Socioeconomic and partner status in chronic heart failure: Relationship to exercise capacity, quality of life, and clinical outcomes.

BACKGROUND: Prognosis in patients with heart failure (HF) is commonly assessed based on clinical characteristics. The association between partner status and socioeconomic status (SES) and outcomes in chronic HF requires further study. METHODS: We performed a post hoc analysis of HF-ACTION, which randomized 2,331 HF patients with ejection fraction ≤35% to usual care ± aerobic exercise training. We examined baseline quality of life and functional capacity and outcomes (all-cause mortality/hospitalization) by partner status and SES using adjusted Cox models and explored an interaction with exercise training. Outcomes were examined based on partner status, education level, annual income, and employment. RESULTS: Having a partner, education beyond high school, an income >$25,000, and being employed were associated with better baseline functional capacity and quality of life. Over a median follow-up of 2.5 years, higher education, higher income, being employed, and having a partner were associated with lower all-cause mortality/hospitalization. After multivariable adjustment, lower mortality was seen associated with having a partner (hazard ratio 0.91, 95% CI 0.81-1.03, P=.15) and more than a high school education (hazard ratio 0.91, CI 0.80-1.02, P=.12), although these associations were not statistically significant. There was no interaction between any of these variables and exercise training on outcomes (all P>.5). CONCLUSIONS: Having a partner and higher SES were associated with greater functional capacity and quality of life at baseline but were not independent predictors of long-term clinical outcomes in patients with chronic HF. These findings provide information that may be considered as potential variables impacting outcomes.

Race, exercise training, and outcomes in chronic heart failure: findings from Heart Failure - a Controlled Trial Investigating Outcomes in Exercise TraiNing (HF-ACTION).

BACKGROUND: The strength of race as an independent predictor of long-term outcomes in a contemporary chronic heart failure (HF) population and its association with exercise training response have not been well established. We aimed to investigate the association between race and outcomes and to explore interactions with exercise training in patients with ambulatory HF. METHODS: We performed an analysis of HF-ACTION, which randomized 2331 patients with HF having an ejection fraction ≤35% to usual care with or without exercise training. We examined characteristics and outcomes (mortality/hospitalization, mortality, and cardiovascular mortality/HF hospitalization) by race using adjusted Cox models and explored an interaction with exercise training. RESULTS: There were 749 self-identified black patients (33%). Blacks were younger with significantly more hypertension and diabetes, less ischemic etiology, and lower socioeconomic status versus whites. Blacks had shorter 6-minute walk distance and lower peak VO2 at baseline. Over a median follow-up of 2.5 years, black race was associated with increased risk for all outcomes except mortality. After multivariable adjustment, black race was associated with increased mortality/hospitalization (hazard ratio [HR] 1.16, 95% CI 1.01-1.33) and cardiovascular mortality/HF hospitalization (HR 1.46, 95% CI 1.20-1.77). The hazard associated with black race was largely caused by increased HF hospitalization (HR 1.58, 95% CI 1.27-1.96), given similar cardiovascular mortality. There was no interaction between race and exercise training on outcomes (P > .5). CONCLUSIONS: Black race in patients with chronic HF was associated with increased prevalence of modifiable risk factors, lower exercise performance, and increased HF hospitalization, but not increased mortality or a differential response to exercise training.

Prehabilitation before total knee arthroplasty increases strength and function in older adults with severe osteoarthritis.

