No difference in fat oxidation, postexercise energy expenditure or energy intake following ingestion of a protein-based breakfast compared to carbohydrate breakfast.

Background: Manipulation of macronutrient intake and exercise can alter overall energy consumption and potentially body composition. Aim: The purpose of this study was to manipulate the macronutrient content of breakfast before exercise to investigate the impact on exercise energy expenditure and postexercise energy intake (EI). Methods: Twelve active men were recruited, 11 finished the study protocol (age: 28 ± 9 years; VO2max: 56 ± 5 ml·kg-1·min-1). In a randomized crossover design, each participant completed 4 trials, 3 consisting of a specific breakfast (protein, PRO; carbohydrate, CHO; noncaloric; NON-CAL) followed in 1 h by a 45 minutes moderate intensity treadmill exercise protocol. The fourth trial consisted of breakfast and no exercise (CON). An ad-libitum lunch and food for the rest of the day were provided and assessed for EI. Measures included resting metabolic rate pre- and postbreakfast along with oxygen uptake (VO2) during and after exercise, along with hunger scales, and blood measures of glucose, insulin and plasma-PYY prebreakfast, pre-exercise, postexercise, and 60 minutes postexercise. Results: Fat oxidation was highest during exercise in the NON-CAL (0.57 g·min-1) trial with similar levels of fat oxidation between PRO (0.50 g·min-1) and CHO trials (0.48 g·min-1). Hunger was not affected by PRO intake or exercise, nor was appetite hormones and glucose. EI at lunch and dinner was not significantly different between trials. Conclusion: Pre-exercise PRO intake did not modify fat oxidation during exercise, did not lead to a larger VO2 versus CHO, nor did it attenuate EI postexercise.

Cardiac Rehabilitation and Cardiopulmonary Fitness in Children and Young Adults With Congenital Heart Diseases: A Critically Appraised Topic.

Public health guidelines and a myriad of studies have proven that exercise is beneficial in the alleviation of various cardio-metabolic diseases. Congenital heart disease (ConHD) is one of the most frequently occurring congenital structural malfunctions in the pediatric population, affecting nine of every 1,000 live births. Only a few studies have established the impact of a structured exercise program on cardiopulmonary fitness in diverse groups of patients with ConHD. It is also alarming to know that a substantial number of these patients and their caregivers often remain very wary of exercise. Anxiety about exercise may increase the risk of developing morbid obesity and other long-term health complications of ConHD. The present review of a critically appraised topic is undertaken to answer the question, "Does structured exercise intervention (cardiac rehabilitation) improve cardiorespiratory fitness in children and young adults with ConHD?" Exercise science and the medical literature were searched for studies that engaged the use of aerobic exercise in patients with different ConHD diagnoses. The search yielded four studies after screening with the inclusion and exclusion criteria, which were further narrowed to three studies after a full-text review. These studies yielded results showing significant increments in peak exercise workload, duration, power output, peak oxygen uptake, or improved tissue oxygenation and muscle strength after an exercise training intervention. It is noteworthy that a group identified as "cyanotic palliated" exhibited the most significant impairment both at baseline and after the exercise intervention. This review provides level 1b medical evidence that a structured exercise program may improve cardiopulmonary fitness in patients with ConHD, which is likely to be beneficial to their overall physical, motor, and psychosocial development. The results of this review may be useful for alleviating the anxiety of patients and their caregivers about participation in structured exercise programs. This review should also motivate future research investigations to develop clinical guidelines for the management of patients with ConHD by adding exercise prescriptions to their daily therapeutic regimens.

Montmorency tart cherry supplementation does not impact sleep, body composition, cellular health, or blood pressure in healthy adults.

