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Biomedical subjects

Alejandro Lucia

Publications and source records attributed to Alejandro Lucia.

At least 19 recordsLinked to original sources

Tumor Signatures of Physical Fitness: Insights from a Preclinical Model.

PURPOSE: Cardiorespiratory fitness (CRF) and muscle strength are associated with cancer risk/mortality in adults. However, there is yet no evidence for pediatric tumors. This study investigated the association of CRF and muscle strength with several tumor-related phenotypes in an aggressive childhood malignancy, high-risk neuroblastoma. METHODS: Twelve mice-bearing orthotopic high-risk neuroblastomas were studied. CRF and muscle strength were assessed using treadmill and grip strength testing, respectively. The following tumor-related outcomes were studied: survival, clinical severity, tumor weight/volume, metastasis, and intratumor immune infiltrates. In addition, tumor samples underwent quantitative proteomic analysis via liquid chromatography-tandem mass spectrometry. Spearman correlations (or logistic regression) were performed between CRF/muscle strength and the abovementioned variables. Proteins that were significantly correlated with CRF or muscle strength were mapped into protein-protein interaction (PPI) networks using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database. RESULTS: CRF was inversely correlated with clinical severity score ( r = -0.657, P = 0.020). Of 6840 identified tumor proteins, 76 correlated significantly with CRF (19 positively, 57 negatively), whereas 194 correlated with muscle strength (97 positively, 97 negatively). Proteins correlated with CRF were primarily involved in metabolic and structural pathways, including angiotensinogen and elastin. In turn, muscle strength-associated proteins were more abundant and included keratin family proteins (e.g., keratin, type I cytoskeletal 14, and type II cytoskeletal 5), proteins involved in cell adhesion (e.g., desmoglein-1-alpha), and translational regulators (e.g., eukaryotic initiation factor 4A). Network analysis revealed significant enrichment in structural organization and cellular adhesion pathways. CONCLUSIONS: Besides the association of CRF with clinical severity of the tumor, distinct novel tumor proteomic signatures associated with CRF and muscle strength were identified, highlighting potential mechanisms linking physical fitness with childhood cancer biology.

Muscle Strength↗

Acute physical exercise and ambulatory blood pressure in resistant hypertension.

OBJECTIVES: The effects of acute physical exercise in patients with resistant hypertension remain largely unexplored compared with hypertensive patients in general. We assessed the short-term effects of acute moderate-intensity (MICE) and high-intensity interval exercise (HIIE) on the clinic (BP) and 24-h ambulatory blood pressure (ABP) of patients with resistant hypertension. METHODS: Using a crossover randomized controlled design, 10 participants (56&#x200a;&#xb1;&#x200a;7&#x200a;years) with resistant hypertension performed three experimental sessions: MICE, HIIE, and control. MICE consisted of continuous treadmill exercise at an intensity of 3-4 metabolic equivalents of energy (METs) until completing 3&#x200a;kcal/kg and was energy-matched to HIIE (which included six to eight intervals of 3&#x200a;min duration at 6-7 METs interspersed with 1.5-min rests at 3 METs). In the control session, participants remained seated for 50&#x200a;min. Flow-mediated vasodilation, autonomic nervous system balance (heart rate variability), exerkines [interleukin (IL)-6, IL-8, IL-15, vascular endothelial growth factor A, irisin, adiponectin, and angiopoietin] and 71 inflammatory-related proteins were also measured. RESULTS: Compared with baseline, HIIE and MICE reduced clinic SBP immediately ( P &#x200a;<&#x200a;0.001 for both) and 90&#x200a;min ( P &#x200a;=&#x200a;0.001 and P &#x200a;=&#x200a;0.041, respectively) postexercise. HIIE and MICE also reduced clinic DBP immediately postexercise ( P &#x200a;=&#x200a;0.003 and P &#x200a;=&#x200a;0.025). By contrast, no changes were found in the control session. On the other hand, no significant effects were noted for 24&#x200a;h ABP measures or for the rest of variables. CONCLUSION: Although in patients with resistant hypertension, acute aerobic exercise induces short-term reductions in clinic BP, this stimulus does not suffice to reduce 24&#x200a;h ABP or to impact on potential biological mechanisms.

