Earlobe Blood Samples Research Articles

Blood Lactate Responses of Male and Female Players Across an International Rugby Sevens Tournament.

This study investigated within- and between-matches blood lactate (La-) responses across an international Rugby Sevens tournament (5 matches over 2d) in male and female players. Earlobe blood samples were taken from 25 professional players around matches: before warm-up (PRE), immediately upon finishing match participation (POST), and 30 minutes postmatch (30min). POST [La-] (mean [SD], range) for males was 10.3 (3.2; 2.9-20.2) mmol·L-1 and for females was 9.1 (2.3; 3.4-14.6) mmol·L-1. Linear mixed-effects models revealed a decrease in POST [La-] after match 5, compared to match 1. Increased PRE [La-] was found before match 2 (+0.8 [0.6-1.1]mmol·L-1), match 3 (+0.8 [0.5-1.1]mmol·L-1), and match 5 (+0.6 [0.4-0.9]mmol·L-1) compared to match 1 (all P < .001). The [La-] remained elevated at 30min, compared to PRE (+1.7 [1.4-2.0]mmol·L-1, P < .001), with ∼20% of values persisting >4mmol·L-1. Higher POST was observed in males compared to females (+1.6 [0.1-3.2]mmol·L-1, P = .042); however, no differences between sexes were found across 30 min or PRE [La-]. No [La-] differences between positions (backs and forwards) were identified. Lactate concentrations above 10mmol·L-1 are required to effectively simulate the anaerobic demands of international Rugby Sevens matches. Practitioners are advised to individualize anaerobic training prescription due to the substantial variability observed within positional groups. Additionally, improving athletes' metabolic recovery capacity through training, nutrition, and recovery interventions may enhance physical preparation for subsequent matches within a day, where incomplete lactate clearance was observed.

A Metabolomic Approach and Traditional Physical Assessments to Compare U22 Soccer Players According to Their Competitive Level.

Simple SummaryDifferent physical tests are applied in the sports context for athlete selection and training prescriptions. Recently, the metabolomics approach has been used to understand biological systems; it has shown high potential to answer integrated questions, including with regard to soccer. Our study is the first to combine traditional physical assessment protocols with metabolomics to detail and compare the physiological profiles of two soccer teams (under-22 soccer players) at different competitive levels. Using anthropometric measurements and the critical velocity model, no differences were observed between elite and non-elite soccer players. However, the metabolomic analysis was able to differentiate among the fasting serum metabolic profiles of athletes of different competitive levels. Our results suggest that the application of metabolomics combined with traditional physical assessment protocols can improve characterizations of athletes, strengthening the differentiation of the physiological profiles of soccer teams. Thus, the metabolomic approach can contribute by offering additional data in individual characterizations of athletes, improving training programs, and consequently, increasing the performance of players during competitions.The purpose of this study was to use traditional physical assessments combined with a metabolomic approach to compare the anthropometric, physical fitness level, and serum fasting metabolic profile among U22 soccer players at different competitive levels. In the experimental design, two teams of male U22 soccer were evaluated (non-elite = 20 athletes, competing in a regional division; elite = 16 athletes, competing in the first division of the national U22 youth league). Earlobe blood samples were collected, and metabolites were extracted after overnight fasting (12 h). Untargeted metabolomics through Liquid Chromatograph Mass Spectrometry (LC-MS) analysis and anthropometric evaluation were performed. Critical velocity was applied to determine aerobic (CV) and anaerobic (ARC) capacity. Height (non-elite = 174.4 ± 7.0 cm; elite = 176.5 ± 7.0 cm), body mass index (non-elite = 22.1 ± 2.4 kg/m2; elite = 21.9 ± 2.3 kg/m2), body mass (non-elite = 67.1 ± 8.8 kg; elite = 68.5 ± 10.1 kg), lean body mass (non-elite = 59.3 ± 7.1 kg; elite = 61.1 ± 7.9 kg), body fat (non-elite = 7.8 ± 2.4 kg; elite = 7.3 ± 2.4 kg), body fat percentage (non-elite = 11.4 ± 2.4%; elite = 10.5 ± 1.7%), hematocrit (non-elite = 50.2 ± 4.0%; elite = 51.0 ± 4.0%), CV (non-elite = 3.1 ± 0.4 m/s; elite = 3.0 ± 0.2 m/s), and ARC (non-elite = 129.6 ± 55.7 m; elite = 161.5 ± 61.0 m) showed no significant differences between the elite and non-elite teams, while the multivariate Partial Least Squares Discriminant Analysis (PLS-DA) model revealed a separation between the elite and non-elite athletes. Nineteen metabolites with importance for projection (VIP) >1.0 were annotated as belonging to the glycerolipid, sterol lipid, fatty acyl, flavonoid, and glycerophospholipid classes. Metabolites with a high relative abundance in the elite group were related in the literature to a better level of aerobic power, greater efficiency in the recovery process, and improvement of mood, immunity, decision making, and accuracy, in addition to acting in mitochondrial preservation and electron transport chain maintenance. In conclusion, although classical physical assessments were not able to distinguish the teams at different competitive levels, the metabolomics approach successfully indicated differences between the fasting metabolic profiles of elite and non-elite teams.

