No description available.

This study compared the plantar force distribution between forward ice hockey skating and treadmill skating. Four varsity hockey players from McGill University (age = 22.1 +/- 1.2 years, height = 1.8 +/- 0.1 m, mass = 82.2 +/- 8.6 kg) skated on ice surface and on a specialized treadmill at three velocities (22, 24 and 26 +/- 0.5 km/hr). Results showed higher plantar forces were seen during treadmill skating prior to push off and this discrepancy was due to consistently larger forces in the fore region of the foot. This phenomenon was speculated to be the result of differences in skate stability during ice and treadmill skating. With respect to the loading dynamics, the heel region was the same during ice and treadmill skating.

The purpose of this study was to investigate the effect of skate blade hollow on oxygen consumption during forward skating on a treadmill. Varsity level female hockey players ( n = 10, age = 21.7 yr) performed skating tests at three blade hollows (0.25 in, 0.50 in, and 0.75 in). The subjects skated for four minutes at three submaximal velocities (12, 14, and 16 km/h), separated by five minutes of passive recovery. In addition, a VO^max test was performed on the day that the subjects skated at the 0.50 in hollow. The VOimax test commenced at 14 km/h and increased by 1 km/h each minute until volitional exhaustion was achieved. Four variables were measured for each skating bout, volume of gas expired (VE), volume of oxygen consumed (VO2), heart rate (HR) and rating of perceived exertion (RPE). No significant differences (pO.05) were found in any of the four test variables (VE, VO2, HR, RPE) across the three skate hollows. These results show that when skating on a treadmill at submaximal velocities, skate blade hollow has no significant effect on VE, VO2, HR or RPE.

No description available.

An abnormal chronotropic response to exercise is a common finding following surgical repair of tetralogy of Fallot (TOF) which has generally been attributed to a putative sympathetic dysfunction. There exists little information on sympathetic function in patients operated for a congenital heart defect to support such a claim. This study used spectral analysis of heart rate (HRV) and blood pressure (BPV) variability to examine sympathovagal influences on the sinus node in 9 adolescents operated for TOF 13.0 +/- 1.12 years previously and in 8 healthy age and sex-matched control (CTRL) subjects. Continuous ECG and BP recordings were obtained under supine or seated resting positions, with or without controlled respiration at 0.20 Hz (CR); after passive 85° head-up tilt (HUT); during cycling at steady-state heart rates of 100 and 120 bpm (Ex 100, Ex 120), and after 10 and 20 minutes of passive seated recovery. (Abstract shortened by UMI.)

Pagrindinis širdies ir kraujagyslių sistemos uždavinys – deguonies ir maisto medžiagų tiekimas. Deguonimi ir maisto medžiagomis kraujas aprūpina dirbančius raumenis ir kitus organus. Darbo tikslas – palyginti ištvermę lavinančių sportininkų ir nesportuojančiųjų širdies funkcinį parengtumo ypatybes taikant elektrokardiografijos metodą ir skirtingo kryptingumo fizinio krūvio mėginius. Uždaviniai: 1 - palyginti nesportuojančiųjų ir ištvermę lavinančių sportininkų ŠSD kaitos ypatybes atliekant pakopomis didėjantį krūvį veloergometru; 2 - palyginti nesportuojančiųjų ir ištvermę lavinančių sportininkų ŠSD kaitos ypatybes atliekant dozuoto krūvio mėginį; 3 - palyginti nesportuojančiųjų ir ištvermę lavinančių sportininkų ŠSD kaitos ypatybes atliekant maksimalaus anaerobinio krūvio mėginį; 4 – palyginti trijų skirtingų fizinio krūvio mėginių informacinės dimensijos reikšmes, kai elektrokardiografijos metodu vertinama funkcinio parengtumo ypatybės. Metodika. Buvo tirta 7 ištvermės rungčių atstovai lengvaatlečiai ir 16 nesportuojančių asmenų. Tiriamieji atliko tris fizinio krūvio mėginius: pakopomis didėjantį krūvį veloergometru; Rufje fizinio krūvio mėginį ir 30 - s vertikalaus šuoliavimo testą. Kompiuterine EKG registravimo ir analizės sistema „Kaunas-krūvis“ buvo registruojama EKG ir vertinama ŠŠD, JT intervalo, ST-segmento depresijos kaita atliekant krūvius ir pirmąsias tris atsigavimo minutes. Rezultatai ir išvados. Pakopomis didėjančio krūvio metu registruojant... [toliau žr. visą tekstą] / Cardiovascular system is the main physiological system determining physical working capasity or endurance. The main task of cardiovascular system to deliver the oxygen anf energy substrates to tisues and muscles as well. The purpors of this study was to compare functional peculiarities of cardiovascular system in endurance and non-sportsmans cohorts while performing various exercise tests. Objectives: 1 - to compare the cardiovascular reactions in endurance and non-sportsmans cohorts while performing graded exercise stress (bycycle ergometry); 2 – to compare the cardiovascular reactions in endurance and non-sportsmans cohorts while performing dosed aerobic exercise test; 3 – to compare the cardiovascular reactions in endurance and non-sportsmans cohorts while performing maximal anaerobic workload (30-s vertical jumps test); 4 – to compare the informativeness of aplyed exercise protocols for assessment of cardiovascular reactions in endurance and non-sportsmans cohorts. Methods. The participant fo this study was 7 endurance athletes and 16 non-sportsman. Subjects performed three exercise tests: graded exercise stress (bycycle ergometry); dosed aerobic exercise test (Roufier Test) maximal anaerobic workload (30-s vertical jumps test). A computerized ECG analysis system "Kaunas-load" was recorded ECG and assessed FCU, JT interval, ST-segment depression changes in workloads and the first three minutes of recovery. Results and Conclusions. The registration of ECG during the... [to full text]

