European Journal of Cardiovascular Medicine

Cardiovascular fitness often interchanged with cardiorespiratory endurance serves as a fundamental indicator of an individual’s physiological resilience and overall health. It reflects the capacity of the heart, lungs, and circulatory system to efficiently deliver oxygenated blood to skeletal muscles during prolonged physical activity (1). Among the numerous parameters used to evaluate cardiovascular performance, the recovery heart rate (RHR) has emerged as a simple yet powerful non-invasive marker. It gauges the rate at which heart rate declines post-exercise, offering insight into the autonomic regulation of the cardiovascular system and the balance between sympathetic and parasympathetic activity (2). Recovery heart rate is commonly assessed at fixed intervals, typically one to two minutes after peak exertion, and has been widely recognized as a surrogate measure of cardiovascular fitness. A brisk decline in heart rate following cessation of physical exertion is indicative of superior vagal reactivation and cardiovascular efficiency, both of which are characteristic of individuals with high fitness levels. In contrast, a delayed return to baseline heart rate may signify autonomic imbalance or poor cardiorespiratory conditioning, and in some cases, may even serve as a predictive marker for cardiovascular morbidity and mortality (3,4).

Within the context of student populations, assessing cardiovascular health is increasingly imperative given the rise of sedentary behaviors, screen-dependent lifestyles, and academic stressors that often displace regular physical activity. The dichotomy between physically active and inactive students presents a valuable opportunity to investigate the functional implications of differing lifestyle patterns on cardiovascular health (5). Students who engage in structured physical activity, whether through athletics or regular fitness regimens, are generally presumed to exhibit more favorable recovery heart rate profiles than their sedentary counterparts. This assumption merits empirical validation to inform health education policies and intervention strategies (6). Although numerous studies have explored the relationship between exercise training and cardiovascular responses, much of the existing literature predominantly centers on elite athletes or clinical populations. There remains a paucity of research specifically targeting non-athletic but otherwise healthy student cohorts (7). The student demographic i.e., diverse in lifestyle, physical activity levels, and stress exposure offers a unique lens through which the real-world applicability of recovery heart rate as a diagnostic and preventive health tool can be assessed. By filling this research gap, the current study aspires to establish a more nuanced understanding of how daily activity levels impact autonomic cardiac regulation (8).

Establishing normative data on recovery heart rate across varying levels of physical activity among students could offer an invaluable resource for educators, clinicians, and health policymakers. It would facilitate early identification of individuals at risk of cardiovascular deconditioning and promote the implementation of tailored physical activity programs within academic institutions (9). Furthermore, such efforts could contribute to the broader objective of cultivating lifelong health-conscious behaviors, as habits developed during adolescence and early adulthood often persist into later life. Importantly, this research endeavors to advocate for the inclusion of recovery heart rate measurement as a standard component of student health assessments. Its simplicity, affordability, and diagnostic relevance render it an ideal tool for large-scale implementation in schools and universities, where time and resource constraints often limit comprehensive physiological screenings. If validated as a reliable fitness marker, recovery heart rate could serve as an accessible and scalable method for monitoring cardiovascular well-being (10).

Moreover, the broader public health implications of cardiovascular fitness among youth cannot be overstated. The increasing global prevalence of non-communicable diseases many of which are rooted in poor lifestyle choices highlights the urgent need for early and proactive health interventions. This study aligns with global health priorities that emphasize prevention over treatment, particularly by empowering educational institutions to become catalysts for health promotion and disease prevention (11). This research aimed to investigate the association between recovery heart rate and cardiovascular fitness among students exhibiting differing levels of physical activity. By conducting a comparative analysis between physically active and inactive cohorts, the research aimed to substantiate the clinical and preventive significance of recovery heart rate as a functional biomarker of cardiorespiratory efficiency. The findings were anticipated to contribute meaningfully to the academic body of knowledge while also offering practical implications for the development of targeted health promotion strategies within student populations.

Aim

This study aimed to examine the relationship between recovery heart rate and cardiovascular fitness among physically active and inactive students.

Objective

The primary objective was to compare post-exercise heart rate recovery patterns between active and inactive student groups to assess its validity as an indicator of cardiovascular fitness.

This investigation was structured as a comparative, cross-sectional study conducted over a period of one year. The primary objective was to evaluate post-exercise recovery heart rate as a physiological indicator of cardiovascular fitness among physically active and inactive male students. A total of 150 male participants, aged between 18 and 25 years, were recruited through purposive sampling from academic institutions. Based on their physical activity patterns, participants were stratified into two cohorts: the “physically active” group, comprising individuals who engaged in moderate-to-vigorous structured physical activity for a minimum of three sessions per week, and the “physically inactive” group, consisting of individuals with a sedentary lifestyle or minimal physical engagement.

Inclusion Criteria

Inclusion criteria encompassed healthy male students within the defined age range who were free from any known cardiovascular, metabolic, or chronic systemic illnesses. Only participants with no history of smoking, recent surgery, or use of medications influencing cardiovascular function were considered eligible. Informed written consent was obtained from all participants prior to inclusion, and the study adhered to ethical research principles in accordance with institutional review standards.

