Accuracy of a smart bottle in measuring fluid intake by American football players during pre-season training.

Rehydration is important for athlete performance and recovery. However, it can be challenging to follow appropriate fluid replacement practices due in part to difficulties in tracking fluid intake in real time. The purpose of this study was to determine the accuracy of a smart bottle in measuring fluid intake during exercise. Thirty male American football athletes drank from bottles equipped with a smart cap during outdoor pre-season practices (110 ± 30 min; 29.3 ± 3.0 °C; 75 ± 11% rh). The cap technology included optical sensors, microprocessors, batteries, and wireless connectivity that transmitted fluid volume data to a smartphone application in real-time. Reference measurements of fluid intake from the smart bottle were determined by gravimetry followed by conversion to volume using the density of the fluid consumed. There was no significant mean difference in fluid intake between the smart bottle and reference method (1220 ± 371 ml vs. 1236 ± 389 ml, p = 0.39 paired t test). Bland-Altman 95% limits of agreement between methods was - 212 to 180 ml. The smart bottle provided accurate measurements of fluid intake during exercise in real-world field conditions on a group level and within limits of agreement of - 212 to 180 ml (or approximately ± 15% of overall fluid intake) on an individual level.

Comparison of a Continuous and Discontinuous GXT on VO2 in Resistance-Trained and Endurance-Trained Males.

Traditional graded exercise testing to assess maximal oxygen uptake (VO2max) may not well represent resistance-trained athletes due to their unfamiliarity with continuous exercise. For this reason, it is possible discontinuous exercise protocols may better represent the maximum capacity for aerobic metabolism in resistance-trained athletes, in order to provide a more valid assessment of VO2max and risk of developing cardiovascular disease. Purpose: The purpose of this experiment was to compare VO2peak during a continuous and discontinuous modified Bruce protocol in both highly resistance-trained and endurance-trained males. Methods: 19 college-aged males (age: 20.6 ± 1.9 yr, height: 176.5 ± 7.6 cm, weight: 85.0 ± 25.6 kg) of intermediate resistance- or endurance-trained status were recruited for this study. Participants completed a continuous and discontinuous modified Bruce protocol on two visits separated by seven days. Results: A 2×2 one-way ANOVA revealed a significant group main effect for VO2peak (p = 0.004) in which endurance athletes achieved significantly higher VO2peak values compared to resistance-trained athletes. A significant group main effect for RPE was found (p = 0.045) in which endurance-trained reported significantly higher RPE values than the resistance-trained. A significant main effect for protocol for heart rate (p = 0.033) was found in which individuals achieved higher heart rates during the continuous protocol compared to the discontinuous. Conclusion: Although a discontinuous protocol with rest periods between stages is comparable to the exercise mode familiar to resistance-trained athletes, it did not provide any additional benefit to VO2peak values.

Central Auditory Processing and the Relationship to Perceived Hearing Difficulty: The Jackson Heart Study.

OBJECTIVE: There are limited population-based studies of central auditory processing (CAP). We aimed to determine the relationship between CAP measures and perceived hearing difficulty (PHD) despite normal pure-tone audiometry in an African-American population. STUDY DESIGN: Cross-sectional. SETTING: Jackson Heart Study (JHS), Jackson, MS. SUBJECTS: Participants of an African-American cohort (26% men; age 54.2, standard deviations [SD] 9.2) who self-reported hearing difficulty despite normal hearing sensitivity defined as audiometric pure-tone average (PTA-4: average of 500, 1000, 2000, and 4000 Hz) less than or equal to 25 dBHL (n = 911) or across all tested frequencies (PT-AF: 250-8000 Hz) less than or equal to 25 dBHL (n = 516). METHODS: The Quick Speech-in-Noise (QuickSIN) and Dichotic Digits, Double Pairs (DDT2) tests were used to assess CAP. Logistic regression was used to examine the association between measures of CAP and PHD; adjusted for age, sex, education, and pure tone audiogram. RESULTS: PHD was present in 251 (28%) and 137 (27%) of participants using the PTA-4 and PT-AF models, respectively. Fully adjusted regression models revealed that each one-point increase in QuickSIN increased the odds of reporting PHD by 13.7% (odds ratio [OR] 1.14, p < 0.01, 95% CI: 1.08, 1.19) using the PTA-4 model and 15.0% (OR 1.15, p < 0.01, 95% CI: 1.08, 1.23) using the PT-AF model. For DDT2 testing, each 1% reduction in score, increased the odds of reporting PHD by 7.7% (OR 0.92, p < 0.01, 95% CI: 0.88, 0.97) in a fully adjusted PTA-4 model and 6.6% (OR 0.93, p = 0.04, 95% CI: 0.87, 0.99) in the PT-AF model. CONCLUSION: CAP deficits were associated with increased odds of PHD in normal hearing participants within the JHS cohort.

