Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
A study investigating the excess post-exercise oxygen consumption (EPOC) following a resistance exercise program designed for muscle hypertrophy. The study found that EPOC remained significantly elevated even at 39 hours post-exercise, suggesting that the energy required to recover from resistance exercise may be more significant to weight management than cardiovascular training. The document also explores the relationship between exercise duration and EPOC, as well as the effects of intensity and substrate utilization on oxygen consumption during exercise and the subsequent EPOC.
Typology: Study notes
1 / 47
This page cannot be seen from the preview
Don't miss anything!
UNIVERSITY OF WISCONSIN-LA CROSSE
MARK SCHUENKE FEBRUARY 2001
To examine the excess postexercise oxygen consumption (EPOC) response following a
177 -+ 8 cm; mass = 83 f 10 kg, percent body fat = 10.4 f 4.2%) who weight bained
of bench press, power cleans, and squats, selected to recruit most major muscle groups. Each set was performed using the subject's predetmnined ten-repetition maximum and
consumption (Va) measurements were obtained at regular intervals throughout the day,
post, 19 h post, 24 h post, 38 h post, 43 h post, 48 h post). Postexercise V measurements were compared to the baseline measurements that comsponded with the same time of day. A repeated measures ANOVA revealed that EPOC was significantly
cumulativeexceed the EPOC produced by following moderate energy expenditure as a result of EPOC^ aerobicfolloving^ exercise. Furthermore, the HRE may exceed the
I would like to express my deepest appreciation to the following people for their integral roles in the completion of this thesis:
physiological aptitude. To Dr. Jeff McBride, for sewing on my committee and for your expertise in research protocol design and manuscript preparation. To Dr. Gary Konas, for sewing on my committee and for your technical writing expertise. To all of my aforementioned committee members, thank you for your patience, insight, and encouraging words. A special thank you is due for my subjects. Without your patience and cooperation, this project literally would not have been possible.
This thesis is dedicated to anyone and everyone who can look me in the eye and, without flinching away, express that you love me. Truly, these people are the composition of my soul.
ACKNOWLEDGEMENT ..................................................................... ... 111 LIST OF TABLES^ ............................................................................ v LIST OF FIGURES ........................................................................ vi LIST OF APPENDICES .................................................................. vii INTRODUCTION ............................................................................... 1 METHODS ........................................................................................ 3 Subject Characteristics^ .................................................................... 3 Study Design^ ................................................................................. 4 One-repetition Maximum Protocol ........................................................ 5 Ten-repetition Maximum Protocol^ ...................................................... 6 V q Measurement^ ........................................................................... 6 Resistance Exercise Protocol .............................................................. 7 Statistical Analysis .......................................................................... 8 RESULTS ........................................................................................ 8 DISCUSSION^ .................................................................................... 10 REFERENCES^ ................................................................................... 16 APPENDICES .................................................................................. 19
1. Mean Oxygen Consumption throughout the Research Protocol ....................... 9 2. Mean Daily Oxygen Consumption ..................................................... 10 3. Comparison of EPOC following Resistance and Aerobic Exercise .................. 12
A. Informed Consent .................................................. .................. 19 B. Review of Related Literature ......................................................... 22
exercise, the body requires oxygen for lactate disposal and rephosphorylation of creatine and ADP (1). Additionally, homeostatic imbalances of hormone levels (19) and protein degradation and reparation also take place (6, 13). EPOC is likely due to a combination of the aforementioned occurrences, but the significance of each factor is unknown. Several studies have examined the EPOC of aerobic exercise with variable results. Many of the studies indicated that oxygen consumption remained elevated for less than 60 minutes (3, 12, 16,24,27,28) following cardiovascular exercise. Conversely, several other studies found that EPOC remained significantly elevated above baseline for 7.5-12 hours (2,5,9, 14, 15). Although exercise intensity and duration are commonly implicated as causes for EPOC, they do not fully account for the aforementioned discrepancy, because studies using similar intensities and durations often had contradictory results. Therefore, the entire range of those results must be considered when comparing results of aerobic exercise to those of resistance exercise. As with aerobic exercise, the duration of EPOC following resistance exercise varies in the literature. Some studies found EPOC to normalize within 60 minutes (7, 10,
emphasizing local muscular endurance (7, 10,21) or muscular strrngth (7). Therefore, it
A major factor in the issue of weight control is the balance of caloric intake and expenditure. Although more energy is expended during activity than afterwards, the amount of calories utilized following exercise is not negligible. Even a small caloric deficit may contribute to an eventual weight loss. The magnitude and duration of EPOC arc, therefore, important components of a success!bi weight loss program. None of the resistance exercise studies that found metabolism to be elevated for 14 hours or more
this study was to extend the examining period to 48 hours post-exercise in an attempt to more clearly quantify excess post-exercise oxygen consumption f~~llowinga resistance
on weight management.
