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Effects of Sit Up Exercise Training On Adipose Cell Size and Adiposity
Abstract
The present experiment evaluated the effects of a 27-day sit up exercise training program on adipose cell size and adiposity. Fat biopsies were taken from the abdomen, subscapular, and gluteal sites by needle aspiration in 13 experimental and 6 control male subjects before and after a five days/week progressive training regimen. Day 1 consisted of 10 bouts of 10-sec exercise, 7 sit ups/bout, with 10-sec rest intervals; on day 27, 14 bouts of 30-sec exercise were performed, 24 sit ups/bout with 10-sec rest intervals. The total number of sit ups done was 5004. Fat cells were isolated using collagenase and photographed to determine cell diameter. Repeated measures ANOVA revealed significant decreases in cell diameter at the three biopsy sites (p<.01), but no significant differences in the rate of change (pre to post) in cell diameter between sites for the experimental and control groups (p>.05). Body weight, total body fat (underwater weighing), and fatfolds and girths remained unaltered. The results demonstrate that (1) the conventional sit up exercise does not preferentially reduce adipose cell size or subcutaneous fat thickness in the abdominal region to a greater extent compared to other adipose sites, and (2) significant changes in fat cell size may occur in the absence of changes in fatfolds, girths or total body composition.
... The majority of investigations (N = 5) examining spot reduction (N = 8) have concluded that it does not occur (2,9,11,20,21). In contrast, Mohr (12), Olsen and Edelstein (16), and Noland and Kearney (15) report that spot reduction occurred as a result of exercise training. These investigators (12,15,16) used samples ranging between 32 and 56 subjects. ...
... These investigators (12,15,16) used samples ranging between 32 and 56 subjects. Sample sizes ranged between 10 and 22 subjects for those reporting a generalized loss of subcutaneous fat (2,9,11,20,21) or those reporting that spot reduction did not occur as a result of exercise training, suggesting that the sample sizes in these studies may not have been sufficient to detect significant changes in subcutaneous fat. The specific area of the body examined also differed greatly among these studies and included subcutaneous fat over the triceps (16,20), forearms (2), thigh (11), and abdomen (9,12,15,21). ...
... Sample sizes ranged between 10 and 22 subjects for those reporting a generalized loss of subcutaneous fat (2,9,11,20,21) or those reporting that spot reduction did not occur as a result of exercise training, suggesting that the sample sizes in these studies may not have been sufficient to detect significant changes in subcutaneous fat. The specific area of the body examined also differed greatly among these studies and included subcutaneous fat over the triceps (16,20), forearms (2), thigh (11), and abdomen (9,12,15,21). Another factor accounting for the discrepancies among studies examining the concept of spot reduction is that the exercise modality used to train subjects (i.e., tennis, calisthenics, sit-ups, and resistance training (2,9,11,20,21)) varied considerably. ...
It is believed spot reduction, the exercise-induced localized loss of subcutaneous fat, does not occur as a result of an exercise program; however, evidence as a whole has been inconsistent. To reexamine this concept, we compared subcutaneous fat measurements before and after resistance training among 104 subjects (45 men, 59 women).
Subjects participated in 12 wk of supervised resistance training of their nondominant arm. Magnetic resonance imaging and skinfold calipers examined subcutaneous fat in the nondominant (trained) and dominant (untrained) arms before and after resistance training. Repeated-measures ANCOVA tested for subcutaneous fat differences within and between arms before, after, and from before to after resistance training by gender and measurement technique, with BMI and age as covariates. Simple linear regression compared subcutaneous fat changes before and after resistance training as assessed by MRI and skinfold.
Subcutaneous fat, measured by skinfold, decreased in the trained arm and not the untrained arm in the men (P < 0.01); it was similar in the total sample and in the women (P > 0.05). MRI determinations of subcutaneous fat changes were not different between arms in the total sample and by gender (P > 0.05).
Subcutaneous fat changes resulting from resistance training varied by gender and assessment technique. Skinfold findings indicate that spot reduction occurred in men but not in women. In contrast, MRI found a generalized subcutaneous fat loss independent of gender, supporting the notion that spot reduction does not occur as a result of resistance training. MRI, sensitive to changes along the entire upper arm, detected greater variation in resistance training responses, preventing significant differences between trained and untrained arms. Variation in upper-arm resistance training response was not evident from a single skinfold measurement at the belly of the muscle.
... However, it is unclear if this modality relying on anaerobic energy systems such as high-energy phosphate bonds or stored muscle glycogen breakdown for fuel (McArdle et al., 2008b) is optimal to evaluate exercise-induced adipose tissue utilization. Some studies have also applied strength training of relatively small muscle mass (Katch et al., 1984;Kostek et al., 2007), or elected to measure subcutaneous tissue changes with caliper (Gwinup et al., 1971;Kostek et al., 2007;Mohr, 1965;Olson & Edelstein, 1968), which is shown to agree poorly with DEXA and magnetic resonance imaging (MRI; Treuth, Hunter, et al., 1985;Treuth, Ryan, et al., 1985). Others have simply neglected to account for total energy expenditure during training (Carns et al., 1960;Schade et al., 1962). ...
