Medicine and Science in Sports and Exercise最新文献

Background: Few studies have examined the longitudinal associations of accelerometer-based measures of sedentary and physical activity behaviors with subclinical heart failure (HF) in midlife. This is a key gap given an improved understanding of modifiable factors associated with HF risk may better inform prevention strategies. We hypothesize that more time in light intensity physical activity (LIPA) and/or moderate or vigorous intensity physical activity (MVPA) and less sedentary time will be related to lower levels of HF biomarkers [N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hscTnT)] across midlife.

Methods: Data are from 2,494 Coronary Artery Risk Development in Young Adults (CARDIA) participants without clinical HF [58.9% women, 45.7% Black persons, mean (± SD) aged 51.1 ± 7.2 years at the baseline contributing exam] with at least one occurrence of concurrent valid accelerometer (ActiGraph 7164/GT3X; Ametris; Pensacola, FL) wear and HF biomarkers at the CARDIA Year 20, 30 and/or Year 35 follow-up examinations. Adjusted linear mixed effects models were used to estimate the associations. Heterogeneity in the associations by the four race-sex groups represented in CARDIA was also examined.

Results: In the fully adjusted models, every 5-minute higher MVPA was associated with -0.05 (95% CI: -0.09 to -0.01, p = 0.022) lower hscTnT. The associations of sedentary and LIPA with hscTnT and associations of any accelerometer estimate with NT-proBNP were not statistically supported (all p>0.05). Findings were similar when clinically relevant categories of HF biomarker outcomes were used in the analysis.

Conclusions: Findings address research gaps in the literature and demonstrate the importance of MVPA during the midlife transition for HF prevention before the onset of overt signs or symptoms.

Purpose: Physical activity (PA) is a key strategy in preventing and treating metabolic syndrome (MetS). The purpose is to investigate the associations of leisure-time PA (LTPA) trajectories across adulthood and current PA with MetS at age 61.

Methods: Participants were 159 Finnish adults (52% women). LTPA frequency was assessed at ages 27, 42, 50, and 61 with a single question. Current PA at age 61 included self-reported vigorous, muscle-strengthening, commuting, and occupational PA. Cardiometabolic risk factors at age 61 included waist circumference, blood pressure, high-density lipoprotein (HDL) cholesterol, triglycerides, and glucose. MetS was defined based on the ATP III criteria. LTPA trajectories were conducted using k means for longitudinal data.

Results: Of the three LTPA trajectories found, consistently inactive (N=34) and increasingly active (N=58) had a higher risk of MetS compared to consistently active (N=67) (odds ratio [95% confidence interval]: 3.93 [1.55, 10.01] and 2.39 [1.14, 4.99], respectively). Only the difference between consistently inactive and consistently active remained statistically significant when the current PA indicators were included in the model. Considering the individual components of MetS, those who were consistently inactive and increasingly active had higher waist circumference, lower HDL, and higher triglyceride levels compared to consistently active. These differences did not remain statistically significant when current PA was included.

Conclusions: Although consistently inactive and increasingly active individuals had higher cardiometabolic risk at age 61 compared to those who were consistently active across adulthood, current PA participation at the beginning of late adulthood attenuated these risks. These findings emphasize the importance of promoting and sustaining PA throughout life to reduce the burden of MetS in the aging population.

Purpose: Although most patients recover well from COVID-19 infection, this may not be the case of those who experienced severe dysfunction after being admitted to intensive care unit (ICU). This study aimed to assess the recovery of patients who experienced severe multiple dysfunctions after being admitted to ICU for COVID-19 infection.

Methods: Forty-seven patients hospitalized and mechanically ventilated in ICU for SARS-CoV-2 infection underwent evaluations at 4 to 8 wk (T1) and 6 months (T2) post-ICU discharge. Evaluations included questionnaires, lung function tests, incremental cardiopulmonary exercise testing, and neuromuscular function tests.

Results: From T1 to T2, the percentage of patients classified as fatigued decreased from 56% to 21% whereas forced vital capacity and the forced expiratory volume in 1 s increased by 13% and 8% ( P < 0.05) to reach 93% and 95% of predicted values at T2, respectively. Peak work rate also increased from 97 to 135 W (+35 ± 32%, P < 0.001). Likewise, V̇O 2peak increased from 18.3 to 21.6 mL·min -1 ·kg -1 (+18 ± 27%, P < 0.001) to reach 72% of predicted values. Maximal strength and the number of contractions during the fatigability test increased between T1 and T2 by 41% and 39%, respectively (both P < 0.001).

