JACCLee et al.cohort
Improving fitness linked to ~52% lower risk of incident metabolic syndrome, while fat gain increases risk.
Fitness gains and fat loss may inform prevention; extends baseline associations to changes but leaves causality open.
Steven N. Blair
Preventive Cardiology
University of South Carolina
About
Steven N. Blair works in Preventive Cardiology affiliated with University of South Carolina.
Steven N. Blair was a Distinguished Professor Emeritus in the Departments of Exercise Science and Epidemiology and Biostatistics at the University of South Carolina's Arnold School of Public Health. He conducted research on the health benefits of physical activity, focusing on its role in preventing cardiovascular disease. He previously served as president and CEO of The Cooper Institute in Dallas, Texas.
Research focus
Cardiorespiratory Fitness and Cardiovascular Risk ReductionExercise EpidemiologyPhysical Activity in Chronic Disease PreventionObesity and Heart HealthLifestyle Interventions for CVD
Impact
501 pubs · 76,144 cites · h-index 112
Training
PhD
Indiana University Bloomington
1968
Postdoctoral Fellowship in Preventive Cardiology
Stanford University School of Medicine
Affiliations
Work Experience
Distinguished Professor Emeritus
University of South Carolina · 2006 - Present
President and CEO
The Cooper Institute · 2002 - 2006
Director
The Cooper Institute · 1980 - 2002
Professor
University of South Carolina · 1966 - 1984
Publications
JACCLavie et al.Prognostic Study
Overweight and mild obesity linked to better prognosis in CVD, highlighting the obesity paradox.
Review discusses how obesity affects cardiovascular health and highlights the obesity paradox regarding survival.
JACCArtero et al.Cohort Study
Estimated cardiorespiratory fitness predicted mortality and CVD events, though measured CRF improved NRI by 12.3% in men and 19.8% in women.
Shows nonexercise estimation of cardiorespiratory fitness predicts mortality and cardiovascular disease risk in adults, indicating a practical alternative to treadmill testing.
JACCLee et al.cohort
Leisure-time running, even 5 to 10 min/day at slow speeds, was associated with 30% and 45% lower adjusted risks of all-cause and cardiovascular mortality compared with nonrunners.
Hypothesis-generating for mortality benefit with leisure-time running; prospective trials needed before clinical adoption.
NutrientsFarrell et al.Original Research
Associations between the Dietary Inflammatory Index and Sleep Metrics in the Energy Balance Study (EBS)
(1) Background: Sleep, a physiological necessity, has strong inflammatory underpinnings. Diet is a strong moderator of systemic inflammation. This study explored the associations between the Dietary Inflammatory Index (DII®) and sleep duration, timing, and quality from the Energy Balance Study (EBS). (2) Methods: The EBS (n = 427) prospectively explored energy intake, expenditure, and body composition. Sleep was measured using BodyMedia’s SenseWear® armband. DII scores were calculated from three unannounced dietary recalls (baseline, 1-, 2-, and 3-years). The DII was analyzed continuously and categorically (very anti-, moderately anti-, neutral, and pro-inflammatory). Linear mixed-effects models estimated the DII score impact on sleep parameters. (3) Results: Compared with the very anti-inflammatory category, the pro-inflammatory category was more likely to be female (58% vs. 39%, p = 0.02) and African American (27% vs. 3%, p < 0.01). For every one-unit increase in the change in DII score (i.e., diets became more pro-inflammatory), wake-after-sleep-onset (WASO) increased (βChange = 1.00, p = 0.01), sleep efficiency decreased (βChange = −0.16, p < 0.05), and bedtime (βChange = 1.86, p = 0.04) and waketime became later (βChange = 1.90, p < 0.05). Associations between bedtime and the DII were stronger among African Americans (βChange = 6.05, p < 0.01) than European Americans (βChange = 0.52, p = 0.64). (4) Conclusions: Future studies should address worsening sleep quality from inflammatory diets, leading to negative health outcomes, and explore potential demographic differences.