No Effect of a Ketone Monoester on Markers of Stress and Performance in a Live-Burn Search and Rescue in Firefighters.

ABSTRACT: Waldman, HS, Bryant, AR, Shepherd, BD, Egan, B, and McAllister, MJ. No effect of a ketone monoester on markers of stress and performance in a live-burn search and rescue in firefighters. J Strength Cond Res 36(3): 763-771, 2022-Firefighters experience a range of stressors that impair performance and elevate the risk for developing cardiometabolic diseases. ß-Hydroxybutyrate (ßHB) has been shown to mitigate markers of oxidative stress and inflammation and serve as an alternative fuel with implications to physical performance. On 2 occasions in a double-blind, counterbalanced, and crossover design, 14 professional firefighters performed a live-burn, search and rescue (S&R) 30 minutes after ingestion of a ketone monoester (KME; 0.5 g·kg-1) or a placebo (PLA). Dependent variables collected before and after the S&R included salivary markers of stress and inflammation (cortisol, α-amylase, interleukin-1 beta, uric acid), perceptual markers (profile of mood state [POMS]), gastrointestinal distress (GI), rating of perceived exertion [RPE]), time to completion, and capillary blood measurement of ßHB and glucose. KME resulted in capillary ßHB concentrations of approximately 2.1-3.2 mM throughout the protocol. Capillary glucose concentrations were lower for the KME compared with PLA (∼7%) (interaction effect, p < 0.001). Salivary markers of stress, GI, and time to complete the S&R (∼10 minutes) did not differ between trials, although KME ingestion resulted in significantly higher RPE after the live-burn S&R (KME,6 ± 1; PLA, 4 ± 1). However, POMS data showed the KME also lowered subjective states of nervousness (KME, 0.0 ± 0.0; PLA, 0.6 ± 0.8) and anxiety (KME, 0.0 ± 0.0; PLA, 0.6 ± 0.7) before the S&R (all p < 0.05; large effect sizes). Compared with PLA, ingestion of a KME by firefighters did not mitigate the rise in various markers of salivary stress or impact physical performance during a live-burn S&R. However, differences in RPE and POMS variables were observed, suggesting a possible cognitive role for ßHB.

Impact of Fat Grip Attachments on Muscular Strength and Neuromuscular Activation During Resistance Exercise.

ABSTRACT: Krings, BM, Shepherd, BD, Swain, JC, Turner, AJ, Chander, H, Waldman, HS, McAllister, MJ, Knight, AC, and Smith, JW. Impact of fat grip attachments on muscular strength and neuromuscular activation during resistance exercise. J Strength Cond Res 35(2S): S152-S157, 2021-The purpose of this study was to examine the acute effects of Fat Gripz (FG) on muscular activation and strength. Resistance trained men (n = 15; age = 22.4 ± 2.3 years; mass = 83.2 ± 11.1 kg) performed 2 experimental trials in a randomized order. Subjects completed 1 repetition maximum (1RM) testing with an Olympic barbell (OB) and with FG attached to an OB during the exercises of deadlift, bent-over row, upright row, concentration curl, and completed maximum repetitions of pull-ups until failure. Surface electromyography (EMG) was used to measure muscle activity from 8 upper extremity muscles (trapezius, medial deltoid, biceps brachii, triceps brachii, flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis, and extensor carpi ulnaris), while performing maximal voluntary isometric contractions during 1RM trials and while performing maximum number of pull-ups. When using the FG, 1RM strength was significantly decreased for each exercise, and the maximal number of pull-ups completed was significantly lower. Electromyography muscle activity was significantly increased in the forearm and shoulder muscles, but significantly decreased in the upper arm muscles with the use of FG during deadlift, bent-over row, and pull-ups. However, there were no differences for EMG activity for upright row and concentration curl. Differences in maximal strength, pull-up performance, and EMG activity with FG use may be due to the different muscle length positions. Although FG training may increase neuromuscular activation, decrements in muscular strength may result in prescribing low training loads that may not be ideal for building muscular strength.