Effects of Chronic Supplementation of L-Arginine on Physical Fitness in Water Polo Players.

Background Ergogenic nutritional supplementation is sought by professional athletes for improving physical performance; nevertheless, scientific evidence to support the chronic use of L-Arginine among water polo players is missing. Methods Seventeen male professional water polo players were randomly assigned to assume 5 grams per day of L-Arginine (n = 9) or placebo (n = 8) for 4 weeks. The players' fitness level was assessed in the maximal speed swimming test. Ear lobe blood samples taken before and after the effort for serum lactate content were analyzed. A speed-to-lactate ratio was generated at the baseline and after 4 weeks of treatment. We also tested the effects of L-Arginine in vitro, measuring NO production, mitochondrial respiration, and gene expression in human fibroblasts. Results L-Arginine did not modify BMI, muscle strength, and maximal speed at 200 meters after 4 weeks. However, L-Arginine ameliorated oxidative metabolism to exercise as suggested by the statistically significant lower lactate-to-speed ratio, which was not observed in placebo-treated controls. In vitro, L-Arginine induced the expression of a key regulator of mitochondrial biogenesis (PGC1α) and genes encoding for complex I and increased the production of nitric oxide and the maximal oxygen consumption rate. Conclusions Chronic L-Arginine is safe and effective in ameliorating the oxidative metabolism of professional water polo players, through a mechanism of enhanced mitochondrial function.

Application of energy cost in evaluating energy expenditure in multi-ball practice with table tennis players

To investigate the feasibility of applying the measure of energy cost, utilized widely in cyclic sports, in table tennis multi-ball practice. Eleven collegiate table tennis players volunteered (18±1 yrs, 177±2 cm, 71±3 kg, approximately 10 yrs' training experience) to participate in one graded exercise test on treadmill, and two step tests (forehand and backhand, 3 min × 6, 35～85 stroke/min). A portable spirometric system and heart rate monitor were utilized for the three trials. Earlobe blood samples were collected and analyzed prior to and post the test. Energy cost was calculated for one stroke at each stroke frequency. The energy cost of loop drive multi-ball practice was decreased with increased stroke frequency (P＜0.05). The energy cost of forehand loop drive was higher than backhand, with the difference significant at 35, 45, 55, 65, and 85 stroke·min-1 (P＜0.05). The function between energy cost and frequency were y=166.4x-0.731 (R2=0.9731), and y=33.21x-0.392 (R2=0.8423), respectively, where y was energy cost, and x was stroke frequency. The measure of energy cost utilized in cyclic sports could be applied to evaluate the energy expenditure in table tennis multi-ball practice of single technique, and indicate the stroke efficiency of table tennis muti-ball practice with different stroke frequencies.

A Novel Nested Real-time Polymerase Chain Reaction for Treponema pallidum DNA in Syphilis Biospecimens.

Early diagnosis of Treponema pallidum infection is helpful for disease management, and conventional PCR is suitable for lesion swabs of patients with probable early syphilis. We thus tested nested and real-time PCR (NR-PCR) in various biosamples from syphilitic patients. Samples were collected from syphilis patients before treatment. Specific primer sequences targeting the T. pallidum gene polA were designed for NR-PCR. Across syphilis types, most samples assayed with NR-PCR returned a positive result, including earlobe blood (92.0%), cerebrospinal fluid (CSF) (90.2%), lesion swabs (74.3%), serum (66.9%), and whole blood (64.2%). No significant differences were observed in positive samples for whole blood, serum, and lesion swabs between primary and secondary syphilis (P > 0.05 for all comparisons). However, more whole-blood samples from patients with secondary syphilis were positive for NR-PCR than whole blood samples from patients with tertiary and latent syphilis (P < 0.05 for all comparisons). For neurosyphilis patients, significantly more earlobe blood samples tested positive than did whole-blood samples (P < 0.05), but there was no difference in positive results for earlobe blood and whole blood in latent syphilis. Significantly more serum samples tested positive in latent syphilis patients with rapid plasma regain (RPR) titers of 1:8 or greater, compared to those with RPR of 1:4 or less. Nested and real-time PCR can be used to identify T. pallidum DNA in biosamples from syphilitic patients, especially earlobe blood.