Exclusion Criteria

• Participants with a history of cardiovascular diseases (e.g., arrhythmia, coronary artery disease).
• Individuals diagnosed with hypertension or diabetes mellitus.
• Subjects with chronic respiratory conditions such as asthma.
• Those with musculoskeletal disorders or injuries that could impair physical activity or exercise testing.
• Participants taking cardioactive or metabolic medications that could influence heart rate response.
• Individuals involved in professional athletic training programs, to avoid bias in recovery heart rate outcomes.

Data Collection

Data collection was conducted in a controlled laboratory or gymnasium setting to ensure consistency in environmental conditions. All participants underwent a standardized submaximal exercise protocol such as the 3-Minute Step Test, designed to safely elicit cardiovascular stress without exceeding individual capacity. Heart rate measurements were recorded using calibrated digital heart rate monitors at three intervals: pre-exercise (resting), immediately post-exercise, and at one- and two-minute marks during the recovery phase. Physical activity levels were further validated through a structured questionnaire aligned with World Health Organization (WHO) guidelines for physical activity assessment.

Data Analysis

Collected data were compiled and statistically processed using IBM SPSS Statistics software. Descriptive statistics, including means and standard deviations, were used to summarize participant demographics and baseline values. Inferential statistical analysis was performed using independent samples t-tests to compare mean recovery heart rate values between the physically active and inactive groups. A p-value of less than 0.05 was considered indicative of statistical significance. The results were represented through tabulated data and graphical plots to facilitate interpretation and illustrate comparative trends.

Table 1: Demographic Profile of Participants (N = 150)

The demographic characteristics of the study participants, as presented in Table 1, revealed that both groups were relatively comparable in terms of age, height, and weight, with no statistically significant differences observed in these variables (p > 0.05). However, a statistically significant difference was noted in Body Mass Index (BMI), wherein the physically inactive group exhibited a higher mean BMI (23.4 ± 2.4 kg/m²) compared to their physically active counterparts (22.5 ± 2.1 kg/m²), with a p-value of 0.043. This finding suggested that regular physical activity may contribute to more favorable body composition and weight regulation, even within a relatively homogeneous young adult male population.

Table 2: Heart Rate Measurements

Table 2 highlighted marked differences in cardiovascular performance between the two groups. The resting heart rate of the physically active group was significantly lower (68.2 ± 5.4 bpm) than that of the inactive group (75.6 ± 6.2 bpm), with a highly significant p-value of < 0.001. This supported the well-documented association between physical conditioning and enhanced parasympathetic tone. Following exercise, although both groups exhibited elevated heart rates, the physically inactive participants demonstrated a higher immediate post-exercise heart rate (146.7 ± 10.1 bpm) than the active group (142.1 ± 9.3 bpm), with this difference also reaching statistical significance (p = 0.007). Most notably, during the recovery phase, the heart rates recorded at both one-minute and two-minute intervals post-exercise were substantially lower in the active group, with mean values of 96.4 ± 8.7 bpm and 82.7 ± 7.6 bpm, respectively, compared to 115.2 ± 9.8 bpm and 102.1 ± 8.2 bpm in the inactive group (p < 0.001 for both). These results clearly illustrated superior autonomic recovery and cardiovascular efficiency in individuals with higher physical activity levels.

Table 3: Recovery Heart Rate Drop Comparison

Further analysis in Table 3 quantified the magnitude of heart rate decline across recovery intervals. The mean heart rate reduction within the first minute post-exercise was significantly greater in the physically active group (45.7 ± 7.2 bpm) than in the inactive group (31.5 ± 6.9 bpm), with a p-value < 0.001, emphasizing the more rapid reactivation of parasympathetic tone in the active cohort. Although the reduction between the first and second minute (13.7 ± 4.1 bpm vs. 13.1 ± 4.7 bpm) did not reach statistical significance (p = 0.419), the total recovery over the full two-minute period was markedly higher among active individuals (59.4 ± 8.3 bpm) compared to their inactive peers (44.6 ± 9.1 bpm), again with a highly significant difference (p < 0.001). These findings reinforced the physiological benefits of habitual exercise on heart rate regulation and recovery kinetics.

Table 4: Heart Rate Recovery Classification

Table 4 provided a categorical classification of heart rate recovery responses, further illustrating the disparity between the two groups. An overwhelming majority of physically active participants (85.3%) were classified as having “excellent” recovery (≥ 30 bpm drop in the first minute), in stark contrast to only 28.0% of the inactive group. Conversely, 26.7% of inactive students exhibited “poor” recovery (< 20 bpm drop), while this was observed in only 1.4% of the active group. This distribution underscored the predictive potential of heart rate recovery as a functional marker of cardiovascular fitness and highlighted the detrimental effects of physical inactivity on autonomic recovery.

