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Comparison of Two Different Resistance Training Intensities on Excess Post-Exercise Oxygen Consumption in African American Women Who Are Overweight
Abstract
The purpose of this study was to compare a low- and high-intensity resistance exercise session of equal work on excess post-exercise oxygen consumption (EPOC). Ten African American (AA) overweight women performed a no-exercise control (CN) session, 3 sets of 9 resistance training exercises, for 15 repetitions (reps) at 45% of their 8-repetition maximum (RM) during 1 session (LO) and for 8 reps at 85% of their 8-RM during another session (HI). For each session heart rate (HR), ventilation volume (VE), oxygen consumption (VO₂), and respiratory exchange ratio, were collected continuously from 15 minutes pre exercise until 30 minutes post exercise. Blood lactate ([Lac]b) was collected pre, immediately post, 15 and 30 minutes post exercise. No significant differences were found between sessions for any pre-exercise measurements (p > 0.05). During exercise, there was no significant difference between the HI and LO sessions, as expected. The [Lac]b immediately post and 15-minute post were significantly higher in both HI and LO sessions compared with the CN session, however; no significant differences were found between the HI and LO sessions. Post-exercise HR for the HI session was significantly greater than the CN session (p = 0.006) but not different from the LO session. There were no significant differences in post-exercise VO₂ between the HI and LO sessions. A trend was observed between exercise sessions with EPOC for HI (1.26 ± 0.567 L·O2) vs. LO (0.870 ± 0.394 L·O2) sessions. These data suggest that resistance training at either a low or high intensity with an equated work volume will produce similar exercise and post-exercise oxygen consumption for AA overweight women. Both of these resistance training programs were well tolerated and could be used for sedentary populations without a preconditioning program.
... This is important as the metabolic effects of RT often go underlooked and may have implications for individuals looking to increase fat-free mass and reduce fat mass. Of the available evidence examining the effects of RT load on oxygen consumption ( _ VO 2 ) or energy expenditure during exercise using a variety of different loads (;20-90% 1RM), number of exercises (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12), and number of sets (1)(2)(3)(4)(5)(6), the data are equivocal (3,9,14,16,17). The majority of these studies matched low-load and high-load RT based on volume or total repetitions and the one that did not match only consisted of 3 sets of leg extensions (3). Additionally, recent work from our group demonstrated greater postexercise metabolism following low-load RT compared with high-load, suggesting perhaps that differences during exercise metabolism could be different between loads (7). ...
... Despite greater repetitions and time per set during the 30% 1RM session, there were no differences in during exercise _ VO 2 (both absolute and relative) between RT sessions, though both were greater than CTRL. This aligns with the previous work that found no differences in _ VO 2 between RT loads (14,16,17). Although 2 studies have detected statistical differences between loads (3,9), one of these studies demonstrated only a 5-kcal difference during 3 sets of leg extensions completed to volitional fatigue (3), which was likely driven by a longer session during the low-load condition as more repetitions were completed compared with the high-load session. ...
... Average HR was greater during 30% 1RM than 90% 1RM, though both were elevated compared with the CTRL. Previous work that has measured HR demonstrated no difference between RT exercise loads (14,17) or greater HR during the high-load RT session (16), and our contradictory data could be a result of how HR was measured with the previous work collecting at the end of each set (16) rather than continuously like the present study. Further, differences could also be attributed to the study population with previous work in female population (16) compared with predominantly male population in our study. ...
McCarthy, SF, Bornath, DPD, Murtaza, M, Ormond, SC, and Hazell, TJ. Effect of resistance training load on metabolism during exercise. J Strength Cond Res 38(12): 2029-2033, 2024-The effect of resistance training (RT) load on energy expenditure during exercise is unclear as most studies match low-load and high-load RT based on volume or total repetitions and matching volume can attenuate benefits of low-load protocols. This study explored the effect of whole-body low-load and high-load RT completed to volitional fatigue (not volume or repetition matched) on metabolism during exercise. Eleven resistance-trained adults (22 6 2 years, 3 F) completed 3 experimental sessions: (a) no-exercise control (CTRL); (b) RT at 30% 1 repetition maximum (1RM; 30%); and (c) RT at 90% 1RM (90%) with oxygen consumption (_ VO 2) and heart rate measured continuously. The RT sessions consisted of 3 sets of back squats, bench press, straight-leg deadlift, military press, and bent-over rows to volitional fatigue completed sequentially with 90 seconds rest between sets and exercises. Changes were considered important if p , 0.100 with a greater than medium effect size. There were main effects of session for relative and absolute _ VO 2 (L·min 21 ; p , 0.001, h 2 p. 0.935), both 30 and 90% were greater than CTRL (p , 0.001, d. 4.33) with no differences between RT protocols (p. 0.999, d 5 0.28). There was a main effect of session for total O 2 consumed (L; p , 0.001, h 2 p. 0.901), both RT sessions were greater than CTRL (p , 0.001, d. 3.08), and 30% was greater than 90% (p 5 0.002, d 5 1.75). Taken together these data suggest that RT load does not affect metabolism during exercise when completing whole-body exercises to volitional fatigue, though lower loads may result in longer session duration generating a greater total amount of O 2 consumed simply because of the extended duration.
... L'attività fisica svolta con i pesi produce un EPOC maggiore rispetto ad un'attività aerobica caratterizzata dal medesimo dispendio calorico 12,52 ; al contrario Crommet non evidenzia alcuna differenza tra i due tipi di allenamento 16 . Diverse modalità di allenamento della forza e l'ordine con cui queste vengono svolte non sembrano invece influenzare l'EPOC 17,60 , mentre i tempi di recupero possono aumentarne il valore con recuperi più brevi 21,28 . ...
... Dal punto di vista pratico, si ritiene che l'EPOC sia importante nel contesto dell'utilizzo dell'esercizio come strumento per il controllo ponderale. Per esempio, il ruolo dell'EPOC è stato considerato ai fini del calcolo del dispendio energetico globale in programmi di esercizio fisico per il controllo del peso 38,50,60 ed alcuni autori hanno riscontrato un valore pari al 6-15% del totale 36 . Considerando più dettagliatamente l'utilizzo dei substrati energetici, è stato osservato che in due sedute d'esercizio fisico di pari dispendio energetico, una svolta ad intensità elevata ed una ad intensità moderata, la prima comporta un EPOC ed un'ossidazione di carboidrati (CHO) significativamente maggiore, ma un'ossidazione di grassi (FAT) leggermente minore rispetto a quella moderata 18,37,49,58 . ...
... Pur non riscontrando differenze statisticamente significative tra le diverse attività, l'allenamento al CT risulta comunque essere quello che determina i valori di EPOC maggiori, a completamento delle indicazioni presenti in letteratura per l'allenamento intervallato 8,17,36,39 . Allo stesso tempo sembra confermato che per ottenere valori di EPOC elevati è necessario avvalersi di attività che implichino lo sviluppo della capacità di forza muscolare 52 o che coinvolgano in modo massivo la muscolatura degli arti inferiori 40,60 . ...
Aim: In the recovery period after exercise there is an increase in oxygen uptake defined as excess post-exercise oxygen consumption (EPOC). The magnitude of EPOC after aerobic exercise may depend on duration and intensity of exercise, on type of exercise (split exercise or continuous sessions) and on subjects’ training status and sex. Weight loss can be achieved by increasing energy expenditure (EE). EPOC causes an increase in caloric burn during the recovery period, to be taken into consideration in relation to energy balance and weight loss. It is not clear whether various modes of aerobic exercise affect EPOC differently. The aim of this study was to evaluate the acute effects of moderate intensity of cycling (C), treadmill (T), arm crank (A) exercises, cross-training exercise (CT) and moderate to vigorous intensity activities of daily living (ADL) on EPOC.
Methods: Six young moderately active females (age, 24.2±0.8 yr; BMI, 21.5±2.4 kg/m2; RMR, 1288±78.2 kcal/day; V.O2peak cycle ergometer, 40.3±4.3 mL/kg/min; V.O2peak treadmill, 40.9±6.9 mL/kg/min; V.O2peak arm ergometer, 22.2±3.4 mL/kg/min) participated in the study over a three-week period. In the first week subjects filled a Baecke questionnaire on habitual physical activity, underwent a resting metabolic rate (RMR) measurement and 3 incremental tests to exhaustion (V.O2peak at treadmill, cycle ergometer and arm ergometer). In the second and third week they completed five bouts of 30 min of exercise at 60% of V.O2peak separated by 48 hours of rest: a continuous C, T, A, a combined running, cycling and arm crank (CT) for 10 min each and ADL (3-6 METs). Before (30 min pre) and after (2 hours post) each exercise bout a RMR measurement was carried out in a sitting position with indirect calorimetry (K4b2, Cosmed, Italy). A MANOVA and a repeated measures ANOVA were used for data analysis.