Humans↗

A proposed molecular diagnostic flowchart for myophosphorylase deficiency (McArdle disease) in blood samples from Spanish patients.

McArdle disease is a metabolic myopathy due to molecular defects in the myophosphorylase gene (PYGM), usually diagnosed in muscle biopsy. The aims of this study were to characterize genetically a large series of patients and to establish a protocol of molecular diagnosis on blood samples. We studied 55 Spanish unrelated patients with McArdle disease. Screening for the three more frequent mutations in the PYGM gene in the Spanish population (c.148C>T, p.R50X; c.613G>A, p.G205S; and c.2392T>C, p.W798R) were performed with polymerase chain-reaction and restriction fragment length polymorphism (PCR-RFLP) methods. To identify other mutant alleles, the coding region of PYGM gene was sequenced. The p.R50X mutation was observed in 38 patients, the p.G205S substitution in eight, and the p.W798R change in nine. Nine novel mutations, five missense (c.247A>T, p.I83F; c.521G>A, p.G174D; c.1094C>T, p.A365V; c.1468C>T, p.R490W; and c.1730A>G, p.Q577R), one nonsense mutation (c.2352C>A, p.C784X), three frameshift (c.402del, p.N134KfsX161; c.212_218dup, p.Q73HfsX7; c.1470dup, p.R491AfsX7), and nine previously reported mutations were found. In addition, we also updated the molecular data of 95 unrelated patients with McArdle disease studied thus far in our center. Of these patients, 56 were either homozygous or compound heterozygous for the p.R50X, p.G205S, or p.W798R mutation. By including in the molecular diagnosis protocol sequencing of the exons 1, 14, 17 and 18 of the PYGM gene, 16 further patients were characterized, and therefore we were able to detect the molecular defect in 72 out of 95 patients. A proposed molecular diagnosis protocol of the disease based on blood DNA would avoid muscle biopsy in 75.8% [95% confidence interval (95% CI): 62.1%-78.6%] of patients with McArdle disease.

Adolescent↗

Double trouble (McArdle's disease and myasthenia gravis): how can exercise help?

We report a 29-year-old patient with McArdle's disease and myasthenia gravis. She had been debilitated with McArdle's disease since childhood (with marked rhabdomyolysis) and was obese. Myasthenia gravis was diagnosed at 24 years of age. After 3 months of aerobic exercise training, her exercise capacity increased significantly and she regained the ability to live independently. We conclude that even patients with profound neuromuscular diseases may benefit from carefully prescribed exercise training.

Adult↗

Effects of an intrahospital exercise program intervention for children with leukemia.

PURPOSE: The purpose was to investigate the effect of a 16-wk intrahospital supervised conditioning program including both resistance and aerobic training and a 20-wk detraining period on measures of aerobic fitness, muscular strength, functional mobility, ankle range of motion, and quality of life (QOL) in children receiving treatment for acute lymphoblastic leukemia (ALL). METHODS: Seven children (four boys, three girls; age: 5.1 +/- 1.2 yr, body mass: 24.0 +/- 5.8 kg, height: 114.6 +/- 7.7 cm) in the maintenance phase of treatment against ALL performed three sessions per week for 16 wk of resistance (one set of 8-15 repetitions of 11 exercises) and aerobic training (30 min at > 70% HRmax) followed by 20 wk of detraining where no structured exercise program was performed. Before training, after training, and after detraining, a treadmill test determining .VO2peak and ventilator threshold (VT), muscular strength (6RM), functional mobility (timed up and down stairs test, time up and go 3-m and 10-m tests), passive and dynamic ankle range of motion, and self-reported quality of living were determined. RESULTS: After training, significant increases in .VO2peak, VT, upper- and lower-body muscular strength, and all measures of functional mobility were shown (P < 0.05). Muscular strength was well maintained (significantly greater than before training and no significant decrease from after training) during detraining, whereas .VO2peak, VT, and functional mobility (not significantly different from before training but no significant decrease from after training) were only partially retained. CONCLUSION: Young children in the maintenance phase of treatment against ALL can safely perform both aerobic and resistance training. Training results in significant increases in measures of aerobic fitness, strength, and functional mobility. During detraining, strength and functional mobility are well maintained, whereas .VO2peak and VT are partially maintained.