The metabolic and performance effects of carbohydrate timing in resistance trained males undergoing a carbohydrate restricted diet.

The purpose of this investigation was to examine the importance of carbohydrate (CHO) timing while consuming a carbohydrate restricted diet (CRD) and completing a high-intensity exercise program. Eighteen males completed 6 weeks of training with the first 2 weeks serving as familiarization. During the final 4 weeks, subjects were randomized into 2 groups and completed 3 days of resistance training and 2 days of high-intensity interval training, while consuming a CRD (∼25%, ∼25%, and ∼50%, CHO, protein, and fat, respectively). The supplemented group (n = 9) ingested 30 g of CHO during exercise and 40 g of CHO immediately after each training session. The non-supplemented group (n = 9) consumed a non-caloric placebo during exercise. Pre- and post-testing measures included back squat and bench press 1-repetition maximums (1-RM), peak oxygen consumption (V̇O2peak), anaerobic power, body composition, fasted glucose, insulin, and total testosterone. Both groups significantly improved back squat and bench press 1-RM, V̇O2peak, and power output (p < 0.05), but there were no differences in blood markers or body composition. Our data suggests that CHO timing does not negatively impact training adaptations during a high-intensity exercise regimen when dietary CHO intake is restricted, but that favorable adaptations can be made while consuming a CRD. Novelty: Carbohydrate restricted dieting has no negative impact on resistance training adaptations. Short-term high-intensity interval training is effective in increasing peak oxygen consumption.

Effects of Carbohydrate Mouth Rinsing on Upper Body Resistance Exercise Performance.

Carbohydrate mouth rinsing has been shown to enhance aerobic exercise performance, but there is limited research with resistance exercise (RE). Therefore, the purpose of this investigation was to examine the effects of carbohydrate mouth rinsing during a high-volume upper body RE protocol on performance, heart rate responses, ratings of perceived exertion, and felt arousal. Recreationally experienced resistance-trained males (N = 17, age: 21 ± 1 years, height: 177.3 ± 5.2 cm, mass: 83.5 ± 9.3 kg) completed three experimental sessions, with the first serving as familiarization to the RE protocol. During the final two trials, the participants rinsed a 25-ml solution containing either a 6% carbohydrate solution or an artificially flavored placebo in a randomized, counterbalanced, and double-blinded fashion. The participants rinsed a total of nine times immediately before beginning the protocol and 20 s before repetitions to failure with the exercises bench press, bent-over row, incline bench press, close-grip row, hammer curls, skull crushers (all completed at 70% one-repetition maximum), push-ups, and pull-ups. Heart rate, ratings of perceived exertion, and felt arousal were measured at the baseline and immediately after each set of repetitions to failure. There were no differences for the total repetitions completed (carbohydrate = 203 ± 25 repetitions vs. placebo = 201 ± 23 repetitions, p = .46, Cohen's d = 0.10). No treatment differences were observed for heart rate, ratings of perceived exertion, or felt arousal (p > .05). Although carbohydrate mouth rinsing has been shown to be effective in increasing aerobic performance, the results from this investigation show no benefit in RE performance in resistance-trained males.

Exogenous Ketone Salts Do Not Improve Cognitive Performance During a Dual-Stress Challenge.

