The demographic questionnaire included age, race, educational attainment, marital status, number of children, employment, insurance, geographic residence, and comorbid conditions.

PCOS-specific HRQoL was measured using the Polycystic Ovary Syndrome Questionnaire (PCOSQ-50). The PCOSQ-50 has been reported to have a construct validity of 0.92 and test-retest reliability of 0.91 [13]. It includes 50 items in six domains: psychosocial/emotional, fertility, sexual function, obesity/menstrual disorders, hirsutism, and coping. Answers are given on a 5-point Likert scale ranging from 1 = always (worst condition) to 5 = never (best condition). A score for each domain was calculated as the sum of all answered items in the domain divided by the number of answered items. The total PCOSQ-50 score was calculated as the sum of all answered items divided by the number of answered items. Lower scores indicate poor HRQoL [13].

The Rapid Assessment of Physical Activity (RAPA) was used to determine participants’ physical activity levels. The RAPA includes seven yes/no questions. The sum of “yes” responses indicates physical activity frequency, and intensity. The second section of the RAPA includes questions about the performance of resistance training and flexibility exercise. The RAPA has been reported to have good sensitivity (100%) and specificity (75%) for determining physical activity level [14]. Positive and negative predictive value for determining physical activity levels were 94.4% and 100% respectively [14].

The Personal Health Questionnaire (PHQ-8) was used to assess prevalence and severity of depressive symptoms occurring within the past two weeks. The scale consists of 8 items with a 4-point rating ranging from 0 (not at all) to 3 (nearly every day). A score of $\ge$10 indicates major depression and $\ge$20 indicates severe major depression [15]. Construct validity was reported at 0.75 and internal reliability was reported at 0.81 [15]. Given the sensitive nature of the questions and the overall purpose of the screening, local and national mental health resources were provided. The resources were verbally mentioned during the informed consent and provided in writing before the depressive symptoms survey.

The modified Bruce treadmill test was used to estimate maximal oxygen consumption (VO${}_2$ max) or cardiorespiratory fitness, as this measure is related to functional capacity and serves as a strong independent predictor of all-cause and disease-specific mortality [5]. The modified version was chosen to ensure safety and comfort when assessing sedentary or physically inactive participants and due to availability and cost of a more direct measure. After a prolonged warm-up (6 minutes), the protocol is divided into 3-minute stages, each with a faster speed and steeper grade. The participant’s heart rate and perceived exertion were monitored throughout the test. The final score was calculated using the total time spent in working phases with the formula [(4.38 $\times$ T) – 3.9 = VO${}_2$ max]. The estimated VO${}_2$ max was then compared to gender- and age-based normative data. The modified Bruce treadmill test was chosen as the safest alternative for sedentary participants. For the modified Bruce treadmill test, a Pearson product moment correlation coefficient between predicted and measured VO${}_2$ max of 0.94 for women without cardiac conditions (n = 5509) [16]. The average predicted error was –0.6 mL$\cdot$kg${}^{-1}$$\cdot$min${}^{-1}$ for the general equation [16].

Using the American College of Sports Medicine (ACSM) protocol, the modified push-up test was used to estimate upper body muscular fitness. This test was chosen as a safer alternative than one-rep-max tests for sedentary or physically inactive participants and due to the availability of normative data. The test involves performing push-ups in a modified position (knees bent with lower legs in contact with the mat). The score is the total number of modified push-ups performed with proper form in one minute. The score was compared to gender- and age-based normative data. The norm-referenced test-retest reliability estimate using intraclass correlations from one-way analysis of variance (ANOVA) was R = 0.99 [16].

Using ACSM protocol, the curl-up test was used to estimate abdominal muscular fitness. This test was chosen as a safer alternative than one-rep-max tests for sedentary or physically inactive participants and due to the availability of normative data. In a supine position, the participant repetitively lifts and lowers the upper body to a metronome set at 40 beats/minute. The score is the number of curl-ups performed with proper form to cadence. The score was compared to gender- and age-based normative data. Psychometric findings included high test-retest reliability (r = 0.98), moderately high inter-apparatus reliability (r = 0.71), and moderately high inter-tester reliability (r = 0.76) [16].

Using ACSM protocol, the sit-and-reach test was used to assess hamstring flexibility. The test was chosen because it assesses the flexibility of several muscle groups with one movement and due to the availability of normative data. This measure was chosen because hamstring flexibility is related to low back and knee joint health. Participants sat against a wall with feet placed at the 15-inch mark on a measuring tape. Keeping knees straight and feet plantarflexed, participants reached forward with both hands. The score was the farthest distance reached of three trials. The score was compared to gender-and age-based normative data. The sit-and-reach test has shown a moderate mean criterion-related validity for estimating hamstring extensibility (r = 0.46–0.67) [16].

Consistent with studies in other populations, VO${}_2$ max had a strong negative relationship with percent bodyfat (R = –0.59, p = 0.02). Debate exists about the causal direction between VO${}_2$ max and body composition. Findings from a cross-sectional study by Maciejczyk and colleagues [23] suggested that high body mass, independent of cause (high lean mass or high bodyfat percentage) decreases VO${}_2$ max relative to total body mass. Whereas a prospective randomized trial conducted by Skrypnik and colleagues [24] concluded that exercise increases VO${}_2$ max, which affects body composition. These studies included obese women, but not women diagnosed with PCOS.