IgM Anti PGL-1 Antibody Level in Patients with Leprosy: A Comparative Study between Ear Lobes Capillary and Median Cubital Vein Blood Samples.

BACKGROUND:To establish the diagnosis of leprosy accurately, additional examination such as serologic examination with ELISA is required. There are considerations about taking a blood sample from the earlobe region.AIM:To determine the differences in IgM anti-PGL-1 antibody levels from earlobe capillary and median cubital vein blood sample in leprosy patients.METHODS:An observational analytic study using a cross-sectional study involving 30 patients with leprosy. ELISA examination of earlobe blood samples with filter paper, and the median cubital vein blood samples with filter paper and conventional methods were performed to determine IgM anti-PGL-1 antibody levels.RESULTS:The mean value of IgM anti PGL-1 antibody levels from earlobe blood samples with filter paper (1476.62 μ/ml) was relatively similar with median cubital vein blood samples with conventional method (1476.77 μ/ml), but the mean value of IgM anti PGL-1 antibody levels from median cubital vein blood samples with filter paper (1210.37 μ/ml) was lower from other methods. However, there was no statistically significant difference between them.CONCLUSION:There are no significant differences between the mean levels of IgM anti-PGL-1 antibody from earlobe and the median cubital vein blood samples.

Application of nested real-time PCR in detecting Treponema palladium DNA in various clinical samples from patients preliminarily diagnosed as syphilis

Objective To investigate the feasibility and prospects of nested real-time PCR (NR-PCR) technique for Treponema palladium (Tp) detection in various samples of different stages of syphilis from patients preliminarily diagnosed as syphilis. Methods Targeting the Tp polA gene, NR-PCR was performed to detect Tp DNA in various samples from the patients with various stages of syphilis at the first clinic visit, including skin tissue fluid swabs, serum, whole blood, cerebrospinal fluid (CSF) and earlobe blood. Data were analyzed with SPSS software version 13. Results A total of 368 clinical samples were collected from 200 patients with syphilis. With a detection limit of 2 Tp/ml, NR-PCR showed that the total positive rate for Tp DNA was 71.7% (264/368) . The Tp DNA positive rate was highest in earlobe blood samples (92.0%, 23/25) , followed by CSF samples (90.2%, 46/51) , skin tissue fluid swabs (74.3%, 26/35) , serum samples (66.9%, 99/148) and whole blood samples (64.2%, 70/109) . There was good agreement between NR-PCR results and serologic test results, with a consistency rate of 76.0% (152/200) . Furthermore, the Tp DNA positive rate did not differ between patients with primary (12/19) and secondary syphilis (14/16) in skin tissue fluid swabs (χ2= 2.62, P > 0.05) , and was slightly but insignificantly higher in patients with secondary syphilis than those with primary syphilis in the serum samples (χ2= 3.6, P= 0.06) . The Tp DNA positive rate of whole blood samples was also higher in patients with secondary syphilis than those with any other types of syphilis. Among patients with neurosyphilis, no significant difference was observed in the Tp DNA positive rate between earlobe blood samples and CSF samples (P= 0.06) . Among patients with latent syphilis, the Tp DNA positive rate was significantly higher in serum samples with an RPR titer of ≥ 1∶8 than those with an RPR titer of ≤ 1∶4. Conclusion NR-PCR is feasible for detecting Tp DNA in various kinds of samples, and the Tp DNA positive rate is influenced by stages of syphilis and types of samples, as well as RPR titers. Key words: Syphilis; Treponema pallidum; Clinical laboratory techniques; Real-time polymerase chain reaction; Nested polymerase chain reaction

Molecular epidemiological survey of Treponema pallidum in pregnant women in the Zhabei District of Shanghai.