British Journal of Sports MedicineSaavedra et al.Cohort Study
Associations of cardiorespiratory fitness and body mass index with incident restrictive spirometry pattern
OBJECTIVES: Restrictive spirometry pattern (RSP) suggests an impairment of lung function associated with a significantly increased risk of premature mortality. We evaluated the independent and joint associations of cardiorespiratory fitness (CRF) and body mass index with incident RSP. METHODS: ). RSP was defined as the simultaneous occurrence of forced expiratory volume in 1 s/force vital capacity ≥lower limit of normal and forced vital capacity <lower limit of normal. RESULTS: There were 900 (7.3%) cases of RSP (mean follow-up: 6.9 years). Compared with category 1 ('least fit'), HRs (95% CIs) of RSP were 0.78 (0.63 to 0.96), 0.68 (0.54 to 0.86), 0.70 (0.55 to 0.88) and 0.59 (0.45 to 0.77) in categories 2, 3, 4 and 5 (most fit), respectively, after adjusting for confounders including body mass index. Compared with normal weight, HRs (95% CIs) of RSP were 1.06 (0.91 to 1.23) and 1.30 (1.03 to 1.64) in overweight and obese, respectively. However, the association between obesity and RSP was attenuated when additionally adjusting for CRF (HR 1.08, 95% CI 0.84 to 1.39). Compared with the 'unfit and overweight/obese' group, HRs (95% CIs) for RSP were 1.35 (0.98 to 1.85), 0.77 (0.63 to 0.96) and 0.70 (0.56 to 0.87) in the 'unfit and normal weight,' 'fit and overweight/obese' and 'fit and normal weight' groups, respectively. CONCLUSIONS: Low CRF was associated with a greater incidence of RSP, irrespective of body mass index. Future studies are needed to explore potential underlying mechanisms of this association and to prospectively evaluate if improving CRF reduces the risk of developing RSP.
JAMA Network OpenHooker et al.Cohort Study
Association of Accelerometer-Measured Sedentary Time and Physical Activity With Risk of Stroke Among US Adults
Importance: The amount and intensity of physical activity required to prevent stroke are yet to be fully determined because of previous reliance on self-reporting measures. Furthermore, the association between objectively measured time spent being sedentary as an independent risk factor for stroke is unknown. Objective: To investigate the associations of accelerometer-measured sedentary time and physical activity of varying intensity and duration with the risk of incident stroke. Design, Setting, and Participants: This cohort study involved participants who were enrolled in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study from February 5, 2003, to October 30, 2007. Accelerometer data were collected from 7607 Black and White adults 45 years or older in the contiguous US between May 12, 2009, and January 5, 2013. Data on other races and ethnicities were not collected for scientific and clinical reasons. By design, Black adults and residents of the southeastern US stroke belt and stroke buckle were oversampled. Data were analyzed from May 5, 2020, to November 11, 2021. Exposures: Sedentary time, light-intensity physical activity (LIPA), and moderate- to vigorous-intensity physical activity (MVPA) were measured using a hip-mounted accelerometer worn for 7 consecutive days and stratified by tertile for the analyses. Main Outcomes and Measures: Incident stroke. Results: Among 7607 participants, the mean (SD) age was 63.4 (8.5) years; 4145 participants (54.5%) were female, 2407 (31.6%) were Black, and 5200 (68.4%) were White. A total of 2523 participants (33.2%) resided in the stroke belt, and 1638 (21.5%) resided in the stroke buckle. Over a mean (SD) of 7.4 (2.5) years of follow-up, 286 incident stroke cases (244 ischemic [85.3%]) occurred. The fully adjusted hazard ratios (HRs) for incident stroke in the highest tertile compared with the lowest tertile were 0.74 (95% CI, 0.53-1.04; P = .08) for LIPA and 0.57 (95% CI, 0.38-0.84; P = .004) for MVPA. Higher sedentary time was associated with a 44% greater risk of incident