In this case series study, pulmonary artery systolic, diastolic, and mean pressures of 2 participants with obesity and heart failure with preserved ejection fraction were measured at zero gravity during parabolic flight to assess the effect of external constraint on left ventricular filling pressures.
PURPOSE: To examine the effects of controlled (volume/body mass) ingestion of cold water and water slushy on performance in a dry, hot environment in subjects of average cardiorespiratory fitness. METHODS: Males (n=15, 23±2 yr, 84±21 kg, 176±7 cm) of average cardiorespiratory fitness (cycle VO2PEAK=38±9 ml·kg-1·min-1) participated in 3 heat trials (34.0±0.6°C, 41±3%RH, 3.6 km·hr-1) where they exercised at 70% VO2PEAK to volitional maximum on a cycle ergometer. During trials subjects consumed 2.5 g·kg-1 of 22°C water (room = RM), 4°C water (cold = CD), or -1°C water slushy (SL) every 10 min in a balanced crossover design. Exercise time (ExT), heart rate (HR), mean skin temperature (MTsk), rating of perceived exertion (RPE, 0-10), sweat rate (SR), and pre/post core temperature change (ΔTco) were measured. Subjects were blind to the measurement of ExT and its use with RPE as a dependent variable. One way (beverage) or two way (beverage x time) repeated measures ANOVA was used (α=0.05). RESULTS: ExT was not different between the trials (CD=34±9, SL=35±10, RM=31±9 min) but a trend was noted (p=0.0680) suggesting SL>RM. Supporting this trend was the fact that all subjects had their longest ExT on CD (n=10) or SL (n=5) trials. Neither ΔTco (CD=0.69±0.4, SL=0.64±0.4, RM=0.77±0.4°C) or SR (CD=1545±1108, SL=1837±691, RM=1890±489 ml·hr-1) differed between trials (p>0.05). As expected, a significant main effect for time was seen in HR, MTsk, and RPE where all three increased with exposure time (p=0.0001). No main effect for beverage was observed for either MTsk (CD=36.1±0.4, SL=36.0±0.4, RM=36.2±0.3°C) or RPE (CD=4.2±1.5, SL=4.5±2.0, RM=4.8±1.9), and no beverage x time interactions (p>0.05) were observed. A main effect for beverage was seen in HR (CD=157±16, SL=153±18, RM=160±17 bpm) where SL
To investigate the acute cardiometabolic responses of a 7-minute bodyweight resistance exercise circuit (HICE) compared to a 7-minute high intensity interval training cycle protocol (HIIE).
South Texas presents a greater risk of heat stress/injury to outdoor athletes than many other regions, particularly in August when high school football practices begin. Texas' governing body of high school athletics (UIL) regulates only when summer practices may begin, practice length, and time between practices. PURPOSE: To describe practice conditions influencing the risk of heat stress to athletes in summer football training in South Texas high schools, and compare these conditions to ACSM recommendations for risk reduction in this population. METHODS: High school summer football practices (N=30) were observed when schools had control over practice scheduling/structure within UIL rules. Wet bulb globe temperature (WBGT) was measured before/after practices and practices were observed for: duration/ structure; athlete clothing; and break frequency/duration/ content. RESULTS: Practice sessions averaged 125+31 min in length and WBGT (pre- to post-practice) was 29.7+2.1°C to 31.2+2.2°C for morning practices, and 31.2+1.6°C to 28.9+1.2°C for evening practices. Most practices included contact (93%), and the majority were full-contact (53%). Most athletes wore full pads (83%) and dressed in medium/dark colored clothing (73%). In a majority of practices, athletes were observed outside of scheduled breaks removing their helmets (63%), sitting/kneeling (63%), and having fluid available to them (90%). Athletic trainers were present on 93% of the practice fields. A typical practice had 3 rest breaks, each lasting approximately 6 min. During most breaks athletes were provided fluid (93%), removed their helmets (89%), and were able to sit/kneel (76%). Rarely was shade available during breaks (2%) and ice tubs were available on-field at only 3% of the practices. CONCLUSIONS: While none of the practice sessions were conducted in conditions warranting the cancellation of outside activity (>33.1°C) according to ACSM, the environmental data presented confirms that this region presents athletes with a very high risk of heat stress/injury. However, it was observed in a majority of the practices that schools were taking most of the precautionary measures recommended by the 2005 ACSM consensus statement. The exceptions being the wearing of light colored clothing, providing of shade during breaks, and access to ice tubs.