Child↗

Novel mutation in the PYGM gene resulting in McArdle disease.

BACKGROUND: McArdle disease is a common metabolic disorder characterized by marked exercise intolerance, premature fatigue during exertion, myalgia, and cramps. Despite the wide knowledge of the molecular basis of McArdle disease, few studies have used a physiological approach or explored the possibility of improving the exercise capacity of these patients. OBJECTIVES: To describe 3 unrelated patients with McArdle disease with a novel mutation in the PYGM gene and to assess the physical capacity in 1 of them. DESIGN: Using molecular genetic approaches, we identified the underlying molecular defect in 3 patients with McArdle disease. Physical performance was evaluated in 1 patient by means of an exercise tolerance test on a bicycle ergometer. SETTING: Two university hospitals. Exercise physiology studies were performed in a university department. Patients The 3 patients showed common features of McArdle disease. They were definitively diagnosed by histochemistry, biochemistry, or molecular genetic analysis. RESULTS: All of the 3 patients were genetic compounds for the common Arg50Stop mutation and a novel c.13_14delCT mutation in the PYGM gene. The peak oxygen uptake (VO(2peak)) of the patient who performed the exercise test was only 20.2 mL x kg(-1) x min(-1). CONCLUSIONS: Together with the novel mutation, there is a markedly decreased exercise capacity in a patient with McArdle disease, which could account for the profound alteration in the capacity for performing normal activities of daily living in this subpopulation.

Adult↗

Physical activity during treatment in children with leukemia: a pilot study.

The purpose of this pilot study was to measure physical activity (PA) levels in children undergoing treatment for acute lymphoblastic leukemia (ALL) and to compare the results with those from age-matched healthy children. We used the MTI Actigraph accelerometer to determine PA (during a 1 week period) in children (n = 7; age = 4-7 y) undergoing maintenance treatment for ALL and in age-matched controls (n = 7). The number of children accumulating at least 60 min of moderate-to-vigorous physical activity (MVPA) for 5 or more days of the week was 3 for the control group, whereas no children with ALL met this criterion. Significantly lower levels of total weekly time of MVPA were seen in children being treated for ALL (328 +/- 107 min) than in controls (506 +/- 175 min) (p < 0.05). When weekday data was analyzed, the ALL patients also had significantly lower mean daily times of MVPA (49 +/- 23 min vs. 79 +/- 25 min). It is thus important that young ALL sufferers are encouraged to participate in appropriate sports, games, and physical activities both in the family and school environments that will prime them with positive attitudes to PA during the critical early years of life.

Antineoplastic Agents↗

Physiological characteristics of the best Eritrean runners-exceptional running economy.