stroke (HR, 1.44; 95% CI, 0.99-2.07; P = .04). When comparing the highest with the lowest tertile, mean sedentary bout duration was associated with a significantly greater risk of incident stroke (HR, 1.53; 95% CI, 1.10-2.12; P = .008). After adjustment for sedentary time, the highest tertile of unbouted MVPA (shorter bouts [1-9 minutes]) was associated with a significantly lower risk of incident stroke compared with the lowest tertile (HR, 0.62; 95% CI, 0.41-0.94; P = .02); however, bouted MVPA (longer bouts [at least 10 minutes]) was not (HR, 0.78; 95% CI, 0.53-1.15; P = .17). When expressed as continuous variables, sedentary time was positively associated with incident stroke risk (HR per 1-hour/day increase in sedentary time: 1.14; 95% CI, 1.02-1.28; P = .02), and LIPA was negatively associated with incident stroke risk (HR per 1-hour/day increase in LIPA: 0.86; 95% CI, 0.77-0.97; P = .02). Conclusions and Relevance: In this cohort study, objectively measured LIPA, MVPA, and sedentary time were significantly and independently associated with incident stroke risk. Longer sedentary bout duration was also independently associated with an increased risk of incident stroke. These findings suggest that replacing sedentary time with LIPA, or even very short bouts of MVPA, may lower stroke risk, supporting the concept of moving more and sitting less as a beneficial stroke risk reduction strategy among adults.
JAMA Internal MedicineShlipak et al.Clinical Trial
Effect of Structured, Moderate Exercise on Kidney Function Decline in Sedentary Older Adults
Importance: Observational evidence suggests that higher physical activity is associated with slower kidney function decline; however, to our knowledge, no large trial has evaluated whether activity and exercise can ameliorate kidney function decline in older adults. Objective: To evaluate whether a moderate-intensity exercise intervention can affect the rate of estimated glomerular filtration rate per cystatin C (eGFRCysC) change in older adults. Design, Setting, and Participants: This ancillary analysis of the Lifestyle Interventions and Independence For Elders randomized clinical trial enrolled 1199 community-dwelling, sedentary adults aged 70 to 89 years with mobility limitations and available blood specimens. The original trial was conducted across 8 academic centers in the US from February 2010 through December 2013. Data for this study were analyzed from March 29, 2021, to February 28, 2022. Interventions: Structured, 2-year, partially supervised, moderate-intensity physical activity and exercise (strength, flexibility) intervention compared with a health education control intervention with 2-year follow-up. Physical activity was measured by step count and minutes of moderate-intensity activity using accelerometers. Main Outcomes and Measures: The primary outcome was change in eGFRCysC. Rapid eGFRCysC decline was defined by the high tertile threshold of 6.7%/y. Results: Among the 1199 participants in the analysis, the mean (SD) age was 78.9 (5.2) years, and 800 (66.7%) were women. At baseline, the 2 groups were well balanced by age, comorbidity, and baseline eGFRCysC. The physical activity and exercise intervention resulted in statistically significantly lower decline in eGFRCysC over 2 years compared with the health education arm (mean difference, 0.96 mL/min/1.73 m2; 95% CI, 0.02-1.91 mL/min/1.73 m2) and lower odds of rapid eGFRCysC decline (odds ratio, 0.79; 95% CI, 0.65-0.97). Conclusions and Relevance: Results of this ancillary analysis of a randomized clinical trial showed that when compared with health education, a physical activity and exercise intervention slowed the rate of decline in eGFRCysC among community-dwelling sedentary older adults. Clinicians should consider targeted recommendation of physical activity and moderate-intensity exercise for older adults as a treatment to slow decline in eGFRCysC. Trial Registration: ClinicalTrials.gov Identifier: NCT01072500.