The concept of understanding attention and its importance to learning and performance has been established in the literature and on the playing field. The identification and application of key attention-related concepts that are useful to athletes can emphasize the following theoretical concepts: (a) attentional focus, (b) arousal, (c) self-talk, and (d) range of motion restriction. The applications of specific strategies (including how to design your own self-talk) that target the aforementioned concepts to improve performance are explained through examples of activities or scenarios appropriateforcoaches.Additionally,thismanuscriptprovidessuggestions that will improve performance by enhancing an athlete’s attentional skills.
Farney, TM, Bliss, MV, Hearon, CM, and Salazar, DA. The effect of citrulline malate supplementation on muscle fatigue among healthy participants. J Strength Cond Res 33(9): 2464-2470, 2019-The focus of the investigation was to examine the effects of citrulline malate (CM) on muscular fatigue in healthy, recreationally trained participants. Twelve participants (men = 6 and women = 6) (24.1 ± 3.9 years) visited the laboratory on 3 separate days, all separated by 1 week. Each visit consisted of consuming 1 of 3 treatments: placebo, CM (8 g), and control in which no drink mixture was consumed. For each day of testing, participants consumed assigned treatment and performed 1 high-intensity exercise trial consisting of squats, lunge jumps, squat jumps, and lateral jumps. Participants performed the exercises in the listed order, which was designated as 1 round. Each participant performed 3 rounds, with the work-to-rest ratio being 20 seconds of work and 30 seconds of rest. A 1-minute rest was given between rounds. A pre/post-exercise isokinetic leg extension test was performed to measure for peak power, peak torque, and rate of fatigue. In addition, blood lactate was obtained pre/post-exercise. There were no treatment or interaction effects (p > 0.05) for peak torque, peak power, rate of fatigue, or blood lactate accumulation. However, there was a statistical significant decrease from pre/post-exercise for peak torque (p = 0.003), peak power (p = 0.003), and rate of fatigue (p = 0.001). In addition, lactate accumulation did increase significantly from pre/post-exercise (p = 0.0001). Finally, neither total work nor final heart rate was statistically significant between the treatments (p > 0.05). Citrulline malate was not effective in improving performance or alleviating fatigue after a high-intensity exercise session.
Background: There are no proven pharmacologic strategies for HFpEF; therefore, lifestyle interventions must be developed to prevent disease progression in those at high risk for developing HFpEF (Stage A). We performed a randomized, double blind, placebo controlled trial evaluating the effect of 1-year of high intensity interval training (HIIT) and polyunsaturated fatty acid supplementation (PUFA) on key risk factors in Stage A HFpEF. Hypothesis: Long duration (1-year) HIIT and PUFA (1.6g/daily Omega-3-Acid Ethyl Esters) will reduce visceral adiposity, improve aerobic fitness, and reverse vascular stiffness in middle-aged subjects with cardio-metabolic risk factors. Methods: Individuals with stage A HFpEF (n= 73; 40-55 years; BMI>30 kg/m 2 ; visceral fat > 2 kg; NT-proBNP>40pg/ml or hscTnT>3.0 pg/ml) were randomized to HIIT + PUFA (n=22)/placebo (n=24) or yoga + PUFA (n=15)/placebo (n=19). We assessed visceral fat (DEXA), aerobic fitness (VO 2 max), cardiac output (Q C , acetylene rebreathe), peripheral oxygen extraction (a-vO 2 -difference), and arterial stiffness (pulse wave velocity and augmentation index; tonometry). Data are presented as mean change and 95% CI. Results: 1-year of HIIT decreased body fat (-1.26%, CI: -2.43 to -0.58; p=0.036) and had a similar but less consistent effect on visceral fat (-0.28 kg, CI: -0.62 to 0.04; p=0.083). Aerobic capacity increased by ~24% (ΔVO 2 : 4.41 mL/kg/min, CI: 3.22 to 5.61; p<0.0001), due to improved peak Q C (1.84 L/min, CI: 0.34 to 2.24; p=0.017) and a-vO 2 -difference (1.31 mL/100mL, CI: 0.13 to 2.49; p=0.031). While large elastic arterial stiffness was unchanged (PWV: -21 cm/s, CI: -61 to 19; p=0.299), augmentation index was reduced (-5.23%, CI: -9.18 to -1.35; p=0.009) indicative of improved ventricular-arterial coupling. There was no independent effect of PUFA, or interaction between HIIT and PUFA for any outcomes. Conclusions: 1-year HIIT improved leanness, aerobic fitness, peak Q C and a-vO 2 -difference, and ventricular-arterial coupling in middle-aged Stage A HFpEF. There was no independent or additive effect of PUFA administration. This is the first randomized trial to demonstrate that regular HIIT can reverse cardiometabolic impairments in Stage A HFpEF.