Preparing for the stress of total knee arthroplasty (TKA) surgery by exercise training (prehabilitation) may improve strength and function before surgery and, if effective, has the potential to contribute to postoperative recovery. Subjects with severe osteoarthritis (OA), pain intractable to medicine and scheduled for TKA were randomized into a usual care (UC) group (n = 36) or usual care and exercise (UC + EX) group (n = 35). The UC group maintained normal daily activities before their TKA. The UC + EX group performed a comprehensive prehabilitation program that included resistance training using bands, flexibility, and step training at least 3 times per week for 4-8 weeks before their TKA in addition to UC. Leg strength (isokinetic peak torque for knee extension and flexion) and ability to perform functional tasks (6-minute walk, 30 second sit-to-stand repetitions, and the time to ascend and descend 2 flights of stairs) were assessed before randomization at baseline (T1) and 1 week before the subject's TKA (T2). Repeated-measures analysis of variance indicated a significant group by time interaction (p < 0.05) for the 30-second sit-to-stand repetitions, time to ascend the first flight of stairs, and peak torque for knee extension in the surgical knee. Prehabilitation increased leg strength and the ability to perform functional tasks for UC + EX when compared to UC before TKA. Short term (4-8 weeks) of prehabilitation was effective for increasing strength and function for individuals with severe OA. The program studied is easily transferred to a home environment, and clinicians working with this population should consider prehabilitation before TKA.

Diurnal variation of hamstring and lumbar flexibility.

This study assessed diurnal variation of hamstring and lumbar flexibility and also measured flexibility differences between men and women. Sixty-seven healthy, recreationally active college students (M=31 and F=36; age, M=22.9+/-3.5 and F=21.7+/-2.8 years old) participated. Hamstring and lumbar flexibility measurements were taken at waking (baseline measure) and every 2 hours through a 12-hour period using the active knee extension test and modified-modified Schober test. Hamstring flexibility (M: -53.1+/-2.3 degrees, F: -46.7+/-2.8 degrees) and lumbar flexion (M: 6.9+/-1.4 cm, F: 6.0+/-1.4 cm) were lowest at baseline. Hamstring flexibility was highest at the 12-hour time point (M: -48.6+/-2.7 degrees, F: -37.4+/-2.9 degrees), whereas lumbar flexion was highest at the 10-hour time point (M: 7.5+/-0.9 cm, F: 6.9+/-1.3 cm). Hamstring flexibility of the women was significantly greater at every time point than the men's (p<0.05). Lumbar flexibility for the men was significantly greater at every time point than women (p<0.05). Both sexes experienced similar increases in flexibility for hamstrings and lumbar spine over 12 hours. Findings of this study indicate that diurnal variation and gender differences in lumbar and hamstring flexibility should be considered and controlled for in flexibility testing, training, and research.

Effect of resistance training and aerobic conditioning on muscular strength and submaximal fitness for individuals with chronic heart failure: influence of age and gender.

The hallmark characteristic of chronic heart failure (CHF) is exercise intolerance. This study evaluated a combined exercise program that would be consistent with current cardiac rehabilitation guidelines. The program consisted of progressive resistance training (intensity progressing from 50 to 80% maximum) and aerobic conditioning (70% of heart rate reserve). Outcomes included muscular strength measured as 8-repetition maximum and submaximal aerobic fitness indicators (measured at 50% of predicted maximal oxygen consumption) including heart rate, blood pressure, and rate pressure product. Subjects were taken retrospectively from a database of CHF patients who underwent cardiac rehabilitation between 1998 and 2004 with the Cardiac Rehabilitation Center of River Cities Cardiology in Jeffersonville, IN. The same data set was used to evaluate 2 research questions: to compare training outcomes between gender (men and women) and to compare outcomes between young (65 years) subjects. Forty-two subjects (15 women and 27 men; 19 were 65 years of age) met inclusion and exclusion criteria and underwent 36 sessions of cardiac rehabilitation over a 14-week time period. Repeated-measures analysis of variance was used to test whether strength and submaximal responses differed across gender or age. Analysis indicated that regardless of gender or age, subjects significantly increased their strength on each of 6 strength tests. Heart rate, systolic blood pressure, and rate pressure product were lower after training indicating increased aerobic efficiency. Progressive resistance training and aerobic conditioning prescribed in a manner consistent with cardiac rehabilitation guidelines resulted in similar improvements regardless of gender or age for individuals with CHF suggesting that no training program adjustments are necessary to accommodate age or gender.