To evaluate the epidemiological characteristics of syphilis, such as incidence, vertical transmission and genotypes, in pregnant women in the Zhabei District of Shanghai. In addition, the changes in genotypes and the efficiency of genotyping were evaluated. We screened 3022 pregnant women for syphilis in the Shanghai Zhabei Central Hospital. Whole blood, plasma, earlobe blood and specimens from genital ulcers or skin/mucosal lesions were collected from syphilis-positive patients. Samples were genotyped by analysing a combination of three genes: tpr, arp and tp0548 (the tpr/arp/tp0548 genotype). Clinical data were further collected to evaluate disease incidence, maternal-neonatal transmission and social factors. Out of 3022 pregnant women screened for syphilis, 41 were syphilis-positive. Of these, 43.9 % showed vertical transmission (18/41). The prevalence of syphilis in pregnant women was 1.32 %, higher than that in other districts in Shanghai in 2014. Genotyping was performed in 10/11 (90.9 %) samples of syphilis lesions, 8/41 (19.5 %) blood samples, 12/41 (29.3 %) plasma samples, and 20/39 (48.7 %) earlobe blood samples. The predominant genotype was 14d/f, followed by 15d/f, 13a/f, 13d/f and 9o/c. Genotype 13a/f was reported for the first time in the Shanghai area since 2010. The prevalence of syphilis in pregnant women in the Zhabei District was higher than that in other areas in Shanghai and the genotype is variable.

Molecular Hydrogen Supplementation and Multiple Sprint Running Performance; a Pilot Investigation.

Recently it has been suggested that molecular hydrogen could attenuate performance decrement during high intensity, short duration interval exercise. Antioxidant properties of molecular hydrogen indicate that it might be beneficial for reducing oxidative stress induced muscle performance decrements. PURPOSE:To examine the effects of molecular hydrogen supplementation on multiple sprint running performance. METHODS:Using a randomized, double-blind, crossover design, 15 physically active men ingested either molecular hydrogen-rich water (400 mg of molecular hydrogen) or a placebo, prior completing an indoor multiple sprint running (12 X 30 m; departing at 35-s intervals). Mean sprint time, fastest time, and fatigue index were recorded via twin-beam photocells, and earlobe blood samples were drawn to evaluate pretest and post-test lactate concentrations. Heart rate was monitored continuously throughout the tests, with RPE recorded after every second sprint. RESULTS:Relative to placebo, molecular hydrogen resulted in a 0.08-s (2%) reduction in mean sprint time (p < 0.05, 95% likely range = 0.04-0.09s) as well as 0.04-s (1%) reduction in fastest time (p < 0.01, 95% likely range = 0.05-0.06s), which corresponded in a 1% improvement in fatigue (p <0.05, 95% likely range = 0.8-1.1%). Molecular hydrogen supplementation also resulted in a 1-bpm increase in mean heart rate (169 ±17 versus 170 ±17; p < 0.01, 95% likely range = 0.3-3.5bpm). There was an increase in blood lactate over the course of each sprint trial (p < 0.01) which was greater in molecular hydrogen group (p < 0.05; 0.6 mMol· -1; 95% likely range = 0.1-1.7 mMol· -1). Rating of perceived exertion (RPE) showed a significant group effect (p < 0.01, 95% likely range = 0.9-1.6). CONCLUSIONS:Results of this pilot study indicate some ergogenic potential of molecular hydrogen supplementation on multiple sprint running performance. Further studies are needed in order to determine the dose response and the potential mechanisms of action for this intervention.

Validity of an On-Court Lactate Threshold Test in Young Basketball Players

The aim of this study was to assess the criterion validity of a submaximal field test (Intermittent Shuttle-Running Test [ISRT]) for lactate threshold (LT) detection in young basketball players. Fourteen basketball players (age 15.3 +/- 0.6 years, height 182 +/- 4.6 cm, and body mass 71.6 +/- 6.3 kg) were submitted in random order and on separate occasions, to ISRT (20-m shuttle running for 4 minutes at 9, 10 and 11 kmxh-1) and to a treadmill intermittent progressive test (criterion validity, TM) devised for the assessment of LT (4-minute stages at 8, 10, 12, 14 kmxh-1). Blood-lactate concentrations [La]b were assessed taking earlobe blood samples at rest and immediately after each of the 4-minute running steps considered for ISRT and TM. Lactate threshold was considered as the running speed attained at 1 mmolxL-1 [La]b above resting levels. Results showed that speed at LT during ISRT and TM was significantly related (r = 0.82, p < 0.001). However, speed at LT during the ISRT showed to be significantly lower than the speed at LT during TM (10.1 +/- 1.7 vs. 12 +/- 2.3 kmxh-1, p < 0.001). During ISRT, players attained 80 +/- 4.7, 87 +/- 4.4, and 92 +/- 3.0% of maximal heart rate (HR) at 9, 10, and 11 kmxh-1, respectively. This study results show that ISRT may be used as a valid field test to assess submaximal aerobic fitness in young team-sport players. Continuous 20-m shuttle running performed at 11 km.h revealed to elicit HR in the range of those reported to induce aerobic-fitness development in trained subjects. In light of study finding, ISRT may be considered in testing batteries for basketball players to complement anaerobic fitness and agility.