Results: EPOC ranged in between 7% and 17% of Total Energy Expenditure. EPOC magnitude was also higher for CT than all the others training modes, even not significantly. O2 consumed during and after T and C was significantly higher than A when normalized to the pre-exercise levels (P<0.001). The higher oxygen consumption (V.O2) during exercise was found for T and C, significantly higher when compared with CT and ADL (P<0.01); on the contrary A was significantly lower than all the other training modes (P<0.001). The respiratory exchange ratio (QR) was significantly lower for T when compared with C during exercise (P<0.01). Differences were detected during exercise between training modes for energy source utilization: fat utilization was significantly higher for T when compared with all the other training modes (P<0.01), otherwise carbohydrates utilization was significantly higher for C when compared with T, A, and ADL (P<0.01). There were no significant differences between training modes for energy sources during the 2-hour post-exercise, although T allowed for a greater fat utilization.
Conclusion: This study shows that 30 min of all exercise modes provided an increase of EE for the first 2-hour after exercise. This study shows that T can be considered the best weight loss exercise when compared with all the other training modes measured. Our results indicate that separating a continuous 30 min exercise into three 10 min exercises will elicit an equivalent EPOC; this could be beneficial for subjects with a low fitness level who are unable to perform one long-bout of exercise on the same ergometer. The equivalent EE during and after exercise between activities of daily Living and the other training modes underlines the importance of an active lifestyle, especially when weight loss is concerned.
... A significant difference was found only in the 8 th minute between the type of exercise (BP and HS) can be explained by the stabilization time is longer in HS compared to BP. These data support previous evidence regarding the influence of intensity in RT, suggesting that the volume of training can be an aspect more relevant to the caloric expenditure during the EPOC when compared with the intensity of training (Thornton et al., 2011). ...
... The largest energy consumption occurs during the fast phase of EPOC (Bahr, 1992), in our study we observed a dramatic decrease immediately after the first minute, stabilizing in the 16 th minute in exercise with greater muscle mass involved (HS) ( Table 1). According to results reported by Bertuzzi et al. (2010) and Thornton et al. (2011), the EPOC was significantly different in the first five minutes after exercise compared to preexercise. These results indicate that the greatest demand energetic after exercise is in fast component of the EPOC. ...
The aim of this study was to analyze the effect of movement velocity and intensity on EPOC fast component in bench press and half squat exercises performed to concentric failure. Twelve healthy recreational bodybuilders performed 10 days of experimental procedures: the 1st and 2nd days were to load determination (1RM test and re-test), the 3rd to 10th days performing the bench press and half squat exercises with 60 and 80% 1RM performed in slow (1s/1s) and high (2s/2s) movement velocity cadence 52 beats. Oxygen consumptionas continuously measured in the first 20-min post-exercise using Cosmed K4 b2 portable device. A multivariate analysis compared the EPOC averaged in each minute post-exercise according to the different exercises, intensities and movement velocities. Was observed that EPOC declines fast from the 1st to 2nd minute and attains almost 100% of the decline near resting VO2 values at the 3rd minute of recovery both exercises. Greatest EPOC accumulated, during the eight minutes, was to exercise that involved the largest muscle group (half squat) with high intensity (80% 1RM) and greater movement velocity (1s/1s). In the full 20-min interval, the half squat had an energy equivalent of almost 80% more compared with the bench press. The higher velocities enhance energy expenditure to a greater extent than a more fatiguing slower exercise.
... Additionally, excess post oxygen consumption (EPOC) of RE may also need to be considered. Study findings related to the EPOC after RE have been mixed (15)(16)(17)(18). In light of this, further investigation is needed to determine if the EPOC of traditional RE is a significant factor in total caloric cost. ...
... This is beneficial to note due to the potential for caloric cost from an initial lift carrying over to the next. Based on the current results, and other literature (15,17,18) the EPOC between resistance exercises in succession would most likely be minimal. ...
The energy expenditure of resistance exercise (RE) is an important consideration for exercise prescription and weight management, yet prediction models are lacking.
Purpose:
This study aimed to develop regression equations to predict energy expenditure (kcal) for RE involving each major muscle group using commonly measured demographic and exercise variables as predictors.
Methods:
Fifty-two healthy, active subjects (27 men, 25 women, age 20-58 yr, height 174.1 ± 10.5 cm, weight 188.7 ± 42.6 kg, V˙O2max 36.8 ± 9.2 mL·kg⋅min) were strength tested to estimate their one-repetition maximum 1 wk before their experimental RE bout. The experimental RE bout consisted of a warm-up set followed by 2-3 sets (2-min turnover) of 8-12 reps at 60%-70% of predicted one-repetition maximum for leg press, chest press, leg curl, lat pull, leg extension, triceps push down, and biceps curl. Kilocalories were estimated from V˙O2 measured continuously throughout the RE bout via an automated metabolic cart. Total exercise volume (TV) was calculated as sets × reps × weight lifted. Multiple linear regression (stepwise removal) was used to determine the best model (highest adjusted R) to predict the kilocalorie consumption of the total workout and of the individual RE lifts.
Results:
The derived regression equation for the net kilocalorie consumption of an RE bout was as follows: total net kilocalorie = 0.874 (height, cm) - 0.596 (age, yr) - 1.016 (fat mass, kg) + 1.638 (lean mass, kg) + 2.461 (TV × 10) - 110.742 (R = 0.773, SEE = 28.5 kcal). Significant equations were also derived for individual lifts (R = 0.62 to 0.83).
Conclusions:
Net energy expenditure for a total RE bout and for individual RE can be reasonably estimated in adult men and women using commonly measured demographic and RE variables.
... Additionally, excess post oxygen consumption (EPOC) of RE may also need to be considered. Study findings related to the EPOC after RE have been mixed (15)(16)(17)(18). In light of this, further investigation is needed to determine if the EPOC of traditional RE is a significant factor in total caloric cost. ...
... This is beneficial to note due to the potential for caloric cost from an initial lift carrying over to the next. Based on the current results, and other literature (15,17,18) the EPOC between resistance exercises in succession would most likely be minimal. ...
... Thorton and Potteiger (29) report that high-intensity RT (85% 1 repetition maximum [1RM]) produces greater EPOC volume than lower intensity (45% 1RM) when equated for load-volume. However, in an alternative study, Thorton et al. (30) state that intensity did not influence EPOC in overweight African American women. As opposed to investigating the influence of intensity, the purpose of this study was to compare the effects of load-volume on EPOC after 2 bouts of RT. ...
... In previous investigations the absolute loads used during RT bouts were not held constant (5,12,13), except in one case in which rest periods were varied (16). In addition, none of the investigations used high-intensity protocols ($85% 1RM) with high resistance-trained recreational lifters (5,12,13,27,29,30). ...
Recent investigations have shown excess post-exercise oxygen consumption (EPOC) to be elevated for up to 48 hrs in both untrained and trained subjects following resistance training (RT). The purpose of the present study was to investigate the effect of load-volume on EPOC. Eight (n = 8) trained males (22 ± 3 yrs.) participated in two randomized RT bouts separated by at least one wk with total load-volumes of 10,000 kg and 20,000 kg. Intensity of RT (85% 1RM) did not differ between trials. Exercise energy expenditure and resting metabolic rate (RMR) were measured by indirect calorimetry at 8.5 hr prior, 1.5 hr prior, and during RT bouts as well as 12, 24, 36, and 48 hr following exercise. Creatine kinase (CK) was measured before and after RT, as well as 12, 24, 36, and 48 hr post-exercise; ratings of perceived muscle soreness (RPMS) were measured on a similar time course save the immediate post-exercise time point. ANOVA with repeated measures was used to analyze dependent variables. During the 20,000 kg trial subjects expended significantly (p < 0.01) more energy (484 ± 29 kcal) than the 10,000 kg lift (247 ± 18 kcal). Following the 20,000 kg lift, 12 hr post-exercise CK (1159 ± 729 U/L) was significantly elevated (p < 0.05) as compared to baseline (272 ± 280 U/L) and immediately post-exercise (490 ± 402 U/L). No significant time or trial differences were found in RMR between the 10,000 kg and 20,000 kg trials. In conclusion, high intensity RT with load-volumes of up to 20,000 kg using resistance trained males does not significantly increase EPOC above baseline RMR.