Despite their young age, limited training history, and lack of running tradition compared with other East African endurance athletes (e.g., Kenyans and Ethiopians), male endurance runners from Eritrea have recently attained important running successes. The purposes of our study were (i) to document the main physical and physiological characteristics of elite black Eritrean distance runners (n = 7; age: 22 +/- 3 years) and (ii) to compare them with those of their elite white Spanish counterparts. For this second purpose we selected a control group of elite Spanish runners (n = 9; 24 +/- 2 years), owing to the traditionally high success of Spanish athletes in long-distance running compared with other white runners, especially in cross-country competitions. The subjects' main anthropometric characteristics were determined, together with their maximum oxygen uptake (VO2 max) and VO2 (mL.kg(-1).min(-1)), blood lactate, and ammonia concentrations while running at 17, 19, or 21 km.h(-1). The body mass index (18.9 +/- 1.5 kg.m(-2)) and maximal calf circumference (30.9 +/- 1.5 cm) was lower in Eritreans than in Spaniards (20.5 +/- 1.7 kg.m(-2) and 33.9 +/- 2.0 cm, respectively) (p < 0.05 and p < 0.01, respectively) and their lower leg (shank) length was longer (44.1 +/- 3.0 cm vs. 40.6 +/- 2.7 cm, respectively) (p < 0.05). VO2 max did not differ significantly between Eritreans and Spaniards (73.8 +/- 5.6 mL.kg(-1).min(-1) vs. 77.8 +/- 5.7 mL.kg(-1).min(-1), respectively), whereas the VO2 cost of running was lower (p < 0.01) in the former (e.g., 65.9 +/- 6.8 mL.kg(-1).min(-1) vs. 74.8 +/- 5.0 mL.kg(-1).min(-1) when running at 21 km.h(-1)). Our data suggest that the excellent running economy of Eritreans is associated, at least partly, with anthropometric variables. Comparison of their submaximal running cost with other published data suggests that superior running economy, rather than enhanced aerobic capacity, may be the common denominator in the success of black endurance runners of East African origin.

Adult↗

Does creatine supplementation improve functional capacity in elderly women?

The purpose of this study was to determine the effects of short-term (7 days) oral creatine supplementation (0.3 g.kg(-1)) in elderly women during exercise tests that reflect functional capacity during daily living tasks. We assessed several indices of endurance capacity (1-mile walk test, gross mechanical efficiency, ventilatory threshold, and peak oxygen intake determined during cycle-ergometry) and lower-extremity functional performance (time to complete sit-stand test). Subjects were assigned to a creatine (n = 10; age 67 +/- 6 years) or placebo (n = 6; age 68 +/- 4 years) group. We found a significant improvement only after creatine loading in the sit-stand test (placebo: 9.7 +/- 0.9 seconds for pretest and 9.3 +/- 0.7 seconds for posttest, p > 0.05; creatine: 10.0 +/- 0.7 seconds for pretest and 8.8 +/- 1.1 seconds for posttest). Significance was recorded at p < 0.05 for the interaction effect (group [creatine, placebo] x time [pretest, posttest]). In elderly women, short-term oral creatine supplementation does not improve endurance capacity but increases the ability to perform lower-body functional living tasks involving rapid movements.

Activities of Daily Living↗

A comparison of visual and mathematical detection of the electromyographic threshold during incremental pedaling exercise: a pilot study.

During exhaustive incremental pedaling exercises, root mean square or amplitude of integrated electromyographic values exhibits a nonlinear increase, i.e., the so-called electromyographic threshold (EMG(Th)). As proposed by various authors, this EMG(Th) could be used as a complementary indicator of the aerobic-anaerobic transition in physiological evaluations. However, most of these studies used visual detection for the EMG(Th) and to date no previous study has shown the reliability of this type of EMG(Th) detection. We aimed to compare a visual and a mathematical method for EMG(Th) detection in each of 8 lower limb muscles during incremental cycling exercise. Our results showed an overestimation in the number of cases in which EMG(Th) was detected when using visual inspection (n = 45) compared with the mathematical method (n = 32). However, no significant differences were observed between the 2 methods concerning the power output at which EMG(Th) occurred. These results suggest that EMG(Th) should be mathematically detected. In this context, coaches can easily perform such measurements in order to evaluate the impact of their training programs on the neuromuscular adaptations of their athletes. For example, an automatic mathematical detection of EMG(Th) could be performed during a pedaling exercise in order to detect neuromuscular fatigue. Furthermore, this index could be used during test or training sessions performed either in a lab or in ecological situations. Moreover, the use of EMG(Th) to predict ventilatory threshold occurrence could be an interesting tool for trainers who cannot use the very expensive devices needed to analyze respiratory gas exchanges.

Adult↗

PPARGC1A genotype (Gly482Ser) predicts exceptional endurance capacity in European men.