Table 5: Correlation Between Physical Activity Level and 1-Minute Recovery Heart Rate

Table 5 summarized the results of a correlation analysis exploring the relationship between physical activity levels and heart rate parameters. A strong, statistically significant positive correlation (r = 0.721, p < 0.001) was identified between physical activity scores and the magnitude of heart rate reduction during the first minute of recovery. This indicated that greater engagement in physical activity was associated with more efficient cardiovascular recovery. Additionally, an inverse correlation (r = –0.603, p < 0.001) was found between physical activity levels and resting heart rate, suggesting that higher activity levels corresponded with lower basal heart rates a recognized indicator of enhanced cardiovascular conditioning. These correlations not only validated the study hypothesis but also reinforced existing physiological models regarding exercise-induced autonomic modulation.

The present study investigated recovery heart rate as a marker of cardiovascular fitness among physically active and inactive male students. The findings revealed statistically significant differences in heart rate dynamics at rest, immediately following exercise, and throughout the recovery phase. Physically active participants consistently demonstrated lower resting heart rates, reduced peak post-exercise heart rates, and significantly faster heart rate recovery over both one- and two-minute intervals. These results collectively suggested enhanced autonomic regulation and superior cardiovascular efficiency in individuals who engaged in regular physical activity.

The outcomes of this study aligned closely with established physiological principles, particularly regarding the impact of habitual exercise on vagal tone and parasympathetic reactivation. The more pronounced drop-in heart rate within the first minute of recovery observed in the physically active group (mean decrease of 45.7 bpm) compared to the inactive group (31.5 bpm) reinforced this relationship. These results echoed the work of Qiu et al., who documented that accelerated post-exercise heart rate recovery reflected increased parasympathetic modulation, serving as a critical index of cardiorespiratory fitness (12). Furthermore, the findings were in concordance with those of Cole et al., who established that delayed heart rate recovery independently predicted mortality, thereby highlighting the clinical significance of this parameter even in non-clinical populations (9).

The classification of participants based on one-minute heart rate recovery provided additional clarity. A vast majority of physically active students achieved an “excellent” classification, while a considerable portion of the inactive group demonstrated “poor” recovery patterns. These results were consistent with those reported by Barak et al., who found that athletes across various age groups and sporting disciplines exhibited superior autonomic recovery post-exercise compared to sedentary individuals (13). The categorical disparities in recovery response further underscored the functional impact of physical activity on autonomic nervous system efficiency and cardiovascular responsiveness.

Moreover, the inverse correlation observed between physical activity levels and resting heart rate was statistically significant and physiologically relevant. The negative correlation (r = –0.603) in this study indicated that higher physical activity levels were associated with lower baseline heart rates an observation well-documented in the literature. Du et al., similarly concluded that enhanced cardiac output and stroke volume among active individuals contribute to a lower resting heart rate, representing improved myocardial efficiency and reduced cardiovascular strain (14).

The strong positive correlation (r = 0.721) between physical activity levels and one-minute heart rate recovery provided further empirical support for the use of recovery heart rate as a surrogate index of cardiovascular fitness, particularly among non-athletic, young adult populations. This finding supported the conclusions of Benjamin et al., who demonstrated that heart rate recovery metrics were sensitive to training adaptation and autonomic balance, even in moderately active cohorts (15). Thus, heart rate recovery appeared to be a valid and reliable physiological marker capable of distinguishing between varying levels of cardiovascular conditioning.

These findings also suggested broader implications for cardiovascular screening and early risk identification. While most cardiovascular screening methods are resource-intensive, recovery heart rate offered a simple, accessible, and non-invasive approach that could be implemented in field-based settings, such as university health programs. Darr et al., emphasized that autonomic dysfunction and poor heart rate recovery, even in asymptomatic individuals, may indicate future cardiovascular risk (16). In this context, the measurement of recovery heart rate in educational institutions could serve both diagnostic and preventive functions.

Furthermore, the study highlighted the practical need for integrating structured physical activity interventions within university environments. A notable proportion of inactive students exhibited diminished recovery responses and elevated resting heart rates, reinforcing the necessity of promoting aerobic conditioning as part of campus-wide health initiatives. As noted by Hochsmann et al., even modest gains in physical fitness can translate into meaningful reductions in cardiovascular disease risk (17). The evidence generated in this study substantiated the potential benefits of institutional efforts aimed at embedding routine physical activity within students’ academic and extracurricular schedules.

Despite its strengths, the study had certain limitations. The sample consisted exclusively of male participants within a narrow age range, which may have restricted the generalizability of the findings to broader or more diverse populations. In addition, the use of self-reported physical activity questionnaires although validated posed a risk of recall bias or overestimation. Nonetheless, the consistency of the present findings with those reported in prior research supported the reliability and external validity of the results.

The study confirmed that physically active male students exhibited superior cardiovascular function, as reflected by faster heart rate recovery and lower resting heart rates, when compared to their inactive counterparts. These findings supported the utility of heart rate recovery as a practical and physiologically meaningful indicator of cardiovascular fitness. Furthermore, the data underscored the critical role of regular physical activity in maintaining autonomic health and reducing early indicators of cardiovascular risk. As such, the study offered valuable insights for public health policy, preventive medicine, and the promotion of lifelong physical activity among young adults.

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