Pedro J. Benito

MCT1 genetic polymorphism influence in high intensity circuit training: a pilot study.

Monocarboxylate Transporter 1 (MCT1) mediates the transport of the main fraction of lactate across the sarcolemma. A common polymorphic MCT1 variant has been identified, but its role in high intensity exercise performance has not been defined. We investigated the influence of MCT1 A1470T polymorphism (rs1049434) on lactate accumulation after high intensity circuit training. Ten men aged 20-26 performed three controlled circuit training (CWT) sessions at 60%, 70%, and 80% of the 15 repetition maximum (15RM), in non-consecutive days. CWT included three sets of a circuit of eight exercises, obtaining lactate measurements immediately after each set had been completed. Two independent variables were analysed: MTC1 genotypes according to the presence or absence of the A1470T polymorphism, and the intensity of circuit training. Genotype distributions were in Hardy-Weinberg equilibrium, being 30% wild-type, 50% heterozygotes, and 20% mutated homozygotes. Mean lactate concentration at 80% of 15RM were significantly higher than the mean lactate values at the other intensities (p<0.01). Significant differences between genetic groups were found in the lactate accumulation slope at 80% of 15RM (p=0.02) and in the maximal lactate concentration reached by all subjects in the study (L(max)) (p=0.03). The carriers of the A1470T polymorphism in the MTC1 gene seem to exhibit a worse lactate transport capability into the less active muscle cells for oxidation.

Influence of the MCT1-T1470A polymorphism (rs1049434) on blood lactate accumulation during different circuit weight trainings in men and women

OBJECTIVES To analyze the effect of the MCT1 T1470A polymorphism (rs1049434) on venous blood lactate levels in men and women, during three different circuit weight training protocols. DESIGN Cross-sectional laboratory study. METHODS 14 women and 15 men, all caucasian and moderately active, performed three circuit training sessions (Weight Machine Protocol, Free Weight Protocol and Combined Protocol) at 70% of the 15 repetition maximum and 70% of the heart rate reserve, in non-consecutive days. The sessions included three sets of a circuit of eight exercises. Venous lactate measurements were obtained after each set and during the recoveries between sets (i.e. in min 3, 5, 7 and 9). One-way analysis of covariance and one-way analysis of covariance with repeated measures were used to determine differences among genotypes (AA, TA and TT) in lactate levels. RESULTS In men, the AA group had higher lactate values than the TT group in all the measures (p ≤ 0.03) except for the average lactate during the Weight Machine Protocol, in which a borderline significant difference was found (p=0.07). We did not observe differences across genotypes in females. CONCLUSIONS Our data suggest an influence of the MCT1 polymorphism on lactate transport across sarcolemma in males. Future studies on lactate transport and metabolism should take into account the gender-specific results.

Nutrition and physical activity programs for obesity treatment (PRONAF study): methodological approach of the project

BackgroundAt present, scientific consensus exists on the multifactorial etiopatogenia of obesity. Both professionals and researchers agree that treatment must also have a multifactorial approach, including diet, physical activity, pharmacology and/or surgical treatment. These two last ones should be reserved for those cases of morbid obesities or in case of failure of the previous ones. The aim of the PRONAF study is to determine what type of exercise combined with caloric restriction is the most appropriate to be included in overweigth and obesity intervention programs, and the aim of this paper is to describe the design and the evaluation methods used to carry out the PRONAF study.Methods/designOne-hundred nineteen overweight (46 males) and 120 obese (61 males) subjects aged 18–50 years were randomly assigned to a strength training group, an endurance training group, a combined strength + endurance training group or a diet and physical activity recommendations group. The intervention period was 22 weeks (in all cases 3 times/wk of training for 22 weeks and 2 weeks for pre and post evaluation). All subjects followed a hypocaloric diet (25-30% less energy intake than the daily energy expenditure estimated by accelerometry). 29–34% of the total energy intake came from fat, 14–20% from protein, and 50–55% from carbohydrates. The mayor outcome variables assesed were, biochemical and inflamatory markers, body composition, energy balance, physical fitness, nutritional habits, genetic profile and quality of life. 180 (75.3%) subjects finished the study, with a dropout rate of 24.7%. Dropout reasons included: personal reasons 17 (28.8%), low adherence to exercise 3 (5.1%), low adherence to diet 6 (10.2%), job change 6 (10.2%), and lost interest 27 (45.8%).DiscussionFeasibility of the study has been proven, with a low dropout rate which corresponds to the estimated sample size. Transfer of knowledge is foreseen as a spin-off, in order that overweight and obese subjects can benefit from the results. The aim is to transfer it to sports centres. Effectiveness on individual health-related parameter in order to determine the most effective training programme will be analysed in forthcoming publications.Trial registrationClinicalTrials.gov NCT01116856