The purpose of this study was to develop a prediction equation for peak oxygen uptake using the Modified BSU Ramp protocol. Thirty-four subjects (14 men and 20 women, age 32-83 years) completed the standard Ball State University Adult Physical Fitness Program quiet and exercise testing sessions, with the maximal exercise test conducted with the Modified BSU Ramp protocol. The modified ramp protocol increases speed and grade every 20 seconds, and it increases by - 0.15 METs every increment for the first 6 minutes and --0.3 METs per increment thereafter. The Modified BSU ramp protocol was developed to allow for reasonable exercise test times from a standardized ramp protocol with individuals with low functional capacities < 10 METs. Pre-test procedures included height and weight measurements, resting blood pressure, resting heart rate, body fat measures, a blood lipid profile, and resting electrocardiogram (ECG). Exercise testing included ECG, heart rate, and blood pressure that were recorded prior to, during, and in the recovery phase of exercise. Subjects were instructed to continue exercise until fatigue, and respiratory gases were collected to determine V02 . Data was then analyzed using multiple regression techniques. Gender, age, body weight, and treadmill test time were the significant predictors, which were used in the regression equation (R2 = 0.586, SEE = 3.54 ml-kg-'.min'). An equation was developed from the lone predictor, treadmill test time with R2 = .37 and SEE = 4.1 ml•kg'•min'. The equation is as follows: VOA = 4.932 + 1.934 (test time (min)). Of the tests conducted on the Modified BSU ramp protocol, 82% were within an "ideal" test time window of 812 minutes, and 97% were within an "acceptable" test time window of 6-15 minutes. In conclusion, VOA can be estimated with acceptable accuracy (i.e. SEE - ± I MET) from the Modified BSU Ramp protocol, and for clinical purposes it is a suitable protocol to use when testing low fit individuals. / School of Physical Education

The purpose of this study was to compare the exercise blood pressure response of subjects with a history of exercise induced hypertension between the submaximal 3-3-3 exercise test and a maximal Bruce treadmill protocol. Seven male and four female subjects with a mean age of 49 ± 2 years were recruited for the study. All subjects were selected based on a previous elevation of exercise diastolic blood pressure >_ 10 mmHg during maximal exercise.The 3-3-3 test is a short, standardized treadmill test protocol that consists of one stage of treadmill walking at a 3% grade, at 3 miles per hour, for 3 minutes. Subjects completed the 3-3-3 test on one day and the Bruce protocol on a different day with 24-48 hours between tests. Test administration order was randomized and all tests were done at the same time of the morning with all blood pressures taken by the same technician with a mercury manometer.The increase in diastolic pressure from rest was significantly lower (p<0.004) during the 3-3-3 protocol compared to the peak of the Bruce protocol. There were no statistical differences between the change in diastolic pressure from rest to peak exercise when the 3-33 protocol was compared to the Bruce Stage I or when the Bruce Stage I was compared to the peak Bruce diastolic measurement. The mean change in diastolic pressure from rest to peak exercise in the3-3-3 protocol was 3.4 ± 2.6 mmHg as compared to 9.9 ± 2.0 mmHg for the Bruce Stage I, and 15.4 ± 2.4 mmHg from rest to peak exercise with the peak Bruce. There were no differences in resting or standing systolic or diastolic blood pressure values between protocols done on separate trial days. The change in systolic response from rest to peak exercise and the peak systolic pressures were significantly different (p<0.001) between the Bruce Stage I and peak Bruce and between the 3-3-3 and peak Bruce. There were no significant differences in the heart rate and rate pressure product between the third minute of the 3-3-3 protocol and the third minute of the Bruce Stage I (p<0.001).The 3-3-3 test was not able to elicit the same rise in diastolic blood pressure as the Bruce treadmill test in this population, although the Bruce Stage I was able to elicit a response that was not statistically different than the response of the peak Bruce protocol. This implies that submaximal treadmill testing may be a feasible method to screen for the presence of an exaggerated diastolic blood pressure response to exercise. / School of Physical Education