Background: Sleep disturbances are linked with cardiovascular and metabolic disease as well as poor body composition. Aim: To investigate the use of tart cherry supplements, which are high in antioxidants and may contain melatonin, on parameters of health such as sleep, body composition, cellular health, and blood pressure (BP). Methods: Forty-four participants had completed sleep record data and were included in this analysis. Participants consumed either two 240 ml bottles per day of Montmorency tart cherry (MTC) juice or placebo or two capsules per day of powdered MTC or placebo for 30 days. Participants tracked their sleep daily via questionnaire and completed body composition and BP assessments at baseline, 14 days, and 30 days after supplementation. Results: There were no significant differences in sleep time or quality between groups, though both increased over 30 days. The capsule groups had significantly lower body mass (BM) 14 days versus baseline for placebo group (p = 0.01, mean difference: 0.70 kg) and at 30 days versus 14 days in MTC group (p = 0.02, mean difference: 0.75 kg). No other differences in body composition or cellular health were found. BP was unaffected by MTC supplementation over 30 days. Despite the potential benefits of antioxidants and melatonin, we did not find improvements in sleep time or quality, cellular health or BP in participants consuming MTC for 30 days, though BM decreased in capsule groups. Conclusion: These results conflict with previous data on MTC and sleep and BP, therefore further investigation is warranted.

Ten Days of Curcumin Supplementation Attenuates Subjective Soreness and Maintains Muscular Power Following Plyometric Exercise.

Curcumin has become a popular product used to decrease inflammation and enhance recovery from exercise. PURPOSE: To determine the effects of curcumin supplementation on delayed onset muscle soreness and muscle power following plyometric exercise. METHODS: Participants (n = 22; five females, 17 males) consumed either curcumin (500 mg) or placebo twice daily for 10 days (6 days pre, day of and 3 days post exercise). Participants completed 5 x 20 drop jumps on day 7. Blood sampling and recovery tests were assessed at pre-supplementation, 24-hours and immediately pre-exercise, and immediately post-, 24, 48 and 72-hours post-exercise. Blood markers included serum creatine kinase (CK) and erythrocyte sedimentation rate (ESR), while soreness was measured during a squat and post vertical jump. RESULTS: Both groups experienced muscle damage post-exercise with elevated CK (403 ± 390 ul; p < 0.01), soreness with squatting (38 ± 29 mm; p < 0.01), and vertical jump (36 ± 30 mm; p < 0.01). Soreness was greater in placebo vs. curcumin 48 h and 72 h post-exercise (p < 0.01); however, CK was not significantly different between groups (p = 0.28) despite being >200 IU·L-1 greater 24 hr post exercise in placebo vs. curcumin. ESR was significantly greater immediately post-exercise (6.3 ± 5.6 vs. 3.4 ± 2.6 mm/hr; p = 0.03), however these were within the normal range for this test and not significantly different between groups (p = 0.25). Vertical jump decreased over time in the placebo, but not curcumin group (19.8 ± 4.8 vs. 21.4 ± 3.2 in; p = 0.01). CONCLUSION: These data suggest curcumin reduces soreness and maintains muscular power following plyometric exercise.

Impact of COVID-19 Stay-at-Home Restrictions on Employment Status, Physical Activity, and Sedentary Behavior.

BACKGROUND: North Americans report insufficient moderate-to-vigorous physical activity (MVPA) and ample sedentary behaviors (SBs), suggesting possible barriers to an active lifestyle. This study compared self-reported MVPA and SB before and during COVID-19 "Stay-at-Home" restrictions as a potential barrier across North America. METHODS: Questionnaires were distributed from 21 April to 9 May 2020. ANOVAs compared data overall and by group (age, sex, race, income, education, employment status). RESULTS: During restrictions, 51.4% (n = 687) of the 1336 responses (991 female, 1187 Caucasian, 634 18-29 years) shifted to work from home and 12.1% (n = 162) lost their job. Overall, during restrictions, 8.3% (n = 110) fewer reported work-related MVPA (-178.6 ± 20.9 min/week). Similarly, 28.0% (n = 374) fewer reported travel-related MVPA, especially females and younger age groups. While the 7.3% (n = 98) fewer reporting recreational MVPA was not statistically significant (-30.4 ± 11.5 min/week), there was an increase in SB (+94.9 ± 4.1 min/week) in all groups, except the oldest age group (70+ years). Locomotive activities and fitness class remained the predominant MVPA mode. Of those reportedly using facilities (68%; n = 709) before COVID, 31.3% (n = 418) would not return due to it "being unsafe". CONCLUSION: While barriers related to pandemic restrictions had a negative short-term impact on MVPA and SB in North America, the long-term impact is unknown.

