Open Access
High muscular fitness has a powerful protective cardiometabolic effect in adults: influence of weight status
(BioMed Central, 2016) Ramírez Vélez, Robinson; Correa Bautista, Jorge Enrique; Lobelo, Felipe; Izquierdo Redín, Mikel; Alonso Martínez, Alicia; Rodríguez Rodríguez, Fernando; Cristi Montero, Carlos; Ciencias de la Salud; Osasun Zientziak
Background: Low levels of muscular fitness (MF) are recognized as an important marker of nutritional status and a predictor of metabolic complications, cardiovascular disease and death, however, the relationship between MF, body mass index (BMI) and the subsequent cardiometabolic protective effects has been less studied among Latin American populations. This study identified an association between MF and the cardiometabolic risk score index (CMRSI) and the lipid-metabolic cardiovascular risk index (LMCRI) in a wide sample of university students grouped according to their BMI. Methods: Six thousand ninety five healthy males (29.6 ± 11.7 year-old) participated in the study. Absolute strength was measured using a T.K.K. analogue dynamometer (handgrip), and the participant’s strength was then calculated relative to their body mass (MF/BM). The LMCRI was derived from the levels of triglycerides, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), and glucose levels in a blood sample. The CMRSI was calculated by summing the standardized residuals (z-score) for waist circumference, total cholesterol, LDL-c, triglycerides, HDL-c, and median blood pressure. Subjects were divided into six subgroups according to BMI (normal vs. overweight/obese) and MF/BM tertiles (unfit, average, fit). Results: The group of participants with low and moderate levels of MF/BM showed higher CMRSI values independent of BMI (P < 0.001). The group with normal BMI and high MF/BM had the highest levels of cardiometabolic protection. All overweight/obese BMI groups had significantly higher LMCRI values independent of the level of MF/BM (P < 0.001). Conclusions: Participants with high MF/BM showed reduced cardiometabolic risk, which increased significantly when they were within normal parameters.
Open Access
The insulin-like growth factor system is modulated by exercise in breast cancer survivors: a systematic review and meta-analysis
(BioMed Central, 2016) Meneses Echávez, José Francisco; González Jiménez, Emilio; Schmidt Río-Valle, Jacqueline; Correa Bautista, Jorge Enrique; Izquierdo Redín, Mikel; Ramírez Vélez, Robinson; Ciencias de la Salud; Osasun Zientziak
Background: Insulin-like growth factors (IGF´s) play a crucial role in controlling cancer cell proliferation, differentiation and apoptosis. Exercise has been postulated as an effective intervention in improving cancerrelated outcomes and survival, although its effects on IGF´s are not well understood. This meta-analysis aimed to determine the effects of exercise in modulating IGF´s system in breast cancer survivors. Methods: Databases of PuMed, EMBASE, Cochrane Central Register of Controlled Trials, EMBASE, ClinicalTrials. gov, SPORTDiscus, LILACS and Scopus were systematically searched up to November 2014. Effect estimates were calculated through a random-effects model of meta-analysis according to the DerSimonian and Laird method. Heterogeneity was evaluated with the I2 test. Risk of bias and methodological quality were evaluated using the PEDro score. Results: Five randomized controlled trials (n = 235) were included. Most women were post-menopausal. Highquality and low risk of bias were found (mean PEDro score = 6.2 ± 1). Exercise resulted in significant improvements on IGF-I, IGF-II, IGFBP-I, IGFBP-3, Insulin and Insulin resistance (P < 0.05). Non-significant differences were found for Glucose. Aerobic exercise improved IGF-I, IGFBP-3 and Insulin. No evidence of publication bias was detected by Egger´s test (p = 0.12). Conclusions: Exercise improved IGF´s in breast cancer survivors. These findings provide novel insight regarding the molecular effects of exercise on tumoral microenvironment, apoptosis and survival in breast cancer survivors.