... Indeed, previous work has indicated that EPOC may be evident only beyond a particular threshold of aerobic exercise capacity (i.e., 40% V O 2max ) and following an exercise bout of a particular exercise duration (7); however, a study of young, sedentary, overweight African American subjects showed no change in EPOC following resistance training with equated work of either low or high intensity (29). Our study subjects' exercise intensity was maintained at ϳ35% of V O 2max in each treatment condition, a low intensity. ...
The objective of this study was to determine the effect of increased physical activity on subsequent sleeping energy expenditure (SEE) measured in a whole room calorimeter under differing levels of dietary fat. We hypothesized that increased physical activity would increase SEE. Six healthy, young men participated in a randomized, single blind, crossover study. Subjects repeated an eight-day protocol under four conditions separated by at least 7 days. During each condition, subjects consumed an isoenergetic diet consisting of 37% fat, 15% protein and 48% carbohydrate for the first four days and for the following four days, SEE and energy balance were measured in a respiration chamber. The first chamber day served as a baseline measurement and for the remaining three days, diet and activity were randomly assigned as high fat/exercise, high fat/sedentary, low fat/exercise, or low fat/sedentary. Energy balance was not different between conditions. When the dietary fat was increased to 50%, SEE increased by 7.4% during exercise (P<0.05) relative to being sedentary (baseline day) but SEE did not increase with exercise when fat was lowered to 20%. SEE did not change when dietary fat was manipulated under sedentary conditions. Physical activity causes an increase in SEE when dietary fat is high (50%), but not when dietary fat is low (20%). Dietary fat content influences the impact of post-exercise induced increases in sleeping energy expenditure. This finding may help explain the conflicting data regarding the effect of exercise on energy expenditure.
... A recent paper describes a new polypeptide hormone, irisin, which is regulated by PGC1-a; it is secreted from muscle into the bloodstream and may activate thermogenic mechanisms in adipose tissuethis might also play a role in short time reported to lower RER (Bostrom et al., 2012). Some concerns could be raised about the feasibility of RT and in particular high-intensity RT in unfit overweight subjects (LaForgia et al., 2006), but there is experimental evidence supporting the suitability of RT in such individuals (Sothern et al., 2000;Bouchard et al., 2009;McGuigan et al., 2009;Ibanez et al., 2010;Idoate et al., 2011;Kreider et al., 2011;Thornton et al., 2011;Willis et al., 2012). More recently, our group has demonstrated the safety and feasibility, after a familiarization period, of high-intensity resistance training in sedentary and overweight subjects (Paoli et al., 2010(Paoli et al., , 2013a Conclusions Taken together, these recent findings suggest that resistance training could positively affect body composition and that it could usefully be included in lifestyle weight control programmes. ...
Although resistance training (RT) has long been accepted as a means for developing and maintaining muscular strength, endurance, power and muscle mass, its beneficial relationship with health factors and chronic disease has only recently been recognized in the scientific literature. Prior to 1990, resistance training was not a part of the recommended guidelines for exercise training and rehabilitation for either the American Heart Association or the American College of Sports Medicine (ACSM). In 1990, the ACSM recognized resistance training as a significant component of a comprehensive fitness programme for healthy adults of all ages, a position subsequently confirmed few years after. At present, even though interest in clinical applications of RT is increasing, there are still some concerns, among physicians, about the use of this exercise methodology in weight control programmes. This review aims to explore the metabolic effects of RT and its efficacy and feasibility in overweight subjects.
Background
Nutrition guidance for athletes must consider a range of variables to effectively support individuals in meeting energy and nutrient needs. Resistance exercise is a widely adopted training method in athlete preparation and rehabilitation and therefore is one such variable that will influence nutrition guidance. Given its prominence, the capacity to meaningfully quantify resistance exercise energy expenditure will assist practitioners and researchers in providing nutrition guidance. However, the significant contribution of anaerobic metabolism makes quantifying energy expenditure of resistance exercise challenging.
Objective
The aim of this scoping review was to investigate the methods used to assess resistance exercise energy expenditure.
Methods
A literature search of Medline, SPORTDiscus, CINAHL and Web of Science identified studies that included an assessment of resistance exercise energy expenditure. Quality appraisal of included studies was performed using the Rosendal Scale.
Results
A total of 19,867 studies were identified, with 166 included after screening. Methods to assess energy expenditure included indirect calorimetry (n = 136), blood lactate analysis (n = 25), wearable monitors (n = 31) and metabolic equivalents (n = 4). Post-exercise energy expenditure was measured in 76 studies. The reported energy expenditure values varied widely between studies.
Conclusions
Indirect calorimetry is widely used to estimate energy expenditure. However, given its limitations in quantifying glycolytic contribution, indirect calorimetry during and immediately following exercise combined with measures of blood lactate are likely required to better quantify total energy expenditure. Due to the cumbersome equipment and technical expertise required, though, along with the physical restrictions the equipment places on participants performing particular resistance exercises, indirect calorimetry is likely impractical for use outside of the laboratory setting, where metabolic equivalents may be a more appropriate method.
PURPOSE This study examined blood lactate concentration and removal rate after aerobic and anaerobic maximal exercise test in sedentary middle-age women. METHODS Ten sedentary middle-age women (aged 52.7±3.3 years) were performed after aerobic (Aero group) and anaerobic maximal exercise (Anaero group) test, VO2max test and Wingate test, by cross-over repeated design with biweekly. The blood was collected from cardinal veins at before and immediately after test for measurement of lactate and lactate dehydrogenase (LDH). And it was also collected from fingertip at before, immediately after and then recovery 5, 10, 15, 30 minutes after each maximal test. Lactate removal rate (%) were calculated by bellow formulas: ={1-[(Lactate at 30 minutes. after test-Resting lactate)/Increased lactate]}×100. RESULTS The blood lactate concentration from fingertip after both maximal test significantly increased immediately after test (p
Objectives
. Resistance training may influence the resting metabolic rate (RMR), which is desirable in weight management programs. However, its impact on excess postexercise oxygen consumption (EPOC) is yet to be defined. The study evaluated the contribution of resistance training variables to EPOC.
Design
. Studies published until November 2011 were systematically reviewed.
Methods
.
MEDLINE
, LILACS, SCIELO, Science Citation Index, Scopus, SPORTDiscus, and CINAHL databases were consulted. The methodological quality of studies was assessed by the PEDro 10-point scale. A total of 155 participants (54% men) aged between
20
±
2
and
34
±
14
years were observed by 16 studies (quality scores ranged from 5 to 7), which were organized according to treatment similarity (number of sets, intensity, rest interval, speed of movement, and exercise order).
Results
. Training volume seemed to influence both EPOC magnitude and duration, whereas workload influenced mostly the magnitude. Short rest intervals (
Aim. The aim of this study was to investigate the effects of movement speed and intensity in the fast excess post-exercise oxygen consumption (EPOC) in bench press (BP) and half squat (SQ) exercises.
Methods. This was a cross-sectional study with 12 healthy subjects (34.50±9.11 years, 80.58±12.07 kg, 176.46±7.41 cm), recreational bodybuilders involved in systematic training three times a week for at least six month. Each subject randomly performed eight exhaustive bouts (four BP and four SQ) combining two movement speeds (40 and 52 beats/min) and two intensities (60% and 80% 1-RM). Recovery between bouts was 48-h. 1-RM was assessed twice before the experiment with two 8-RM test separated by 72-h. Expired gases were continuously measured during exercise and in the first 8-min post-exercise with a Cosmed K4 portable device.
Results. For the bench press, the repeated measures revealed a significant effect of movement speed and time, with the lower movement speed (40 beats/min) resulting in higher VO2 mean values. For the SQ exercise, significant differences were found for the main effect of time, but not for intensity, neither for movement speed. In addition, the fast EPOC after BP was also greater when the slow movement speed was applied, while no significant effect of the movement speed was observed in the SQ exercise.
