Obesity has become one of the leading health concerns worldwide, particularly after the COVID-19 pandemic. Obesity is defined as excessive accumulation or abnormal distribution of body fat that affects health (Strüven et al., 2021). Obesity is primarily diagnosed by estimating an individual's body mass index (BMI) (Strüven et al., 2021). WHO defines obesity as a BMI greater than or equal to 30 kg/m2, however, the cut-off differs with ethnicity (World Health Organization, 2020). The criteria for the Asian population to be defined as overweight is >23 to 24.9 kg/m2, and obese is >25 kg/m2 (World Health Organization, 2020).

The prevalence of overweight and obesity has dramatically increased over the last century (> 2 billion people), and it is estimated that the prevalence will double over the next decade (Rastović et al., 2019). WHO estimated that at least 2.8 million die each year as a result of being overweight or obese (World Health Organization [WHO], 2020). Obesity can be a precursor to various other illnesses and is often associated with conditions such as type 2 diabetes mellitus, cardiovascular disease, hypertension, hepatic steatosis, stroke, gallbladder issues, osteoarthritis, dyslipidemia, sleep apnea and certain types of cancer (Chung et al., 2024; Zhang et al., 2023; Rossing et al., 2024; Stedman et al., 2023; Sinha et al., 2022; Baser et al., 2024). In India, the most often associated with obesity is hypertension (Verma et al., 2024). The presence of morbidities further increases the disease burden of obesity leading to a reduction in the quality of life of an individual.

During the COVID-19 pandemic, sedentary lifestyles poor eating habits and physical inactivity were the leading risk factors for developing obesity. A WHO/Europe report showed that post the COVID-19 pandemic, there is an increased incidence of obesity among school-aged children and this was attributed predominantly to physical inactivity (WHO, 2024). The evidence warrants the need to make lifestyle modifications that can prevent and manage the rising concern of obesity.

Physical activity (PA) is a powerful modulator of cardiovascular risk associated with obesity and is one of the key factors in confronting the obesity epidemic (Perissiou et al., 2020). Correlational research in patients with obesity recommends that physical activity can benefit many essential health markers (Sinha et al., 2023). Research by Hernández- Reyes et al. showed that body fat was lower in women who exercised at moderate intensity compared to those who only ate a hypocaloric diet, but high-intensity physical activity was the most effective program for reducing body fat while maintaining muscle mass (Hernández-Reyes, 2019). This proves the need to synthesize a structured high- intensity training program that can potentially improve body composition in overweight and obese individuals.

Badminton is a racket sport for two or four individuals characterized by short-duration, high-intensity physical activity. A typical match has a rally time of 7 seconds and a rest time of 15 seconds, with an effective playing duration of 31% (Hoffmann et al., 2024). This sport is highly demanding, with an average heart rate (HR) that exceeds 90% of the player's maximum HR (Hoffmann et al., 2024). The intermittent actions throughout a game place stress on both the aerobic and anaerobic systems: 60-70% on the aerobic system and around 30% on the anaerobic system (Hoffmann et al., 2024). The unique nature of the sport brings about adaptations that benefit the overall health of an individual.

Heart rate variability (HRV) is an indicator of the autonomic nervous system of the heart (Shaffer & Ginsberg, 2017). It is measured as the beat-to-beat variations between two successive heartbeats. Higher HRV indicates a more balanced system and is generally regarded as good (Shaffer & Ginsberg, 2017). It is often considered a significant marker of the physiological status of the body (Shaffer & Ginsberg, 2017). Research has demonstrated an inverse association between obesity and HRV with lower HRV values being obtained from obese individuals (Strüven et al., 2021). Additionally, inverse relationships were found between vagal modulation and high body mass, waist circumference, and body fat percentage (Strüven et al., 2021). Measuring HRV is also essential to evaluate the physiological effect of weight loss on the overall health of an individual.

Existing research has consistently demonstrated the benefits of physical activity in improving body composition and cardiovascular health among overweight and obese individuals (Perissiou et al, 2020; Lin et al., 2022; O’Donoghue et al., 2021). Numerous studies have highlighted the role of exercise in HRV and reducing body fat, particularly through high- intensity interval training (HIIT) and aerobic exercises (Martin-Smith et al., 2020; Fisher et al., 2015; Cao et al., 2021). However, while sports like running, cycling, and swimming have been extensively studied, the specific effects of racket sports like badminton on HRV and body composition have not been thoroughly explored (Yi et al., 2024; Jakše et al., 2024; Bagot et al., 2024; Jebb et al., 1991). This study fills a critical gap by focusing on badminton, a sport that combines high-intensity bursts with periods of rest, making it uniquely suited for improving both aerobic and anaerobic fitness. The novelty of this research lies in its focus on badminton as a structured intervention, providing empirical evidence for its effectiveness in improving HRV and body composition, which has been underexplored in the context of overweight and obese populations.