Conclusions: Six months of recovery improved patients' physical function and reduced fatigue.

Purpose: We aimed to investigate whether the addition of carbohydrates (sucrose [Suc] or isomaltulose [Iso]) to a beverage containing glycerol (Gly) and sodium (Na) would enhance fluid balance, thermoregulatory response, and high-intensity exercise capacity during exercise in hot environments.

Methods: In a randomized, double-blinded, and crossover study, 13 healthy men consumed 1 L of beverage containing 1) 7% Gly + 0.5% Na (Gly + Na), 2) Gly + Na with 7% Suc (Gly + Na + Suc), 3) Gly + Na with 7% Iso (Gly + Na + Iso), or 4) water (CON) over 40 min in a hot environment (32°C, 50% relative humidity). Participants then completed three 30-min cycling bouts at 50% peak oxygen consumption (V̇O 2peak ), followed by a time-to-exhaustion (TTE) trial at 80% V̇O 2peak . Fluid balance and thermoregulatory response were assessed throughout the experiment.

Results: Compared with CON, beverages containing Gly and Na attenuated the total urine volume (all P < 0.001), and the addition of Iso (331 ± 84 g) further encouraged this response compared with Gly + Na and Gly + Na + Suc (429 ± 68 and 445 ± 133 g, respectively, both P ≤ 0.030). Compared with CON, the plasma volume increased with Gly + Na + Suc during the first exercise bout (-2.2% ± 6.7% and 4.3% ± 5.4%, respectively, P = 0.048) and with Gly + Na + Iso during the TTE (-9.1% ± 4.4% and -4.1% ± 4.0%, respectively, P = 0.025). The rectal temperature increased whereas local sweating responses were reduced more with Gly- and Na-containing beverages than with CON (all P ≤ 0.028). No differences were found in TTE among the beverages ( P = 0.159).

Conclusions: Adding Suc or Iso to Gly- and Na-contained beverages partially improves fluid balance but does not improve thermoregulatory responses and performance during moderate-intensity exercise in hot environments.

Purpose: Load carriage and tactical mobility are military tasks that pose significant risks for musculoskeletal injuries (MSKI) in military personnel. This investigation compared biomechanical and physiological demands of a load carriage and tactical mobility task and examined their differences between sexes using reliable and validated wearables among United States Marine officer candidates.

Methods: Forty-one candidates (16 women) performed a 15.8-km loaded ruck march and a 4.0-km endurance course that assessed load carriage and tactical mobility performance, respectively. Inertial measurement units on the distal tibia and wrist-worn watches collected biomechanical (total step count, impact load, bone stimulus, average intensity, low-/medium-/high-g step count) and physiological (heart rate (HR mean , HR min , HR max ), physical activity energy expenditure (PAEE), and metabolic equivalent (MET mean )) data. Paired sample t -tests compared metrics between events. Principal component (PC) analyses interpreted event demands. Independent samples t -tests analyzed sex differences between PCs ( α = 0.05).

Results: Impact load (+1259.70 g ·min -1 , P < 0.001), average intensity (+7.20 g , P < 0.001), bone stimulus (+126.73 AU, P < 0.001), high- g steps (+559.34 g , P < 0.001), HR min (+13.15 bpm, P < 0.001), HR mean (+28.79 bpm, P < 0.001), HR max (+16.95 bpm, P < 0.001), and MET mean (-1.93 kcal·kg -1 ·h -1 , P < 0.001) were higher during the endurance course than the ruck; step count (-14,934, P < 0.001) and PAEE (-713 kcal, P < 0.001) were lower. Three PCs explained 84.3% and 81.5% of variance for the ruck and endurance course. PC1 represented biomechanical variables, PC2 physiological variables, and PC3 g step count. Sex differences were found in PC2 ( P = 0.039) and PC3 ( P = 0.002) for the ruck, and PC3 ( P < 0.01) for the endurance course revealing greater demands on women.

Conclusions: Tactical mobility requires greater biomechanical and physiological demands than load carriage and places greater demands on women. Task and sex-specific training strategies may improve performance and mitigate MSKI risk.