Predictors of functional task performance among patients scheduled for total knee arthroplasty.

Osteoarthritis (OA) is a common health problem affecting more than 7 million Americans. Declines in strength, flexibility, and knee joint pain reduce functional ability and contribute to decisions for total knee arthroplasty (TKA). This study describes predictors of functional ability among knee patients scheduled for TKA and proposes a preoperative exercise program to improve functional ability. A total of 82 knee OA patients (average age = 62.7 +/- 7.48 years, 70% women) were recruited from a single orthopedic surgeon's office. Muscular fitness assessments included knee flexion, extension strength, and range of motion (ROM) of the surgical and nonsurgical knees. Functional ability was assessed by 6-minute walk, number of chair rises in 30 seconds, and time required to ascend and descend 2 flights of stairs. Perceived functional ability and pain were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index. Correlation matrices determined which measures of muscular fitness, pain, and perceptions were associated with measures of functional ability. Significant correlates were entered into regression equations that determined the significant predictors of the functional tasks. These regression equations identified flexion strength of the nonsurgical knee as predicting 24-45% of the variance of functional ability assessments that involved independent or consecutive knee movement. Other variables that, to a lesser degree, predicted performance of the functional ability assessments included knee joint ROM and body mass index. Because functional ability after TKA is strongly dependent on presurgical functional ability, future investigators may wish to examine the impact of improving presurgical functional ability of TKA patients through resistance training, particularly closed-kinetic chain exercises that transfer fewer forces through the knee joint.

The acute effects of dynamic and ballistic stretching on vertical jump height, force, and power.

Stretching before performance is a common practice among athletes in hopes of increasing performance and reducing the risk of injury. However, cumulative results indicate a negative impact of static stretching and proprioceptive neuromuscular facilitation (PNF) on performance; thus, there is a need for evaluating other stretching strategies for effective warm-up. The purpose of this study was to compare the differences between two sets of ballistic stretching and two sets of a dynamic stretching routine on vertical jump performance. Twenty healthy male and female college students between the ages of 22 and 34 (24.8 +/- 3 years) volunteered to participate in this study. All subjects completed three individual testing sessions on three nonconsecutive days. On each day, the subjects completed one of three treatments (no stretch, ballistic stretch, and dynamic stretch). Intraclass reliability was determined using the data obtained from each subject. A paired samples t-test revealed no significant difference in jump height, force, or power when comparing no stretch with ballistic stretch. A significant difference was found on jump power when comparing no stretch with dynamic stretch, but no significant difference was found for jump height or force. Statistics showed a very high reliability when measuring jump height, force, and power using the Kistler Quattro Jump force plate. It seems that neither dynamic stretching nor ballistic stretching will result in an increase in vertical jump height or force. However, dynamic stretching elicited gains in jump power poststretch.

Evaluation of anticipation bias for RPE during progressive exercise testing.

This study evaluated a possible anticipation bias when ratings of perceived exertion (RPE) were obtained during submaximal progressive exercise testing. Perceptual estimates were obtained using the CR-10 category-ratio scale. 13 subjects, 7 men and 6 women (M age = 26.8 +/- 6.4 yr., height = 2.7 +/- .17 m, weight = 73.0 +/- 18.2 kg, VO2 peak = 46.7 +/- 5.6 ml x kg(-1) x min(-1) for men and 47.8 +/- 7.3 ml x kg(-1) x min(-1) for women) recruited from the university student population participated. Each subject underwent two submaximal progressive exercise tests separated by at least 48 hr. using the cycle as test mode and the YMCA protocol. Power outputs established during the first test were presented in random order during the second test. Differentiated RPE for the Peripheral, Respiratory-Metabolic, and the undifferentiated signals, and heart rate, were measured during the last 15 sec. of each of the four stages of exercise. In comparing responses between the two tests, significant differences were observed for both heart rate and the Respiratory-Metabolic signal during power output 4, using repeated-measures analysis of variance. However, a 95% limit of agreement test was significant only for heart rate as the 95% confidence interval for the Respiratory-Metabolic signal overlapped zero and thus was not significantly different. No significant differences were found for the undifferentiated or peripheral signals between the two tests. Results indicate that both undifferentiated and differentiated RPE are given without significant anticipation bias during submaximal progressive cycle exercise.

