Bone Response to High-Intensity Interval Training versus Moderate-Intensity Continuous Training in Adolescents with Obesity

<b><i>Introduction:</i></b> Since adolescents with obesity are prone to bone fragility during weight loss, the aim was to compare the impact of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on bone density, geometry, and strength. <b><i>Methods:</i></b> Sixty-one adolescents were randomly assigned to 2 cycling trainings (HIIT and MICT) and a control (CTR, without training) group. Anthropometry, dual-energy X-ray absorptiometry with hip structural analysis and the trabecular bone score (TBS) were assessed before and after the 16-week intervention. <b><i>Results:</i></b> Body mass index (BMI) and fat mass (FM) percentage decreased at T1 versus T0 in both training groups (<i>p</i> &#x3c; 0.001 for HIIT, <i>p</i> = 0.01 for MICT), though to a larger extent in HIIT (<i>p</i> &#x3c; 0.05). Total body bone mineral density (BMD) and bone mineral content (BMC) increased in both training groups (<i>p</i> &#x3c; 0.001), but to a greater extent in HIIT for BMC (<i>p</i> &#x3c; 0.05). Lumbar spine BMD and BMC increased in both training groups (<i>p</i> &#x3c; 0.001 for HIIT, <i>p</i> &#x3c; 0.01 for MICT), with a time × group interaction between HIIT and CTR (<i>p</i> &#x3c; 0.05) only. TBS increased in both training groups (<i>p</i> &#x3c; 0.01 for HIIT, <i>p</i> &#x3c; 0.05 for MICT). Hip BMD and BMC increased in both HIIT (<i>p</i> &#x3c; 0.001 and <i>p</i> &#x3c; 0.01) and MICT (<i>p</i> &#x3c; 0.01 and <i>p</i> &#x3c; 0.05). At the narrow neck (NN), endocortical diameter, width (<i>p</i> &#x3c; 0.01), cross-sectional moment of inertia, and section modulus (Z) (<i>p</i> &#x3c; 0.05) increased only in the HIIT group, such as BMD and Z (<i>p</i> &#x3c; 0.05) at the intertrochanteric region (IT) and average cortical thickness (<i>p</i> &#x3c; 0.001) and width (<i>p</i> &#x3c; 0.05) at the femoral shaft. At the NN and IT, the buckling ratio decreased only in the HIIT group (<i>p</i> &#x3c; 0.05), predicting higher resistance to fracture. <b><i>Conclusions:</i></b> In addition to inducing greater BMI and FM percentage decreases in comparison to MICT, HIIT improves multisite bone density, geometry, and strength, which heighten the justification for HIIT as part of weight loss interventions in adolescents with obesity.

Effect of Continuous and Interval Training on Amyloid β 42 (Aβ42) and Malondialdehyde (MDA) Levels in Hippocampus of Elderly Rats

Introduction: Amyloid plaques in the brain increase with age. Thus, the present study aimed to evaluate the effect of continuous and interval training on Amyloid β 42 (Aβ42) and Malondialdehyde (MDA) levels in hippocampus of elderly rats. Methods: The present study was experimental one with two experimental groups and one control group. Thirty old male Wistar rats (18 weeks-old) divided into 3 groups, including interval training, continuous training, and control. Continuous training was performed for 8 weeks with 65 to 70% VO2max and interval training was performed for 8 weeks with 5-8 repetitions of 2 minutes of working with 80-100% VO2max and 2 minutes active rest with 50% of VO2max for 8 weeks. Hippocampal samples were extracted 48 hours after the last training session to measure protein levels of Aβ42 and MDA. One-way ANOVA and Tukey post hoc test was used for data analysis. Results: Hippocampus Aβ42 levels in continuous training groups were significantly lower than the control group (P=0.001). In addition, Aβ42 levels in hippocampus of interval training groups were significantly lower than the control group (P=0.001). However, no significant differences were found in Aβ42 levels between continuous and interval training groups (p=0.502). MDA levels in continuous training groups were significantly lower than the control group (P=0.016). In addition, MDA levels in interval training groups were significantly lower than the control group (P=0.046) But no significant differences were found in hippocampal MDA protein levels between continuous and interval training groups (p=866). Conclusion: Continuous and interval training through decreasing oxidative stress, decrease Aβ42 levels in the hippocampus of the elderly rat, thus probably continuous and interval training can prevent neurodegenerative disease caused by aging through modulating oxidative stress and Aβ42.