Effects of dietary restriction combined with different exercise programs or physical activity recommendations on blood lipids in overweight adults

BACKGROUND AND AIM Many exercise studies, although generally showing the beneficial effects of supervised aerobic, resistance or combined exercise on blood lipids, have sometimes reached equivocal conclusions. The aim of this study is to evaluate the impact of different programs that combined exercise and dietary restriction on blood lipids versus a clinical practice intervention for weight loss, in overweight adults. METHODS For this study 66 subjects participated in a supervised 22 weeks training program, composed of three sessions per week and they were randomized in three groups: strength training (S; n = 19), endurance training (E; n = 25), a combination of E and S (SE; n = 22). Eighteen subjects served as physical activity group (PA) that followed a clinical intervention consisted of physical activity recommendations. All groups followed the same dietary treatment, and blood samples were obtained for lipids measurements, at the beginning and end of the study. RESULTS Lipid profile improved in all groups. No significant differences for baseline and post-training values were observed between groups. In general, SE and PA decreased low-density lipoprotein cholesterol (LDL-C) values (p < 0.01). S decreased triglyceride levels (p < 0.01) and E, SE, and PA decreased total cholesterol levels (p < 0.05, p < 0.01 and p < 0.01, respectively). CONCLUSIONS These results suggest that an intervention program of supervised exercise combined with diet restriction did not achieved further improvements in blood lipid profile than diet restriction and physical activity recommendations, in overweight adults. (Clinical Trials gov number: NCT01116856).

Physical activity, hydration and health

Since the beginning of mankind, man has sought ways to promote and preserve health as well as to prevent disease. Hydration, physical activity and exercise are key factors for enhancing human health. However, either a little dose of them or an excess can be harmful for health maintenance at any age. Water is an essential nutrient for human body and a major key to survival has been to prevent dehydration. However, there is still a general controversy regarding the necessary amount to drink water or other beverages to properly get an adequate level of hydration. In addition, up to now the tools used to measure hydration are controversial. To this end, there are several important groups of variables to take into account such as water balance, hydration biomarkers and total body water. A combination of methods will be the most preferred tool to find out any risk or situation of dehydration at any age range. On the other hand, physical activity and exercise are being demonstrated to promote health, avoiding or reducing health problems, vascular and inflammatory disea ses and helping weight management. Therefore, physical activity is also being used as a pill within a therapy to promote health and reduce risk diseases, but as in the case of drugs, dose, intensity, frequency, duration and precautions have to be evaluated and taken into account in order to get the maximum effectiveness and success of a treatment. On the other hand, sedentariness is the opposite concept to physical activity that has been recently recognized as an important factor of lifestyle involved in the obesogenic environment and consequently in the risk of the non-communicable diseases. In view of the literature consulted and taking into account the expertise of the authors, in this review a Decalogue of global recommendations is included to achieve an adequate hydration and physical activity status to avoid overweight/obesity consequences.