Prognostic significance of depression in blacks with heart failure: insights from Heart Failure: a Controlled Trial Investigating Outcomes of Exercise Training.

BACKGROUND: Although studies have shown that depression is associated with worse outcomes in patients with heart failure, most studies have been in white patients. The impact of depression on outcomes in blacks with heart failure has not been studied. METHODS AND RESULTS: We analyzed 747 blacks and 1420 whites enrolled in Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training, which randomized 2331 patients with ejection fraction ≤35% to usual care with or without exercise training. We examined the association between depressive symptoms assessed by the Beck Depression Inventory-II (BDI-II) at baseline and after 3 months with all-cause mortality/hospitalization. A race by baseline BDI-II interaction was observed (P=0.003) in which elevated baseline scores were associated with worse outcomes in blacks versus whites. In blacks, the association was nonlinear with a hazard ratio of 1.44 (95% confidence interval, 1.24-1.68) when comparing the 75th and 25th percentile of BDI-II (score of 15 and 5, respectively). No race interaction was observed for mortality (P=0.34). There was no differential association between BDI-II change and outcomes in blacks versus whites. In blacks, an increase in BDI-II score from baseline to 3 months was associated with increased mortality/hospitalization (hazard ratio, 1.33; 95% confidence interval, 1.12-1.57 per 10 point increase), whereas a decrease was not related to outcomes. CONCLUSIONS: In blacks with heart failure, baseline symptoms of depression and worsening of symptoms over time are associated with increased all-cause mortality/hospitalization. Routine assessment of depressive symptoms in blacks with heart failure may help guide management. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00047437.

6-min walk test provides prognostic utility comparable to cardiopulmonary exercise testing in ambulatory outpatients with systolic heart failure.

OBJECTIVES: The goal of this study was to compare the prognostic efficacy of the 6-min walk (6MW) and cardiopulmonary exercise (CPX) tests in stable outpatients with chronic heart failure (HF). BACKGROUND: CPX and 6MW tests are commonly applied as prognostic gauges for systolic HF patients, but few direct comparisons have been conducted. METHODS: Stable New York Heart Association (NYHA) functional class II and III systolic HF patients (ejection fraction ≤ 35%) from the HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) trial were studied. 6MW distance (6MWD) and CPX indices (peak oxygen consumption [VO(2)] and ventilatory equivalents for exhaled carbon dioxide [VE/VCO(2)] slope) were compared as predictors of all-cause mortality/hospitalization and all-cause mortality over 2.5 years of mean follow-up. RESULTS: A total of 2,054 HF-ACTION participants underwent both CPX and 6MW tests at baseline (median age 59 years; 71% male; 64% NYHA functional class II and 36% NYHA functional class III/IV). In unadjusted models and in models that included key clinical and demographic covariates, C-indices of 6MWD were 0.58 and 0.65 (unadjusted) and 0.62 and 0.72 (adjusted) in predicting all-cause mortality/hospitalization and all-cause mortality, respectively. C-indices for peak VO(2) were 0.61 and 0.68 (unadjusted) and 0.63 and 0.73 (adjusted). C-indices for VE/VCO(2) slope were 0.56 and 0.65 (unadjusted) and 0.61 and 0.71 (adjusted); combining peak VO(2) and VE/VCO(2) slope did not improve the C-indices. Overlapping 95% confidence intervals and modest integrated discrimination improvement values confirmed similar prognostic discrimination by 6MWD and CPX indices within adjusted models. CONCLUSIONS: In systolic HF outpatients, 6MWD and CPX indices demonstrated similar utility as univariate predictors for all-cause hospitalization/mortality and all-cause mortality. However, 6MWD or CPX indices added only modest prognostic discrimination to models that included important demographic and clinical covariates.