Effect of changes in blood fatigue indicators, inflammatory markers, and stress hormone levels on 100-m records of sprinters following an 8-week intense interval training

This study aimed to examine the changes in the blood fatigue indicators, inflammatory markers, and stress hormones following an 8-week intensity interval training in sprinters, and to investigate the effects on changes in the 100-m sprint records. Twenty sprinters from a boys’ high school were equally assigned to high-intensity and medium-intensity interval training groups, and three 60-min interval training sessions were performed per week for 8 weeks, for a total of 24 sessions. Exercise intensity was defined as 85%–95% and 75%–85% of heart rate reserve for high- and medium-intensity training, respectively. At rest, both groups had an exercise intensity of 60% of the heart rate reserve. Our results showed decreased fatigue indicators, inflammatory markers, and stress hormone levels after high-intensity and medium-intensity interval training, with no difference between the training levels. In addition, the 100-m sprint records were different in high- and medium-intensity interval training groups, based on the lactate dehydrogenase and adrenocorticotropic hormone levels. In conclusion, medium-intensity interval training with a reserve heart rate of ≥ 75% can have a positive effect on blood fatigue indicators, inflammatory markers, and stress hormones in sprinters. Specifically, the changes in adrenocorticotropic hormone level seen in the high-intensity interval training group were found to have a significant effect on the 100-m sprinting records.

Modulation of Fibroblast Growth Factor-21 and βklotho Proteins Expression in Type 2 Diabetic Women with Non-alcoholic Fatty Liver Disease Following Endurance and Strength Training

Background: There is limited research on the effects of physical activity with moderate intensity on βklotho (BKL) and fibroblast growth factor-21 (FGF-21) proteins expression in diabetic patients with non-alcoholic fatty liver disease (NAFLD). Objectives: This study was aimed to determine the effects of eight weeks of endurance and resistance training on BKL and FGF-21 proteins expression in diabetic women with NAFLD. Methods: Forty-five diabetic women (age: 51 ± 8 years, height: 158 ± 2 cm, weight: 75 ± 8 kg) with NAFLD participated. The subjects were randomly divided into three groups, including control (n = 15), endurance training (n = 15), and resistance training (n = 15). The enzyme-linked immunosorbent assay (ELISA) was used to measure BKL and FGF-21 proteins. Two-way ANOVA with repeated measures was applied to determine differences at a significant level of P < 0.05. Results: Eight weeks of endurance and resistance training reduced AST, ALT, and FGF-21 (25, 26, 19% and 13, 16, 13%, respectively) and increased BKL (16% and 18, respectively). However, in the variables of HDL, insulin, AST, ALT, FGF-21, and BKL, a significant difference was observed in the control group (P < 0.05). Also, there was a significant difference between the control and training groups in BKL and FGF21 proteins expression (P < 0.05), but no significant difference was observed between the two training groups (P > 0.05). Conclusions: The results suggest that both moderate-intensity endurance and resistance training can modulate the destructive effects of type 2 diabetes and NAFLD on BKL and FGF-21 proteins expression, and there is no difference between the two training methods.