Exercise with hypoventilation induces lower muscle oxygenation and higher blood lactate concentration: role of hypoxia and hypercapnia

Eight men performed three series of 5-min exercise on a cycle ergometer at 65% of normoxic maximal O(2) consumption in four conditions: (1) voluntary hypoventilation (VH) in normoxia (VH(0.21)), (2) VH in hyperoxia (inducing hypercapnia) (inspired oxygen fraction [F(I)O(2)] = 0.29; VH(0.29)), (3) normal breathing (NB) in hypoxia (F(I)O(2) = 0.157; NB(0.157)), (4) NB in normoxia (NB(0.21)). Using near-infrared spectroscopy, changes in concentration of oxy-(Delta[O(2)Hb]) and deoxyhemoglobin (Delta[HHb]) were measured in the vastus lateralis muscle. Delta[O(2)Hb - HHb] and Delta[O(2)Hb + HHb] were calculated and used as oxygenation index and change in regional blood volume, respectively. Earlobe blood samples were taken throughout the exercise. Both VH(0.21) and NB(0.157) induced a severe and similar hypoxemia (arterial oxygen saturation [SaO(2)] < 88%) whereas SaO(2) remained above 94% and was not different between VH(0.29) and NB(0.21). Arterialized O(2) and CO(2) pressures as well as P50 were higher and pH lower in VH(0.21) than in NB(0.157), and in VH(0.29) than in NB(0.21). Delta[O(2)Hb] and Delta[O(2)Hb - HHb] were lower and Delta[HHb] higher at the end of each series in both VH(0.21) and NB(0.157) than in NB(0.21) and VH(0.29). There was no difference in Delta[O(2)Hb + HHb] between testing conditions. [La] in VH(0.21) was greater than both in NB(0.21) and VH(0.29) but not different from NB(0.157). This study demonstrated that exercise with VH induced a lower tissue oxygenation and a higher [La] than exercise with NB. This was caused by a severe arterial O(2) desaturation induced by both hypoxic and hypercapnic effects.

Effect Of Caffeine Ingestion After Creatine Supplementation On High-intensity Cycling Sprint Performance

Previous studies showed that ingestion of caffeine together with creatine may inhibit the effects of creatine on anaerobic exercise. Although some studies indicated that ingested caffeine after short-term creatine supplementation could increase maximal accumulated oxygen deficit, there was no evidence to prove whether this supplementary method could facilitate stop-and-go exercise performance. PURPOSE: This study was to investigate the effects of caffeine ingestion after creatine supplementation on intermittent high-intensity cycling sprints performance. METHODS: Twelve physically active men were administered in a double-blind, randomized, counterbalanced design to perform intermittent high-intensity sprints (6×10-s; repeated at 60-s intervals, HIS) on a cycling ergometer with or without caffeine ingestion. After short-term creatine monohydrate supplementation (0.3 g · kg-1 · day-1, 5 days), subjects ingested 6 mg · kg-1 caffeine or placebo (maltodextrin) 1 hour before HIS trials. Heart rate was monitored continuously throughout the tests, with rating of perceived exertion (RPE) recorded after each sprint. Earlobe blood samples were also drawn immediately after each sprint to evaluate lactate and glucose concentrations. RESULTS: Compared with placebo, caffeine did not resulted in higher maximal power output (842.3±102.2 vs. 813.5±95.3 watts, p>0.05). However, the relative peak power output in caffeine treatment was significantly higher than in placebo during the first sprint (11.7±0.7 vs. 11.3±0.7 watts · kg-1, p<0.05) and second sprint (11.5±0.7 vs. 10.8±0.7 watts · kg-1, p<0.05). Heart rates were significantly increased with caffeine treatment from the third sprint to the final sprint, and the blood lactate and glucose concentrations were also significantly elevated through the HIS trial. Furthermore, there were no significant effects of caffeine ingestion on the RPE scores. CONCLUSIONS: The present study showed that caffeine ingestion after short-term creatine supplementation could improve intermittent high-intensity sprints performance, but might also induce higher metabolic stress.