Modest increase in peak VO2 is related to better clinical outcomes in chronic heart failure patients: results from heart failure and a controlled trial to investigate outcomes of exercise training.

BACKGROUND: The prognostic ability of a single measurement of peak oxygen uptake (VO(2)) is well established in patients with chronic heart failure. The relation between a change in peak VO(2) and clinical outcomes is not well defined. METHODS AND RESULTS: This investigation determined whether an increase in peak VO(2) was associated with a lower risk of the primary end point of time to all-cause mortality or all-cause hospitalization and 3 secondary end points. In Heart Failure and a Controlled Trial to Investigate Outcomes of Exercise Training, an exercise training trial for patients with systolic heart failure, cardiopulmonary exercise tests were performed at baseline and ≈3 months later in 1620 participants. Median peak VO(2) in the combined sample increased from 15.0 (11.9-18.0 Q1-Q3) to 15.4 (12.3-18.7 Q1-Q3) mL·kg(-1)·min(-1). Every 6% increase in peak VO(2,) adjusted for other significant predictors, was associated with a 5% lower risk of the primary end point (hazard ratio=0.95; CI=0.93-0.98; P<0.001); a 4% lower risk of the secondary end point of time to cardiovascular mortality or cardiovascular hospitalization (hazard ratio=0.96; CI=0.94-0.99; P<0.001); an 8% lower risk of cardiovascular mortality or heart failure hospitalization (hazard ratio=0.92; CI=0.88-0.96; P<0.001); and a 7% lower all-cause mortality (hazard ratio=0.93; CI=0.90-0.97; P<0.001). CONCLUSIONS: Among patients with chronic systolic heart failure, a modest increase in peak VO(2) over 3 months was associated with a more favorable outcome. Monitoring the change in peak VO(2) for such patients may have benefit in assessing prognosis.

Prehabilitation versus usual care before total knee arthroplasty: A case report comparing outcomes within the same individual.

This case report compared pre- and postoperative functional ability, knee strength, and pain of a female who underwent two separate total knee arthroplasty (TKA) procedures. The female patient was part of a larger research study. The first surgery on the right knee was preceded with usual care and the second surgery on the left knee was preceded by prehabilitation. Functional ability was assessed by a 6-minute walk, chair raises, and the time required to ascend and descend stairs. Knee extension and flexion isokinetic strength was assessed using the KinCom Isokinetic Dynamometer. Pain was assessed using the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC). Functional abilities, knee strength, and pain were assessed at baseline measurements 4 weeks before surgery, 1 week before surgery, and at 1 and 3 months post surgery during each TKA procedure. Results indicate that the prehabilitation intervention had a favorable impact on improving functional ability up to 30%, increasing knee strength by 50% and decreasing pain prior to the left knee TKA. For this patient, prehabilitation increased functional ability and strength prior to surgery. Gains in strength were maintained in the nonsurgical knee after surgery. These findings indicate that prehabilitation may be effective at facilitating the rehabilitation following a TKA.

The effect of prehabilitation exercise on strength and functioning after total knee arthroplasty.