Cardiac Dimensions over 5 Years in Highly Trained Long-Distance Runners and Sprinters

Abstract Aims: We assessed the changes in cardiac morphology between elite endurance-trained runners (n = 42) and elite sprinters (n = 34) over a 5-year period. In addition, we studied the relationship between heart size and maximum oxygen consumption (VO2 max). Methods: At the beginning of 5 consecutive seasons, all athletes underwent an incremental running test to determine VO2 max and a color-coded pulsed Doppler examination to determine baseline echocardiographic variables. We hypothesized that cardiac morphology had reached its upper limit in elite athletes, and showed only minor changes during 5 years of regular training. Results: Although all echocardiographic variables remained stable in nearly all sprinters studied, in the endurance runners (who presented higher cardiac cavity dimensions compared with sprinters), variations in heart morphology became evident from the third season, and were within established physiological limits. Conclusion: Only 6 (17%) endurance runners and 3 (9%) sprinters showed a left ventricular internal diameter of > 60 mm (the threshold pathological value) at end diastole at some point during the observational period. Moreover, no statistically significant association was detected between changes in VO2 max and changes in heart size. After 5 years of intense training, the changes of the echocardiographic variables examined remained different between endurance runners and sprinters.

Physical activity assessment in the general population: instrumental methods and new technologies

The objective measurement of human movement and the quantification of energy expenditure due to physical activity is an identified need in both research and the clinical setting. Validated and well-defined reference methods (double labelled water, direct calorimetry, indirect calorimetry) are expensive and mostly limited to the laboratory setting. Therefore, in the last years, several objective measurement devices have been developed which are appropriate for field studies and clinical settings. There is no gold standard among them, as all have limitations. Pedometers are small, non-expensive, count the steps taken and give information on total physical activity, but not about physical activity patterns and behaviour. Accelerometers are expensive, save information about frequency and intensity of physical activity, but not about type of physical activity. Both pedometers and accelerometers only save information about lower body movement, but reliability about the estimation of energy expenditure is limited. Heart rate monitoring relates intensity to energy expenditure, but gives no information about physical activity. GPS watches are portable, relatively inexpensive, non-invasive and provide distance, speed, and elevation with exact time and location, but are maybe limited for the assessment of brief higher speed movement and energy expenditure. Combined motion sensors combine accelerometry with the measurement of physiological variables and share advantages of single devices and are more precise. Manufacturer software which applies activity-specific algorithms for the calculation of energy expenditure can affect energy expenditure results. Most of the devices estimate energy expenditure more accurately at light to moderate intensities; underestimation increases at very light and higher intensity activities.

CAN THE EXERCISE MODE DETERMINE LIPID PROFILE IMPROVEMENTS IN OBESE PATIENTS

INTRODUCTION Unfavorable lipid profile is associated with developed cardiovascular diseases. It is necessary to know the beneficial effects of different mode exercises to improve lipid profile. OBJECTIVE To investigate, in obese men and women, the effect on lipid profile of hypocaloric diet combined with structured exercise programs or recommendations of physical activity. METHODS Ninety six obese subjects (59 women and 61 men; 18 - 50 years; BMI >30 and < 34.9 kg/m(2)) were randomised into four supervised treatment groups: strength training (S; n = 24), endurance training (E; n = 26), combined S + E (SE; n = 24), and and received recommendations of physical activity (PA; n = 22). Energy intake, body composition, training variables (VO(2peak), strength index, dynamometric strength index) and blood lipid profile were recorded at baseline and after 24 weeks of treatment. RESULTS Blood lipid profile improved in all groups. No statistically significant differences in baseline and posttraining values were observed between groups. HDLCholesterol showed no changes. A decrease in LDLCholesterol values was observed in all groups after the intervention (S: 11.2%, E: 10.8%, SE: 7.9%, PA: 10.8%; p < 0.01). S, E and PA subjects showed decrease in triglycerides (S: 14.9%, E: 15.8%, PA: 15.7%; p < 0.01). Total cholesterol decreased in all groups (S: 8.4%, p < 0.01; E: 8.8%, p < 0.01; SE: 4.9%, p < 0.01; PA: 8.3%, p < 0.05). CONCLUSION All protocols proposed in our study improved blood lipid profile in obese people. There were no significant differences about the effect on the lipid profile between the implementation of a structured training protocol with physical activity professional supervision and follow recommendations of physical activity.