In the present study, our team aimed to investigate the effects of acute ingestion of a ketone salt (KS) supplement on the cognitive performance in healthy college-aged males during a dual-stress challenge (DSC). Following a peak oxygen uptake test and DSC familiarization, 16 males completed a DSC while cycling at 60% of their respective peak oxygen uptake after ingesting either a commercially available racemic (D- and L-)ß-hydroxybutyrate (ß-OHB) KS (0.38 g/kg body mass) or a placebo, using a triple-blinded, crossover, and counterbalanced design. The participants consumed the KS or placebo at -60 and -15 min prior to the start of the DSC. Heart rate, rating of perceived exertion, and blood ß-OHB and glucose were sampled throughout. The DSC consisted of a mental arithmetic challenge and a modified Stroop Color Word, which alternated every 2 min for 20 min. Upon completion of the DSC, responses for correct, incorrect, and no responses were recorded for the mental arithmetic challenge and Stroop Color Word. Blood ß-OHB was elevated with KS by -15 min and remained so throughout (p < .001), peaking at 0.76 ± 0.32 mM. Blood glucose was lower with KS compared with the placebo at -15 and 10 min by 9% and 5%, respectively (both ps < .05). There were no differences between the treatments for heart rate, rating of perceived exertion, mental arithmetic challenge, or Stroop Color Word. Overall, this study suggests that KSs are not effective aids for enhancing cognitive performance during a DSC, which might partially be explained by the inability of currently available commercial KS supplements to elevate ß-OHB blood concentrations above ∼1.0 mM.

Effects of carbohydrate and branched-chain amino acid beverage ingestion during acute upper body resistance exercise on performance and postexercise hormone response.

The purpose of this investigation was to examine the individual and combined effects of ingesting carbohydrates (CHO) and branched-chain amino acids (BCAA) during high-volume upper body resistance exercise (RE) on markers of catabolism and performance. Thirteen resistance-trained males completed 4 experimental trials with supplementation, ingesting beverages containing CHO, BCAA, CHO+BCAA, or placebo (PLA) in a randomized, double-blind design. The beverages were ingested in 118-mL servings 6 times during an ∼60-min RE session consisting of bench press, bent-over row, incline press, and close-grip row. Each RE was performed with 5 sets of repetitions at 65% 1-repetition maximum until volitional fatigue. Blood samples were collected at baseline, immediately postexercise, and 60 min postexercise to assess glucose and insulin. Cortisol was assessed immediately and at 60 min postexercise. No significant performance benefits were observed for any RE. CHO+BCAA (152.4 ± 71.4 ng/mL) resulted in the lowest cortisol levels, which was lower than BCAA and PLA (193.7 ± 88.5, 182.8 ± 67.5 ng/mL, p < 0.05), but not different from CHO (165 ± 76.5 ng/mL, p = 0.342). Postexercise insulin concentrations were significantly higher with CHO (4.79 ± 3.4 mU/L) compared with BCAA and PLA (3.7 ± 2.0, 3.5 ± 1.8 mU/L, p < 0.05), but not different from CHO+BCAA (4.3 ± 2.5 mU/L, p = 0.339). There was no treatment effect for glucose, but glucose significantly increased from baseline to immediately postexercise and significantly decreased at 60 min postexercise. Ingesting beverages containing CHO with or without BCAA during upper body resistance exercise may promote a more favorable postexercise less catabolic environment.

Effects of Carbohydrate Ingestion and Carbohydrate Mouth Rinse on Repeat Sprint Performance.

The purpose of this investigation was to examine to the influence of carbohydrate ingestion (CHOI) and carbohydrate mouth rinse (CHOR) on acute repeat maximal sprint performance. Fourteen healthy males (age: 21.7 ± 1.8 years, mass: 82.3 ± 12.3 kg) completed a total of five 15-s maximal repeat sprints on a cycle ergometer against 0.075 kg ・ kg-1 body mass each separated by 4 min of active recovery. Subjects completed four experimental trials and were randomly assigned one of four treatments: (1) CHOI, (2) CHOR, (3) placebo mouth rinse (PLAR), (4) placebo ingestion (PLAI). Subjects rinsed or ingested six 50 mL 10% CHO solutions throughout each trial. Performance variables measured included rating of perceived exertion, peak heart rate, peak and mean power output, fatigue index, and total work. Significant treatment main effects were observed for mean power output (p = 0.026), total work (p = 0.020), fatigue index (p = 0.004), and heart rate (p = 0.013). Overall mean power output and total work were significantly greater with CHOI (659.3 ± 103.0 watts, 9849.8 ± 1598.8 joules) compared with CHOR (645.8 ± 99.7 watts, 9447.5 ± 1684.9 joules, p < .05). CHOI (15.3 ± 8.6 watts/s) significantly attenuated fatigue index compared with CHOR (17.7 ± 10.4 watts/s, p < .05). Based on our findings, CHOI was more likely to provide a beneficial performance effect compared with CHOR, PLAI, and PLAR. Athletes required to complete repeat bouts of high intensity exercise may benefit from CHOI.

