Siddhartha S. Angadi

High-intensity interval training vs. moderate-intensity continuous exercise training in heart failure with preserved ejection fraction: a pilot study.

Heart failure with preserved ejection fraction (HFpEF) is a major cause of morbidity and mortality. Exercise training is an established adjuvant therapy in heart failure; however, the effects of high-intensity interval training (HIIT) in HFpEF are unknown. We compared the effects of HIIT vs. moderate-intensity aerobic continuous training (MI-ACT) on peak oxygen uptake (V̇o₂peak), left ventricular diastolic dysfunction, and endothelial function in patients with HFpEF. Nineteen patients with HFpEF (age 70 ± 8.3 yr) were randomized to either HIIT (4 × 4 min at 85-90% peak heart rate, with 3 min active recovery) or MI-ACT (30 min at 70% peak heart rate). Fifteen patients completed exercise training (HIIT: n = 9; MI-ACT: n = 6). Patients trained 3 days/wk for 4 wk. Before and after training patients underwent a treadmill test for V̇o₂peak determination, 2D-echocardiography for assessment of left ventricular diastolic dysfunction, and brachial artery flow-mediated dilation (FMD) for assessment of endothelial function. HIIT improved V̇o₂peak (pre = 19.2 ± 5.2 ml·kg(-1)·min(-1); post = 21.0 ± 5.2 ml·kg(-1)·min(-1); P = 0.04) and left ventricular diastolic dysfunction grade (pre = 2.1 ± 0.3; post = 1.3 ± 0.7; P = 0.02), but FMD was unchanged (pre = 6.9 ± 3.7%; post = 7.0 ± 4.2%). No changes were observed following MI-ACT. A trend for reduced left atrial volume index was observed following HIIT compared with MI-ACT (-3.3 ± 6.6 vs. +5.8 ± 10.7 ml/m(2); P = 0.06). In HFpEF patients 4 wk of HIIT significantly improved V̇o₂peak and left ventricular diastolic dysfunction. HIIT may provide a more robust stimulus than MI-ACT for early exercise training adaptations in HFpEF.

Exercise and Diet, Independent of Weight Loss, Improve Cardiometabolic Risk Profile in Overweight and Obese Individuals

Abstract Diet and/or exercise are routinely advised as methods for weight loss in overweight/obese individuals, particularly those who are at high risk for cardiovascular disease and type 2 diabetes mellitus. However, physical activity and structured exercise programs rarely result in significant loss of body weight or body fat, and weight-loss diets have extraordinarily high recidivism rates. Despite only modest effects on body weight, exercise and ad libitum nutrient-dense diets for overweight/obese individuals have many health benefits, including skeletal muscle adaptations that improve fat and glucose metabolism, and insulin action; enhance endothelial function; have favorable changes in blood lipids, lipoproteins, and hemostatic factors; and reduce blood pressure, postprandial lipemia and glycemia, and proinflammatory markers. These lifestyle-induced adaptations occur independently of changes in body weight or body fat. Thus, overweight/obese men and women who are at increased risk for cardiovascular disease and type 2 diabetes as a result of sedentary lifestyle, poor diet, and excess body weight should be encouraged to engage in regular physical activity and improve their diet, regardless of whether the healthier lifestyle leads to weight loss.

The effects of caffeine, nicotine, ethanol, and tetrahydrocannabinol on exercise performance

Caffeine, nicotine, ethanol and tetrahydrocannabinol (THC) are among the most prevalent and culturally accepted drugs in western society. For example, in Europe and North America up to 90% of the adult population drinks coffee daily and, although less prevalent, the other drugs are also used extensively by the population. Smoked tobacco, excessive alcohol consumption and marijuana (cannabis) smoking are addictive and exhibit adverse health effects. These drugs are not only common in the general population, but have also made their way into elite sports because of their purported performance-altering potential. Only one of the drugs (i.e., caffeine) has enough scientific evidence indicating an ergogenic effect. There is some preliminary evidence for nicotine as an ergogenic aid, but further study is required; cannabis and alcohol can exhibit ergogenic potential under specific circumstances but are in general believed to be ergolytic for sports performance. These drugs are currently (THC, ethanol) or have been (caffeine) on the prohibited list of the World Anti-Doping Agency or are being monitored (nicotine) due to their potential ergogenic or ergolytic effects. The aim of this brief review is to evaluate the effects of caffeine, nicotine, ethanol and THC by: 1) examining evidence supporting the ergogenic or ergolytic effects; 2) providing an overview of the mechanism(s) of action and physiological effects; and 3) where appropriate, reviewing their impact as performance-altering aids used in recreational and elite sports.