The Journals of Gerontology Series AZhao et al.Original Research
Effect of High-Intensity Power Training on Cognitive Function in Older Adults With Type 2 Diabetes: Secondary Outcomes of the GREAT2DO Study
We sought to determine the effects of 12 months of power training on cognition, and whether improvements in body composition, muscle strength, and/or aerobic capacity (VO2peak) were associated with improvements in cognition in older adults with type 2 diabetes (T2D). Participants with T2D were randomized to power training or low-intensity sham exercise control condition, 3 days per week for 12 months. Cognitive outcomes included memory, attention/speed, executive function, and global cognition. Other relevant outcomes included VO2peak, strength, and whole body and regional body composition. One hundred and three adults with T2D (mean age 67.9 years; standard deviation [SD] 5.9; 50.5% women) were enrolled and analyzed. Unexpectedly, there was a nearly significant improvement in global cognition (p = .05) in the sham group relative to power training, although both groups improved over time (p < .01). There were significant interactions between group allocation and body composition or muscle strength in the models predicting cognitive changes. Therefore, after stratifying by group allocation, improvements in immediate memory were associated with increases in relative skeletal muscle mass (r = 0.38, p = .03), reductions in relative body fat (r = -0.40, p = .02), and increases in knee extension strength were directly related to changes in executive function (r = -0.41, p = .02) within the power training group. None of these relationships were present in the sham group (p > .05). Although power training did not significantly improve cognition compared to low-intensity exercise control, improvements in cognitive function in older adults were associated with hypothesized improvements in body composition and strength after power training.
Sports Medicine and Health SciencePfeifer et al.Cohort Study
Are flexibility and muscle-strengthening activities associated with functional limitation?
= 122) were associated with 24% and 38% decreased odds of incident functional limitation, respectively. General muscle-strengthening, stretching, and calisthenics activities are prospectively associated with decreased risk of incident functional limitation in generally healthy, middle-aged and older adults. Thus, both public health and rehabilitation programs should highlight the importance of flexibility and muscle-strengthening activities during adulthood to help preserve functional capacity.
SHILAP Revista de lepidopterologíaHoule et al.cohort
The association between change in nonexercise eCRF and mortality risk may be equation dependent (statistical results truncated in source text).
Equation-dependent associations limit nonexercise eCRF change as a mortality predictor in men; leaves open validation of optimal equations.
StrokeDuran et al.Cohort Study
Objectively Measured Physical Activity and Sedentary Time Among Adults With and Without Stroke: A National Cohort Study
Background and Purpose: We examined differences in the volume and pattern of physical activity (PA) and sedentary behavior between adults with and without stroke. Methods: We studied cohort members with an adjudicated or self-reported stroke (n=401) and age-, sex-, race-, region of residence-, and body mass index-matched participants without a history of stroke (n=1203) from the REGARDS study (Reasons for Geographic and Racial Differences in Stroke). Sedentary behavior (total volume and bouts), light-intensity PA, and moderate-to-vigorous-intensity PA were objectively measured for 7 days via hip-worn accelerometer. Results: Sedentary time (790.5±80.4 versus 752.4±81.9 min/d) and mean sedentary bout duration (15.7±12.6 versus 11.9±8.1 min/d) were higher and PA (light-intensity PA: 160.5±74.6 versus 192.9±73.5 min/d and moderate-to-vigorous-intensity PA: 9.0±11.9 versus 14.7±17.0 min/d) lower for stroke survivors compared with controls (P<0.001). Stroke survivors also accrued fewer activity breaks (65.5±21.9 versus 73.31±18.9 breaks/d) that were shorter (2.4±0.7 versus 2.7±0.8 minutes) and lower in intensity (188.4±60.8 versus 217.9±72.2 counts per minute) than controls (P<0.001). Conclusions: Stroke survivors accrued a lower volume of PA, higher volume of sedentary time, and exhibited accrual patterns of more prolonged sedentary bouts and shorter, lower intensity activity breaks compared with persons without stroke.
Cardiovascular ResearchSanchis‐Gomar et al.review
Higher levels of physical activity, exercise training, and cardiorespiratory fitness are correlated with reduced risk of CVD, including myocardial infarction, CVD-related death, and all-cause mortality.