Animal and human data indicate a role for the peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PPARGC1A) gene product in the development of maximal oxygen uptake (V(O2 max)), a determinant of endurance capacity, diabetes, and early death. We tested the hypothesis that the frequency of the minor Ser482 allele at the PPARGC1A locus is lower in World-class Spanish male endurance athletes (cases) [n = 104; mean (SD) age: 26.8 (3.8) yr] than in unfit United Kingdom (UK) Caucasian male controls [n = 100; mean (SD) age: 49.3 (8.1) yr]. In cases and controls, the Gly482Ser genotype met Hardy-Weinberg expectations (P > 0.05 in both groups tested separately). Cases had significantly higher V(O2 max) [73.4 (5.7) vs. 29.4 ml x kg(-1) x min(-1) (3.8); P < 0.0001] and were leaner [body mass index: 20.6 (1.5) vs. 27.6 kg/m2 (3.9); P < 0.0001] than controls. In unadjusted chi2 analyses, the frequency of the minor Ser482 allele was significantly lower in cases than in controls (29.1 vs. 40.0%; P = 0.01). To assess the possibility that genetic stratification could confound these observations, we also compared Gly482Ser genotype frequencies in Spanish (n = 164) and UK Caucasian men (n = 381) who were unselected for their level of fitness. In these analyses, Ser482 allele frequencies were very similar (36.9% in Spanish vs. 37.5% in UK Caucasians, P = 0.83), suggesting that confounding by genetic stratification is unlikely to explain the association between Gly482Ser genotype and endurance capacity. In summary, our data indicate a role for the Gly482Ser genotype in determining aerobic fitness. This finding has relevance from the perspective of physical performance, but it may also be informative for the targeted prevention of diseases associated with low fitness such as Type 2 diabetes.

Adult↗

Frequency of the C34T mutation of the AMPD1 gene in world-class endurance athletes: does this mutation impair performance?

The C34T mutation in the gene encoding for the skeletal muscle-specific isoform of AMP deaminase (AMPD1) is a common mutation among Caucasians (i.e., one of five individuals) that can impair exercise capacity. The purpose of this study was twofold. First, we determined the frequency distribution of the C34T mutation in a group of top-level Caucasian (Spanish) male endurance athletes (cyclists and runners, n = 104). This group was compared with randomly selected Caucasian (Spanish) healthy (asymptomatic) nonathletes (n = 100). The second aim of this study was to compare common laboratory indexes of endurance performance (maximal oxygen uptake or ventilatory thresholds) within the group of athletes depending on their C34T AMPD1 genotype. The frequency of the mutant T allele was lower (P < 0.05) in the group of athletes (4.3%) compared with controls (8.5%). On the other hand, indexes of endurance performance did not differ (P > 0.05) between athlete carriers or noncarriers of the C34T mutation (e.g., maximal oxygen uptake 72.3 +/- 4.6 vs. 73.5 +/- 5.9 ml.kg(-1).min(-1), respectively). In conclusion, although the frequency distribution of the mutant T allele of the AMPD1 genotype is lower in Caucasian elite endurance athletes than in controls, the C34T mutation does not significantly impair endurance performance once the elite-level status has been reached in sports.

AMP Deaminase↗

How do endurance runners actually train? Relationship with competition performance.

PURPOSE: To quantify the relationship between total training load and running performance during the most important competitions of the season (national cross-country championships, 4.175- and 10.130-km races). METHODS: Eight well-trained, subelite endurance runners (age (mean+/-SD): 23+/-2 yr; VO2max: 70.0+/-7.3 mL.kg.min) performed a maximal cardiorespiratory exercise test before the training period to determine ventilatory threshold (VT) and respiratory compensation threshold (RCT). Heart rate was continuously recorded using telemetry during each training session over a 6-month macrocycle, designed to achieve peak performance during the aforementioned cross-country races, lasting from late August to the time that these races were held, that is, mid-February. This allowed us to quantify the total cumulative time spent in three intensity zones calculated as zone 1 (low intensity, lower than the VT); zone 2 (moderate intensity, between VT and RCT); and zone 3 (high intensity, above the RCT). RESULTS: Total training time in zone 1 (4581+/-979 min) was significantly higher (P<0.001) than that accumulated in zones 2 (1354+/-583 min) and 3 (487+/-154 min). Total time in zone 2 was significantly higher than time in zone 3 (P<0.05). A correlation coefficient of r=-0.79 (P=0.06) and r=-0.97 (P=0.008) was found between the total training time spent in zone 1 and performance time during the short and long cross-country races, respectively. CONCLUSIONS: Our findings suggest that total training time spent at low intensities might be associated with improved performance during highly intense endurance events, especially if the event duration is approximately 35 min. Interventional studies (i.e., improving or reducing training time in zone 1) are needed to corroborate our findings and to elucidate the physiological mechanisms behind them.

