Sex Differences in the Ergogenic Response of Acute Caffeine Intake on Muscular Strength, Power and Endurance Performance in Resistance-Trained Individuals: A Randomized Controlled Trial.

BACKGROUND: This study assessed the impact of acute caffeine intake on muscular strength, power, and endurance performance between resistance-trained male and female individuals according to load in upper- and lower-body exercises. METHODS: Here, 76 resistance-trained individuals (38 females, 38 males) participated in a study comparing caffeine and a placebo. Each received either 3 mg/kg of caffeine or a placebo 60 min before tests measuring muscular strength and power through bench press and back squat exercises at different intensities (25%, 50%, 75%, 90% 1RM). Muscular endurance at 65% 1RM was also assessed by performing reps until reaching task failure. RESULTS: Compared to placebo, caffeine increased mean, peak and time to reach peak velocity and power output (p < 0.01, ηp2 = 0.242-0.293) in the muscular strength/power test in males and females. This effect was particularly observed in the back squat exercise at 50%, 75% and 90% 1RM (2.5-8.5%, p < 0.05, g = 1.0-2.4). For muscular endurance, caffeine increased the number of repetitions, mean velocity and power output (p < 0.001, ηp2 = 0.177-0.255) in both sexes and exercises (3.0-8.9%, p < 0.05, g = 0.15-0.33). CONCLUSIONS: Acute caffeine intake resulted in a similar ergogenic effect on muscular strength, power, and endurance performance in upper- and lower-body exercises for male and female resistance-trained participants.

A factorization-based algorithm to predict EMG data using only kinematics information.

EMG analyses have several applications, such as identifying muscle excitation patterns during rehabilitation or training plans, or controlling EMG-driven devices. However, experimental measurements can be time consuming or difficult to obtain. This study presents a simple algorithm to predict EMG signals that can be applied in real time during running, given only the instantaneous vector of kinematics. We hypothesize that the factorization of the kinematics of the skeleton together with the EMG data of calibration subjects could be used to predict EMG data of another subject only using the kinematic information. The results showed that EMG signals of lower-limb muscles can be predicted accurately in less than a second using this method. Correlation coefficients between predicted and experimental EMG signals were higher than 0.7 in 10 out of 11 muscles for most prediction trials and subjects, and their overall median value was higher than 0.8. These values confirm that this method could be used to accurately predict EMG signals in real time when only kinematics are measured.

Real-world use of key performance indicators for point-of-Care Testing network accredited by ISO 22870.

OBJECTIVE: We aimed to evaluate the results of key performance indicators (KPIs) for a period of over three years, as well as their effectiveness as an improvement tool, to provide information about Point-of-Care Testing (POCT) management system performance and quality assurance. DESIGN AND METHODS: KPIs regarding the global POCT process, extra-analytical phase, quality assurance and staff training and competency were evaluated for blood gases, HbA1c, sweat test and non-connected and connected glucose in an ISO 22870 accredited network. We established the definition of every KPI and its corresponding target. The results of KPIs from all clinical settings were appraised every month during the study period, taking corrective actions when necessary. RESULTS: Annual global results were generally acceptable. However, some clinical areas displayed deviations in specific months. The monitoring of these KPIs allowed us to detect the deviations immediately and identify their causes. These included errors in patient identification, consumables, strips, reagents, analyzers, calibration, internal and external quality control, sample management, connectivity, and operator identification strategy, among others. CONCLUSIONS: The evaluation of these KPIs over time has shown their appropriateness. This set of quality indicators could be a useful tool for laboratory medicine leading POCT networks for better and safer patient care.

Dosimetric Comparison of Four Volumetric-Modulated Arc Therapy Beam Arrangements Utilized for Hippocampal-Sparing Whole-Brain Radiation Therapy.

PURPOSE: In the present study, the performance of four VMAT beam arrangements used for hippocampal-sparing whole-brain radiation therapy is addressed. MATERIAL AND METHODS: Data corresponding to 20 patients were utilized so as to generate plans for every beam configuration. A preliminary study was conducted to assess the optimal distance between optimization structures (PTVx) and hippocampi. V25, V30, D50%, D2%, D98%, homogeneity index (HI) and Paddick conformity factor (CF) were evaluated for PTV. D100% and Dmax were considered for hippocampi. All plans were required to perform at least as recommended in RTOG 0933 trial regarding organs at risk (OAR) sparing and PTV objectives. RESULTS: Considerable hippocampi sparing alongside with a reasonably low decrease in PTV coverage was achieved using a 7 mm distance between hippocampi and PTV optimization structure. Beam setup 3 (comprised of two full arcs with 0° couch angle and two half arcs with 90° couch angle) achieved the best PTV coverage, HI and CF, while it performed the second-best sparing in hippocampi and lenses. Moreover, beam setup 3 was the second-fastest treatment, although it resulted in the highest number of delivered MU among all beam setups. Beam setup 1 (comprised of two full arcs with no couch angles) was the fastest and it delivered a significantly less amount of monitor units compared with the other beam setups evaluated. Furthermore, a higher robustness was obtained by using no couch angles. Although beam setup 1 was the least optimal considering OAR sparing, it still performed better than required in the RTOG 0933 trial. CONCLUSIONS: Overall, beam setup 3 was considered to be the best. It is worth mentioning that, apart from our results, the election of one of these beam arrangements might be dependent on the amount of patient workload at a specific institution.

Performance of the eclipse monitor unit objective tool utilizing volumetric modulated arc therapy for rectal cancer.

AIM: To assess the performance of the monitor unit (MU) Objective tool in Eclipse treatment planning system (TPS) utilizing volumetric modulated arc therapy (VMAT) for rectal cancer. BACKGROUND: Eclipse VMAT planning module includes a tool to control the number of MUs delivered: the MU Objective tool. This tool could be utilized to reduce the total number of MUs in rectal cancer treatments. MATERIALS AND METHODS: 20 rectal cancer patients were retrospectively studied using VMAT and the MU Objective tool. The baseline plan for each patient was selected as the one with no usage of the MU Objective tool. The number of MUs of this plan was set to be the reference number of MUs (MUref). Five plans were re-optimized for each patient only varying the Max MU parameter. The selected values were 30%, 60%, 90%, 120% and 150% of MUref for each patient. Differences with respect to the baseline plan were evaluated regarding MU number and parameters for PTVs coverage evaluation, PTVs homogeneity and OARs doses assessment. A two-tailed, paired-samples t-test was used to quantify these differences. RESULTS: Average relative differences in MU number obtained was 10% for Max MU values of 30% and 60% of MUref, respectively (p < 0.03). PTVs coverage and homogeneity were not compromised and discrepancies obtained with respect to baseline plans were not significant. Furthermore, maximum OARs doses deviations were also not significant. CONCLUSIONS: A 10% reduction in the MU number could be obtained without an alteration of PTV coverage and OARs doses for rectal cancer.