TP8.2.15 Higher General Surgical Trainee preferences for Annual Review of Competency Progression during COVID-19 Pandemic

Aims The COVID-19 pandemic has caused significant disruption in surgical training. We aim to explore the preferences of higher general surgical trainees for Annual Review of Competency Progression (ARCP) also compare the responses across different training grades. Methods All higher general surgical trainee in a single deanery were invited to participate in an online voluntary anonymous survey. The respondents were divided in two groups: junior (ST3-ST5) and senior higher surgical trainees (ST6-ST8) and responses compared. Results Sixty-four of 88 trainees responded. Thirty-three (51.6%) were ST3–ST5, 24 (37.5%) were ST6–ST8 and 7 (10.9%) were out-of-training. More trainees in ST3–ST5 group preferred to defer the next rotation for 12 months (18.2% vs 0%, p = 0.034), repeat current sub-specialty (33.3% vs 4.2%, p = 0.009), or add 12 months to training and delay predicted CCT date by 12 months (18.2% vs 0%, p = 0.034). Most trainees in both groups preferred the option of prolonging training should be offered to all trainees with an option to decline extension if ARCP competencies met (66.7% vs 50.0%, p = 0.276). Conclusions The preference for ARCP and length of training was different between two training groups, hence the need of trainees should be considered by training committees when addressing the impact of COVID-19.

The Effect of Endurance Training on Plasma Levels of ICAM, VCAM, and OPG in Rats with Experimental Myocardial Infarction: A Gender-Based Study

Background: The purpose of this study was to investigate the effect of four weeks of endurance training (EXE) on inflammatory markers predicting atherosclerosis by gender. Materials and Methods: Forty male and female Wistar rats were divided into 4 groups including male myocardial infarction (MI), male MI + EXE, female MI, and female MI+EXE. After the induction of MI with two intraperitoneal injections of isoproterenol (150 mg/kg), the training groups performed an (EXE) program for 4 weeks on a treadmill (speed 18 m/min, 30 minutes, 5 sessions per week). The animals were sacrificed 24 hours after the last training session. Finally, data were analyzed using a two-way analysis of variance and Fishers’ least significant difference post hoc test. Results: Despite the clinical difference in the training groups, the intercellular adhesion molecule (ICAM, 3.74±0.61 ng/mL) was more significant in the female MI + EXE group (P=0.009). Conclusion: In general, despite observing clinical changes, there were no significant vascular cell adhesion molecules and osteoprotegerin (OPG) after EXE in cardiovascular inflammatory factors in male and female rats following MI. Nevertheless, gender had a significant independent effect on the ICAM index. The results showed that ICAM values were higher in female rats in comparison with male rats.

Acute cellular and molecular responses and chronic adaptations to low-load blood flow restriction and high-load resistance exercise in trained individuals

Blood flow restriction (BFR) with low-load resistance exercise (RE) is often used as a surrogate to traditional high-load RE to stimulate muscular adaptations, such as hypertrophy and strength. However, it is not clear whether such adaptations are achieved through similar cellular and molecular processes. We compared changes in muscle function, morphology and signaling pathways between these differing training protocols. Twenty-one males and females (mean ± SD: 24.3 ± 3.1 years) experienced with resistance training (4.9 ± 2.6 years) performed nine weeks of resistance training (three times per week) with either high-loads (75-80% 1RM; HL-RT), or low-loads with BFR (30-40% 1RM; LL-BFR). Before and after the training intervention, resting muscle biopsies were collected, and quadricep cross-sectional area (CSA), muscular strength and power were measured. Approximately 5 days following the intervention, the same individuals performed an additional 'acute' exercise session under the same conditions, and serial muscle biopsies were collected to assess hypertrophic- and ribosomal-based signaling stimuli. Quadricep CSA increased with both LL-BFR (7.4±4.3%) and HL-RT (4.6±2.9%), with no significant differences between training groups (p=0.37). Muscular strength also increased in both training groups, but with superior gains in squat 1RM occurring with HL-RT (p<0.01). Acute phosphorylation of several key proteins involved in hypertrophy signaling pathways, and expression of ribosomal RNA transcription factors occurred to a similar degree with LL-BFR and HL-RT (all p>0.05 for between-group comparisons). Together, these findings validate low-load resistance training with continuous BFR as an effective alternative to traditional high-load resistance training for increasing muscle hypertrophy in trained individuals.