Thirty Days of Montmorency Tart Cherry Supplementation Has No Effect on Gut Microbiome Composition, Inflammation, or Glycemic Control in Healthy Adults.

Tart cherries possess properties that may reduce inflammation and improve glycemic control, however human data on supplementation and the gut microbiota is equivocal. Processing (i.e., juice concentrate, dried, frozen) may affect the properties of tart cherries, and therefore alter their efficacious health benefits. Therefore, the purpose of this study was to investigate the effect of 30 days of supplementation with Montmorency tart cherry (MTC) in concentrate or freeze-dried form on the gut microbiome and markers of inflammation and glycemic control. Healthy participants with no known disease (n = 58, age: 28 ± 10 y, height: 169.76 ± 8.55 cm, body mass: 72.2 ± 12.9 kg) were randomly allocated to four groups and consumed either concentrate or freeze-dried capsules or their corresponding placebos for 30 days. Venous blood samples were drawn at baseline, day 7, 14, and 30 and analyzed for inflammatory markers TNF-alpha, uric acid, C-reactive protein, and erythrocyte sedimentation rate and glycemic control markers glycated albumin, glucose and insulin. A fecal sample was provided at baseline, day 14 and 30 for microbiome analysis. TNF-alpha was significantly lower at 30 vs. 14 days (p = 0.01), however there was no other significant change in the inflammatory markers. Insulin was not changed over time (p = 0.16) or between groups (p = 0.24), nor was glycated albumin different over time (p = 0.08) or between groups (p = 0.56), however glucose levels increased (p < 0.001) from baseline (4.79 ± 1.00 mmol·L-1) to 14 days (5.21 ± 1.02 mmol·L-1) and 30 days (5.61 ± 1.22 mmol·L-1) but this was no different between groups (p = 0.33). There was no significant change in composition of bacterial phyla, families, or subfamilies for the duration of this study nor was there a change in species richness. These data suggest that 30 days of MTC supplementation does not modulate the gut microbiome, inflammation, or improve glycemic control in a healthy, diverse group of adults. Clinical Trail Registration:https://clinicaltrials.gov/ct2/show/NCT04467372, identifier: NCT04467372.

Effects of Acute High-Intensity Exercise With the Elevation Training Mask or Hypoxicator on Pulmonary Function, Metabolism, and Hormones.

ABSTRACT: Ott, T, Joyce, MC, and Hillman, AR. Effects of acute high-intensity exercise with the elevation training mask or hypoxicator on pulmonary function, metabolism, and hormones. J Strength Cond Res 35(9): 2486-2491, 2021-The elevation training mask (ETM) 2.0 is an increasingly popular hands-free respiratory muscle training modality proposing to mimic altitude; however, the degree to which this occurs has been questioned. The purpose of this study was to investigate the efficacy of this modality in comparison with using a hypoxicator (HYP) during acute aerobic exercise. Eight regularly active subjects (age: 25 ± 8 years; height: 166 ± 12 cm; body mass 64 ± 10 kg; and V̇o2max: 46 ± 6 ml·kg-1·min-1) completed 3 trials, each including resting metabolic rate measurement, pulmonary function tests, and 13 sprint intervals at 90% V̇o2max using either the HYP, ETM, or control. There was no significant difference in metabolism or heart rate between conditions. Fraction of expired air in the first second was greater after exercise (p = 0.02), while oxygen saturation was lower during exercise with the HYP (p < 0.001). Human growth hormone increased with exercise, but no differences were found between conditions; however, a trend was observed for higher growth hormone after exercise in HYP vs. ETM (p = 0.08). Elevation training mask does not seem to change acute pulmonary function, metabolism, heart rate, or oxygen saturation, indicating it likely does not create a hypoxic environment or mimic altitude.

Acute Ingestion of Montmorency Tart Cherry Reduces Serum Uric Acid but Has no Impact on High Sensitivity C-Reactive Protein or Oxidative Capacity.