This paper aims to evaluate the effect of badminton as a sport on heart rate variability and body composition of overweight and obese amateur badminton players. The findings of this study may benefit badminton players, coaches, sports trainers, sports medicine and sports science professionals, and the general public in implementing a badminton-based program for various health benefits. The results may add to physical activity guidelines and promote badminton as a potential exercise option for weight management.

Demographics

The study examined a range of variables, including age, RMSSD, SDNN, LF, HF, LF/HF, SD1/SD2, BMI, TBF, and WHR across two groups: BDT and CNT. The mean age of the total population was 41.97 +/- 6.72 (n=100). The mean age of participants in the BDT group was 41.96 years (+/- 7.15), and in the CNT group, the mean age was 41.98 years (+/- 6.35). There were 30 males and 20 females in each group. There was no significant difference in age between the groups (p = 0.988), indicating a well-matched population in terms of age (Table 1 ). Independent t-test used to analyze the baseline data revealed no statistical significance between the two group’s RMSSD, SDNN, HF, LF/HF, SD1/SD2, BMI, TBF% or WHR as well (Table 1 )

RMSSD, Root mean square of successive differences between normal heartbeats; SDNN, Standard deviation of NN intervals; LF, Low frequency; HF, High frequency; SD1, Standard deviation 1; SD2, Standard deviation 2; BMI, Body mass index; TBF%, Total body fat percentage; WHR, Waist hip ratio.

RMSSD

The BDT group had a mean RMSSD of 44.34 +/- 10.26, while the CNT group showed a slightly higher mean of 48.28 +/- 10.75. Over 12 weeks, RMSSD increased significantly in both groups, with the BDT group showing a rise from 44.34 at baseline to 58.06 by the end of 12 weeks. In comparison, the CNT group showed a smaller increase, from 48.28 at baseline to 55.92 at the 12-week mark (Table 2 ; Figure 3 ). MANOVA revealed a signification time and time-by-group interaction (both p’s < 0.001). The main effect of treatment was also found to be statistically significant (p<0.001).

Figure 3 Mean RMSSD of BDT and CNT group across time

Note: The figure shows the mean value of RMSSD plotted against various time points.

RMSSD, Root mean square of successive differences between normal heartbeats; BDT, Badminton intervention group; CNT, Control group

SDNN

Similarly, SDNN values, which reflect overall variability in heart rate, also improved in both groups. The BDT group exhibited a baseline SDNN of 50.94, which increased to 62.16 by week 12 (Table 3 ). The CNT group showed a smaller improvement, increasing from 52.40 at baseline to 58.98 at the end of the study (Table 3 ; Figure 4 ). MANOVA revealed significant values for time, time-by-group, and the main effect of treatment indicating that the intervention may have had a more profound impact on heart rate variability in the BDT group (all p’s <0.001).

Figure 4 Mean SDNN of BDT and CNT group across time

Note: The figure shows the mean value of SDNN plotted against various time points. SDNN, Standard deviation of NN intervals; BDT, Badminton intervention group; CNT, Control group.

LF, HF and LF/HF

The LF component of heart rate variability, often linked to sympathetic activity, was significantly higher in the CNT group (62.40 +/- 13.58) compared to the BDT group (53.10 +/- 10.42) at baseline (p < 0.001). Over time, LF values decreased in both groups, but the difference remained significant throughout the study. HF, associated with parasympathetic activity, remained relatively stable in both groups, with minimal fluctuations.

The LF/HF ratio, an indicator of the balance between sympathetic and parasympathetic activity, showed no significant differences between the groups at baseline (p = 0.474). Both the BDT and CNT groups exhibited similar reductions in the LF/HF ratio over the 12 weeks, with the BDT group decreasing from 1.62 to 1.05, while the CNT group decreased from 1.76 to 1.05. MANOVA tested for time, time-by-group interaction and overall main effect of treatment indicate significant differences between the groups (all p's <0.001). These changes suggest a shift toward greater parasympathetic dominance over time, particularly in the BDT group (Table 4 ) (Figure 5 ).