Reinforces exercise-CVD associations from prior data; leaves open causal effects and optimal interventions for practice.
Journal of Applied StatisticsHuang et al.cohort
Resistance exercise reduced the risk of total cardiovascular disease events with a natural direct effect.44 compared to no resistance exercise.
Supports resistance exercise in primary CVD prevention; hypothesis-generating pending randomized confirmation of direct effects.
SHILAP Revista de lepidopterologíaBrellenthin et al.Cohort Study
Resistance exercise, alone and in combination with aerobic exercise, and obesity in Dallas, Texas, US: A prospective cohort study
Background Obesity is a significant and growing public health problem in high-income countries. Little is known about the relationship between resistance exercise (RE), alone and in combination with aerobic exercise (AE), and the risk of developing obesity. The purpose of this prospective cohort study was to examine the associations between different amounts and frequencies of RE, independent of AE, and incident obesity. Methods and findings Participants were 11,938 healthy adults ages 18–89 years with a BMI < 30 kg/m 2 at baseline who completed at least 2 clinical examinations during 1987–2005 as part of the Aerobics Center Longitudinal Study. Self-reported RE participation in minutes/week and days/week was collected from a standardized questionnaire. Incident obesity was defined as a BMI ≥ 30 kg/m 2 at follow-up. Incident obesity was also defined by waist circumference (WC) > 102/88 cm for men/women and percent body fat (PBF) ≥ 25%/30% for men/women at follow-up in participants who were not obese by WC ( n = 9,490) or PBF ( n = 8,733) at baseline. During the average 6-year follow-up, 874 (7%), 726 (8%), and 1,683 (19%) developed obesity defined by BMI, WC, or PBF, respectively. Compared with no RE, 60–119 min/wk of RE was associated with 30%, 41%, and 31% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.70 [0.54–0.92], p = 0.008), WC (0.59 [0.44–0.81], p < 0.001), and PBF (0.69 [0.57–0.83], p < 0.001), respectively, after adjusting for confounders including age, sex, examination year, smoking status, heavy alcohol consumption, hypertension, hypercholesterolemia, diabetes, and AE. Compared with not meeting the RE guidelines of ≥2 d/wk, meeting the RE guidelines was associated with 18%, 30%, and 30% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.82 [0.69–0.97], p = 0.02), WC (0.70 [0.57–0.85], p < 0.001), and PBF (0.70 [0.62–0.79], p < 0.001), respectively. Compared with meeting neither guideline, meeting both the AE and RE guidelines was associated with the smallest hazard ratios for obesity. Limitations of this study include limited generalizability as participants were predominantly white men from middle to upper socioeconomic strata, use of self-reported RE, and lack of detailed diet data for the majority of participants. Conclusions In this study, we observed that RE was associated with a significantly reduced risk of obesity even after considering AE. However, meeting both the RE and AE guidelines was associated with the lowest risk of obesity.
Journal of Physical Activity and HealthCoelho‐Ravagnani et al.cohort
Consistently meeting the PA guidelines, compared with not meeting, was associated with a 47% decreased risk of CVD mortality after controlling for confounders.
Supports PA guideline adherence to lower CVD mortality in men; hypothesis-generating, needs RCTs to confirm causality.