Open Access
Ejercicio físico en pacientes con diabetes e hipertensión: prevalencia de respondedores y no respondedores para mejorar factores de riesgo cardiometabólicos
(Sociedad Médica de Santiago, 2018) Cano Montoya, Johnattan; Ramírez Campillo, Rodrigo; Sade Calles, Farid; Izquierdo Redín, Mikel; Fritz Silva, Nicole; Ciencias de la Salud; Osasun Zientziak
Background: There is a wide interindividual variability in the response to a period of exercise training. The science have reported that a minimum of participants could be non-responders for improving different health-related outcomes after training. Aim: To compare the effects of a 6-weeks exercise program on body composition, cardiovascular and metabolic outcomes patients with type 2 diabetes and hypertension. Material and Methods: Data from 23 trained subjects were used in a secondary analysis of the response to exercise. Of these, 14 were considered adherent to training and nine as non-adherent. Body mass, height, waist circumference, four skinfolds and their sum, blood pressure and plasma triglyceride levels were assessed before and after the training period. Results: Among adherent participants, significant reductions were observed in the sum of four skinfolds (30 ± 7 to 27 ± 6 mm, p ≤ 0.05), systolic blood pressure (133 ± 18 to 127 ± 20 mmHg; p ≤ 0.05) and plasma triglycerides (125 ± 58 to 102 ± 34 mg/dL; p ≤ 0.05). No changes were observed in weight or diastolic blood pressure. Among non-adherent participants, no changes of measured parameters were observed. Among adherent participants, 57% were considered as non-responders for waist circumference, 7% for the sum of skinfold thickness, 50% for systolic blood pressure, 64% for diastolic blood pressure and 57% for plasma triglycerides. Conclusions: Participants with a good adherence to a 6-weeks exercise training program experienced overall improvement in body composition, blood pressure and plasma triglycerides. The prevalence of non-responders varied considerably among measured outcomes.
Open Access
The effect of 12 weeks of water-aerobics on health status and physical fitness: an ecological approach
(Public Library of Science, 2018) Neiva, Henrique P.; Faíl, Luís Brandão; Izquierdo Redín, Mikel; Marqués, Mário C.; Marinho, Daniel; Ciencias de la Salud; Osasun Zientziak
The main purpose of the present study was to verify the effects of a 12-week water aerobics program in a real-life context on health indicators and physical fitness in adults and older adults. Fifteen volunteers (58.80 ± 14.32 years old) were part of an experimental group (Exercise), and eight volunteers (59.00 ± 12.26 years old) were part of the control group (Control). The Exercise performed 45 min of water aerobics twice a week for 12 weeks; no physical exercise was permitted for the Control during the same period. The evaluations were performed the week before (pre-training) and after the training program (post-training). The primary outcomes were the strength and cardiorespiratory fitness variables and the secondary outcomes included body anthropometry, lipid profile and blood pressure. Adjusted analysis for age and baseline values showed no differences between Exercise and Control in post-training moment. However, there was a moderated tendency for increased explosive strength of the upper limbs (ηp2 = 0.17), reduced body fat (ηp2 = 0.17), reduced systolic blood pressure (ηp2 = 0.14) and triglycerides (ηp2 = 0.19) in Exercise. Within groups changes showed that the training program caused an increase mainly in explosive strength in the upper limbs (0.26 m, 95% CI, 0.03, 0.49; ES = 0.63) In addition, there was a significant decrease in fat mass (-0.89%, 95% CI, -1.74, -0.03; ES = 0.61) and in the systolic blood pressure (-0.83 mmHg, -1.46, -0.19; ES = 0.71). Nonetheless, no significant changes were observed for the lipid profile. These results suggest that 12 weeks of water aerobics performed twice a week in a real-life context seem to benefit the explosive strength, body composition, and blood pressure of adults and older adults but is insufficient to alter cardiorespiratory fitness and lipid profiles.