Adaptation, Physiological↗

Regulation of energy expenditure during prolonged athletic competition.

BACKGROUND: Athletic competitions, such as the Tour de France, demand both momentary bursts of very high power output and the ability to provide high levels of energy expenditure for several weeks. As such, they provide a model of the ability for sustained muscular activity, which is important in terms of how humans are understood, not only as athletes, but also within an evolutionary context. METHODS: Laboratory correlated HR responses were made of elite professional cyclists (N=7) during successive competitions in one of the three grand tours in cycling in successive years, with the intent of evaluating the magnitude and pattern of energy expenditure. HR recordings were normalized into a training impulse (TRIMP) score, summating the intensity and duration of each race, and tracked over the duration of successive tours. RESULTS: Although the day-by-day pattern of HR responses in exercise intensity zones associated with exercise intensities below the first ventilatory threshold, between the first and second ventilatory thresholds, and above the second ventilatory threshold varied in response to the course and competitive situation, the net accumulation of both time in each of the HR zones and TRIMP was remarkably constant from one tour to the next, both within the group at large as well as within individual athletes. The magnitude of accumulation of TRIMP was similar to that of previous reports on elite tour cyclists. CONCLUSIONS: We interpret these results as evidence that humans adopt a pacing strategy designed to optimally distribute energy reserves over the duration of each tour.

Adaptation, Physiological↗

Effect of warm-up on cycle time trial performance.

PURPOSE: This study was designed to determine the effect of warm-up on 3-km cycling time trial (TT) performance, and the influence of accelerated VO(2) kinetics on such effect. METHODS: Eight well-trained road cyclists, habituated to 3-km time trials, performed randomly ordered 3-km TT after a) no warm-up (NWU), b) easy warm-up (EWU) (15 min comprised of 5-min segments at 70, 80, and 90% of ventilatory threshold (VT) followed by 2 min of rest), or c) hard warm-up (HWU) (15 min comprised of 5-min segments at 70, 80, and 90% VT, plus 3 min at the respiratory compensation threshold (RCT) followed by 6 min of rest). VO(2) and power output (SRM), aerobic and anaerobic energy contributions, and VO(2) kinetics (mean response time to 63% of the VO(2) observed at 2 km) were determined throughout each TT. RESULTS: Three-kilometer TT performance was (P < 0.05) improved for both EWU (266.8 +/- 12.0 s) (-2.8%) and HWU (267.3 +/- 10.4 s) (-2.6%) versus NWU (274.4 +/- 12.1 s). The gain in performance was predominantly during the first 1000 m in both EWU (48% of gain) and HWU (53% of gain). This reflected a higher power output during the first 1000 m in both EWU (384 W) and HWU warm-up (386 W) versus NWU (344 W) trials. The mean response time was faster in both EWU (45 +/- 10 s) and HWU (41 +/- 12 s) versus NWU (52 +/- 13 s) trials. There were no differences in anaerobic power output during the trials, but aerobic power output during the first 1000 m was larger during both EWU (203 W) and HWU (208 W) versus NWU (163 W) trials. CONCLUSIONS: During endurance events of intermediate duration (4-5 min), performance is enhanced by warm-up irrespective of warm-up intensity. The improved performance is related to an acceleration of VO(2) kinetics.

