Document Type : Original Article
1. Introduction and Purpose
The increase in life expectancy in recent decades has led to a significant growth of the elderly population worldwide. Aging is associated with numerous physiological changes across various body systems, among the most critical of which are skeletal disorders, decreased muscle mass and strength, impaired balance, reduced mobility, and an increased risk of falls. These issues are further exacerbated in elderly women, particularly in the presence of obesity and overweight. Obesity can increase the risk of musculoskeletal problems and balance disorders by increasing the mechanical load on joints, reducing physical activity levels, and promoting metabolic disturbances. On the other hand, bone is a dynamic tissue that is constantly remodeling and is influenced by mechanical, hormonal, and molecular factors. One of the most important molecular pathways in regulating bone homeostasis is the Wnt/β-catenin pathway, which plays an essential role in the differentiation and activity of bone-forming cells. In this pathway, certain molecules act as inhibitors, most notably Sclerostin (SOST) and Dickkopf-1 (DKK1). Increased expression of these genes is associated with decreased osteoblast activity, reduced bone formation, and an elevated risk of osteoporosis. Evidence suggests that aging and obesity may be linked to the increased expression of these inhibitors, thereby affecting bone health. Physical activity and exercise training have been proposed as among the most effective non-pharmacological strategies to maintain bone health and improve physical function in the elderly. In recent years, high-intensity interval training (HIIT) has attracted the attention of researchers. Tabata training is a type of HIIT that, due to its short duration, suitable intensity, and feasibility in various conditions, can be an appropriate option for elderly exercise programs. Nevertheless, limited research has investigated the effect of Tabata resistance training on molecular indices related to bone metabolism as well as functional indicators in obese elderly women. Therefore, the purpose of the present study was to investigate the effect of ten weeks of Tabata resistance training on the expression of SOST and DKK1 genes, as well as certain functional balance indices in obese elderly women.
2. Materials and Methods
This semi-experimental study was conducted using a pretest-posttest design with a control group. The statistical population of the study consisted of obese elderly women in Kerman. A total of 28 obese elderly women were selected purposively and, after providing informed consent to participate in the study, were randomly assigned to either the training or control group. The sample size was determined using G*POWER 3.1 software, considering a significance level of 0.05, a statistical power of 0.8, and an effect size of 0.27. Inclusion criteria included having a body mass index (BMI) of approximately 30 ± 5 kg/m2, no participation in regular exercise programs over the past two years, absence of chronic conditions such as cardiovascular disease, type 2 diabetes, hypertension, or malignant systemic diseases, no smoking or consumption of dietary supplements within the last two months, and no mobility limitations. Exclusion criteria consisted of absence from training sessions, use of medications or supplements during the study, onset of illness during the study, or unwillingness to continue cooperation. The training group participated in a Tabata resistance training program for 10 weeks. This program consisted of three training sessions per week, with each session lasting approximately 45 to 60 minutes. Each training session began with a warm-up, followed by the main components of the exercise, and concluded with a cool-down. The exercises included resistance and functional movements such as squats, planks, crunches, mountain climbers, modified burpees, and other modified movements that engaged the upper limbs, lower limbs, and core muscles. The intensity, number of intervals, and execution time were progressively increased over the course of the 10 weeks. Standard elderly assessments were utilized to evaluate functional indices. Upper limb muscle strength and endurance were measured using the 30-second arm curl test, lower limb strength and endurance were evaluated using the 30-second chair stand test, aerobic endurance was measured with the 2-minute step-in-place test, and balance was assessed using the Fullerton Advanced Balance (FAB) scale. Blood samples were drawn from the brachial vein 24 hours before and after the testing period. Following RNA extraction and cDNA synthesis, gene expression was measured using the Real-Time PCR method. The Gapdh gene was utilized as the reference gene, and relative analysis of gene expression was performed using the 2-∆∆CT formula. Data were reported as mean ± standard deviation. The normality of data distribution was evaluated using the Shapiro-Wilk test, and two-way analysis of variance (ANOVA) was used for data analysis. If significant differences were observed, Tukey's post-hoc test was applied for between-group comparisons. The significance level for all tests was set at P ≥ 0.05.
3. Results
The results of the study demonstrated that after ten weeks of Tabata resistance training, the expression of SOST and DKK1 genes in the training group significantly decreased compared to the control group. This reduction was statistically significant for both genes (P = 0.01). Additionally, functional indices showed a remarkable improvement in the training group. Specifically, the functional balance of the participants increased significantly (P = 0.011). Upper limb muscular endurance (P = 0.029) and lower limb muscular endurance (P < 0.020) also demonstrated significant improvements. Furthermore, aerobic endurance increased significantly in the training group compared to the control group (P < 0.047).
4. Conclusions
Based on the results of the present study, performing ten weeks of Tabata resistance training can significantly improve functional indices, including balance, muscular endurance, and aerobic capacity in obese elderly women. Moreover, this type of training is associated with a decrease in the gene expression of Wnt pathway inhibitors, namely Sclerostin and Dickkopf-1, which may indicate its positive effects on regulating processes related to bone metabolism. Therefore, Tabata resistance training can be used as an effective, low-cost, and feasible exercise strategy in physical activity programs for the elderly, particularly obese women.
5. Acknowledgment & Funding
We would like to thank all individuals involved in conducting this research. This study was carried out within the framework of the university's research activities.
6. Ethical Consideration
This study received ethical approval under code IR.IAU.KERMAN.REC.1403.086 from Islamic Azad University, Kerman Branch.
7. Authors' Contributions
All authors contributed to the article. All authors have read and approved the final manuscript.
8. Conflict of interest
The authors declare no conflicts of interest.