Gluten-Free Diet: Imprudent Dietary Advice for the General Population?

As of April 20, 2012, Amazon.com listed 4,765entriesforthetopic“gluten-free.”AGooglesearchatthesametime for “gluten-free diet” produced more than 4.2 millionresults. The number-one reason consumers cite for buyinggluten-freeproductsisthattheyareperceivedtobehealthierthan their gluten-containing counterparts.

High-intensity interval training for health and fitness: can less be more?

exercise is an established therapeutic adjunct in the management of several chronic diseases. Traditionally, the form of exercise most commonly prescribed by clinicians is continuous moderate-to-vigorous-intensity exercise that can be sustained for ∼20–60 min. This is consistent with current US

Effects of an Intensive Short-term Diet and Exercise Intervention: Comparison Between Normal Weight and Obese Children

Lifestyle intervention programs currently emphasize weight loss secondary to obesity as the primary determinant of phenotypic changes. We examined whether the effects of a short-term lifestyle intervention program differ in normal-weight versus overweight/obese children. Nineteen overweight/obese (O; BMI = 33.6 ± 1.9 kg/m(2)) and 14 normal-weight (N; BMI = 19.9 ± 1.5 kg/m(2)) children participated in a 2-wk program consisting of an ad libitum high-fiber, low-fat diet and daily exercise (2-2.5 h). Fasting serum samples were taken pre- and postintervention for determination of lipids, glucose homeostasis, inflammatory cytokines, and adipokines. Only the O group lost weight (3.9%) but remained overweight/obese (32.3 ± 1.9 kg/m(2)). Both groups exhibited significant intervention-induced decreases (P < 0.05) in serum insulin (N: 52.5% vs. O: 28.1%; between groups, P = 0.38), homeostatic model assessment for insulin resistance (N: 53.1% vs. O: 28.4%, P = 0.43), leptin (N: 69.3% vs. O: 44.1%, P = 0.10), amylin (N: 28.7% vs. O: 26.1%, P = 0.80), resistin (N: 40.0% vs. O: 35.1%, P = 0.99), plasminogen activator-inhibitor-1 (N: 30.8% vs. O: 25.6%, P = 0.59), IL-6 (N: 58.8% vs. O: 48.5%, P = 0.78), IL-8 (N: 46.0% vs. O: 42.2%, P = 0.49), and TNFα (N: 45.8% vs. O: 40.8%, P = 0.99). No associations between indices of weight change and phenotypic changes were noted. A short-term, intensive lifestyle modification program is effective in ameliorating metabolic risk factors in N and O children. These results suggest that obesity per se was not the primary driver of the phenotypes noted and that dietary intake and physical inactivity induce the phenotypic abnormalities. These data may have implications for the weight loss-independent management of cardiometabolic risk in pediatric populations.

Effect of fractionized vs continuous, single-session exercise on blood pressure in adults

Exercise training-induced reduction in blood pressure (BP) 1 may be in part due to the BP lowering effects of acute exercise (postexercise hypotension, PEH). 2 PEH has been reported to be ~7-14 mm Hg, can occur within 5 min after exercise, and may persist for up to 22 h. 2,3 .

Excess Postexercise Oxygen Consumption After High-Intensity and Sprint Interval Exercise, and Continuous Steady-State Exercise

Abstract Tucker, WJ, Angadi, SS, and Gaesser, GA. Excess postexercise oxygen consumption after high-intensity and sprint interval exercise, and continuous steady-state exercise. J Strength Cond Res 30(11): 3090–3097, 2016—Higher excess postexercise oxygen consumption (EPOC) after high-intensity interval exercise (HIE) and sprint interval exercise (SIE) may contribute to greater fat loss sometimes reported after interval training compared with continuous steady-state exercise (SSE) training. We compared EPOC after HIE, SIE, and SSE. Ten recreationally active men (age 24 ± 4 years) participated in this randomized crossover study. On separate days, subjects completed a resting control trial and 3 exercise conditions on a cycle ergometer: HIE (four 4-minute intervals at 95% peak heart rate (HRpeak), separated by 3 minutes of active recovery), SIE (six 30-second Wingate sprints, separated by 4 minutes of active recovery), and SSE (30 minutes at 80% of HRpeak). Oxygen consumption (V[Combining Dot Above]O2) was measured continuously during and for 3 hours after exercise. For all conditions, V[Combining Dot Above]O2 was higher than resting control only during the first hour postexercise. Although 3-hour EPOC and total net exercise energy expenditure (EE) after exercise were higher (p = 0.01) for SIE (22.0 ± 9.3 L; 110 ± 47 kcal) compared with SSE (12.8 ± 8.5 L; 64 ± 43 kcal), total (exercise + postexercise) net O2 consumed and net EE were greater (p = 0.03) for SSE (69.5 ± 18.4 L; 348 ± 92 kcal) than those for SIE (54.2 ± 12.0 L; 271 ± 60 kcal). Corresponding values for HIE were not significantly different from SSE or SIE. Excess postexercise oxygen consumption after SIE and HIE is unlikely to account for the greater fat loss per unit EE associated with SIE and HIE training reported in the literature.