Longitudinal changes in response to a cycle-run field test of young male national "talent identification" and senior elite triathlon squads.

Abstract Díaz, V, Peinado, AB, Vleck, VE, Alvarez-Sánchez, M, Benito, PJ, Alves, FB, Calderón, FJ, and Zapico, AG. Longitudinal changes in response to a cycle-run field test of young male national “talent identification” and senior elite triathlon squads. J Strength Cond Res 26(8): 2209–2219, 2012—This study investigated the changes in cardiorespiratory response and running performance of 9 male “Talent Identification” (TID) and 6 male Senior Elite (SE) Spanish National Squad triathletes during a specific cycle-run (C-R) test. The TID and SE triathletes (initial age 15.2 ± 0.7 vs. 23.8 ± 5.6 years, p = 0.03; V[Combining Dot Above]O2max 77.0 ± 5.6 vs. 77.8 ± 3.6 ml·kg−1·min−1, nonsignificant) underwent 3 tests through the competitive period and the preparatory period, respectively, of 2 consecutive seasons: test 1 was an incremental cycle test to determine the ventilatory threshold (Thvent); test 2 (C-R) was 30-minute constant load cycling at the Thvent power output followed by a 3-km time-trial run; and test 3 (isolated control run [R]) was an isolated 3-km time-trial control run, in randomized counterbalanced order. In both seasons, the time required to complete the C-R 3-km run was greater than for R in TID (11:09 ± 00:24 vs. 10:45 ± 00:16 min:ss, p < 0.01 and 10:24 ± 00:22 vs. 10:04 ± 00:14, p = 0.006, for season 2005–2006 and 2006–2007, respectively) and SE (10:15 ± 00:19 vs. 09:45 ± 00:30, p < 0.001 and 09:51 ± 00:26 vs. 09:46 ± 00:06, p = 0.02 for season 2005–2006 and 2006–2007, respectively). Compared with the first season, the completion of the time-trial run was faster in the second season (6.6%, p < 0.01 and 6.4%, p < 0.01, for C-R and R tests, respectively) only in TID. Changes in post cycling run performance were accompanied by changes in pacing strategy, but there were only slight or nonsignificant changes in the cardiorespiratory response. Thus, the negative effect of cycling on performance may persist, independently of the period, over 2 consecutive seasons in TID and SE triathletes; however, improvements over time suggests that monitoring running pacing strategy after cycling may be a useful tool to control performance and training adaptations in TID.

EL EJERCICIO AGUDO AUMENTA LAS CONCENTRACIONES DE HOMOCISTEÍNA EN VARONES FÍSICAMENTE ACTIVOS

INTRODUCTION High levels of homocysteine (Hcy) have been identified as a cardiovascular risk factor. Regarding physical exercise, the results are contradictory. OBJECTIVES The aim of this study was to determine the influence of maximal intensity exercise and submaximal constant exercise on total serum homocysteine concentrations (tHcy) and other related parameters. MATERIAL AND METHODS Ten physically active male subjects (mean age: 23.51 ± 1.84), performed two treadmill tests, a maximal test and a stable submaximal test at an intensity of 65% of maximal oxygen uptake (VO2max). Serum concentrations of tHcy, Folate, Vitamin B12 and creatinine were analysed before and after each test. RESULTS Significant increase in serum tHcy concentrations after the maximal (p < 0.05) and submaximal (p < 0.01) tests were observed. Folate and vitamin B12 concentrations also increased significantly after both tests (p < 0.05). Creatinine levels increased only after the maximal test (p < 0.001). A statistically significant inverse relationship was found between folate and tHcy concentrations (p < 0.05) at all the measurement points. CONCLUSION THcy levels increased significantly after acute exercise in both maximum and submaximal intensity exercises.