Caffeine Supplementation and Multiple Sprint Running Performance

The aim of this study was to examine the effects of caffeine supplementation on multiple sprint running performance. Using a randomized double-blind research design, 21 physically active men ingested a gelatin capsule containing either caffeine (5 mg x kg(-1) body mass) or placebo (maltodextrin) 1 h before completing an indoor multiple sprint running trial (12 x 30 m; repeated at 35-s intervals). Venous blood samples were drawn to evaluate plasma caffeine and primary metabolite concentrations. Sprint times were recorded via twin-beam photocells, and earlobe blood samples were drawn to evaluate pretest and posttest lactate concentrations. Heart rate was monitored continuously throughout the tests, with RPE recorded after every third sprint. Relative to placebo, caffeine supplementation resulted in a 0.06-s (1.4%) reduction in fastest sprint time (95% likely range = 0.04-0.09 s), which corresponded with a 1.2% increase in fatigue (95% likely range = 0.3-2.2%). Caffeine supplementation also resulted in a 3.4-bpm increase in mean heart rate (95% likely range = 0.1-6.6 bpm) and elevations in pretest (+0.7 mmol x L(-1); 95% likely range = 0.1-1.3 mmol x L(-1)) and posttest (+1.8 mmol x L(-1); 95% likely range = 0.3-3.2 mmol x L(-1)) blood lactate concentrations. In contrast, there was no significant effect of caffeine supplementation on RPE. Although the effect of recovery duration on caffeine-induced responses to multiple sprint work requires further investigation, the results of the present study show that caffeine has ergogenic properties with the potential to benefit performance in both single and multiple sprint sports.

Prediction of arterial blood gas values from arterialized earlobe blood gas values in patients treated with mechanical ventilation

Background/Objective:Arterial blood gas (ABG) analysis is useful in evaluation of the clinical condition of critically ill patients; however, arterial puncture or insertion of an arterial catheter may sometimes be difficult and cause many complications. Arterialized ear lobe blood samples have been described as adequate to gauge gas exchange in acute and chronically ill pediatric patients.Purpose:This study evaluates whether pH, partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), base excess (BE), and bicarbonate (HCO3) values of arterialized earlobe blood samples could accurately predict their arterial blood gas analogs for adult patients treated by mechanical ventilation in an intensive care unit (ICU).Setting:A prospective descriptive studyMethods:Sixty-seven patients who were admitted to ICU and treated with mechanical ventilation were included in this study. Blood samples were drawn simultaneously from the radial artery and arterialized earlobe of each patient.Results:Regression equations and mean percentage-difference equations were derived to predict arterial pH, PCO2, PO2, BE, and HCO3-values from their earlobe analogs. pH, PCO2, BE, and HCO3 all significantly correlated in ABG and earlobe values. In spite of a highly significant correlation, the limits of agreement between the two methods were wide for PO2. Regression equations for prediction of pH, PCO2, BE, and HCO3- values were: arterial pH (pHa) = 1.81+ 0.76 × earlobe pH (pHe) [r = 0.791, P < 0.001]; PaCO2 = 1.224+ 1.058 × earlobePCO2 (PeCO2) [r = 0.956, P < 0.001]; arterial BE (BEa) = 1.14+ 0.95 × earlobe BE (BEe) [r= 0.894, P < 0.001], and arterial HCO3- (HCO3-a) = 1.41+ earlobe HCO3(HCO3-e) [r = 0.874, P < 0.001]. The predicted ABG values from the mean percentage-difference equations were derived as follows: pHa = pHe × 1.001; PaCO2 = PeCO2 × 0.33; BEa = BEe × 0.57; and HCO3-a = HCO3-e × 1.06.Conclusions:Arterialized earlobe blood gas can accurately predict the ABG values of pH, PCO2, BE, and HCO3- for patients who do not require regular continuous blood pressure measurements and close monitoring of arterial PO2 measurements.