Conclusion. It was concluded that, at least for BP exercise, a slow movement speed seems to be the best way to promote an increase in energy expenditure during the postexercise period.
Thermogenesis after exercise was studied by measuring oxygen consumption in 23 subjects who were classified into three groups according to their routine level of physical activity. VO2 was first measured after a 30-minute rest period 4-hours after breakfast. Then each subject either exercised for 20 minutes at approximately the anaerobic threshold or on a separate non-exercise day remained recumbent. The subject then returned to, or remained, at rest. There was no significant difference in VO2 from the resting level from 40 minutes to 3 hours after exercise, between exercise and non-exercise days in any fitness group. Seven subjects also exercised for a longer period or at a higher intensity. Again, there was no significant difference in the time course of VO2 from 40 minutes to 220 minutes after exercise, between exercise and non-exercise days. Because no sustained effect of moderate or intense exercise on VO2 was demonstrated, we conclude that no appreciable caloric loss beyond that generated by the exercise period itself and the early recovery phase is found in either fit or unfit subjects. These data do not support claims for sustained increases in metabolic rate after exercise in weight-control programs.
It has been shown that basal metabolic rate (BMR) decreases with age. The extent to which some of the decrease can be reversed by exercise in older men and women is unclear. Resistance exercise has been shown to significantly increase muscle mass in older individuals, and because muscle is a highly active metabolic tissue there is potential to increase BMR as a secondary outcome to the training adaptation.
Twelve healthy men aged 59-77 years performed single-leg knee extension exercise (right and left leg) and bench press lifts (16 sets, 10 reps/set with timed recovery between sets) at 75% of the individual's 3RM. Subjects only performed the concentric phase of the lift. BMR was measured on two separate occasions, once after a nonexercise control period and again 48 hrs after a bout of resistance exercise.
BMR was significantly increased (p < .006) 48 hrs after exercise (EX) compared to control (CON) (284.0 +/- 34.0 vs 274.9 +/- 34.0 kJ/hr, respectively). Calculated over a 24-hour period, the energy expenditure corresponded to 1570 +/- 193 and 1627 +/- 193 kcal/24 hr (p < .0002) for the CON and EX measures, respectively. VO2 (L/min) was higher (p < .0002) 48 hrs after the EX bout compared to 48 hrs post-CON (0.232 +/- 0.03 vs 0.225 +/- 0.03 L/min, respectively).
We conclude that in healthy 59-77-year-old men, an acute bout of resistance exercise causes a sustained increase in BMR that persists for up to 48 hours after exercise.
When prescribed appropriately, resistance training is effective for developing fitness, health, and for the prevention and rehabilitation of orthopedic injuries. Because resistance training is an integral component in the comprehensive health program promoted by the major health organizations (e.g., American College of Sports Medicine, American Heart Association, American Association of Cardiovascular and Cardiopulmonary Rehabilitation, Surgeon General's Office), population-specific guidelines have recently been published. The current research indicates that, for healthy persons of all ages and many patients with chronic diseases, single set programs of up to 15 repetitions performed a minimum of 2 d x wk(-1) are recommended. Each workout session should consist of 8-10 different exercises that train the major muscle groups. Single set programs are less time consuming and more cost efficient, which generally translates into improved program compliance. Further, single set programs are recommended for the above-mentioned populations because they produce most of the health and fitness benefits of multiple set programs. The goal of this type of program is to develop and maintain a significant amount of muscle mass, endurance, and strength to contribute to overall fitness and health. Patients with chronic diseases (e.g., arthritis) may have to limit range of motion for some exercises and use lighter weights with more repetitions.
There is a paucity of research concerning energy expenditure during and after circuit weight training (CWT). There is evidence that duration of rest between sets affects metabolic responses to resistive exercise. The purpose of the study was to determine the effect of rest-interval duration upon the magnitude of 1 h of excess postexercise oxygen consumption (EPOC).
Seven healthy men completed two randomized circuit weight training sessions using 20-s and 60-s rest intervals (20 RI, 60 RI). Sessions included two circuits of eight upper and lower body resistive exercises in which 20 repetitions were performed at 75% of a previously determined 20 repetition maximum.
The 1 h EPOC of 10.3 +/- 0.57 L for the 20 RI session was significantly higher than 7.40 +/- 0.39 L for the 60 RI session. The net caloric expenditure during 1 h of recovery from the 20 RI session was significantly higher than that of the 60 RI session (51.51 +/- 2.84 vs 37.00 +/- 1.97 kcal); however, total gross energy expenditure (exercise + 1 h recovery) was significantly greater for the 60 RI protocol (277.23 kcal) than the 20 RI protocol (242.21 kcal).
Data demonstrate that shortening the rest interval duration will increase the magnitude of 1 h EPOC from CWT; however, the exercise + recovery caloric costs from CWT are slightly greater for a longer rest interval duration protocol. These data suggest that total caloric cost be taken into account for CWT.
Two studies were conducted to assess the potential of an increase in exercise intensity to alter energy and lipid metabolism and body fatness under conditions mimicking real life.
Study 1 was based on the comparison of adiposity markers obtained in 352 male healthy adults who participated in the Québec Family Study who either regularly participated in high-intensity physical activities or did not. Study 2 was designed to determine the effects of high-intensity exercise on post-exercise post-prandial energy and lipid metabolism as well as the contribution of beta-adrenergic stimulation to such differences under a real-life setting.
Results from Study 1 showed that men who regularly take part in intense physical activities display lower fat percentage and subcutaneous adiposity than men who never perform such activities, and this was true even if the latter group reported a lower energy intake (917 kJ/day, P<0.05). In Study 2, the high-intensity exercise stimulus produced a greater post-exercise post-prandial oxygen consumption as well as fat oxidation than the resting session, an effect which disappeared with the addition of propranolol. In addition, the increase in post-prandial oxygen consumption observed after the high-intensity exercise session was also significantly greater than that promoted by the low-intensity exercise session.
These results suggest that high-intensity exercise favors a lesser body fat deposition which might be related to an increase in post-exercise energy metabolism that is mediated by beta-adrenergic stimulation.
It has been suggested that lactate concentrations may provide a guide to an optimal training intensity. However, lactate concentrations established during incremental exercise in the laboratory are not always indicative of what is occurring during constant-load exercise at the same intensity. Ideally, lactate concentrations should be measured during a training session and immediately reported to the athlete to ensure that the athlete is working at the desired intensity. The purpose of this investigation was, therefore, to determine the reliability and validity of a compact, portable lactate analyser (ACCUSPORT; Boeringer Mannheim, Castle Hill, Australia). A total of 224 capillary blood samples were taken from athletes who took part in routine laboratory testing. Seventy-three of these capillary blood samples were analysed in duplicate with the Accusport for determination of intraclass, single-trial reliability. Day-to-day intraclass reliability of the Accusport was assessed by analyzing known concentrations of aqueous lactate solutions on seven consecutive days. The validity of the Accusport analyser was assessed by comparing the 224 capillary blood lactate concentrations determined on the Accusport with the lactate concentration obtained using a MICRO STAT LM3 (Analox Instruments Ltd., London, UK). In addition, lactate parameters derived from the lactate concentrations obtained with the two analysers were compared. The Accusport showed high single-trial intraclass reliability (R = 0.992; Standard Error of Measurement [SE(M)] = 0.3 mmol x l(-1); n = 73) and high day-to-day intraclass reliability (R = 0.993; SE(M) = 0.4 mmol x l(-1); n = 42). Despite a strong correlation between blood lactate concentrations obtained on the two analysers (r = 0.96; n = 224) the limits of agreement were + 1.9 to - 2.2 mmol x l(-1). Although the mean values for power output, HR and lactate concentration associated with the lactate parameters were not significantly different when determined on the Accusport or Micro Stat, some individuals did record large differences between analysis methods. In summary, the results of this investigation have shown that lactate concentrations can be reliably determined within a single trial and from day-to-day using the Accusport analyser. However, for some athletes, it is not valid to compare lactate concentrations or lactate parameters determined on the Accusport with those determined using the Micro Stat LM3 lactate analyser.