OBJECTIVE: The purpose of this study was to examine the effect of a preoperative exercise intervention on knee pain, functional ability, and quadriceps strength among patients with knee osteoarthritis before and after total knee arthroplasty (TKA) surgery. DESIGN: A repeated-measures design was used to compare 2 groups over 4 data collection points. SETTING AND PATIENTS: Community-dwelling subjects with osteoarthritis of the knee who were scheduled for a unilateral TKA were recruited from a single orthopedic surgeon's office and were randomized into control (n = 28) or prehab groups (n = 26). INTERVENTIONS: The control patients maintained usual care before their TKA. The exercisers performed prehabilitation exercises, which included resistance training, flexibility, and step training, 3 times per week before their TKA. OUTCOME MEASURES: Knee pain, functional ability, quadriceps strength, and strength asymmetry were assessed at baseline (T1), at 1 week before the patients' TKA (T2), and again at 1 (T3) and 3 (T4) months after TKA. RESULTS: The exercisers improved their sit-to-stand performance at T2, whereas the control group did not change their performance of functional tasks and had increased pain at T2. At T3 the exercisers demonstrated improved sit-to-stand performance. The control patients at T3 exhibited decreases in pain, their 6-minute walk, surgical leg strength and an increase in their nonsurgical leg strength and leg strength asymmetry. At T4 the exercisers improved in their performance of 3 of the 4 functional tasks, decreased all of their pain measures, and increased their surgical and nonsurgical quadriceps strength. At T4 the control group improved their performance on 2 of the 4 functional tasks, decreased all of their pain measures, increased their nonsurgical leg strength, and exhibited greater leg strength asymmetry. CONCLUSION: These findings appear to indicate the efficacy of prehabilitation among TKA patients and support the theory of prehabilitation.

Relation of depression to severity of illness in heart failure (from Heart Failure And a Controlled Trial Investigating Outcomes of Exercise Training [HF-ACTION]).

Depression is common in patients with heart failure (HF), prognostic for adverse outcomes and purportedly related to disease severity. Psychological and physiologic factors relevant to HF were assessed in HF-ACTION, a large randomized study of aerobic exercise training in patients with systolic HF. The relation of objective and subjective parameters was compared with scores on the Beck Depression Inventory (BDI) to examine the hypothesis that depressive symptoms are better associated with perception of disease severity than with objective markers of HF severity. At baseline, 2,322 of 2,331 subjects entered into HF-ACTION completed questionnaires to assess depression (BDI) and quality of life (Kansas City Cardiomyopathy Questionnaire [KCCQ]). Objective markers of HF severity included ejection fraction, B-type natriuretic peptide, and peak oxygen consumption (using cardiopulmonary exercise testing, with evaluation of duration and respiratory exchange ratio also performed). Measures more likely to be affected by perceived functional status included New York Heart Association (NYHA) classification and the 6-minute walk test. Objective assessments of disease severity were slightly related (peak oxygen consumption) or not related (B-type natriuretic peptide and ejection fraction) to BDI scores. Using multivariate analysis (KCCQ not included), only age, gender, cardiopulmonary exercise testing duration, NYHA class, 6-minute walk distance, and peak respiratory exchange ratio independently correlated with BDI scores. In conclusion, depression was minimally related to objective assessments of severity of disease in patients with HF, but was associated with patient (and clinician) perceptions of disease severity. Addressing depression might improve symptoms in patients with HF.

Effects of aerobic training prior to and during chemotherapy in a breast cancer patient: a case study.

Treatment for breast cancer patients includes surgical removal of the tumor followed by chemotherapy. Chemotherapy frequently results in difficult to manage symptoms that threaten compliance with the therapy. Symptoms include fatigue, declines in functional ability, muscle wasting, and a decreased quality of life. Preparing the body to tolerate a stressful event such as chemotherapy has been termed "prehabilitation". This case study determined the efficacy of introducing aerobic training 1 week prior to and continuing through 8 weeks of chemotherapy on fatigue and functional ability in a 42-year-old newly diagnosed breast cancer patient. The patient participated in a supervised and home-based walking program. Fatigue during daily activities and functional ability (12-minute walk, ascending and descending stairs, sit to stand, getting to and rising from the floor, 30-second bicep curl) were measured before and after exercise training. Results indicate that 5 of 7 functional measures demonstrated improvement, ranging from 23.4- 54.5%. In addition, fatigue while performing activities of daily living, as well as following the performance of the functional tasks, was reduced. The findings of this case study indicate that fatigue can be decreased and functional ability can be improved as a result of aerobic training initiated 1 week before and continued throughout chemotherapy. This case study presents a novel approach to introducing exercise prior to and continued during 8 weeks of chemotherapy in a way that may reduce the cumulative effects of this stressor.