Caffeine Supplementation and Multiple Sprint Running Performance

PURPOSE The aim of this study was to examine the effects of caffeine supplementation on multiple sprint running performance. METHODS: Using a randomised double-blind research design, 21 physically active men ingested a gelatine capsule containing either caffeine (5 mg-kg body mass-1) or the same volume (4 mg-kg body mass-1) of placebo (maltodextrin) one hour before completing an indoor multiple sprint running trial (12 × 30 m; repeated at 35 s intervals). Sprint times were recorded via twin-beam photocells and earlobe blood samples were drawn to evaluate pre and post-test lactate concentrations. Heart rates were monitored continuously throughout the tests with ratings of perceived exertion (RPE) recorded after every third sprint. RESULTS: Relative to placebo, caffeine supplementation resulted in a 0.06 s reduction in fastest sprint time (95% likely range: 0.04 to 0.09 s), a 1.2% increase in fatigue (95% likely range: 0.3 to 2.2%), a 3.4 b·min-1 increase in mean heart rate (95% likely range: 0.1 to 6.6 b·min-1), and significant (p < 0.05) elevations in pre (+ 0.69 mmol·L-1) and post-test (+ 1.76 mmol-L·1) blood lactate concentrations. In contrast, there was no significant effect of caffeine supplementation on RPE. CONCLUSION: The results of the present study show that caffeine has ergogenic properties with the potential to benefit performance in both single and multiple sprint sports. Supported by St. Mary's College Research Support Fund.

CREATINE SUPPLEMENTATION AND MULTIPLE SPRINT RUNNING PERFORMANCE

The aim of this study was to examine the effects of short-term creatine monohydrate supplementation on multiple sprint running performance. Using a double-blind research design, 42 physically active men completed a series of 3 indoor multiple sprint running trials (15 3 30 m repeated at 35-second intervals). After the first 2 trials (familiarization and baseline), subjects were matched for fatigue score before being randomly assigned to 5 days of either creatine (4·d−1 × 5 g creatine monohydrate 1 1g maltodextrin) or placebo (4·d−1 × 6 g maltodextrin) supplementation. Sprint times were recorded via twin-beam photocells, and earlobe blood samples were drawn to evaluate posttest lactate concentrations. Relative to placebo, creatine supplementation resulted in a 0.7 kg increase in body mass (95% likely range: 0.02 to 1.3 kg) and a 0.4% reduction in body fat (95% likely range: 20.2 to 0.9%). There were no significant (p > 0.05) between-group differences in multiple sprint measures of fastest time, mean time, fatigue, or posttest blood lactate concentration. Despite widespread use as an ergogenic aid in sport, the results of this study suggest that creatine monohydrate supplementation conveys no benefit to multiple sprint running performance.

Creatine Supplementation and Multiple Sprint Running Performance

The aim of this study was to examine the effects of short-term creatine monohydrate supplementation on multiple sprint running performance. Using a double-blind research design, 42 physically active men completed a series of 3 indoor multiple sprint running trials (15 x 30 m repeated at 35-second intervals). After the first 2 trials (familiarization and baseline), subjects were matched for fatigue score before being randomly assigned to 5 days of either creatine (4 x d(-1) x 5 g creatine monohydrate + 1 g maltodextrin) or placebo (4 x d(-1) x 6 g maltodextrin) supplementation. Sprint times were recorded via twin-beam photocells, and earlobe blood samples were drawn to evaluate posttest lactate concentrations. Relative to placebo, creatine supplementation resulted in a 0.7 kg increase in body mass (95% likely range: 0.02 to 1.3 kg) and a 0.4% reduction in body fat (95% likely range: -0.2 to 0.9%). There were no significant (p > 0.05) between-group differences in multiple sprint measures of fastest time, mean time, fatigue, or posttest blood lactate concentration. Despite widespread use as an ergogenic aid in sport, the results of this study suggest that creatine monohydrate supplementation conveys no benefit to multiple sprint running performance.

Creatine Supplementation And Multiple Sprint Running Performance

PURPOSE The aim of this study was to examine the effects of short-term creatine monohydrate supplementation on multiple sprint running performance. METHODS Using a double-blind research design, 54 physically active subjects (42 males; 12 females) completed a series of 3 indoor multiple sprint running trials (15 × 30 m repeated at 35 s intervals). After the first 2 trials (familiarisation and baseline), subjects were matched for gender and fatigue score before being randomly assigned to 5 days of either creatine (4.d−1 × 5 g creatine monohydrate + 1 g maltodextrin) or placebo (4.d−1 × 6 g maltodextrin) supplementation. Sprint times were recorded via twin-beam photocells and earlobe blood samples were drawn to evaluate post-test lactate concentrations. RESULTS Relative to placebo, creatine supplementation resulted in a 0.5 kg increase in body mass (95% likely range: −0.1 to 1.0 kg), and a 0.2% reduction in body fat (95% likely range: −0.2 to 0.7%). There were no significant (p >0.05) between-group differences in multiple sprint measures of fastest time, mean time, fatigue, or post-test blood lactate concentration. CONCLUSION Despite widespread use as an ergogenic aid in sport, the results of this study suggest that creatine monohydrate supplementation conveys no benefit to multiple sprint running performance.