Figure 5 Mean LF/HF of BDT and CNT group across time

Note: The figure shows the mean value of LF/HF plotted against various time points. LF, Low frequency; HF, High frequency; BDT, Badminton intervention group; CNT, Control group

SD1/SD2

The SD1/SD2 ratio also showed no significant difference between the groups at baseline (p = 0.611). However, both groups demonstrated increases in the SD1/SD2 ratio over time, with the BDT group rising from 1.105 at baseline to 1.316 at week 12 (Table 5 ). The CNT group also showed an increase, though smaller in magnitude, from 1.145 to 1.179 (Table 5 ). These MANOVA results for time, time-by-group interaction and overall main effect of treatment indicate an overall improvement in heart rate variability, particularly in the BDT group (all p’s <0.001)(Figure 6 ).

Figure 6 Mean SD1/SD2 of BDT and CNT group across time

Note: The figure shows the mean value of SD1/SD2 plotted against various time points. SD1, Standard deviation 1; SD2, Standard deviation 2; BDT, Badminton intervention group; CNT, Control group

BMI

There was no significant difference in BMI between the groups at baseline (p = 0.806). The BDT group had a mean BMI of 26.81 +/- 2.07 and the CNT group had a mean BMI of 26.72 +/- 1.60 (Table 6 ). Over the 12 weeks, both groups showed a reduction in BMI (both p's < 0.001), with the BDT group showing a more pronounced decrease from 26.82 at baseline to 24.27 at week 12 (Table 6 ). Similarly, the CNT group exhibited a reduction in BMI from 26.72 to 24.83 over the same period. Statistical analysis using MANOVA for time, time-by-group interaction and main effect of treatment showed significantly lower values in the BDT group (all p's <0.001) (Figure 7 ).

FIGURE 7 Mean BMI of BDT and CNT group across time

Note: The figure shows the mean value of BMI plotted against various time points. BMI, Body mass index; BDT, Badminton intervention group; CNT, Control group

TBF%

TBF% also decreased in both groups over time. The BDT group exhibited a substantial reduction from 24.79% at baseline to 20.63% by week 12 (p <0.001), while the CNT group showed a decrease from 24.56% to 21.31% (p <0.001)(Table 7 ). Although both groups experienced reductions in TBF, the BDT group appeared to show a more significant improvement as indexed by MOVA for time and time-by-group interaction and main effect of treatment (all p's <0.001) (Figure 8 ).

WHR

No significant difference was observed in WHR between the groups at baseline (p = 0.740). The BDT group had a mean WHR of 0.97, while the CNT group had a similar value of 0.96 (Table 8 ). Over the 12 weeks, both groups demonstrated reductions in WHR, with the BDT group decreasing from 0.97 to 0.91, and the CNT group decreasing from 0.96 to 0.92 (Table 8 ). Though both groups WHR significantly reduced over time, MANOVA showed greater improvements in the BDT group as indexed by time, time-by-group and overall main effect of treatment analysis (all p's <0.001) (Figure 9 ).

Figure 9 Mean WHR of BDT and CNT group across time

Note: The figure shows the mean value of WHR plotted against various time points. WHR, Waist hip ratio; BDT, Badminton intervention group; CNT, Control group

The BDT group were more compliant with the training program; The participants could complete 96.67% of all the sessions prescribed to them. Meanwhile, the CNT group had a compliance rate of 92.23%. Adherence was significantly higher in the BDT group with participants missing 1.23 +/- 0.19 sessions per month while the CNT group missed 1.94 +/- 0.34 sessions (p<0.001).

This RCT investigated the effect of badminton on HRV and body composition in overweight and obese amateur badminton players. The results demonstrated significant improvements in HRV indices and body composition among participants in both the BDT and CNT groups. However, the badminton intervention led to more pronounced improvements, particularly in HRV markers like RMSSD and SDNN, as well as BMI) and TBF%. These findings suggest that structured badminton training is effective in improving autonomic regulation and body composition among overweight individuals.

Heart Rate Variability Improvements

The increase in HRV indices, such as RMSSD and SDNN, in the BDT group is consistent with other studies that have examined the effects of physical exercise on autonomic function. HRV reflects the balance between sympathetic and parasympathetic nervous system activity, with higher values indicating better cardiovascular health (Rastović et al., 2019; Shaffer & Ginsberg, 2017). Previous research supports the association between physical activity and improved HRV, particularly in overweight individuals (Dias et al., 2022; Guimarães et al., 2024; Godfrey et al., 2019; Dias et al., 2021; Plaza-Florido, 2019). A study by Songsorn et al. showed that HIIT increased HRV in overweight individuals, aligning with our findings on the efficacy of badminton, a high-intensity, intermittent sport, in promoting autonomic regulation (Songsorn et al., 2022).

