scholarly journals The Effect of Eight Weeks of Continuous and Interval Training with Citrus Aurantium Consumption on Autophagy Markers and MyoD Activation in the Muscle Tissue of Elderly Rats

Author(s):  
Mina Jafari ◽  
Sedigheh Hosseinpour Delavar ◽  
Hassan Safikhani ◽  
Masoomeh Azizi

Introduction: Although exercise training and herbs consumption have protective effects on many diseases, the mechanism of action of exercise training with different intensities and citrus aurantium (CA) extract consumption on the autophagy-dependent MyoD activation pathway is not yet known. The aim of this study was to investigate the effect of eight weeks of moderate intensity continuous training (MICT) and high intensity interval training (HIIT) with CA consumption on the expression of LC3-II, Beclin-1 and MyoD as autophagy related markers in the muscle tissue of elderly rats. Methods: In this experimental study, 42 elderly female rats were randomly assigned to (1) control (C) (2) MICT, (3) HIIT, (4) MICT + CA, (5) HIIT + CA, (6) CA and (7) sham (normal saline) groups. HIIT was performed at 85-110% VO2max intensity and 15-25 m / min speed and MICT at 65% VO2max intensity and 20-25 m / min speed; 300 mg / kg / day CA was received peritoneally. One-way analysis of variance with Tukey's post hoc test was used to analyze the findings. Findings were analyzed using Graph Pad Prism 8.3.0 software (p ≤ 0.05). Results: MICT and HIIT increased LC3II, Bclin1 and MyoD gene expression (p ≤ 0.05); The effect of HIIT on MyoD increase was greater than MICT (p ≤ 0.05). CA increased the expression of LC3II and Bclin1 (p ≤ 0.05). MICT + CA and HIIT + CA increased the expression of LC3II, Bclin1 and MyoD in the muscle tissue of elderly rats (p ≤ 0.05). Conclusion: It seems that exercise training and CA consumption with different mechanism of action activate autophagy in the soleus muscle tissue, however the simultaneous use of HIIT, MICT and CA also has favorable effects on the autophagy-dependent MyoD activation pathway.

2018 ◽  
Vol 30 (1) ◽  
pp. 38-41
Author(s):  
Keith Tolfrey ◽  
Julia Kirstey Zakrzewski-Fruer ◽  
Alice Emily Thackray

Two publications were selected because they are excellent representations of studies examining different ends of the exercise-sedentary behavior continuum in young people. The first study is an acute response study with 13 mixed-sex, mid to late adolescents presenting complete data from 4 different randomized experimental crossover conditions for analyses. Continuous glucose monitoring showed that interrupting prolonged continuous sitting with body-weight resistance exercises reduced the postprandial glucose concentration compared with a time-matched uninterrupted period of sitting. Furthermore, the effects of the breaks in sitting time were independent of the energy content of the standardized meals, but variations in the area under the glucose time curves expression were important. The second study adopted a chronic 12-week exercise training intervention design with a large sample of obese children and adolescents who were allocated randomly to high-intensity interval training (HIIT), moderate-intensity continuous training, or nutritional advice groups. HIIT was the most efficacious for improving cardiorespiratory fitness compared with the other interventions; however, cardiometabolic biomarkers and visceral/subcutaneous adipose tissue did not change meaningfully in any group over the 12 weeks. Attrition rates from both HIIT and moderate-intensity continuous training groups reduce the validity of the exercise training comparison, yet this still provides a solid platform for future research comparisons using HIIT in young people.


2017 ◽  
Vol 122 (5) ◽  
pp. 1188-1197 ◽  
Author(s):  
Kumail K. Motiani ◽  
Anna M. Savolainen ◽  
Jari-Joonas Eskelinen ◽  
Jussi Toivanen ◽  
Tamiko Ishizu ◽  
...  