VO${}_2$ max had a small, positive association with lean muscle mass (R = 0.09, p 0.001). Studies among the general population reveal that higher lean muscle mass contributes to metabolic capacity, which can elevate cardiorespiratory fitness dependent on total bodyfat percentage [25]. A study among women with PCOS revealed that women had lower cardiovascular capacity and muscular endurance than women without PCOS. The authors hypothesized that metabolic and hormonal factors specific to PCOS (e.g., central obesity, insulin resistance) may affect muscle function in women with PCOS [26].

VO${}_2$ max had a strong, positive association with SHBG (R = 0.73, p 0.001). SHBG production is regulated by androgens (decrease), estrogens (increase), and insulin (decrease). The participants in this study presented with low levels of SHBG, which is often related to hyperandrogenism (also present in the participants in this study). The association between physical activity or cardiovascular fitness might be mediated, in part, through androgens; however, this has only been studied in men [27]. Findings from a systematic review about exercise effects on hormones suggest that SHBG was largely unaffected by aerobic exercise but increased with either the isolated use of resistance training or the combination of cardiovascular and resistance exercise [28]. Additionally, women with PCOS who exercised at vigorous intensities had higher levels of SHBG than women who exercised at lower intensities [28].

VO${}_2$ max had a strong, positive relationship with HRQoL (R = –0.72, p 0.01). Several studies have shown that women with PCOS have reduced HRQoL, especially in the psychosocial domain. However, only three randomized controlled exercise trials included HRQoL, all which revealed improved physical functioning, general health, social functioning, and mental health [29]. Therefore, by improving VO${}_2$ max with exercise, women with PCOS may improve their HRQoL [30].

VO${}_2$ max had a strong, negative association with depressive symptoms (R = –0.67, p = 0.01). VO${}_2$ max as a predictor of depressive symptoms has not been extensively studied among the general population and not at all among women with PCOS. In a cross-sectional study of women without PCOS (aged 26–43) who did not meet physical activity guidelines, VO${}_2$ max was found to be the only physiologic characteristic (as compared to bodyfat percentage, autonomic indices, and physical activity levels) to independently predict depressive symptom scores [31].

The relationship between abdominal fitness and obesity indices among women in general is not well studied. A cross-sectional study of healthy men and women aged 18–30 found that women had lower abdominal strength due to anatomical differences and higher bodyfat mass [35]. Findings from another cross-sectional study indicated that obesity had a significant negative impact on core muscular endurance among young adult men, regardless of which obesity measure was assessed [36]; however, a prospective study comparing normal-weight women with PCOS (phenotype D) to women without PCOS, using obesity indices, revealed that women with PCOS had lower muscle endurance than the control group of normal-weight women [30]. The researchers hypothesized that factors such as insulin resistance and visceral adiposity may damage muscle function in women with PCOS by slowing protein synthesis [26].

Women with PCOS and increased levels of lean muscle mass demonstrated strong and significant performance with abdominal strength. However, less than half of the women had normal to elevated lean muscle mass. This finding indicates that increased lean muscle mass can yield greater core strength, thus providing evidence for resistance training as a component of physical fitness. Resistance training studies for women with PCOS have resulted in improved strength measures, although core strength was not directly measured [37, 38].

Contrary to other research [39], the women in this study had high HDL, a protective factor for cardiovascular disease. The finding of high HDL was counter-intuitive, given the fair VO${}_2$ max and high bodyfat percentages. The high HDL may be due to unique characteristics of this small sample. More research is needed with a larger sample.

The strong negative association between physical activity level and percent bodyfat is consistent with the literature. Many studies have revealed that performing regular aerobic exercise, especially of vigorous intensity, decreases bodyfat percentage over time [41]. This was true among women with and without PCOS [42]. Performing other modalities of physical activity, such as resistance training, also reduces percent bodyfat over time, especially at higher intensities and in presence of greater lean mass [43].

The negative association between resistance training and LDL is supported by the scientific literature. Research findings of a systematic review revealed that LDL decreased with resistance training, especially when the resistance training involved either an increased volume of movement (i.e., an increased numbers of sets and/or repetitions) or a larger load (i.e., weight lifted X repetitions X number of sets). All studies examining the differential effects of exercise types showed that resistance training had a greater impact on LDL (decrease) than either fewer sets or the isolated use of aerobic activity [44]. Other researchers reported that as little as one hour per week of high-volume resistance training, independent of aerobic activity, conferred a 40–70% lower risk for cardiovascular disease [45].

While increased lean muscle mass was inversely related to flexibility, we argue that those with lean muscle mass would also benefit from flexibility training, of which less than half participated. Fitness for anyone involves a holistic approach of cardiovascular, strength, and flexibility traing [46]. Despite debate [47], these authors hypothesize that full range of motion, provided by flexibility training, enables strength gains from resistane exercise.