Purpose: This secondary analysis of a randomized controlled trial (RCT) of resistance exercise training (RET) compared with a waitlist quantified the acute effects of a single resistance exercise session on depressed mood state.

Methods: Sixty-two young adults (26.6 ± 5.6 yr; 39 female) were randomized to 8 wk of World Health Organization and American College of Sports Medicine guidelines-based RET or a waitlist, with an acute RCT nested in at week 1. In the first session, RET participants completed moderate-intensity resistance exercise, comprising two sets of 8-12 repetitions of eight exercises targeting the major muscle groups. Waitlist participants completed 30 min of quiet rest. The Depression subscale of the Profile of Mood States Brief Form (POMS-B) measured depressed mood state pre- and 10 min post-session. Two group × two time (pre/post) RMANOVAs examined differences between resistance exercise and quiet rest. Subanalyses were conducted among young adults with analogue generalized anxiety disorder (AGAD), major depressive disorder (AMDD), comorbid AGAD and AMDD, and pre-exercise POMS-B ≥1 and ≥4.

Results: No significant group-time interaction ( F(1,59) = 1.70, P = 0.198) was found for depressed mood state. Significant main effects for time were found among the total ( F(1,59) = 14.74, P < 0.001), AGAD ( F(1,28) = 13.22, P ≤ 0.001), AMDD ( F(1,12) = 5.12, P ≤ 0.043), POMS-B ≥1 ( F(1,31) = 30.29, P < 0.001) and ≥4 ( F(1,11) = 10.71, P = 0.007) samples, such that depressed mood state reduced following a single bout of resistance exercise ( d = 0.29 to 1.26) and quiet rest ( d = 0.27 to 0.39).

Conclusions: Resistance exercise and quiet rest elicited significant small-to-large and small-to-moderate magnitude reductions in depressed mood state, respectively, that were not significantly different from each other.

Background/purpose: Current knowledge of the association between body composition and health outcomes is based on traditional regression techniques, where the components of body composition are treated as noncompositional independent variables. Mounting evidence suggests that body tissues are biologically co-dependent and therefore, require a statistical technique that considers this. This study used a compositional data analysis framework to explore the longitudinal association between body composition and a continuous metabolic syndrome score.

Methods: Participants included 288 physically inactive adults (age: 56 ± 12 yr [mean ± SD]; 56% female) with overweight or obesity (body mass index: 31.3 ± 3.5 kg·m 2 ) who participated in randomized controlled trials that determined the effects of exercise on adipose tissue (visceral, abdominal subcutaneous, peripheral subcutaneous, other adipose tissues) and lean tissues (skeletal muscle, other lean tissues) assessed by whole-body magnetic resonance imaging.

Results: Visceral adipose tissue, relative to the mass of the remaining tissues, was significantly associated with the metabolic syndrome score preintervention and postintervention ( P < 0.05). The slopes and intercepts of the preintervention and postintervention regression lines between relative visceral adipose tissue mass and metabolic syndrome did not differ ( P > 0.2). For a given weight loss, the greater the relative reduction in visceral adipose tissue, the larger the decrease in the predicted metabolic syndrome score.

Conclusions: This novel compositional data analysis reinforces that visceral adipose tissue is an important marker of cardiometabolic risk and should be a primary target for therapeutic strategies in individuals with overweight or obesity.

Purpose: Military training includes multiple stressors that together may increase risk for illness by degrading immune function and altering gut microbiota. However, whether sex differences exist in those responses is undetermined. This study aimed to determine immune and gut microbiota responses during military training and identify sex differences in those responses.

Methods: Seventy-two military cadets (33% female) participated in an arduous 17-d training event. Blood, saliva, and stool were collected upon beginning (PRE) and completing (POST) training. Immune function was assessed by salivary secretory IgA (SIgA), latent virus reactivation, peripheral leukocyte distribution, circulating cytokines, and mitogen-stimulated cytokine profiles. Gut microbiota composition was assessed by 16S rRNA amplicon sequencing.