Postexercise hypotension after continuous, aerobic interval, and sprint interval exercise

Abstract Angadi, SS, Bhammar, DM, and Gaesser, GA. Postexercise hypotension after continuous, aerobic interval, and sprint interval exercise. J Strength Cond Res 29(10): 2888–2893, 2015—We examined the effects of 3 exercise bouts, differing markedly in intensity, on postexercise hypotension (PEH). Eleven young adults (age: 24.6 ± 3.7 years) completed 4 randomly assigned experimental conditions: (a) control, (b) 30-minute steady-state exercise (SSE) at 75–80% maximum heart rate (HRmax), (4) aerobic interval exercise (AIE): four 4-minute bouts at 90–95% HRmax, separated by 3 minutes of active recovery, and (d) sprint interval exercise (SIE): six 30-second Wingate sprints, separated by 4 minutes of active recovery. Exercise was performed on a cycle ergometer. Blood pressure (BP) was measured before exercise and every 15-minute postexercise for 3 hours. Linear mixed models were used to compare BP between trials. During the 3-hour postexercise, systolic BP (SBP) was lower (p < 0.001) after AIE (118 ± 10 mm Hg), SSE (121 ± 10 mm Hg), and SIE (121 ± 11 mm Hg) compared with control (124 ± 8 mm Hg). Diastolic BP (DBP) was also lower (p < 0.001) after AIE (66 ± 7 mm Hg), SSE (69 ± 6 mm Hg), and SIE (68 ± 8 mm Hg) compared with control (71 ± 7 mm Hg). Only AIE resulted in sustained (>2 hours) PEH, with SBP (120 ± 9 mm Hg) and DBP (68 ± 7 mm Hg) during the third-hour postexercise being lower (p ⩽ 0.05) than control (124 ± 8 and 70 ± 7 mm Hg). Although all exercise bouts produced similar reductions in BP at 1-hour postexercise, the duration of PEH was greatest after AIE.

Effects of Fractionized and Continuous Exercise on 24-h Ambulatory Blood Pressure

PURPOSE The objective of this study is to compare the effects of fractionized aerobic exercise (three 10-min exercise sessions) and continuous exercise (one 30-min exercise session) on 24-h ambulatory blood pressure (ABP). METHODS Eleven healthy prehypertensive subjects (28.3 ± 8.0 (SD) yr) completed three randomly assigned conditions: 1) three 10-min sessions of aerobic exercise (3 × 10 min), 2) one continuous 30-min session of aerobic exercise (1 × 30 min), and 3) a nonexercise control trial (control). The mode of exercise was walking on a motor-driven treadmill at 75%-79% of maximum heart rate (HRmax) (60%-65% V˙O2peak). Twenty-four-hour ABP was monitored with an automated ABP device (Oscar 2™; SunTech Medical, Morrisville, NC). Linear mixed models were used to compare 24-h ABP responses between trials. RESULTS The mean ± SD 24-h systolic blood pressure (SBP) was significantly lower during the 3 × 10-min trial (127 ± 15 mm Hg) compared with control (130 ± 15 mm Hg) (P < 0.001). Although both 3 × 10-min and 1 × 30-min trials reduced SBP compared with control during daytime/evening (1300-2300 h), only the 3 × 10-min trial reduced SBP during nighttime (2300-0800 h, 118 ± 16 vs 122 ± 14 mm Hg, P = 0.024) and the following morning (0800-1200 h, 127 ± 15 vs 131 ± 15 mm Hg, P = 0.016). For 24 h, 26.7% of SBP values during 3 × 10 min were normal (i.e., <120 mm Hg) compared with 18.3% for 1 × 30 min and 19.4% for control (P < 0.001). CONCLUSIONS In prehypertensive individuals, fractionized exercise (e.g., three 10-min aerobic exercise sessions spread and effective exercise alternative to continuous exercise for cardiovascular risk reduction in this population.