In the recovery period after exercise there is an increase in oxygen uptake termed the ‘excess post-exercise oxygen consumption’ (EPOC), consisting of a rapid and a prolonged component. While some studies have shown that EPOC may last for several hours after exercise, others have concluded that EPOC is transient and minimal. The conflicting results may be resolved if differences in exercise intensity and duration are considered, since this may affect the metabolic processes underlying EPOC. Accordingly, the absence of a sustained EPOC after exercise seems to be a consistent finding in studies with low exercise intensity and/or duration. The magnitude of EPOC after aerobic exercise clearly depends on both the duration and intensity of exercise. A curvilinear relationship between the magnitude of EPOC and the intensity of the exercise bout has been found, whereas the relationship between exercise duration and EPOC magnitude appears to be more linear, especially at higher intensities.
Differences in exercise mode may potentially contribute to the discrepant findings of EPOC magnitude and duration. Studies with sufficient exercise challenges are needed to determine whether various aerobic exercise modes affect EPOC differently. The relationships between the intensity and duration of resistance exercise and the magnitude and duration of EPOC have not been determined, but a more prolonged and substantial EPOC has been found after hardversus moderate-resistance exercise. Thus, the intensity of resistance exercise seems to be of importance for EPOC.
Lastly, training status and sex may also potentially influence EPOC magnitude, but this may be problematic to determine. Still, it appears that trained individuals have a more rapid return of post-exercise metabolism to resting levels after exercising at either the same relative or absolute work rate; however, studies after more strenuous exercise bouts are needed. It is not determined if there is a sex effect on EPOC.
Finally, while some of the mechanisms underlying the more rapid EPOC are well known (replenishment of oxygen stores, adenosine triphosphate/creatine phosphate resynthesis, lactate removal, and increased body temperature, circulation and ventilation), less is known about the mechanisms underlying the prolonged EPOC component. A sustained increased circulation, ventilation and body temperature may contribute, but the cost of this is low. An increased rate of triglyceride/fatty acid cycling and a shift from carbohydrate to fat as substrate source are of importance for the prolonged EPOC component after exhaustive aerobic exercise. Little is known about the mechanisms underlying EPOC after resistance exercise.
To the Editor: Borer et al.
Few studies have examined excess postexercise oxygen consumption (EPOC) following resistance exercise. This study was designed to (a) assess the magnitude and duration of EPOC following resistance exercise typical of recreational exercisers and (b) compare the magnitude and duration of EPOC following two resistance exercise protocols. Seven active male volunteers had respiratory gas-exchange parameters, rectal temperature, and heart rate measured for a 5-hr period during each of three conditions: after sitting quietly for 60 min (resting condition), after 60 min of resistance exercise using 75% of one repetition maximum (1-RM; heavy condition), and after 60 min of resistance exercise using 60% 1-RM (light condition). EPOCs following resistance exercise ranged from 0.7 to 27 L O2, showing large interindividual differences. These values are modest but larger than values reported for isocaloric aerobic exercise. In 10 of the 14 trials, metabolic rate had returned to baseline levels within 60 min of the exercise. There were no significant differences (p>.05) between EPOCs following the heavy versus light conditions. The results suggest that EPOC following resistance exercise is unlikely to contribute significantly to modifications of body composition.
(C) 1993 National Strength and Conditioning Association
Post-exercise energy expenditure has not been studied after resistance exercise. In this study, metabolic rate was measured by indirect calorimetry for nine volunteers after 40 minutes of cycling (80 percent of maximal heart rate), 40 minutes of circuit training (50 percent of individuals' maximum lift [1 RM] x 15 repetitions x 4 sets), 40 minutes of heavy resistance lifting (80 to 90 percent of 1 RM x 3-8 repetitions x 3 sets) and a control interval. Weight training included use of eight stations of Universal multi- and unistation equipment. All forms of exercise increased the metabolic rate immediately after exertion (p < 0.01). For circuit and heavy resistance lifting, the increase also was significant 30 minutes after exertion (p < 0.05). The absolute total increment in caloric use (mean +/- standard deviation) after exertion was comparable among circuit training (49 +/- 20 kilocalories), heavy lifting (51 +/- 31 kilocalories), and cycling (32 +/- 16 kilocalories). However, cycling was less (p < 0.05) than both forms of weight training. Our findings suggest that dynamic exertion is not required to augment post-exercise oxygen consumption (EPOC), and that the amount of exercising skeletal mass is an additional variable to consider when relating exercise to EPOC.
(C) 1992 National Strength and Conditioning Association
The purpose of this study was to compare the effects of standard set weight training (SWT) and circuit weight training (CWT) on excess post-exercise oxygen consumption (EPOC). The type and order of exercises were the same for both programs. The programs differed in three respects: a circuit approach as opposed to three sets of the same exercise; the percent of maximum weight used was 80 percent in SWT and 50 percent CWT; and rest periods were shorter for CWT (30 seconds) than SWT (120 seconds). This longer rest period resulted in a longer SWT program (50 minutes) than the CWT program (19 minutes). Ten untrained college men performed both weight-training programs. Resting metabolic rate (RMR) was determined before each weight program, followed by a determination of EPOC.
The magnitude and duration of EPOC produced by CWT were significantly (p < 0.01) greater than those produced by SWT. The EPOC produced by CWT was 20 minutes in duration with a net caloric cost estimated at 24.9 kilocalories, while that produced by SWT was 15 minutes in duration with an estimated net caloric cost of 13.5 kilocalories. The intensity of CWT (289 kilograms per minute) was also greater than that of SWT (106 kilograms per minute).
It was concluded that the magnitude and duration of EPOC is greater for CWT in comparison to SWT and the EPOC produced by weight training is somewhat less than that found for aerobic exercise.
(C) 1992 National Strength and Conditioning Association
Little is known about the effect of non-steady state resistive exercise on postexercise energy expenditure. Using a counterbalanced design, energy expenditure was measured by indirect calorimetry in six adult males (mean age +/- SD = 24.5 +/- 6.1) for 30 min before and 60 min after a single 42 min bout of weight lifting, and again on a separate day for 30 min before and 60 min after a 42 min control period of quiet sitting. For the exercise condition the subjects performed 4 sets of upper and 3 sets of lower body resistive exercises at weights equivalent to a 12 repetition maximum for each respective lift. Metabolic rate remained significantly elevated at the end of the 60 min recovery period compared to the control condition, although the excess postexercise oxygen consumption accounted for only approximately 19 additional kcal expended. These data suggest that while postexercise metabolic remains elevated for at least one hour following a moderate level of resistive exercise, the caloric cost of this elevation during a one hour recovery period is small and similar to that induced by steady-state exercise of moderate intensity.
After exercise, there is an increase in O2 consumption termed the excess postexercise O2 consumption (EPOC). In this study, we have examined the effect of exercise intensity on the time course and magnitude of EPOC. Six healthy male subjects exercised on separate days for 80 minutes at 29%, 50%, and 75% of maximal O2 uptake (VO2max) on a cycle ergometer. O2 uptake, R value, and rectal temperature were measured while the subjects rested in bed for 14 hours postexercise, and the results were compared with those of an identical control experiment without exercise. An increase in O2 uptake lasting for 0.3 +/- 0.1 hour (29% exercise), 3.3 +/- 0.7 hour (50%) and 10.5 +/- 1.6 hour (75%) was observed. EPOC was 1.3 +/- 0.46 I(29%), 5.7 +/- 1.7 I (50%), and 30.1 +/- 6.4 I (75%). There was an exponential relationship between exercise intensity and total EPOC, both during the first 2 hours and the next 5 hours of recovery. Hence, prolonged exercise at intensities above 40% to 50% of VO2max is required in order to trigger the metabolic processes that are responsible for the prolonged EPOC component extending beyond 2 hours postexercise.
Despite many reports of long-lasting elevation of metabolism after exercise, little is known regarding the effects of exercise intensity and duration on this phenomenon. This study examined the effect of a constant duration (30 min) of cycle ergometer exercise at varied intensity levels [50 and 70% of maximal O2 consumption (VO2max)] on 3-h recovery of oxygen uptake (VO2). VO2 and respiratory exchange ratios were measured by open-circuit spirometry in five trained female cyclists (age 25 +/- 1.7 yr) and five untrained females (age 27 +/- 0.8 yr). Postexercise VO2 measured at intervals for 3 h after exercise was greater (P less than 0.01) after exercise at 50% VO2max in trained (0.40 +/- 0.01 l/min) and untrained subjects (0.39 +/- 0.01 l/min) than after 70% VO2max in (0.31 +/- 0.02 l/min) and untrained subjects (0.29 +/- 0.02 l/min). The lower respiratory exchange ratio values (P less than 0.01) after 50% VO2max in trained (0.78 +/- 0.01) and untrained subjects (0.80 +/- 0.01) compared with 70% VO2max in trained (0.81 +/- 0.01) and untrained subjects (0.83 +/- 0.01) suggest that an increase in fat metabolism may be implicated in the long-term elevation of metabolism after exercise. This was supported by the greater estimated fatty acid oxidation (P less than 0.05) after 50% VO2max in trained (147 +/- 4 mg/min) and untrained subjects (133 +/- 9 mg/min) compared with 70% VO2max in trained (101 +/- 6 mg/min) and untrained subjects (85 +/- 7 mg/min).