Furthermore, this study corroborates the results of Kim et al., which demonstrated significant improvements in HRV following a 12-week circuit training intervention in obese female adults with metabolic syndrome (Kim et al., 2018). The badminton group's improvements in RMSSD and SDNN may reflect the sport's unique demands, involving rapid bursts of movement followed by short recovery periods, which likely contribute to improved vagal tone and autonomic adaptability (Hoffmann et al., 2024).

Body Composition Changes

In terms of body composition, both the badminton and control groups experienced reductions in BMI and TBF%. However, the more pronounced changes observed in the badminton group suggest that this form of intervention offers superior benefits compared to conventional aerobic and resistance training. This finding is consistent with the work of Boutcher, which emphasized that high-intensity intermittent exercises like badminton are particularly effective at reducing fat mass while preserving lean muscle mass (Boutcher, 2011). The badminton intervention in our study resulted in a significant reduction in BMI (from 26.81 to 24.27) and TBF% (from 24.79% to 20.63%), supporting the hypothesis that badminton as a sport when given as a structured intervention improves fat metabolism (Martínez-Rodríguez et al., 2021). The intermittent nature of the sport likely promotes both caloric expenditure and metabolic adaptations that support fat loss (Martínez-Rodríguez et al., 2021).

Superiority of badminton training

While both the intervention and control groups showed significant improvements, the badminton group outperformed the control group in terms of HRV and body composition improvements. This suggests that badminton, as a sport, may offer unique benefits beyond those associated with traditional forms of exercise, such as gym-based aerobic and resistance training. The moderate-intensity aerobic and resistance training performed by the control group led to notable, but comparatively smaller, changes in HRV and body composition. The greater improvements in RMSSD and SDNN in the badminton group are also indicative of enhanced parasympathetic activity, which is a critical marker of cardiovascular health (Dias et al., 2021). The control group's improvements were likely the result of increased overall physical activity and energy expenditure, but the unique structure of badminton training, involving short bursts of high-intensity activity followed by rest, appears to offer superior benefits for autonomic regulation.

Autonomic dysfunction is common in obesity, increasing cardiovascular risks and hindering recovery from physical activity. Our findings align with several recent studies that have examined the effects of different exercise modalities on HRV and body composition in overweight populations. Wewege et al. found that HIIT was more effective than moderate- intensity continuous training (MICT) at improving HRV and reducing body fat in overweight adults (Wewege et al., 2017).

Similarly, our study found that badminton, which mirrors the intermittent nature of HIIT, outperformed traditional aerobic and resistance training in improving both HRV and body composition.

Additionally, Liu et al. demonstrated that racquet sports, including badminton, were associated with greater improvements in cardiorespiratory fitness and metabolic health compared to non-specific physical activity (Liu et al., 2024). This supports the idea that the unique demands of badminton, including rapid acceleration, deceleration, and changes in direction, may be particularly effective at stimulating metabolic and autonomic adaptations that enhance health outcomes in overweight individuals. Moreover, a study by Spring et al. (2020) showed that long-term participation in sports with intermittent activity patterns, like badminton and tennis, was associated with greater reductions in cardiovascular risk factors, including visceral fat, compared to more sustained forms of exercise like jogging or cycling. The intermittent nature of badminton, as highlighted in our study, likely provides a metabolic stimulus that leads to superior reductions in fat mass and improvements in autonomic regulation.

Implications for Practice

The findings from this study have significant implications for the design of physical activity programs aimed at improving autonomic regulation and body composition in overweight and obese individuals. Given the superior improvements observed in the badminton group, sports-based interventions that combine high- intensity activity with short recovery periods should be considered as an effective alternative to traditional exercise programs for this population.

Furthermore, our study adds to the growing body of evidence that sports like badminton can be integrated into weight management programs to provide both physical and psychological benefits, as the enjoyment and engagement associated with playing a sport may enhance adherence to physical activity recommendations.

Limitations and Future Research

While this study provides valuable insights into the benefits of badminton for overweight and obese individuals, several limitations should be acknowledged. The relatively short duration of the intervention (12 weeks) limits our ability to assess the long-term effects of badminton on HRV and body composition. Future research should explore the sustainability of these improvements over longer periods and investigate whether badminton can lead to more permanent changes in autonomic function and body composition.

Additionally, the study focused exclusively on overweight and obese individuals, limiting the generalizability of the findings to other populations. Future studies should explore the effects of badminton on HRV and body composition in different age groups, fitness levels, and individuals with comorbidities such as diabetes or cardiovascular disease.