Tart cherries are particularly high in anthocyanins and are believed to have many health benefits, including reducing inflammation and oxidative stress. However, comparison between dosages and formulations are lacking. Forty-eight participants were randomly allocated to one of six experimental treatment groups where they ingested tart cherry or placebo in either juice (240 ml per bottle) or powdered capsule form (480 mg per capsule) once or twice daily for 48 h and markers of inflammation (uric acid (UA), high-sensitivity C-reactive protein (hsCRP)) and oxidative capacity (plasma oxygen radical absorbance capacity (ORAC)) were measured. There was a group x time interaction for UA (p = 0.02), which declined up to 24 h post ingestion for a single capsule dose, up to 8 h for a two capsule dose, and up to 2 h for a single juice dose. There was an increase in UA from 8 h until 48 h post ingestion in a single juice dose. Overall, there was an average 8% decrease in UA. There was no significant change over time in hsCRP (p = 0.64) or ORAC (p = 0.42) or between groups in hsCRP (p = 0.47) or ORAC (p = 0.21). Our data indicates tart cherry ingestion can transiently decrease UA and not maintained with continued supplementation. Additionally, there were differences in formulations and doses indicating a single powdered capsule is most effective for lowering UA suggesting capsules may be used by those who do not enjoy the taste of tart cherry juice. This study was registered at ClinicalTrials.gov , NCT04497077, 7/29/2020, retrospectively registered.

The effects of training status and exercise intensity on exercise-induced muscle damage.

BACKGROUND: Individuals participating in exercise beyond their level of fitness may be at higher risk for exercise-induced muscle damage, however the impact of training status on muscle damage development is not well understood. The purpose of this study was to measure skeletal muscle damage and soreness after five days of high and low intensity exercise in previously trained and untrained individuals. METHODS: Eighteen males and females (9 trained and 9 untrained) completed five consecutive days of high intensity (HI) exercise and five consecutive days of low intensity (LI) exercise. Blood was drawn at the initial visit and after completion of each exercise intensity period. RESULTS: CK was elevated post exercise for both groups during both intensities, but was greater in trained vs. untrained (HI: 203.6 vs. 143.4 IU/L and LI: 156.4 vs. 109.3 IU/L; P<0.01). Myoglobin was significantly higher after exercise for both groups (P<0.01) and was higher following high vs. low intensity in trained (P<0.01), but not untrained (P=0.052). Untrained experienced soreness following one day of high intensity exercise vs. after 3 days in trained participants (P=0.04, P=0.02). CONCLUSIONS: The current study suggests that high intensity exercise results in greater muscle damage in both trained and untrained individuals vs. low intensity exercise. However untrained participants experience more pain and with earlier onset and should therefore take caution when beginning exercise programs that require consecutive sessions of high intensity exercise.

Exercising in the Fasted State Reduced 24-Hour Energy Intake in Active Male Adults.

The effect of fasting prior to morning exercise on 24-hour energy intake was examined using a randomized, counterbalanced design. Participants (12 active, white males, 20.8 ± 3.0 years old, VO2max: 59.1 ± 5.7 mL/kg/min) fasted (NoBK) or received breakfast (BK) and then ran for 60 minutes at 60% VO2max. All food was weighed and measured for 24 hours. Measures of blood glucose and hunger were collected at 5 time points. Respiratory quotient (RQ) was measured during exercise. Generalized linear mixed models and paired sample t-tests examined differences between the conditions. Total 24-hour (BK: 19172 ± 4542 kJ versus NoBK: 15312 ± 4513 kJ; p < 0.001) and evening (BK: 12265 ± 4278 kJ versus NoBK: 10833 ± 4065; p = 0.039) energy intake and RQ (BK: 0.90 ± 0.03 versus NoBK: 0.86 ± 0.03; p < 0.001) were significantly higher in BK than NoBK. Blood glucose was significantly higher in BK than NoBK before exercise (5.2 ± 0.7 versus 4.5 ± 0.6 mmol/L; p = 0.025). Hunger was significantly lower for BK than NoBK before exercise, after exercise, and before lunch. Blood glucose and hunger were not associated with energy intake. Fasting before morning exercise decreased 24-hour energy intake and increased fat oxidation during exercise. Completing exercise in the morning in the fasted state may have implications for weight management.