Open Access
High intensity interval- vs resistance or combined-training for improving cardiometabolic health in overweight adults (cardiometabolic HIIT-RT study): study protocol for a randomised controlled trial
(BioMed Central, 2016) Ramírez Vélez, Robinson; Hernández, Alejandra; Castro, Karem; Tordecilla Sanders, Alejandra; González Ruiz, Katherine; Correa Bautista, Jorge Enrique; Izquierdo Redín, Mikel; García Hermoso, Antonio; Ciencias de la Salud; Osasun Zientziak
Background: Although evidence shows the positive health effects of physical activity, most of the adult population in Colombia are sedentary. It is, therefore, important to implement strategies that generate changes in lifestyle behaviours. This protocol describes a study in which we will compare the effects of 12 weeks of high-intensity interval training (HIIT), resistance training (RT) or combined training (HIIT + RT) on the improvement of body composition, endothelial function, blood pressure, blood lipids, and cardiorespiratory fitness in a cohort of sedentary, overweight adults (aged 30–50 years). Methods/design: Sixty sedentary, overweight adults attending primary care in Bogotá, Colombia will be included in a factorial randomised controlled trial. Participants will be randomly assigned to the following intervention groups: (1) non-exercise group: usual care with dietary support, (2) HIIT group: 4 × 4-min intervals at 85–95 % maximum heart rate (HRmax) (with the target zone maintained for at least 2 minutes), interspersed with a 4-min recovery period, at 65 % HRmax, (3) RT group: completing a resistance circuit (including upper and lower muscle groups) as many times as needed according to subject’s weight until an expenditure of 500 kcal at 40–80 % of one-rep max (1RM) has been achieved, and (4) combined group: HIIT + RT. The primary end point for effectiveness is vascular function as measured by flow-mediated vasodilatation 1 week after the end of exercise training. Discussion: The results of this study will provide new information about the possible effect of the programme in improving the cardiometabolic health of overweight adults, making a more efficient use of an adult’s resources over time.
Open Access
Acute effects of high intensity, resistance, or combined protocol on the increase of level of neurotrophic factors in physically inactive overweight adults: the brainfit study
(Frontiers Media, 2018) Domínguez Sánchez, María Andrea; Bustos Cruz, Rosa H.; Velasco Orjuela, Gina P.; Quintero, Andrea P.; Izquierdo Redín, Mikel; Ciencias de la Salud; Osasun Zientziak
The purpose of this study was to compare the neurotrophic factor response following one session of high-intensity exercise, resistance training or both in a cohort of physically inactive overweight adults aged 18–30 years old. A randomized, parallel-group clinical trial of 51 men (23.6 ± 3.5 years; 83.5 ± 7.8 kg; 28.0 ± 1.9 kg/m2) who are physically inactive (i.e., < 150 min of moderate-intensity exercise per week or IPAQ score of <600 MET min/week for >6 months) and are either abdominally obese (waist circumference ≥90 cm) or have a body mass index, BMI ≥25 and ≤ 30 kg/m2 were randomized to the following four exercise protocols: high-intensity exercise (4 × 4 min intervals at 85–95% maximum heart rate [HRmax] interspersed with 4 min of recovery at 75–85% HRmax) (n = 14), resistance training (12–15 repetitions per set, at 50–70% of one repetition maximum with 60 s of recovery) (n = 12), combined high-intensity and resistance exercise (n = 13), or non-exercising control (n = 12). The plasma levels of neurotrophin-3 (NT-3), neurotrophin-4 (also known as neurotrophin 4/5; NT-4 or NT-4/5), and brain-derived neurotrophic factor (BDNF) were determined before (pre-exercise) and 1-min post-exercise for each protocol session. Resistance training induced significant increases in NT-3 (+39.6 ng/mL [95% CI, 2.5–76.6; p = 0.004], and NT-4/5 (+1.3 ng/mL [95% CI, 0.3–2.3; p = 0.014]), respectively. Additionally, combined training results in favorable effects on BDNF (+22.0, 95% CI, 2.6–41.5; p = 0.029) and NT-3 (+32.9 ng/mL [95% CI, 12.3–53.4; p = 0.004]), respectively. The regression analysis revealed a significant positive relationship between changes in BDNF levels and changes in NT-4/5 levels from baseline to immediate post-exercise in the combined training group (R2 = 0.345, p = 0.034) but not the other intervention groups. The findings indicate that acute resistance training and combined exercise increase neurotrophic factors in physically inactive overweight adults. Further studies are required to determine the biological importance of changes in neurotrophic responses in overweight men and chronic effects of these exercise protocols.