Nine males with mean maximal oxygen consumption (VO2max) = 63.0 ml.kg-1.min-1, SD 5.7 and mean body fat = 10.6%, SD 3.1 each completed nine counterbalanced treatments comprising 20, 50 and 80 min of treadmill exercise at 30, 50 and 70% VO2max. The O2 deficit, 8 h excess post-exercise oxygen consumption (EPOC) and EPOC:O2 deficit ratio were calculated for all subjects relative to mean values obtained from 2 control days each lasting 9.3 h. The O2 deficit, which was essentially independent of exercise duration, increased significantly (P less than 0.05) with intensity such that the overall mean values for the three 30%, 50% and 70% VO2max workloads were 0.83, 1.89 and 3.09 l, respectively. While there were no significant differences (P greater than 0.05) between the three EPOCs after walking at 30% VO2max for 20 (1.01 l), 50 (1.43 l) and 80 min (1.04 l), respectively, the EPOC thereafter increased (P less than 0.05) with both intensity and duration such that the increments were much greater for the three 70% VO2max workloads (EPOC: 20 min = 5.68 l; 50 min = 10.04 l; 80 min = 14.59 l) than for the three 50% VO2max workloads (EPOC: 20 min = 3.14 l; 50 min = 5.19 l; 80 min = 6.10 l). An analysis of variance indicated that exercise intensity was the major determinant of the EPOC since it explained five times more of the EPOC variance than either exercise duration or the intensity times duration interaction. The mean EPOC:O2 deficit ratio ranged from 0.8 to 4.5 and generally increased with both exercise intensity and duration.(ABSTRACT TRUNCATED AT 250 WORDS)
In 1949 Weir (3) demonstrated that the metabolic rate calculated from respiratory gas exchange measurements is to a close approximation proportional to the difference in percentage oxygen content between inspired and expired air. Although values for the energy equivalent of oxygen consumed and for the respiratory quotient for the oxidation of various nutrients have been revised since 1949, we show that the error in the calculation remains generally below 0.5% for the oxidation of dietary carbohydrate, fat, and protein. Where the original equation is uncritically applied to situations in which other nutrients are being oxidized, the error may reach 3%, although alternative methods for calculating the metabolic rate may be similarly in error. We give the derivation from first principles of the general mathematical solution to the calculation of the metabolic rate following Weir's method. Examples are provided of the subsequent derivation of specific equations for the more precise calculation of the metabolic rate where different combinations of nutrients are being oxidized.
This study was designed to investigate the effect of fitness level on excess postexercise oxygen consumption (EPOC) in five endurance trained and five sedentary male volunteers. The possible influence of differences in body weight and exercise energy expenditure were controlled by employing a weight-supported (cycle ergometer), 300 kilocalorie exercise. Exercise intensity was equal to 50% of each subject's previously determined peak oxygen uptake (VO2). VO2 was measured for 1 hr prior to exercise to establish the baseline value, and continuously in the postexercise period until the baseline value was achieved. Duration of EPOC was 16.6 +/- 3.1 minutes and 20.4 +/- 7.8 minutes in the fit and unfit groups, respectively (p > 0.05). Magnitude of EPOC, which was not significantly different between the groups, averaged 12.2 +/- 3.1 kcal in the fit and 12.2 +/- 4.3 kcal in the unfit group. The results suggest that EPOC following a weight-supported exercise of an intensity and duration frequently used by individuals who begin an exercise program for weight control is not compromised by differences in body weight or fitness level.
Postexercise energy metabolism was examined in male subjects age 22-35 years in response to three different treatments: a strenuous bout of resistive exercise (REx), a bout of stationary cycling (AEx) at 50% peak VO2, and a control condition (C) of quiet sitting. Resting metabolic rate (RMR) was measured the morning of and the morning following each condition. Recovery oxygen consumption (RcO2) was measured for 5 hr following each treatment. Total 5-hr RcO2 was higher for the REx treatment relative to both AEx and C, with the largest treatment differences occurring early during recovery. There were no large treatment differences in postexercise respiratory exchange ratio values, except for the first hour of recovery following REx. RMR measured 14.5 hr postexercise for the REx condition was significantly elevated compared to C. These results suggest that strenuous resistive exercise results in a greater excess postexercise oxygen consumption compared to steady-state endurance exercise of similar estimated energy cost.
Two separate experiments were performed to determine the effect of acute resistive exercise on postexercise energy expenditure in male subjects previously trained in resistive exercise. In experiment 1, after measurement of their resting metabolic rate (RMR) at 0700 h and their ingestion of a standardized meal at 0800 h, seven subjects (age range 22-40 yr) beginning at 1400 h completed a 90-min weight-lifting protocol. Postexercise metabolic rate (PEMR) was measured continuously for 2 h after exercise and compared with a preexercise baseline. RMR was measured the following morning 15 h after completion of the workout. In experiment 2, six different men (age range 20-35 yr) completed a similar experimental protocol as well as a control condition on a separate day in which metabolic rate was measured for 2 h after a period of quiet sitting. For both experiments, PEMR remained elevated for the entire 2-h measured recovery period, with the average oxygen consumption for the last 6 min elevated by 11-12%. RMR measured the morning after exercise was 9.4% higher in experiment 1 and 4.7% higher in experiment 2 than on the previous day. In experiment 2, the postabsorptive respiratory exchange ratio was significantly lower the morning after the exercise bout. Strenuous resistive exercise may elevate PEMR for a prolonged period and may enhance postexercise lipid oxidation.
This study investigated the effects of blood lactate and norepinephrine levels and rectal temperature on excess postexercise oxygen consumption (EPOC) following two different exercise intensities. Six trained and seven untrained women each performed two exercise tests, short-term high-intensity exercise ([HI] approximately 80% maximum oxygen consumption [VO2max]) and long-term low-intensity exercise ([LOW] approximately 65% VO2max) until 300 kcal were expended. Rectal temperature, oxygen consumption (VO2), and lactate and norepinephrine levels were monitored at rest, during exercise, and for 60 minutes into recovery. Exercise times averaged 30.0 +/- 4.5 and 23.7 +/- 0.9 minutes in trained women and 45 +/- 3.6 and 30.0 +/- 0.4 minutes in untrained women for LOW and HI, respectively. Rectal temperature, VO2, and lactate and norepinephrine levels were significantly elevated (P < .05) during HI compared with LOW in both groups. VO2 was elevated throughout recovery following LOW and HI in untrained women only. Additionally, VO2 was elevated until minutes 50 and 40 following LOW and HI, respectively, in trained subjects. Rectal temperature returned to resting levels after 30 minutes of recovery following LOW, but remained significantly elevated throughout minute 50 of recovery following HI in trained women. However, values remained significantly elevated throughout recovery following both exercise bouts in untrained subjects. Norepinephrine levels remained elevated above resting levels throughout recovery following HI and until minute 50 following LOW in trained subjects, whereas levels remained elevated for 5 minutes following LOW and 50 minutes following HI in untrained subjects. Lactate levels remained elevated above baseline values throughout recovery following HI and LOW in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)
The effects of low and high intensity exercise, of similar energy output, on exercise and post-exercise energy expenditure and substrate oxidation were studied in eight active, eumenorrheic females (aged 22 to 31).
Continuous indirect calorimetry was performed during cycle ergometry exercise and for 3 hours following each of the following three protocols administered in random order: 1) low intensity exercise (LIE: 500 calories 50% VO2 max), 2) high intensity exercise (HIE: 500 calories 75% VO2 max), and 3) control condition (C) of quiet sitting for 1 hour, rather than exercise. Excess postexercise oxygen consumption (EPOC), energy expenditure and total fat and carbohydrate oxidation for the entire exercise/control plus 3-hour recovery period were determined by indirect calorimetry.