Ramp-incremented and RPE-clamped test protocols elicit similar VO2max values in trained cyclists.

PURPOSE: The present study compared the efficacy of ramp incremented and ratings of perceived exertion (RPE)-clamped test protocols for eliciting maximal oxygen uptake (VO2max). METHODS: Sixteen trained cyclists (age 34 ± 7 years) performed a ramp-incremented protocol and an RPE-clamped protocol 1 week apart in a randomized, counterbalanced order. The RPE-clamped protocol consisted of five, 2-min stages where subjects self-selected work rate and pedal cadence to maintain the prescribed RPE. After completing both test protocols subjects were asked which they preferred. RESULTS: The mean ± SD test time of 568 ± 72 s in the ramp protocol was not significantly different to the 600 ± 0 s in the RPE-clamped protocol (mean difference = 32 s; p = 0.09), or was the VO2max of 3.86 ± 0.73 L min(-1) in the ramp protocol significantly different to the 3.87 ± 0.72 L min(-1) in the RPE-clamped protocol (mean difference = 0.002 L min(-1); p = 0.97). Furthermore, no significant differences were observed for peak power output (p = 0.21), maximal minute ventilation (p = 0.97), maximal respiratory exchange ratio (p = 0.09), maximal heart rate (p = 0.51), and post-test blood lactate concentration (p = 0.58). The VO2max attained in the preferred protocol was significantly higher than the non-preferred protocol (mean difference = 0.14 L min(-1); p = 0.03). CONCLUSION: The RPE-clamped test protocol was as effective as the ramp-incremented protocol for eliciting VO2max and could be considered as a valid alternative protocol, particularly where a fixed test duration is desirable.

A comparison of hyperhydration versus ad libitum fluid intake strategies on measures of oxidative stress, thermoregulation, and performance.

Dehydration has been shown to augment cellular stress. Glycerol hyperhydration can delay dehydration, which may decrease the level of pre- and post-exercise oxidative stress. This study aimed to compare the effects of glycerol (G) or water (W) hyperhydration with no hyperhydration (C) on oxidative stress, thermoregulation, and cycle performance. Seven trained males consumed 1.2 g of glycerol·kg⁻¹ body mass (BM) in 26 ml·kg⁻¹ BM water or equal volume water to achieve hyperhydration followed by a 90 min time trial. Total glutathione increased post exercise (PE) in all trials (p < 0.01), while oxidized glutathione (p < 0.05) and protein carbonyl concentrations (p < 0.001) were increased PE for the C trial only. Mean body temperature and heart rate increased with exercise but were not different between interventions. Total distance covered and power outputs were not different between interventions. Fluid intake attenuated oxidative stress but did not enhance thermoregulation or performance.

The physiological stress response to high-intensity sprint exercise following the ingestion of sodium bicarbonate.

The purpose of this study was to investigate the effects of pre-exercise alkalosis on the physiological stress response to high-intensity exercise. Seven physically active males (age 22 ± 3 years, height 1.82 ± 0.06 m, mass 81.3 ± 8.4 kg and peak power output 300 ± 22 W) performed a repeated sprint cycle exercise following a dose of 0.3 g kg(-1) body mass of sodium bicarbonate (NaHCO(3)) (BICARB), or a placebo of 0.045 g kg(-1) body mass of sodium chloride (PLAC). Monocyte-expressed heat shock protein 72 (HSP72) and plasma thiobarbituric acid reactive substances (TBARS) were significantly attenuated in BICARB compared to PLAC (p = 0.04 and p = 0.039, respectively), however total anti-oxidant capacity, the ratio of oxidised to total glutathione, cortisol, interleukin 6 and interleukin 8 were not significantly induced by the exercise. In conclusion, monocyte-expressed HSP72 is significantly increased following high-intensity anaerobic exercise, and its attenuation following such exercise with the ingestion of NaHCO(3) is unlikely to be due to a decreased oxidative stress.