Open Access
Effects of different concurrent resistance and aerobic training frequencies on muscle power and muscle quality in trained elderly men: a randomized clinical trial
(Aging and Disease, 2016) Ferrari, Rodrigo; Fuchs, Sandra C.; Kruel, Luiz Fernando Martins; Lusa Cadore, Eduardo; Alberton, Cristine Lima; Pinto, Ronei Silveira; Radaelli, Régis; Schoenell, Maira; Izquierdo Redín, Mikel; Tanaka, Hirofumi; Umpierre, Daniel; Ciencias de la Salud; Osasun Zientziak
Muscle power is a strong predictor of functional status in the elderly population and is required to perform different daily activities. To compare the effects of different weekly training frequencies on muscle power and muscle quality induced by concurrent training (resistance + aerobic) in previously trained elderly men. Twenty-four trained elderly men (65 ± 4 years), previously engaged in a regular concurrent training program, three times per week, for the previous five months, were randomly allocated to concurrent training programs in which training was performed either twice a week (2·week-1, n = 12) or three times per week (3·week-1, n = 12). The groups trained with an identical exercise intensity and volume per session for 10 weeks. Before and after the exercise training, we examined muscle power, as estimated by countermovement jump height; knee extensor isokinetic peak torque at 60 and 180o.s-1; and muscle quality, a quotient between the one-repetition maximum of the knee extensors and the sum of quadriceps femoris muscle thickness determined by ultrasonography. Additionally, as secondary outcomes, blood pressure and reactive hyperemia were evaluated. Two-way ANOVA with repeated measures were used and statistical significance was set at α = 0.05. Muscular power (2·week-1: 7%, and 3·week-1: 10%) and muscle quality (2·week-1: 15%, and 3·week-1: 8%) improved with the concurrent exercise training (p < 0.001) but with no differences between groups. The isokinetic peak torque at 60 (2·week-1: 4%, and 3·week-1: 2%) and 180o.s-1 (2·week-1: 7%, and 3·week-1: 1%) increased in both groups (p = 0.036 and p=0.014, respectively). There were no changes in blood pressure or reactive hyperemia with the concurrent training. Concurrent training performed twice a week promotes similar adaptations in muscular power and muscle quality when compared with the same program performed three times per week in previously trained elderly men.
Open Access
Increased PIO2 at exhaustion in hypoxia enhaces muscle activation and swifty relieves fatigue: a placebo or a PIO2 dependent effect?