Subiect Characteristics Seven males volunteered to participate in the present study as a result of in-class d t m e n t at the University of Wisconsin-La Crosse. All subjects had been weight
injuries or illness that could inhibit lifting performance or metabolism. Selected
treatmats involved in this study were examined and approved by the University of
preceded by a 30-minute period of supine rest, except the evening measurement of the
bench press, power cleans, and squats, was used in place of the habituation period. V&
Maximal strength (1RM) was assessed for the bench press, power cleans, and parallel squats. However, it is difficult to determine absolute strength in power
relative imccuracy, weight selection was conducted using a one-repetition maximum (IRM) protocol similar to that outlined by McBride et al. (18). First, a theoretical IRM
singular repetition with that weight, the resistance was adjusted according to performance on the b t lift. Increments and decrements of five or ten pounds were used at the
Ten-Revetition Maximum Protocol Following determination of the IRM, a theoretical IORM was approximated using 80,70, and 75% of IRM for the bench press, power clean, and squat, respectively. Using these IORM estimations, the subjects familiarized themselves with the liftiig protocol by performing four circuits of the aforementioned exercises. Each lift was performed until failure, and two-minute rest intervals were given between sets. Loads were adjusted after each set in order to maintain 10 repetitions on subsequent sets.
Wisconsin-La Crosse Human Performance Lab using a Quinton@metabolic cart (Model
and relative humidity. Calibration included the injection of one liter of a known gas mixture into the pneumotach. Prior to testing, subjects underwent 30 minutes of supine rest. At the end of this habituation period, subjects were fitted with a facemask, enclosing both the nose and mouth, which collected expired air for analysis in the
means of indirect calorimetry and found no significant differences. One-minute averages were obtained throughout the 30 minutes of resting V@ collection. For a given day, V 9 measurements were conducted at 5-hour intervals (morning, midday, and evening), and
i (^) Table 2. Mean repetitions and intensity during the resistance exercise protocol
Bench Press Power Cleans Squats
Trial 1 2 3 4 1 2 3 4 1 2 3 4 Repetitions 10.8 9 8 9.2 12.2 8.8 8.4 9.6 10.8 8 8.8 10
Statistical Analvsis Prior to statistical analysis, outliers, identified as data with a Z-score greater than or equal to 3, were removed. Baseline and exercise V@ data were then compared using a repeated measures ANOVA (Treatment * Time) with specialized contrasts. Mean daily oxygen consumption for pre- and post-exercise days were analyzed using a single factor repeated measures ANOVA, with Scheffe F-test post-hoc comparisons. Significance was set at p 5 0.05. RESULTS The comparison of pre- and post-exercise measurements at cormponding times of day revealed that significant @ 5 0.05) differences exist between the morning baseline (34 h pre) and both mornings following the exercise (14 and 38 h postexercise). The 19- hour post-exercise measurement also differed significantly from the corresponding baseline time (29 h pre). The only evening measurement that revealed a significant difference occurred immediately after the weight lifting session (Figure I).
34 29 24 10 5 0.5 14 19 24 38 43 48 Hours he-Activity Hours Post-Activity Time (hours)
Figure 1. Mean oxygen consumption throughout the research protocol (Note: Data points marked with indicate significance (v - 5 0.05) over the baseline value for the comspondiig time of dai.)
The baseline measurements reveal a constant increase throughout the day. This is
stimulation is unavoidable. As a result, there is likely to be more between-subject
of the baseline day. These findings parallel the results of Melby, et al. (20), Gillette, et
elevated at IS, 14.5, and 16 hours post-exercise, respectively. It is important to note that
not contradicted by the present findings. However, none of these studies continued data collection for more than 90 minutes following the resistance exercise, so they did not indicate the duration of EPOC. Results from the present study are in disagreement with
found that EPOC had returned to baseline within one hour. This finding may be due to variations in the intensity and duration of the different resistance exercise protocols. Application of these results suggests that the energy required to recover From
cardiovascular training. For the first 24-hour period following exercise, the mean
&kg-'min". Similarly, the second 24-hour period following exercise had a 0.63 ml &kg-'mixi' mean difference over baseline. This equates to a 21.2% and 19.3% increase in metabolism for those two days, respectively. Assuming that an individual
(5), when their subjects cycled for an hour at 70% of V& max, they had a mean exercise
V02 of 95.26 liters. In the 204 minutes that it took for their EPOCs to return to baseline,
kilocalories for each liter of oxygen consumed, their subjects expended about 556.3 kcal
energy required solely for the post-exercise metabolic costs of resistance exercise ( kcal). However, with the relatively few data collections throughout each day, we cannot be sure that the subjects' oxygen consumption is consistently elevated. Therefore, these calculations are only estimations.
EPOC (kcal)
Chad(1 (^8) 988) Wenger Present Study