Invasive fungal sinusitis in the pediatric population: Systematic review with quantitative synthesis of the literature.

BACKGROUND: Invasive fungal sinusitis (IFS) represents an often fatal condition within the pediatric population. In an effort to characterize demographics, treatment modalities, and prognostic factors, we performed a systematic review. METHODS: We systematically reviewed EMBASE, Medline, TRIPdatabase, SCOPUS and the Cochrane database for invasive fungal nasal and sinus infections limited to individuals <18 years of age. Case series including 3 or more patients were included. Demographics, treatment and outcomes were analyzed using R Gui statistical software. RESULTS: Twelve studies met inclusion criteria (103 patients). There was male preponderance of 48.5% with median age of 11 years old. Majority of patients had underlying leukemia (44.6%). Aspergillus was the predominant organism (47%). Isolated nasal findings occurred in 14% of patients and nasal findings occurred in 49% overall. Absolute neutrophil count (ANC) of immunocompromised patients was below 600 in most patients (99%). Average and median length of neutropenia was 2 weeks. All patients were prescribed amphoterocin with 50% as single medicinal therapy. Surgery occurred in 82.8% of cases. The mortality rate was 46%. Univariate analysis identified presenting with facial pain as a negative predictor of overall mortality (OR 0.296, 95% CI: 0.104-0.843, p < 0.05). CONCLUSION: Mortality remains high in pediatric patients with IFS. An ANC of <600 occurred in the majority of immunocompromised patients at a duration of 2 weeks. Presenting with facial pain was a negative predictor of mortality. Many studies label this condition as invasive fungal sinusitis; however, approximately one seventh presented with only nasal findings and half overall had nasal involvement.

Bradford's law: identification of the core journals for neurosurgery and its subspecialties.

OBJECTIVE: Bradford's law describes the scatter of citations for a given subject or field. It can be used to identify the most highly cited journals for a field or subject. The objective of this study was to use currently accepted formulations of Bradford's law to identify core journals of neurosurgery and neurosurgical subspecialties. METHODS: All original research publications from 2009 to 2013 were analyzed for the top 25 North American academic neurosurgeons from each subspecialty. The top 25 were chosen from a ranked career h-index list identified from previous studies. Egghe's formulation and the verbal formulation of Bradford's law were applied to create specific citation density zones and identify the core journals for each subspecialty. The databases were then combined to identify the core journals for all of academic neurosurgery. RESULTS: Using Bradford's verbal law with 4 zone models, the authors were able to identify the core journals of neurosurgery and its subspecialties. The journals found in the most highly cited first zone are presented here as the core journals. For neurosurgery as a whole, the core included the following journals: Journal of Neurosurgery, Neurosurgery, Spine, Stroke, Neurology, American Journal of Neuroradiology, International Journal of Radiation Oncology Biology Physics, and New England Journal of Medicine. The core journals for each subspecialty are presented in the manuscript. CONCLUSIONS: Bradford's law can be used to identify the core journals of neurosurgery and its subspecialties. The core journals vary for each neurosurgical subspecialty, but Journal of Neurosurgery and Neurosurgery are among the core journals for each neurosurgical subspecialty.

Bibliometric evaluation of pediatric neurosurgery in North America.