Previous studies have suggested that if exercise intensity is established by perceived effort, the metabolic demand varies among exercise machines and the treadmill optimizes energy expenditure (EE). However, these studies have been completed utilizing young people with normal body fat percentages. Therefore, the purpose of this study was to assess whether there was a difference in acute energy expenditure when obese people used different exercise modes at a self-selected intensity (RPE 11-12) commonly recommended for overweight individuals. Twelve obese subjects (7 male; 5 female; BMI >29 kg/m2), aged 37-71 years completed two familiarization trials on four machines: treadmill (TM), stationary cycle (C), Body Trec elliptical arm/leg (BT), and Airdyne (AD). On separate days, subjects then completed a 15 minute trial on each machine at a self-selected intensity corresponding to a target RPE of I 1-12 on the Borg 15 point scale. Machine order was randomly assigned, and subjects were blinded to the workload throughout each trial. Workload was self-adjusted during the first 5 minutes and then remained stable for the rest of the trial. Physiological data were obtained during the last five minutes of each trial via HR telemetry and the Aerosport TEEM 100. The group means were compared across modes using a one-way repeated measures ANOVA. Significant differences (p <0.05) were observed across exercise modes for energy expenditure. The BT produced the highest rate of energy expenditure among exercise machines and C the lowest (8.0±2.0, 6.6±2.1, 6.3±2.0, 5.3±2.1 Kcal/min, for BT, TM, AD, and C, respectively). These results suggest that perceptually-based exercise prescriptions are not reliable across modes typically found in a fitness center environment, and that weight-bearing arm/leg exercise optimizes EE during self-selected exercise of moderate intensity in obese subjects. / School of Physical Education

The effect of heat acclimatization on aerobic exercise tolerance in the heat, and on subsequent anaerobic exercise performance was investigated. Ten male subjects were acclimatized by exercising 90 minutes per day for eight days in the heat (39.7 C db, 31.0% RH) on a bicycle ergometer at a workload corresponding to 54% of V02 max. Prior to, and following heat acclimatization, the subjects performed six hours of intermittent, submaximal (50% V02 max) exercise in the heat (HET). A 45 sec maximal bicycle ride was performed before (sprint 1) and after (sprint 2) each HET. Mean ( ± SE) resting plasma volume was higher (+9.2 + 1.7%) in acclimatized subjects (ACC) compared with unacclimatized (UN) subjects (P<0.001). Acclimatization resulted in reductions in the mean exercise heart rate (160 + 3 vs. 144 ± 3, P<0.001) and mean rectal temperature (38.13 + 0.08 vs 37.91 + 0.05, P<0.01). Muscle glycogen utilization during the HET was greater in the UN trial (57.4 + 5.1 mmol/kg) than the ACC trial (28.6 + 6.4 mmol/kg, P<0.05). No differences were noted between the UN and ACC trials with respect to blood glucose, lactate (LA), or respiratory exchange ratio during the HET. Total work output during sprint 2 was reduced compared with sprint 1 in the UN trial (24.01 ± 0.80 vs. 21.56 + 1.18 kJ, P<0.05). Post exercise muscle pH was significantly (P<0.05) higher following sprint 2 (6.86) than sprint 1 (6.67) in the UN trial. Associated with this reduction in anaerobic exercise performance, an attenuated accumulation of LA and fall in pH was noted in the blood. No differences between sprints 1 and 2 were observed for the ACC trial in total work, musce pH, or blood LA. As a result of sprint exercise in both UN and ACC trials, a decrease in muscle potassium (K+) was noted (P<0.05), which was accompanied by a 0.8 to 2.2 mmol/l increase in antecubital venous blood K+. Following sprint exercise, serum K+ was below pre sprint values for up to 15 minutes, suggesting a rapid and accelerated uptake of K+.These data indicate that eight days of heat acclimatization produced a shift in fuel selection during submaximal exercise in the heat through an enhanced delivery of blood borne substrate. The observed muscle glycogen sparing during submaximal exercise may be associated with the enhanced ability to maintain high levels of anaerobic energy release and performance of highly intense exercise following prolonged exertion in the heat.