Creatine Supplementation And Multiple Sprint Running Performance

PURPOSE The aim of this study was to examine the effects of short-term creatine monohydrate supplementation on multiple sprint running performance. METHODS Using a double-blind research design, 54 physically active subjects (42 males; 12 females) completed a series of 3 indoor multiple sprint running trials (15 × 30 m repeated at 35 s intervals). After the first 2 trials (familiarisation and baseline), subjects were matched for gender and fatigue score before being randomly assigned to 5 days of either creatine (4.d−1 × 5 g creatine monohydrate + 1 g maltodextrin) or placebo (4.d−1 × 6 g maltodextrin) supplementation. Sprint times were recorded via twin-beam photocells and earlobe blood samples were drawn to evaluate post-test lactate concentrations. RESULTS Relative to placebo, creatine supplementation resulted in a 0.5 kg increase in body mass (95% likely range: −0.1 to 1.0 kg), and a 0.2% reduction in body fat (95% likely range: −0.2 to 0.7%). There were no significant (p >0.05) between-group differences in multiple sprint measures of fastest time, mean time, fatigue, or post-test blood lactate concentration. CONCLUSION Despite widespread use as an ergogenic aid in sport, the results of this study suggest that creatine monohydrate supplementation conveys no benefit to multiple sprint running performance.

Prediction of performance in the 5 000 m run by means of laboratory and field tests in male distance runners

As curvas de lactato sangüíneo, durante o exercício, têm sido amplamente utilizadas na prescrição do estímulo de treinamento para corredores de longa distância. Uma vez que a transferência dos resultados do laboratório para a situação de campo tem demonstrado ser inadequada, o objetivo deste estudo foi propor um protocolo de campo para predição do desempenho na corrida de 5.000 m. Vinte e oito corredores de média e longa distância (idade = 28±6 anos; peso = 61,5±6,1 kg) foram submetidos ao: a) ESTEI - teste na esteira ergométrica sem inclinação, consistindo de quatro velocidades, com cada estágio de cinco minutos separados por um minuto de repouso (15, 17, 18 e 19 km.h'1 ou 17, 19, 20 e 21 km.li'1), com as velocidades escolhidas para os sujeitos baseando-se no tempo mais recente na maratona (abaixo ou acima de duas horas e 30 minutos); b) CAMPO - quatro repetições de 1.600 metros com velocidades progressivas (3,5% abaixo da velocidade na esteira), separados por um minuto de repouso, como o empregado em a); e c) CORR - teste de corrida de 5.000 m. Amostras de sangue arterializado do lóbulo da orelha foram coletadas durante os primeiros 30 segundos dos períodos de recuperação nas condições ESTEI e CAMPO, com a concentração de lactato sendo analisada pelo método eletro enzimático (YSI 1500 Sport; Yellovv Springs Inc., Ohio). As velocidades e freqüências cardíacas nas duas situações de testes foram comparadas nas concentrações fixas de lactato de 2, 4 e 8 mmol.l'1 (ESTEIR: V2niM = 17,1±1,2, V4mM = 19,1±1,4, V8mM = 20,9±1,8 km.h'1 e FC2mM = 164±7, FC4mM = 178±6. FC8mM = 193±8 bpm; CAMPO: V2mM = 16,6±1,0, V4mM = 18,1±1,0, V8mM = 19,5+1,2 km.h*1 e FC2mM = 165±6, FC4mM = 178±8, FC8111M = 190±9 bpm). Correlações significativas foram observadas entre as condições ESTEI e o CAMPO nas três concentrações fixas de lactato (p&lt; 0,05). Sendo que não foi observada correlação significativa para a freqüência cardíaca a 8 mmol.l' Os coeficientes de correlação para teste/reteste na condição CAMPO, foram na faixa de 0,72 a 0,96 (todos sig. p&lt; 0,05) para as FC e para as V, nas três concentrações fixas. O melhor preditor da velocidade de corrida nos 5.000 m foi a velocidade nos 4 m m ol.r1 na condição CAMPO (r= 0,90, p&lt; 0,001; Y (m .m in1) = 13,4196 + 0,9997X, SEE = 9,62 m.min*1). Baseado nos presentes resultados foi concluído que referências originadas no protocolo de campo são mais relacionadas ao desempenho na corrida de 5.000 m, do que as originadas no laboratório