Comparison between incremental shuttle run test and Harvard’s step test on peak exercise performance in healthy males: a cross-sectional study

Background: Cardiovascular fitness is directly related to the physical health of the person. Aerobic capacity (VO2max) is one of the major criteria to decide the cardiovascular fitness of an individual. To help quantify the fitness level by calculating their VO2max, there are various indirect maximal tests available but out of these, which one would predict VO2max better, is a major concern. Hence the purpose of this study was to compare the effects of two indirect maximal tests i.e. Incremental Shuttle Run Test (ISRT) and Harvard’s Step Test (HST) on peak exercise performance in young healthy males.Methods: A cross-sectional study with purposive sampling was performed on healthy untrained 100 males of age group 18-25 years. Day 1 subjects performed ISRT on 20 m track and after a 48 hours rest period, on day 3 same subject performed Harvard’s step test. Pre and post-test parameters (Pulse rate, respiratory rate, systolic and diastolic blood pressure and RPE) were measured and predicted VO2max was calculated.Results: Post-test parameters i.e. PR, RR, SBP significantly increased (p=0.00*) by Harvard’s step test. The diastolic blood pressure did not change significantly (p=0.3) for both the tests. Rating of perceived exertion by both the test was of the range 17-19 (very hard to maximal). Calculated predicted VO2max was significantly more by ISRT than HST in males (p=0.00*).Conclusions: Incremental shuttle run test is more efficient in predicting VO2max than Harvard’s step test in healthy adult’s males.

Strength and power training did not modify cardiovascular responses to aerobic exercise in elderly subjects

Resistance training increases muscle strength in older adults, decreasing the effort necessary for executing physical tasks, and reducing cardiovascular load during exercise. This hypothesis has been confirmed during strength-based activities, but not during aerobic-based activities. This study determined whether different resistance training regimens, strength training (ST, constant movement velocity) or power training (PT, concentric phase performed as fast as possible) can blunt the increase in cardiovascular load during an aerobic stimulus. Older adults (63.9 ± 0.7 years) were randomly allocated to: control (N = 11), ST (N = 13, twice a week, 70-90 percent 1-RM) and PT (N = 15, twice a week, 30-50 percent 1-RM) groups. Before and after 16 weeks, oxygen uptake (VO2), systolic blood pressure (SBP), heart rate (HR), and rate pressure product (RPP) were measured during a maximal treadmill test. Resting SBP and RPP were similarly reduced in all groups (combined data = -5.7 ± 1.2 and -5.0 ± 1.7 percent, respectively, P < 0.05). Maximal SBP, HR and RPP did not change. The increase in measured VO2, HR and RPP for the increment in estimated VO2 (absolute load) decreased similarly in all groups (combined data = -9.1 ± 2.6, -14.1 ± 3.9, -14.2 ± 3.0 percent, respectively, P < 0.05), while the increments in the cardiovascular variables for the increase in measured VO2 did not change. In elderly subjects, ST and PT did not blunt submaximal or maximal HR, SBP and RPP increases during the maximal exercise test, showing that they did not reduce cardiovascular stress during aerobic tasks.

Effects of changing daily exercise habit on body composition and maximal exercise test. One-year follow-up study of healthy males and males with mild hypertension / 体力科学

The effects of changing daily exercise habit on body fat, serum lipids and symptom-limited maximal exercise test (treadmill by Balke protocol) were evaluated in healthy males and males with mild hypertension (MHT) aged 30 to 59 yr during a period of one year. The subjects were selected from males who underwent physical examination. The results were as follows :<BR>A. HEALTHY MALES<BR>Study 1 : Subjects who exercised regularly (3 times or more/week) showed higher exercise tolerance and HDL cholesterol (HDLC) and less body fat. Compared to inactive subjects (sports 0-2 times/week), exercise tolerance was higher in the group who tried to walk as much as possible in their every day life.<BR>Study 2 : Inactive subjects without a family history of HT were classified by percentage body fat into three groups (H, M and L) . The obese group showed lower exercise tolerance, higher total cholesterol (TC) and lower HDLC. Heart rate (HR) and systolic blood pressure (BPs) at the same load during the exercise test were higher in the obese group.<BR>Study 3 : Revisited subjects who did not change their dietary habit for one year were selected from the average group of study 2. The subjects who increased their daily physical activity showed reduced body weight and body fat, increased exercise tolerance and HDLC, and lower HR and BPs under the same work load.<BR>B. MALES WITH MILD HYPERTENSION<BR>Study 4 : A similar study was conducted in inactive men with MHT (diastolic BP 90-104 mmHg), non-drug therapy at the first visit and no change in dietary habit for one year. Subjects who increased their daily activity for one year showed reduced body weight and body fat, and both resting BPs and BPd fell by 7 mmHg. HR and BPs decreased under the same work load.<BR>These results suggest that an increase in daily physical activity improves physical fitness, reduces blood pressure and decreases body fat in previously healthy males and in males with MHT.

Effects of Intensive Training on Cardiorespiratory Response to Maximal Exercise Loading in Soccer Players

BACKGROUND: In order to investigate the effects of intensive training on cardiorespiratory response to maximal exercise in soccer players, graded excercise stress tests were carried out before and after the training, and the results were compared. METHODS: Fourteen male soccer players of a university team with the mean age and career of 19.9 and 7.8 years, respectively, underwent intensive training for approximately 20 weeks, 6 days a week and 4 hours a day, which included running of 2 km daily during the last 8-9 weeks. The symptom-limited maximal exercise test was done by Bruce protocol. RESULTS: After the training. HR max showed no significant changes but Vo2 max, O2 pulse and AT were increased approximately 13%, 12% and 10%, respectively. At maximal exercise, the V(E)/M2 was also increased 18%, but VE/MVV was significantly decreased owing to a marked increase in MVV. However, the rest of various ventilatory parameters showed no significant changes. CONCLUSION: These data indicate that the intensive training of about 20 weeks duration can further improve the level of cardiorespiratory fitness in the soccer players who have been regularly trained and are already highly fit.