OBJECT: The application of bibliometric techniques to academic neurosurgery has been the focus of several recent publications. The authors provide here a detailed analysis of all active pediatric neurosurgeons in North America and their respective departments. METHODS: Using Scopus and Google Scholar, a bibliometric profile for every known active pediatric neurosurgeon in North America was created using the following citation metrics: h-, contemporary h-, g-, and e-indices and the m-quotient. Various subgroups were compared. Departmental productivity from 2008 through 2013 was measured, and departments were ranked on the basis of cumulative h- and e-indices and the total number of publications and citations. Lorenz curves were created, and Gini coefficients were calculated for all departments with 4 or more members. RESULTS: Three hundred twelve pediatric neurosurgeons (260 male, 52 female) were included for analysis. For the entire group, the median h-index, m-quotient, contemporary h-, g-, and e-indices, and the corrected g- and e-indices were 10, 0.59, 7, 18, 17, 1.14, and 1.01, respectively; the range for each index varied widely. Academic pediatric neurosurgeons associated with fellowship programs (compared with unassociated neurosurgeons), academic practitioners (compared with private practitioners), and men (compared with women) had superior measurements. There was no significant difference between American and Canadian pediatric neurosurgeons. The mean Gini coefficient for publications was 0.45 (range 0.18-0.70) and for citations was 0.53 (range 0.25-0.80). CONCLUSIONS: This study represents the most exhaustive evaluation of academic productivity for pediatric neurosurgeons in North America to date. These results should serve as benchmarks for future studies.

An application of Bradford's law: identification of the core journals of pediatric neurosurgery and a regional comparison of citation density.

PURPOSE: Bradford's law describes the number of core journals in a given field or subject and has recently been applied to neurosurgery. The objective of this study was to use currently accepted formulations of Bradford's law to identify core journals of pediatric neurosurgery. An additional analysis was completed to compare regional dependence on citation density among North American and European neurosurgeons. METHODS: All original research publications from 2009 to 2013 were analyzed for the 25 top publishing pediatric neurosurgeons in North America and Europe, which were sampled to construct regional citation databases of all journal references. Regional differences were compared with each database. Egghe's formulation and the verbal formulation of Bradford's law were applied to create specific citation density zones and identify the core journals. RESULTS: Regional comparison demonstrated a preference for the Journal of Neurosurgery and Child's Nervous System, respectively, but four of the top five journals were common to both groups. Applying the verbal formulation of Bradford's law to the North American citation database, a pattern of citation density was identified across the first three zones. Journals residing in the most highly cited first zone are presented as the core journals. CONCLUSION: Bradford's law can be applied to identify the core journals of neurosurgical subspecialties. While regional differences exist between the most highly cited and most frequently published in journals among North American and European pediatric neurosurgeons, there is commonality between the top five core journals in both groups.

Image-guided convection-enhanced delivery into agarose gel models of the brain.

Convection-enhanced delivery (CED) has been proposed as a treatment option for a wide range of neurological diseases. Neuroinfusion catheter CED allows for positive pressure bulk flow to deliver greater quantities of therapeutics to an intracranial target than traditional drug delivery methods. The clinical utility of real time MRI guided CED (rCED) lies in the ability to accurately target, monitor therapy, and identify complications. With training, rCED is efficient and complications may be minimized. The agarose gel model of the brain provides an accessible tool for CED testing, research, and training. Simulated brain rCED allows practice of the mock surgery while also providing visual feedback of the infusion. Analysis of infusion allows for calculation of the distribution fraction (Vd/Vi) allowing the trainee to verify the similarity of the model as compared to human brain tissue. This article describes our agarose gel brain phantom and outlines important metrics during a CED infusion and analysis protocols while addressing common pitfalls faced during CED infusion for the treatment of neurological disease.

Development of polymer-membrane based electrodes for suramin.

The development of a polymer membrane-based electrode to measure the anionic drug suramin in buffered saline and biological samples is described. A large non-equilibrium, steady state EMF response is observed toward suramin, and judicious choice of the polymer membrane components allows for adjustment of the dynamic range of the electrode. The optimized membrane for use in the toxic suramin range consists of 25 wt% tridodecylmethyl ammonium chloride, 55 wt% bis-2-ethylhexyl sebacate, and 20 wt% Pellethane. Although this electrode can be used to directly quantify suramin in human plasma, determination of suramin that is not affected by the background concentration of small anions is best achieved by simple potentiometric titrations with polycationic protamine monitored with a protamine-sensitive electrode.