GeriatricsHaghighi et al.RCT
The Effect of High-Intensity Power Training on Habitual, Intervention and Total Physical Activity Levels in Older Adults with Type 2 Diabetes: Secondary Outcomes of the GREAT2DO Randomized Controlled Trial
Background: We examined the effect of power training on habitual, intervention and total physical activity (PA) levels in older adults with type 2 diabetes and their relationship to metabolic control. Materials and Methods: 103 adults with type 2 diabetes were randomized to receive supervised power training or sham exercise three times/week for 12 months. Habitual, intervention, and total PA, as well as insulin resistance (HOMA2-IR) and glycosylated hemoglobin (HbA1c), were measured. Results: Participants were aged 67.9 ± 5.5 yrs, with well-controlled diabetes (HbA1c = 7.1%) and higher than average habitual PA levels compared to healthy peers. Habitual PA did not change significantly over 12 months (p = 0.74), and there was no effect of group assignment on change over time in habitual PA over 0–6 (p = 0.16) or 0–6–12 months (p = 0.51). By contrast, intervention PA, leg press tonnage and total PA increased over both 6- and 12-month timepoints (p = 0.0001), and these changes were significantly greater in the power training compared to the sham exercise group across timepoints (p = 0.0001). However, there were no associations between changes in any PA measures over time and changes in metabolic profile. Conclusion: Structured high-intensity power training may be an effective strategy to enhance overall PA in this high-risk cohort.
Scandinavian Journal of Medicine and Science in SportsGando et al.cohort
Compared with the lowest flexibility (quartile 1), the) was 0.83.
A high level of body flexibility is independently associated with a lower incidence of hypertension in middle-aged adults.
Journal of Physical Activity and HealthKawakami et al.Cohort Study
A Prospective Cohort Study of Muscular and Performance Fitness and Incident Glaucoma: The Niigata Wellness Study
BACKGROUND: To examine the association between muscular and performance fitness (MPF) and the incidence of glaucoma. METHODS: A total of 27,051 glaucoma-free participants aged 20-87 years underwent physical fitness tests between April 2001 and March 2002. The MPF index was calculated using an age- and sex-specific summed z-score from grip strength, vertical jump, single-leg balance, forward bending, and whole-body reaction time. The participants were divided into quartiles according to the MPF index and each physical fitness test. Participants were followed up for the development of glaucoma, which was defined based on physician-diagnosed glaucoma at an annual health examination between April 2002 and March 2008. Hazard ratios for the incidence of glaucoma were estimated using Cox proportional hazards models. RESULTS: During follow-up, 303 participants developed glaucoma. Compared with the lowest MPF index group, hazard ratio (95% confidence interval) of developing glaucoma was 0.64 (0.46-0.89) for the highest MPF index group (P for trend = .001). Vertical jump and whole-body reaction time were associated with incident glaucoma (P for trend = .01 and <.001, respectively). There were no associations between the other physical fitness tests and the incidence of glaucoma. CONCLUSION: Higher MPF is associated with lower incidence of glaucoma.
PLoS ONENelms et al.Cohort Study
Adding waist circumference fails to improve fatal CVD risk prediction over the Framingham Risk Score.
Despite considerable evidence demonstrating that waist circumference (WC) is independently associated with cardiovascular disease (CVD) and/or all-cause mortality, whether the addition of WC improves risk prediction models is unclear. The objective was to evaluate the improvement in risk prediction with the addition of WC, alone or in combination with BMI, to the Framingham Risk Score (FRS) and a population specific model. 34,377 men and 9,477 women aged 20 to 79 years who completed a baseline examination at the Cooper Clinic (Dallas, TX) during 1977-2003 and enrolled in the Aerobics Center Longitudinal Study (ACLS). WC was measured at the level of the umbilicus and expressed as a continuous variable. Deaths among participants were identified using the National Center for Health Statistics National Death Index. A total of 728 fatal cardiovascular disease (CVD) events occurred over a mean follow-up period of 13.1 ± 7.5 years. WC was significantly higher in CVD decedents (P = .002). The FRS C-statistic for fatal CVD in men was 0.836 (0.816-0.855) and 0.883 (0.851-0.915) in women. The addition of WC did not improve the C-statistic in men (0.831 (0.809-0.853)) or women (0.883 (0.850-0.916)). Similar findings were observed for non-fatal CVD and all-cause mortality, and when WC was added to a population specific model. Upon adding WC, the net-reclassification index was 0.024 with an integrated discrimination improvement of -0.0004. The addition of WC, alone or in combination with BMI, did not substantively improve risk prediction for CVD or all-cause mortality compared to the Framingham Risk Score or a population specific model.