Adult↗

Reliability of the Lode Excalibur Sport Ergometer and applicability to Computrainer electromagnetically braked cycling training device.

New technology allows cyclists to train via power output (PO) in addition to heart rate (HR). For those athletes undertaking seasonal laboratory testing (e.g., Vo(2), lactate threshold), it is imperative that athletes be able to directly apply this information to their training device. We examined the reliability of a standardized laboratory ergometer (Lode Excalibur Sport) and its applicability to an electromagnetically braked ergometer (Computrainer) in 2 phases. Phase I (n = 12) examined the reliability of the Lode. Phase II (n = 14) compared the Lode to the Computrainer using a randomized, counterbalance assignment. Following warm-up, each trial started at 100 W, progressing 50 W every 3 minutes to exhaustion. Outcomes were time-to-exhaustion (TTE), peak PO (W) (PO(peak)), peak HR (HR(peak)), and ventilatory (VT) and respiratory compensation (RCP) thresholds. We used a repeated measures analysis of variance (ANOVA), Tukey post hoc analysis, regression analysis, Bland-Altman plots, and coefficient of variation (CV) analysis for each variable. During phase I, we found no significant difference for any variable, minimal dispersion of Vo(2) during Bland-Altman analysis, and a low CV at each test stage (</= 5%). During phase II, significant differences and higher CV for most parameters (all data; p < 0.001) were observed for Lode versus Computrainer: TTE (21 minutes, 12 seconds +/- 3 minutes, 12 seconds vs. 19 minutes, 9 seconds +/- 2 minutes, 36 seconds; CV = 16%), PO(peak) (335 +/- 57.8 W vs. 295 +/- 47.1 W, CV = 17%), as well as PO at VT (CV = 51%) and RCP (CV = 24%; p < 0.01). We conclude that coaches and cyclists may need to use some caution when directly transferring results obtained from laboratory testing to the Computrainer training device.

Bicycling↗

Effects of a commercial herbal-based formula on exercise performance in cyclists.

INTRODUCTION/PURPOSE: We examined the effects of a commercially marketed herbal-based formula purported to increase endurance on oxygen consumption (VO2) in 17 competitive category III/IV amateur cyclists [mean (SEM) age: 31.1 (1.8) yr; height: 178.5 (1.8) cm; weight: 77.1 (1.6) kg]. METHODS: Each cyclist participated in two (pre/post) cycling tests progressing 25 W.4 min(-1) starting at 100 W administered in a randomized, placebo-controlled, double-blind fashion. The second trial was performed 14 d after the ingestion of a manufacturer recommended loading phase (4 d x 6 caps.d(-1)) and a maintenance phase (11 d x 3 caps.d(-1)). Three treatment capsules contained 1000 mg of Cordyceps sinensis (CS-4) and 300 mg Rhodiola rosea root extract as the primary ingredients; 800 mg of other ingredients included calcium pyruvate, sodium phosphate, potassium phosphate, ribose, and adenosine and 200 mcg of chromium. RESULTS: Using a 2 x 2 ANOVA, we observed no significant treatment effect for any between or within group variables including peak VO2 [treatment 4.14 (0.2) L.min(-1); placebo 4.10 (0.2) L.min(-1)], time to exhaustion [treatment 38.47 (1.7) min; placebo 36.95 (1.8) min], peak power output (PO) [treatment 300.00 (12.1) W; placebo 290.63 (12.9) W], or peak heart rate. We also observed no differences for any subpeak exercise variable including the PO eliciting 2 mmol.L(-1) blood lactate (BLa) [treatment 201.00 (18.1) W; placebo 167.50 (19.2) W] and 4 mmol.L(-1) BLa [treatment 235.88 (15.8) W; placebo 244.78 (14.9) W], ventilatory threshold, respiratory compensation point, or Vo2 L.min(-1) gross efficiency at each stage. CONCLUSION: A 2-wk ingestion schema of a commercial herbal-based formula is insufficient to elicit positive changes in cycling performance.

Adult↗