Elevated total white blood cell (WBC) count is associated with an increased risk of coronary heart disease and death. Aerobic exercise is associated with lower total WBC, neutrophil, and monocyte counts. However, no studies have evaluated the effect of the amount of aerobic exercise (dose) on total WBC and WBC subfraction counts. To examine the effects of 3 different doses of aerobic exercise on changes in total WBC and WBC subfraction counts and independent effects of changes in fitness, adiposity, markers of inflammation (IL-6, TNF-α, C-reactive protein), fasting glucose metabolism, and adiponectin. Data from 390 sedentary, overweight/obese postmenopausal women from the DREW study were used in these analyses. Women were randomized to a non-exercise control group or one of 3 exercise groups: energy expenditure of 4, 8, or 12 kcal kg⁻¹⋅week⁻¹ (KKW) for 6 months at an intensity of 50% VO_2peak. A dose-dependent decrease in total WBC counts (trend P = 0.002) was observed with a significant decrease in the 12KKW group (−163.1±140.0 cells/µL; mean±95%CI) compared with the control (138.6±144.7 cells/µL). A similar response was seen in the neutrophil subfraction (trend P = 0.001) with a significant decrease in the 12KKW group (−152.6±115.1 cells/µL) compared with both the control and 4KKW groups (96.4±119.0 and 21.9±95.3 cells/µL, respectively) and in the 8KKW group (−102.4±125.0 cells/µL) compared with the control. When divided into high/low baseline WBC categories (median split), a dose-dependent decrease in both total WBCs (P = 0.003) and neutrophils (P<0.001) was observed in women with high baseline WBC counts. The effects of exercise dose on total WBC and neutrophil counts persisted after accounting for significant independent effects of change in waist circumference and IL-6. Aerobic exercise training reduces total WBC and neutrophil counts, in a dose-dependent manner, in overweight/obese postmenopausal women and is especially beneficial for those with systemic low grade inflammation.

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.

Weight loss induced only by exercise is frequently less than expected, possibly because of compensatory changes in energy intake and/or energy expenditure. The purpose of the Examination of Mechanisms (E-MECHANIC) of Exercise-Induced Weight Compensation trial is to examine whether increased energy intake and/or reduced spontaneous activity or energy expenditure (outside of structured exercise) account for the less than expected, exercise-associated weight loss.

Fluid and electrolyte status have a significant impact on physical performance and health. Pre-exercise recommendations cite the possibility of consuming beverages with high amounts of sodium. In this sense, non-alcoholic beer can be considered an effective pre-exercise hydration beverage. This double-blind, randomized study aimed to compare the effect of beer, non-alcoholic beer and water consumption before exercise on fluid and electrolyte homeostasis. Seven male soccer players performed 45 min of treadmill running at 65% of the maximal heart rate, 45 min after ingesting 0.7 L of water (W), beer (AB) or non-alcoholic beer (NAB). Body mass, plasma Na⁺ and K⁺ concentrations and urine specific gravity (USG) were assessed before fluid consumption and after exercise. After exercise, body mass decreased (p < 0.05) in W (−1.1%), AB (−1.0%) and NAB (−1.0%). In the last minutes of exercise, plasma Na⁺ was reduced (p < 0.05) in W (−3.9%) and AB (−3.7%), plasma K⁺ was increased (p < 0.05) in AB (8.5%), and USG was reduced in W (−0.9%) and NAB (−1.0%). Collectively, these results suggest that non-alcoholic beer before exercise could help maintain electrolyte homeostasis during exercise. Alcoholic beer intake reduced plasma Na⁺ and increased plasma K⁺ during exercise, which may negatively affect health and physical performance, and finally, the consumption of water before exercise could induce decreases of Na⁺ in plasma during exercise.