Prehabilitation before knee arthroplasty increases postsurgical function: a case study.

Conditioning the body to undergo physical stress such as joint arthroplasty has been termed prehabilitation. This case study examined the effect of a 4-week prehabilitation intervention on functional outcomes after total knee arthroplasty (TKA). Two female subjects completed baseline strength and functional assessments before TKA. Subjects were randomized to either a 4-week prehabilitation intervention (ES) aimed at increasing strength and range of motion or a usual care condition (CS). After 4 weeks of training, subjects were reassessed and underwent TKA. Subjects completed a final assessment 12 weeks after TKA. Functional outcomes included 6-minute walk, number of times up from a chair in 30 seconds, proprioception, and self-reported function and pain using the Western Ontario and McMaster Universities Osteoarthritis Index. The data suggest that 4 weeks of prehabilitation had a positive effect on functional task performance and knee proprioception before surgery. After surgery, the ES continued to exhibit higher levels of functioning and less pain compared with the CS. Prehabilitation before TKA may contribute to improved recovery after surgery.

Echocardiographic evaluation of stress test for determining safety of participation in strength training.

Suitability for safe participation in aerobic exercise is typically determined by a cardiopulmonary exercise test, using a treadmill or cycle. With increased participation in strength training by healthy clients as well as rehabilitation patients, there is a need to develop a test for determining suitability for safe participation in strength training. This investigation describes a strength stress test that may be used for determining safety of participation in strength training. Ten healthy subjects (28.3 +/- 5.9 years and 75.3 +/- 14.4 kg) with strength training experience participated. Following a resting echocardiogram, subjects performed 3 sets of leg presses at an 8 repetition maximum. Resting and exercise end-diastolic and end-systolic volumes were obtained during the last repetition of each set and were indexed for body surface area (ESV(I), EDV(I)). Ejection fraction, cardiac output, and stroke volume were calculated. Cardiac output increased significantly (p < 0.05) for each set in comparison to rest and also during the third set in comparison to sets 1 and 2. Ejection fraction increased, whereas ESV(I) and EDV(I) decreased significantly for each set compared to rest, and also during sets 2 and 3 when compared to set 1. Responses to sets 2 and 3 indicate increased cardiac stress with increasing sets to exhaustion analogous to changes observed during tests designed to assess anaerobic and aerobic power. Thus, this protocol may be used as a test for evaluating the ability to participate in modest strength training consistent with exercise prescriptions developed for participants of health clubs and rehabilitation facilities. Strength testing protocol described may be adapted and modified for evaluating other lifts such as arm work and job-related tasks.

Impact of prior exercise on hamstring flexibility: a comparison of proprioceptive neuromuscular facilitation and static stretching.

Position stands from the American College of Sports Medicine and the Surgeon General site a need for strategies capable of enhancing the effectiveness of stretching on flexibility and joint range of motion. One strategy for enhancing flexibility that has received anecdotal support but lacks substantial experimental evidence is the impact of prior exercise. This study compared 5 minutes of static stretching and proprioceptive neuromuscular facilitation (PNF) on hamstring flexibility performed with and without exercise. Forty undergraduate student-athletes participated in a repeated measure, counterbalanced experimental design. Within-group comparisons indicated that PNF resulted in a significant (p < 0.05) increase in flexibility after 60 minutes of exercise when compared with baseline (9.6%) and without exercise (7.8%). No differences were observed with static stretching across time. In addition, no differences were observed between the groups at any time point. Results demonstrated that PNF performed after exercise enhanced acute hamstring flexibility, and implementing a PNF stretching routine following exercise may augment current stretching practices among athletes.