Similar to muscles, the intestine is also insulin resistant in obese subjects and subjects with impaired glucose tolerance. Exercise training improves muscle insulin sensitivity, but its effects on intestinal metabolism are not known. We studied the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on intestinal glucose and free fatty acid uptake from circulation in humans. Twenty-eight healthy, middle-aged, sedentary men were randomized for 2 wk of HIIT or MICT. Intestinal insulin-stimulated glucose uptake and fasting free fatty acid uptake from circulation were measured using positron emission tomography and [18F]FDG and [18F]FTHA. In addition, effects of HIIT and MICT on intestinal GLUT2 and CD36 protein expression were studied in rats. Training improved aerobic capacity ( P = 0.001) and whole body insulin sensitivity ( P = 0.04), but not differently between HIIT and MICT. Insulin-stimulated glucose uptake increased only after the MICT in the colon (HIIT = 0%; MICT = 37%) ( P = 0.02 for time × training) and tended to increase in the jejunum (HIIT = −4%; MICT = 13%) ( P = 0.08 for time × training). Fasting free fatty acid uptake decreased in the duodenum in both groups (HIIT = −6%; MICT = −48%) ( P = 0.001 time) and tended to decrease in the colon in the MICT group (HIIT = 0%; MICT = −38%) ( P = 0.08 for time × training). In rats, both training groups had higher GLUT2 and CD36 expression compared with control animals. This study shows that already 2 wk of MICT enhances insulin-stimulated glucose uptake, while both training modes reduce fasting free fatty acid uptake in the intestine in healthy, middle-aged men, providing an additional mechanism by which exercise training can improve whole body metabolism. NEW & NOTEWORTHY This is the first study where the effects of exercise training on the intestinal substrate uptake have been investigated using the most advanced techniques available. We also show the importance of exercise intensity in inducing these changes.


Obesities ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 72-87
Author(s):  
Alexis Marcotte-Chénard ◽  
Dominic Tremblay ◽  
Marie-Michelle Mony ◽  
Pierre Boulay ◽  
Martin Brochu ◽  
...  

Objective: To compare the acute and chronic effects of low-volume high-intensity interval training (HIIT) to moderate-intensity continuous training (MICT) on glycemic control, body composition and continuous glucose monitoring (CGM) in older women with type 2 diabetes (T2D). Methods: Thirty older women (68 ± 5 years) with T2D were randomized in two groups—HIIT (75 min/week) or MICT (150 min/week). Glucose homeostasis (A1c, glucose, insulin, HOMA-IR2) and body composition (iDXA) were measured before and after the 12-week exercise intervention. During the first and last week of training (24-h before and 48-h after exercise), the following CGM-derived data were measured: 24-h and peak glucose levels, glucose variability and time spent in hypoglycemia as well as severe and mild hyperglycemia. Results: While lean body mass increased (p = 0.035), total and trunk fat mass decreased (p ≤ 0.007), without any difference between groups (p ≥ 0.81). Fasting glucose levels (p = 0.001) and A1c (p = 0.014) significantly improved in MICT only, with a significant difference between groups for fasting glucose (p = 0.02). Neither HIIT nor MICT impacted CGM-derived data at week 1 (p ≥ 0.25). However, 24-h and peak glucose levels, as well as time spent in mild hyperglycemia, decreased in HIIT at week 12 (p ≤ 0.03). Conclusion: These results suggest that 12 weeks of low-volume HIIT is enough to provide similar benefit to MICT for body composition and improve the acute effect of exercise when measured with CGM.


Author(s):  
Neumir Sales de Lima ◽  
Ricardo Augusto Leoni De Sousa ◽  
Fabiano Trigueiro Amorim ◽  
Fernando Gripp ◽  
Caíque Olegário Diniz e Magalhães ◽  
...  

Author(s):  
Abdullah Alansare ◽  
Ken Alford ◽  
Sukho Lee ◽  
Tommie Church ◽  
Hyun Jung

Physically inactive adults are prevalent worldwide. This study compared the effects of short-term high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on heart rate variability (HRV) in physically inactive adults as a preliminary study. Thirteen physically inactive male adults (27.5 ± 3.80 years) were randomly assigned to HIIT (N = 7) or MICT (N = 6). The HIIT program consisted of 20 min of interval training with cycling to rest ratio of 10/50 s at ≥90% HRpeak, while the MICT program consisted of 40 min of continuous cycling at 60–75% HRpeak. Both groups completed eight sessions of training within two weeks. Time and frequency domains of HRV were measured for 20 min with Actiwave-Cardio monitor (CamNtech, UK). The number of R-R interval and inter-beat interval (IBI) were significantly improved (p < 0.05) in both HIIT and MICT programs following eight sessions of training. A significant interaction effect for group by time was found in the lnLF/HF ratio (p < 0.05) where it was only improved in the HIIT group from pre- to post-test. The HIIT program is superior to MICT in improving HRV in physically inactive adults. The HIIT program can be applied as a time-efficient program for improving cardiac-autoregulation.


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