(Frontiers Media, 2016) Torres Peralta, Rafael; Losa Reyna, José; Morales Alamo, David; González Izal, Miriam; Pérez Suárez, Ismael; Ponce González, Jesús G.; Izquierdo Redín, Mikel; Calbet, José A. L.; Ciencias de la Salud; Osasun Zientziak
To determine the level of hypoxia from which muscle activation (MA) is reduced during incremental exercise to exhaustion (IE), and the role played by PIO2 in this process, ten volunteers (21 ± 2 years) performed four IE in severe acute hypoxia (SAH) (PIO2 = 73 mmHg). Upon exhaustion, subjects were asked to continue exercising while the breathing gas mixture was swiftly changed to a placebo (73 mmHg) or to a higher PIO2 (82, 92, 99, and 142 mmHg), and the IE continued until a new exhaustion. At the second exhaustion, the breathing gas was changed to room air (normoxia) and the IE continued until the final exhaustion. MA, as reflected by the vastus medialis (VM) and lateralis (VL) EMG raw and normalized root mean square (RMSraw, and RMSNz, respectively), normalized total activation index (TAINz), and burst duration were 8–20% lower at exhaustion in SAH than in normoxia (P < 0.05). The switch to a placebo or higher PIO2 allowed for the continuation of exercise in all instances. RMSraw, RMSNz, and TAINz were increased by 5–11% when the PIO2 was raised from 73 to 92, or 99 mmHg, and VL and VM averaged RMSraw by 7% when the PIO2 was elevated from 73 to 142 mmHg (P < 0.05). The increase of VM-VL average RMSraw was linearly related to the increase in PIO2, during the transition from SAH to higher PIO2 (R2 = 0.915, P < 0.05). In conclusion, increased PIO2 at exhaustion reduces fatigue and allows for the continuation of exercise in moderate and SAH, regardless of the effects of PIO2 on MA. At task failure, MA is increased during the first 10 s of increased PIO2 when the IE is performed at a PIO2 close to 73 mmHg and the PIO2 is increased to 92 mmHg or higher. Overall, these findings indicate that one of the central mechanisms by which severe hypoxia may cause central fatigue and task failure is by reducing the capacity for reaching the appropriate level of MA to sustain the task. The fact that at exhaustion in severe hypoxia the exercise was continued with the placebo-gas mixture demonstrates that this central mechanism has a cognitive component.
Open Access
Effects of an exercise program on hepatic metabolism, hepatic fat, and cardiovascular health in overweight/obese adolescents from Bogotá, Colombia (the HEPAFIT study): study protocol for a randomized controlled trial
(BioMed Central, 2018) González Ruiz, Katherine; Correa Bautista, Jorge Enrique; Izquierdo Redín, Mikel; García Hermoso, Antonio; Domínguez Sánchez, María Andrea; Ciencias de la Salud; Osasun Zientziak
Background: A considerable proportion of contemporary youth have a high risk of obesity-related disorders such as cardiovascular disease, metabolic syndrome, or non-alcoholic fatty liver disease (NAFLD). Although there is consistent evidence for the positive effects of physical activity on several health aspects, most adolescents in Colombia are sedentary. It is, therefore, important to implement strategies that generate changes in lifestyle. The HEPAFIT study aims to examine whether a 6-month exercise program has benefits for hepatic fat content and cardiovascular health outcomes among overweight/obese adolescents from Bogotá, Colombia. Methods/design: Altogether, 100 hundred overweight/obese, sedentary adolescents (aged 11–17 years) attending two public schools in Bogotá, Colombia, will be included in a parallel-group randomized controlled trial. Adolescents will be randomly assigned to an intervention group following one of four curricula: (1) the standard physical education curriculum (60 min per week of physical activity, n = 25) at low-to-moderate intensity; (2) a high-intensity physical education curriculum (HIPE, n = 25), consisting of endurance and resistance games and non-competitive activities, such as running, gymkhanas, lifting, pushing, wrestling, or hauling, for 60-min sessions, three times per week, with an energy expenditure goal of 300 to 500 kcal/session at 75–85% maximum heart rate (HRmax); (3) a low-to-moderate intensity physical education curriculum (LIPE, n = 25) consisting of endurance and resistance games and non-competitive activities (e.g., chasing, sprinting, dribbling, or hopping) for 60-min sessions, three times per week with an energy expenditure goal of 300 kcal/session at 55–75% HRmax; and (4) a combined HIPE and LIPE curriculum (n = 25). The HIPE, LIPE, and combined interventions were performed in addition to the standard physical education curriculum. The primary outcome for effectiveness is liver fat content, as measured by the controlled attenuation parameter 1 week after the end of the intervention program. Discussion: The translational focus may be suitable for collecting new information in a school setting on the possible effects of physical activity interventions to reduce liver fat content and to improve metabolic profiles and the cardiometabolic health of overweight/obese adolescents. This may lead to the more efficient use of school physical education resources.