Mean EPOC for the 3-hour post-exercise period for HIE (9.0 +/- 1.7 L, 41 kcals) was significantly greater than EPOC for low intensity exercise (4.8 +/- 1.6 L, 22 kcals). Oxygen consumption (VO2) following HIE, but not LIE remained elevated at the end of the 3-hour post-exercise period. Total carbohydrate oxidation (exercise plus postexercise period) was significantly higher for HIE (116 +/- 8.6 g) compared to LIE (85.0 +/- 5.2 g). Total fat oxidation was lower for HIE (27.7 +/- 3.3 g) compared to LIE (36.9 +/- 3.0 g), but this difference did not reach statistical significance (p = 0.07). At the end of the 3-hour recovery period, the rate of fat oxidation was higher following HIE compared to LIE.
These data indicate that the recovery period should also be considered when determining the impact of different exercise intensities on total energy expenditure and fat and carbohydrate utilization in women.
The purpose of this study was to determine whether aerobic fitness level would influence measurements of excess postexercise oxygen consumption (EPOC) and initial rate of recovery. Twelve trained [Tr; peak oxygen consumption (VO2 peak) = 53.3 +/- 6.4 ml . kg-1 . min-1] and ten untrained (UT; VO2 peak = 37.4 +/- 3.2 ml . kg-1 . min-1) subjects completed two 30-min cycle ergometer tests on separate days in the morning, after a 12-h fast and an abstinence from vigorous activity of 24 h. Baseline metabolic rate was established during the last 10 min of a 30-min seated preexercise rest period. Exercise workloads were manipulated so that they elicited the same relative, 70% VO2 peak (W70%), or the same absolute, 1.5 l/min oxygen uptake (VO2) (W1.5), intensity for all subjects, respectively. Recovery VO2, heart rate (HR), and respiratory exchange ratio (RER) were monitored in a seated position until baseline VO2 was reestablished. Under both exercise conditions, Tr had shorter EPOC duration (W70% = 40 +/- 15 min, W1.5 = 21 +/- 9 min) than UT (W70% = 50 +/- 14 min; W1.5 = 39 +/- 14 min), but EPOC magnitude (Tr: W70% = 3.2 +/- 1.0 liters O2, W1.5 = 1.5 +/- 0.6 liters O2; UT: W70% = 3.5 +/- 0.9 liters O2, W1.5 = 2.4 +/- 0.6 liters O2) was not different between groups. The similarity of Tr and UT EPOC accumulation in the W70% trial is attributed to the parallel decline in absolute VO2 during most of the initial recovery period. Tr subjects had faster relative decline during the fast-recovery phase, however, when a correction for their higher exercise VO2 was taken. Postexercise VO2 was lower for Tr group for nearly all of the W1.5 trial and particularly during the fast phase. Recovery HR kinetics were remarkably similar for both groups in W70%, but recovery was faster for Tr during W1.5. RER values were at or below baseline throughout much of the recovery period in both groups, with UT experiencing larger changes than Tr in both trials. These findings indicate that Tr individuals have faster regulation of postexercise metabolism when exercising at either the same relative or same absolute work rate.
Excess post-exercise oxygen consumption (EPOC) is normally not considered in determinations of the metabolic cost of activity. This approach overlooks an important energetic cost that an animal incurs as a result of activity. To examine the importance of EPOC, we determined how the energetic cost of locomotion was affected by activity of short duration and high intensity. Mice were run at maximum speed on a treadmill while enclosed in an open-flow respirometry system. After sprinting for 5, 15, 30, or 60 sec, each mouse was allowed to recover while remaining enclosed in the respirometry chamber. Exercise oxygen consumption (EOC), the volume of oxygen consumed during the exercise, increased linearly with sprint duration. EPOC was determined as the volume of oxygen consumed after exercise ended until rest was reached. EPOC volumes were found to be constant following 5-60 sec of activity and accounted for > or = 90% of the total metabolic cost. The average EPOC volume of all treatments was 0.76 +/- 0.456 ml O2.gm-1. The net cost of activity (Cact), which considers both EOC and EPOC, decreased as sprint duration increased and varied between 500 ml O2.g-1.km-1 for 5 sec to 30 ml O2.g-1.km-1 for 60 sec of activity. The values for Cact were 15 to 250 times higher than traditional estimates of locomotor costs. From these data, it can be concluded that (1) EPOC is not affected by short exercise durations; (2) EPOC is an important energetic consideration when exercise durations are short; and (3) the metabolic costs of brief, vigorous locomotion may be much higher than previously estimated.
Effect of weight training exercise and treadmill exercise on postexercise oxygen consumption. Med. Sci. Sports Exerc., Vol. 30, No. 4, pp. 518-522, 1998. To compare the effect of weight training (WT) and treadmill (TM) exercise on postexercise oxygen consumption (VO2), 15 males (mean +/- SD) age = 22.7 +/- 1.6 yr; height = 175.0 +/- 6.2 cm; mass = 82.0 +/- 14.3 kg) performed a 27-min bout of WT and a 27-min bout of TM exercise at matched rates of VO2. WT consisted of performing two circuits of eight exercises at 60% of each subject's one repetition maximum with a work/rest ratio of 45 s/60 s. Approximately 5 d after WT each subject walked or jogged on the TM at a pace that elicited an average VO2 matched with his mean value during WT. VO2 was measured continuously during exercise and the first 30 min into recovery and at 60 and 90 min into recovery. VO2 during WT (1.58 L.min-1) and TM exercise (1.55 L.min-1) were not significantly (P > 0.05) different; thus the two activities were matched for VO2. Total oxygen consumption during the first 30 min of recovery was significantly higher (P < 0.05) as a result of WT (19.0 L) compared with that during TM exercise (12.7 L). However, VO2 values at 60 (0.32 vs 0.29 L.min-1), and 90 min (0.33 vs 0.30 L.min-1) were not significantly different (P > 0.05) between WT and TM exercise, respectively. The results suggest that, during the first 30 min following exercise. WT elicits a greater elevated postexercise VO2 than TM exercise when the two activities are performed at matched VO2 and equal durations. Therefore, total energy expenditure as a consequence of WT will be underestimated if based on exercise VO2 only.
In this brief review we examine the effects of resistance training on energy expenditure. The components of daily energy expenditure are described, and methods of measuring daily energy expenditure are discussed. Cross-sectional and exercise intervention studies are examined with respect to their effects on resting metabolic rate, physical activity energy expenditure, postexercise oxygen consumption, and substrate oxidation in younger and older individuals. Evidence is presented to suggest that although resistance training may elevate resting metabolic rate, it does not substantially enhance daily energy expenditure in free-living individuals. Several studies indicate that intense resistance exercise increases postexercise oxygen consumption and shifts substrate oxidation toward a greater reliance on fat oxidation. Preliminary evidence suggests that although resistance training increases muscular strength and endurance, its effects on energy balance and regulation of body weight appear to be primarily mediated by its effects on body composition (e.g., increasing fat-free mass) rather than by the direct energy costs of the resistance exercise.
This study involved examining how splitting a 30-min exercise bout on a cycle ergometer into two equal sessions affects excess postexercise oxygen consumption (EPOC) and resting metabolic rate (RMR). In this study, 10 male volunteers (age = 23+/-3.8) participated in two exercise trials, which were randomly assigned in a counterbalanced design and separated by 40 hr. One trial was 30 min of exercise at 70% VO(2)max (CONT), followed by a 40-min measurement of EPOC. The second trial was divided into two 15-min sessions (SPLIT), separated by 6 hr. A 20-min measurement of EPOC followed each SPLIT session. Results indicated that the combined magnitude of EPOCs from SPLIT (7,410+/-1,851 ml) was significantly greater than that from CONT (5,278+/-1305 ml). Data indicate that dividing a 30-min exercise session in to two parts for these individuals significantly increases magnitude of EPOC but does not affect RMR.
