Browsing by Author "Alvarez, Cristian"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Association of maximal voluntary isometric handgrip strength with age, gender and handedness in older people
    (2018) Hernandez-Martinez, Jordan; Cisterna, Diego; Ramirez-Campillo, Rodrigo; Alvarez, Cristian; Guede-Rojas, Francisco; De la Fuente, Carlos; Castro Sepúlveda, Mauricio; Moran, Jason
  • No Thumbnail Available
    Item
    Cardiorespiratory optimal point as a submaximal evaluation tool in endurance athletes: An exploratory study
    (2023) Oyarzo-Aravena, Alexis; Arce-Alvarez, Alexis; Salazar-Ardiles, Camila; Ramirez-Campillo, Rodrigo; Alvarez, Cristian; Toledo, Camilo; Izquierdo, Mikel; Andrade, David C.
    Introduction: The cardiorespiratory optimal point (COP) represents the lowest minute ventilation to oxygen consumption ratio (VE/VO2) and can be estimated during a CPET at submaximal intensity when an exercise test until volitional fatigue is not always advisable (i.e., a conflict zone where you cannot be confident of the security because near-competition, off-season, among other). COP's physiological components have not been wholly described yet. Therefore, this study seeks to identify the determinants of COP in highly trained athletes and its influence on maximum and sub-maximum variables during CPET through principal c omponent analysis (PCA) (explains the dataset's variance).Methods: Female (n = 9; age, 17.4 +/- 3.1 y; maximal VO2 [VO2max]), 46.2 +/- 5.9 mL/kg/min) and male (n = 24; age, 19.7 +/- 4.0 y; VO2max, 56.1 +/- 7.6 mL/kg/min) athletes performed a CPET to determine the COP, ventilatory threshold 1 (VT1) and 2 (VT2), and VO2max. The PCA was used to determine the relationship between variables and COP, explaining their variance.Results: Our data revealed that females and males displayed different COP values. Indeed, males showed a significant diminished COP compared to the female group (22.6 +/- 2.9 vs. 27.2 +/- 3.4 VE/VO2, respectively); nevertheless, COP was allocated before VT1 in both groups.Discussion: PC analysis revealed that the COP variance was mainly explained (75.6%) by PC1 (expired CO2 at VO2max) and PC2 (VE at VT2), possibly influencing cardiorespiratory efficiency at VO2max and VT2. Our data suggest that COP could be used as a submaximal index to monitor and assess cardiorespiratory system efficiency in endurance athletes. The COP could be particularly useful during the offseason and competitive periods and the return to the sports continuum.
  • Thumbnail Image
    Item
    Higher levels of self-reported sitting time is associated with higher risk of type 2 diabetes independent of physical activity in Chile
    (2018) Díaz-Martínez, Ximena; Steell, Lewis; Martinez, María Adela; Leiva, Ana María; Salas Bravo, Carlos; Labraña, Ana María; Duran, Eliana; Cristi-Montero, Carlos; Livingstone, Katherine M.; Garrido-Méndez, Alex; Alvarez, Cristian; Poblete-Valderrama, Felipe; Zagalaz, María Luisa; Valdivia-Moral, Pedro; Cuadra, Liliana; Ulloa, Natalia; Willis, Naomi D.; Celis-Morales, Carlos A.
  • Thumbnail Image
    Item
    Joint effect of physical activity and sedentary behaviour on cardiovascular risk factors in Chilean adults
    (2018) Cristi Montero, Carlos; Steell, Lewis; Petermann, Fanny; Garrido Méndez, Alex; Díaz Martínez, Ximena; Salas Bravo, Carlos; Ramirez Campillo, Rodrigo; Alvarez, Cristian; Rodriguez, Fernando; Aguilar Farias, Nicolas
  • Thumbnail Image
    Item
    No cumplir con las recomendaciones de actividad física se asocia a mayores niveles de obesidad, diabetes, hipertensión y síndrome metabólico en población chilena
    (2018) Díaz-MartÍnez, Ximena; Petermann, Fanny; Leiva, Ana María; Garrido-Méndez, Alex; Salas Bravo, Carlos; Martínez, María Adela; Labraña, Ana María; Duran, Eliana; Valdivia Moral, Pedro; Zagalaz, María Luisa; Poblete-Valderrama, Felipe; Alvarez, Cristian; Celis-Morales, Carlos
  • No Thumbnail Available
    Item
    Oscillatory pattern of glycemic control in patients with diabetes mellitus
    (2021) Vasquez-Munoz, Manuel; Arce-Alvarez, Alexis; von Igel, Magdalena; Veliz, Carlos; Ruiz-Esquide, Gonzalo; Ramirez-Campillo, Rodrigo; Alvarez, Cristian; Ramirez-Velez, Robinson; Crespo, Fernando A.; Izquierdo, Mikel; Del Rio, Rodrigo; Andrade, David C.
    Daily glucose variability is higher in diabetic mellitus (DM) patients which has been related to the severity of the disease. However, it is unclear whether glycemic variability displays a specific pattern oscillation or if it is completely random. Thus, to determine glycemic variability pattern, we measured and analyzed continuous glucose monitoring (CGM) data, in control subjects and patients with DM type-1 (T1D). CGM data was assessed for 6 days (day: 08:00-20:00-h; and night: 20:00-08:00-h). Participants (n =172; age =18-80 years) were assigned to T1D (n =144, females = 65) and Control (i.e., healthy; n = 28, females = 22) groups. Anthropometry, pharmacologic treatments, glycosylated hemoglobin (HbA1c) and years of evolution were determined. T1D females displayed a higher glycemia at 10:00-14:00-h vs. T1D males and Control females. DM patients displays mainly stationary oscillations (deterministic), with circadian rhythm characteristics. The glycemia oscillated between 2 and 6 days. The predictive model of glycemia showed that it is possible to predict hyper and hypoglycemia (R-2 =0.94 and 0.98, respectively) in DM patients independent of their etiology. Our data showed that glycemic variability had a specific oscillation pattern with circadian characteristics, with episodes of hypoglycemia and hyperglycemia at day phases, which could help therapeutic action for this population.
  • No Thumbnail Available
    Item
    Pattern analysis of a complete Achilles tendon rupture suffered during high jump preparation in an official national-level athletic competition
    (2022) De la Fuente, Carlos; Ramirez-Campillo, Rodrigo; Gallardo-Fuentes, Francisco; Alvarez, Cristian; Bustamante, Carlos; Henriquez, Hugo; Carpes, Felipe P.
    Elite athletes are subject to injuries like the Achilles tendon rupture. This injury requires a long recovery process, with no guarantee of returning to the pre-injury level. When a rupture happens during natural life, movement analysis can provide useful insights concerning patterns of rupture to understand and prevent Achilles tendon injuries. Here we determined the pattern of rupture of an Achilles tendon (AT) in an elite high-jumper athlete who ruptured an AT during the straight line running phase in preparation for a high-jump attempt. This study is a novel case report regarding a national-level elite athlete. The main outcomes were kinematics parameters obtained from video analysis. The pattern of the rupture was determined by pixel intensity and outlier analysis. The rupture occurred at 44% of the single stance. The injured leg showed a higher ankle dorsal flexion and knee-ankle ratio, and a lower knee flexion compared to contralateral leg. An eccentric pattern of rupture occurred during the transition from the mid to terminal stance phases of running. The lower knee flexion and the increased ankle dorsal flexion during the stance suggest a loss of knee-ankle coordination. This might have favoured a major elongation of Achilles tendon causing the rupture.