Results: Participants experienced a ~4% body weight loss and sex-independent increases in concentrations of cortisol, myoglobin, catecholamines, and multiple cytokines. The granulocyte-to-lymphocyte ratio increased and SIgA decreased PRE to POST in males but not females ( Pinteraction ≤ 0.02). Mitogen-stimulated cytokine profiles were generally reduced at POST versus PRE independent of sex. No differences in virus reactivation were observed. Sex differences in gut microbiota responses were limited to Bifidobacterium and Ruminococcus , which increased in males relative to females (log 2 fold change (FC) = 2.0-2.4; qinteraction = 0.19). Independent of sex, 24 genera differed at POST versus PRE with Lactobacillus demonstrating the largest decrease (log 2 FC = -0.90; qtime = 0.02) and Veillonella the largest increase (log 2 FC = 1.09; qtime = 0.03). Multiple correlations between markers of stress, immune function, and gut microbiota composition were observed ( q ≤ 0.15).

Conclusions: Immune redistribution, leukocyte compromise, and interrelated changes in gut microbiota composition were evident within this training environment. Those responses demonstrated associations with markers of stress severity but also sex differences, suggesting a more pronounced depression of immune function in males.

Background: Prior high-intensity exercise (priming) has been shown to accelerate the oxygen uptake (V̇O 2 ) kinetics, as well as improve exercise tolerance during subsequent high-intensity exercise, yet the mechanisms underpinning the performance changes are unclear. In theory, a reduced reliance on non-oxidative energy input afforded by the faster V̇O 2 response may improve subsequent performance by delaying muscle fatigue; however, this effect has yet to be conclusively shown.

Purpose: Our purpose was to explore the impact of priming exercise on the energetic response, exercise tolerance, and the kinetics of muscle fatigue during severe-intensity cycling exercise.

Methods: Fourteen participants completed constant power cycling trials in the severe domain, preceded by either a bout of heavy intensity or an equivalent duration cycling at 20 W. Muscle fatigue was assessed in real time via femoral nerve stimulation while pedaling, and energetic contributions were assessed via V̇O 2 and changes in blood lactate concentration. Quadriceps oxygenation and surface electromyography (EMG) were also measured.

Results: Priming improved time-to-task failure (450 ± 74 s) compared with control (391 ± 92 s) ( P = 0.008). Relative oxidative contributions increased following priming ( P = 0.001), whereas the non-oxidative glycolytic contribution was reduced ( P < 0.0001), and this was accompanied by a reduction in the rate of quadriceps twitch force decline ( P = 0.041). Vastus lateralis EMG root mean square amplitude and M-wave amplitude increased across the trial similarly in both conditions, but priming resulted in a relative "downshift" in both measures ( P ≤ 0.027).

Conclusions: Priming exercise resulted in an improvement in exercise tolerance, attenuation in muscle fatigue, and reduction in EMG and M-wave amplitude. We speculate that these effects may arise in part from the interaction between a reduction in metabolite accumulation and altered sarcolemmal excitability.

Purpose: A common side effect of cancer and anticancer treatment is cancer-associated cachexia (CAC), a multifactorial syndrome characterized by the loss of bodyweight, skeletal muscle, and adipose tissue. Recommended therapeutic options are multidimensional, including nutritional, pharmacological, and exercise interventions. A novel therapeutic approach is the use of low-load resistance training combined with blood flow restriction to the trained limbs (LL-BFR). It has been shown to induce adaptations in muscle mass and strength despite a low training load in various clinical populations and might be a suitable training modality for cancer patients suffering from CAC.

Methods: A 56-year-old female patient diagnosed with stage IV gallbladder cancer, suffering from CAC, performed LL-BFR training twice weekly for 12 wk and received a guideline-based nutritional intervention. All outcome measures (maximal strength (8RM), handgrip strength, body mass, lean body mass, body cell mass, quality of life (QoL), and symptom burden) were evaluated before and directly after the training period.

Results: Adherence was moderate (67% of all training sessions completed), and no adverse events were noted. All measures of physical capacity and body composition improved between 19% to 55% and 9% to 11%, respectively. QoL decreased in 5/6 subscales, while symptom burden increased in 2/4 subscales.

Conclusions: Treatment of CAC requires a multitargeted and interdisciplinary approach. This is the first case study using LL-BFR training in an oncological patient during active therapy. Our results show that LL-BFR was feasible and, despite no positive effect on QoL and symptom burden, could induce relevant changes of muscle strength and muscle mass in a relatively short training period. Further research is necessary to confirm the results of this case study in randomized controlled trials.