The effects of the menstrual cycle on excess postexercise oxygen consumption (EPOC) were studied in seven healthy young women aged 18 to 20 years. EPOC, resting metabolic rate (RMR), and energy expenditure during exercise (EEDE) in the fasting state were measured in the follicular and luteal phases. On the experimental days, subjects exercised for 60 minutes on a bicycle ergometer at an intensity of 60% maximal oxygen consumption (VO2max) followed by rest for 6 hours. The EPOC and RMR were significantly higher (P < .05) and the postexercise respiratory exchange ratio (RER) was significantly lower (P < .05) in the luteal phase versus the follicular phase, whereas differences in the EEDE and basal and exercise RER were negligible in both phases. Fat oxidation during the experimental period was significantly greater in the luteal phase (P < .05). These results suggest that exercise in the luteal phase results in greater postexercise energy expenditure and fat utilization than in the follicular phase.
This study determined the effect of an intense bout of resistive exercise on postexercise oxygen consumption, resting metabolic rate, and resting fat oxidation in young women (N=7, ages 22-35). On the morning of Day 1, resting metabolic rate (RMR) was measured by indirect calorimetry. At 13:00 hr, preexercise resting oxygen consumption was measured followed by 100 min of resistive exercise. Postexercise oxygen consumption was then measured for a 3-hr recovery period. On the following morning (Day 2), RMR was once again measured in a fasted state at 07:00. Postexercise oxygen consumption remained elevated during the entire 3-hr postexercise recovery period compared to the pre-exercise baseline. Resting metabolic rate was increased by 4.2% (p<.05) from Day 1 (morning prior to exercise: 1,419 +/- 58 kcal/24hr) compared to Day 2 (16 hr following exercise: 1,479 +/- kcal/24hr). Resting fat oxidation as determined by the respiratory exchange ratio was also significantly elevated on Day 2 compared to Day 1. These results indicate that among young women, acute strenuous resistance exercise of the nature used in this study is capable of producing modest but prolonged elevations of postexercise metabolic rate and possibly fat oxidation.
This study investigated the acute effects of 45 min of resistance exercise (RE) on excess postexercise oxygen consumption (EPOC) and substrate oxidation 120 min after exercise in moderately trained women.
Ten RE trained women (age = 29 +/- 3 yr; ht = 168 +/- 8.3 cm; wt = 59 +/- 5.7 kg; VO2max = 38.3 +/- 4.7 mL.kg-1.min-1) underwent two trials: control sitting and RE. Subjects acted as their own controls in a random counterbalanced design. A 2-d nonexercise period was established between testing trials. Oxygen consumption (VO2) and respiratory exchange ratio (RER) were measured continuously by indirect calorimetry before, during, and after exercise and on a separate control day. RE consisted of 3 sets of 10 exercises at 10-repetition maximum with a 1-min rest period between each set. Fingertip samples of blood lactate concentration [BL] were collected immediately postexercise and every 30 min thereafter until [BL] returned to resting baseline values after exercise.
The overall 2-h EPOC was 6.2-L (RE = 33.4 +/- 5.1 L vs control = 27.2 +/- 0.3 L), corresponding to an 18.6% elevation over the control period. RER was significantly (P < 0.01) below the control RER from minute 30 to minute 120 postexercise (RE = 0.75 +/- 0.01 vs control = 0.85 +/- 0.01). During the last 30 min of recovery, VO2 and [BL] had returned to control/baseline values and fat oxidation was significantly (P < 0.0001) higher (29.2 vs 16.3 kcal) after RE compared with the control trial.
These data indicate that in young RE trained women, acute RE produces a modest increase in VO2 during a 2-h recovery period and an increase in fat oxidation.
The purpose of this investigation was to examine the effect of interval (INT) and continuous (CON) cycle exercise on excess post-exercise oxygen consumption (EPOC). Twelve males first completed a graded exercise test for VO2max and then the two exercise challenges in random order on separate days approximately 1 wk apart. The INT challenge consisted of seven 2 min work intervals at 90% VO2max, each followed by 3 min of relief at 30% VO2max. The CON exercise consisted of 30 to 32 min of continuous cycling at 65% VO2max. Gas exchange and heart rate (HR) were measured for 30 min before, during, and for 2 h post-exercise. Three methods were used to analyze post-exercise oxygen consumption and all produced similar results. There were no significant differences in either the magnitude or duration of EPOC between the CON and INT protocols. HR, however, was higher (P < 0.05) while respiratory exchange ratio (RER) was lower (P < 0.05) following INT. These results indicate that when total work was similar, the magnitude and duration of EPOC were similar following CON or INT exercise. The differences in HR and RER during recovery suggest differential physiological responses to the exercise challenges.
The purpose of the study was to evaluate the effects of circuit training (CT) and treadmill exercise performed at matched rates of oxygen consumption and exercise duration on elevated post-exercise oxygen consumption (EPOC) in untrained women, while controlling for the menstrual cycle. Eight, untrained females (31.3±9.1 years; 2.04±0.26 l min−1 estimated VO2max; BMI=24.6±3.9 kg/m2) volunteered to participate in the study. Testing was performed during the early follicular phase for each subject to minimize hormonal variability between tests. Subjects performed two exercise sessions approximately 28 days apart. Resting, supine energy expenditure was measured for 30 min preceding exercise and for 1 h after completion of exercise. Respiratory gas exchange data were collected continuously during rest and exercise periods via indirect calorimetry. CT consisted of three sets of eight common resistance exercises. Pre-exercise and exercise oxygen consumption was not different between testing days (P>0.05). Thus, exercise conditions were appropriately matched. Analysis of EPOC data revealed that CT resulted in a significantly higher (p<0.05) oxygen uptake during the first 30 min of recovery (0.27±0.01 l min−1 vs 0.23±0.01 l min−1); though, at 60 min, treatment differences were not present. Mean VO2 remained significantly higher (0.231±0.01 l min−1) than pre-exercise measures (0.193±0.01 l min−1) throughout the 60-min EPOC period (p<0.05). Heart rate, RPE, V
E and RER were all significantly greater during CT (p<0.05). When exercise VO2 and exercise duration were matched, CT was associated with a greater metabolic disturbance and cost during the early phases of EPOC.
In 1995 the American College of Sports Medicine and the Centers for Disease Control and Prevention published national guidelines on Physical Activity and Public Health. The Committee on Exercise and Cardiac Rehabilitation of the American Heart Association endorsed and supported these recommendations. The purpose of the present report is to update and clarify the 1995 recommendations on the types and amounts of physical activity needed by healthy adults to improve and maintain health. Development of this document was by an expert panel of scientists, including physicians, epidemiologists, exercise scientists, and public health specialists. This panel reviewed advances in pertinent physiologic, epidemiologic, and clinical scientific data, including primary research articles and reviews published since the original recommendation was issued in 1995. Issues considered by the panel included new scientific evidence relating physical activity to health, physical activity recommendations by various organizations in the interim, and communications issues. Key points related to updating the physical activity recommendation were outlined and writing groups were formed. A draft manuscript was prepared and circulated for review to the expert panel as well as to outside experts. Comments were integrated into the final recommendation. PRIMARY RECOMMENDATION: To promote and maintain health, all healthy adults aged 18 to 65 yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. [I (A)] Combinations of moderate- and vigorous-intensity activity can be performed to meet this recommendation. [IIa (B)] For example, a person can meet the recommendation by walking briskly for 30 min twice during the week and then jogging for 20 min on two other days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by performing bouts each lasting 10 or more minutes. [I (B)] Vigorous-intensity activity is exemplified by jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every adult should perform activities that maintain or increase muscular strength and endurance a minimum of two days each week. [IIa (A)] Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity. [I (A)].
Perceived exertion as an indicator of somatic stress.
- Borg
Yoshioka, M, Doucet, E, St-Pierre, S, Almeras, N, Richard, D, Labrie, A, Despres, JP, Bouchard, C, and Tremblay, A. Impact of high-intensity exercise on energy expenditure, lipid oxidation and body fatness.
Baker, EJ and Gleeson, TT. EPOC and the energetics of brief locomotor activity in Mus domesticus.
Burleson, MA, OBryant, HS, Stone, MH, Collins, MA, and Triplett-McBride, T. Effect of weight training exercise and treadmill exercise on post-exercise oxygen consumption.
Haltom, RW, Kraemer, RR, Sloan, RA, Hebert, EP, Frank, K, and Tryniecki, JL. Circuit weight training and its effects on excess postexercise oxygen consumption.
Haskell, WL, Lee, IM, Pate, RR, Powell, KE, Blair, SN, Franklin, BA, Macera, CA, Heath, GW, Thompson, PD, and Bauman, A. Physical activity and public health: Updated Recommendation for Adults from the American College of Sports Medicine and the American Heart Association.