Hypoxia-mediated prior induction of monocyte-expressed HSP72 and HSP32 provides protection to the disturbances to redox balance associated with human sub-maximal aerobic exercise.

HSP72 is rapidly expressed in response to a variety of stressors in vitro and in vivo (including hypoxia). This project sought a hypoxic stimulus to elicit increases in HSP72 and HSP32 in attempts to confer protection to the sub-maximal aerobic exercise-induced disturbances to redox balance. Eight healthy recreationally active male subjects were exposed to five consecutive days of once-daily hypoxia (2,980 m, 75 min). Seven days prior to the hypoxic acclimation period, subjects performed 60 min of cycling on a cycle ergometer (exercise bout 1-EXB1), and this exercise bout was repeated 1 day post-cessation of the hypoxic period (exercise bout 2-EXB2). Blood samples were taken immediately pre- and post-exercise and 1, 4 and 8 h post-exercise for HSP72 and immediately pre, post and 1 h post-exercise for HSP32, TBARS and glutathione [reduced (GSH), oxidised (GSSG) and total (TGSH)], with additional blood samples obtained immediately pre-day 1 and post-day 5 of the hypoxic acclimation period for the same indices. Monocyte-expressed HSP32 and HSP72 were analysed by flow cytometry, with measures of oxidative stress accessed by commercially available kits. There were significant increases in HSP72 (P < 0.001), HSP32 (P = 0.03), GSSG (t = 9.5, P < 0.001) and TBARS (t = 5.6, P = 0.001) in response to the 5-day hypoxic intervention, whereas no significant changes were observed for GSH (P = 0.22) and TGSH (P = 0.25). Exercise-induced significant increases in HSP72 (P < 0.001) and HSP32 (P = 0.003) post-exercise in EXB1; this response was absent for HSP72 (P ≥ 0.79) and HSP32 (P ≥ 0.99) post-EXB2. The hypoxia-mediated increased bio-available HSP32 and HSP72 and favourable alterations in glutathione redox, prior to exercise commencing in EXB2 compared to EXB1, may acquiesce the disturbances to redox balance encountered during the second physiologically identical exercise bout.

Exercise-induced dehydration with and without environmental heat stress results in increased oxidative stress.

While in vitro work has revealed that dehydration and hyperthermia can elicit increased cellular and oxidative stress, in vivo research linking dehydration, hyperthermia, and oxidative stress is limited. The purpose of this study was to investigate the effects of exercise-induced dehydration with and without hyperthermia on oxidative stress. Seven healthy male, trained cyclists (power output (W) at lactate threshold (LT): 199 ± 19 W) completed 90 min of cycling exercise at 95% LT followed by a 5-km time trial (TT) in 4 trials: (i) euhydration in a warm environment (EU-W, control), (ii) dehydration in a warm environment (DE-W), (iii) euhydration in a thermoneutral environment (EU-T), and (iv) dehydration in a thermoneutral environment (DE-T) (W: 33.9 ± 0.9 °C; T: 23.0 ± 1.0 °C). Oxidized glutathione (GSSG) increased significantly postexercise in dehydration trials only (DE-W: p < 0.01, DE-T: p = 0.03), and while not significant, total glutathione (TGSH) and thiobarbituric acid reactive substances (TBARS) tended to increase postexercise in dehydration trials (p = 0.08 for both). Monocyte heat shock protein 72 (HSP72) concentration was increased (p = 0.01) while lymphocyte HSP32 concentration was decreased for all trials (p = 0.02). Exercise-induced dehydration led to an increase in GSSG concentration while maintenance of euhydration attenuated these increases regardless of environmental condition. Additionally, we found evidence of increased cellular stress (measured via HSP) during all trials independent of hydration status and environment. Finally, both 90-min and 5-km TT performances were reduced during only the DE-W trial, likely a result of combined cellular stress, hyperthermia, and dehydration. These findings highlight the importance of fluid consumption during exercise to attenuate thermal and oxidative stress during prolonged exercise in the heat.