), and ROS production (p < 0.001) all increased following training. The frequency of cluster of differentiation 14-positive (CD14+)/CD16+ monocytes was reduced (p = 0.002), with both nonclassical (CD14dim/CD16bright) and intermediate (CD14bright/CD16positive) monocytes being reduced (both p < 0.05). Following training, the cell surface expression of intermediate monocyte Toll-like receptor 2 (TLR2), TLR4, and HLA-DR was reduced (all p < 0.05), and monocyte phagocytosis of E. coli increased (p = 0.02). No changes were observed for inflammatory markers IL-1β, IL-6, CXCL-8, IL-10, CRP, or TNF-α.ConclusionsWe report for the first time, to our knowledge, that a high-intensity interval walking protocol in older adults with stable RA is associated with reduced disease activity, improved cardiovascular fitness, and improved innate immune functions, indicative of reduced infection risk and inflammatory potential. Importantly, the exercise program was well tolerated by these ...

Exercise provides a robust physiological stimulus that evokes cross-talk among multiple tissues that when repeated regularly (i.e., training) improves physiological capacity, benefits numerous organ systems, and decreases the risk for premature mortality. However, a gap remains in identifying the detailed molecular signals induced by exercise that benefits health and prevents disease. The Molecular Transducers of Physical Activity Consortium (MoTrPAC) was established to address this gap and generate a molecular map of exercise. Preclinical and clinical studies will examine the systemic effects of endurance and resistance exercise across a range of ages and fitness levels by molecular probing of multiple tissues before and after acute and chronic exercise. From this multi-omic and bioinformatic analysis, a molecular map of exercise will be established. Altogether, MoTrPAC will provide a public database that is expected to enhance our understanding of the health benefits of exercise and to provide insight into how physical activity mitigates disease.