... This may be part of the explanation, given that findings from studies applying strength training, with varying degrees of volume, to examine this concept vary quite considerably. While some strength training studies utilizing intraindividual designs suggest spot reduction may occur (Mohr, 1965;Olson & Edelstein, 1968), possibly due to reduced fat cell size (Katch et al., 1984;Krotkiewski et al., 1979), others have rebuffed this notion (Kostek et al., 2007). ...
The existence of spot reduction, exercise‐induced local body fat reduction, has been debated for half a century. Although the evidence is equivocal, no study has applied aerobic endurance training closely matching interventions for energy expenditure. Sixteen overweight (BMI: 29.8 ± 3.3(SD) kg m ⁻² ) males (43 ± 9 years) were randomized to: (1) abdominal endurance exercise (AG), combining treadmill running at 70% HR max (27 min) with 4 × 4 min (30%–40% maximal strength, 1RM) of torso rotation and abdominal crunches (57 min), 4 days⋅week ⁻¹ for 10 weeks; or (2) control group (CG) performing only treadmill running (45 min) at 70% HR max . Local fat mass was measured by dual‐energy x‐ray absorptiometry (DEXA), along with 1RM, and pulmonary oxygen uptake (to control energy expenditure during training). Trunk fat mass decreased more (697 g, 3%, p < 0.05) in AG (1170 ± 1093 g, 7%; p < 0.05) than in CG (no change). Total fat mass (AG: 1705 ± 1179 g, 6%; CG: 1134 ± 731 g, 5%; both p < 0.01) and body weight (AG: 1.2 ± 1.2 kg, 1%, p < 0.05; CG: 2.3 ± 0.9 kg, 3%, p < 0.01) decreased similarly in AG/CG. Torso rotation (AG: 32 ± 16 kg, 39%, p < 0.01; CG: no change) and abdominal crunch 1RM (AG: 35 ± 16 kg, 36%, p < 0.01; CG: 13 ± 12 kg, 17%, p < 0.05) increased more ( p < 0.05/0.01) in AG than CG. Abdominal endurance exercise utilized more local fat than treadmill running, indicating that spot reduction exists in adult males.
... Abdominal exercises are helpful for strengthening the abdominal muscles.They are known to increase the strength and endurance of the abdominal muscles [13].They are frequently recommended as successful means to lessen abdominal fat and reduce the waistline.It has been highly disputed whether or not abdominal exercises have any reducing effects on abdominal fat. Fat cell size of adipose tissue was investigatedto determine the efficacy of abdominal exercises on subcutaneous fattissue [14]. The researchers demonstrated that progressive abdominal exercises canproduce a perceptible decrease in the size of the fat cell within the abdominalarea.On the other hand, it was reported that abdominal exercise training alone is not adequate to decrease abdominal fat and circumference and it is important to incorporate aerobic exercises to gain more beneficial effects on abdominal obesity [13]. ...
... Additionally, Katch et al [14] investigated the efficacy of abdominal training on subcutaneous fat. After randomly assigning 19 young Caucasian men into two groups (exercise &control groups) for four weeks, the investigators showed that a progressive sit-up exercise program is effectivein reducing the size of the fat cells in the abdominal, subscapular, and gluteal region. ...
Background: Obesity is a medical condition that may adversely affect wellbeing and leading to increased incidence of many health problems. Abdominal obesity tends to be associated with weight gain and obesity and it is significantly connected with different disorders like coronary heart disease and type II diabetes mellitus.This study was conducted to investigate the efficacy of vacuum therapy as compared to abdominal exercises on abdominal obesity in overweight and obese women.
Methods: Thirtyoverweight and obese women participated in this study with body mass index > 25 kg/m2andwaist circumference ≥ 85 cm. Their ages ranged from 28 - 40 years old.The subjects were excluded if they have diabetes, abdominal infection diseases or any physical limitation restricting exercise ability. They were randomly allocated into two equal groups; group I and group II. Group I received vacuum therapy sessions (by the use of LPG device) in addition to aerobic exercise training. Group II received abdominal exercises in addition to the same aerobic exercisesgiven to group I. This study was extended for successive 8 weeks (3 sessions/ week). All subjects were assessed for thickness ofnthe abdominal skin fold, waist circumference and body mass index.
Results: The results of this study showeda significant difference between group I and group II post-interventionas regarding to the mean values of waist circumference and abdominal skin fold thickness (p
... There is little theoretical basis for weight loss to affect fats in a targeted and especially localized way. Katch et al [54] refuted this hypothesis. They demonstrated that if enough exercise is done to achieve fat loss, it will come from the whole body and not from one part of the body specifically exercised. ...
Summary
The management of obesity essentially involves two aspects. The decrease of energy intake and increased energy expenditure. Regular physical activity contributes to the increase of energy expenditure and negative energy balance. Reducing weight and fat mass is supported by regular physical exercise. Likewise, maintaining weight and reducing fat is strongly linked to the continuity of physical activity. The management of obesity must integrate appropriate physical rehabilitation programs aimed not only at but also at metabolism. For this purpose, endurance training appears to be the most effective physical activity, although resistance training and high-intensity interval training play distinct roles. Physical activity is an essential tool, but it is often underestimated, in the management of obesity. The goal of this study is to highlight the evidence for the effectiveness of physical exercise in the management of obesity. The effects of exercise on the loss and stabilization of body weight and fat are going to be discussed. We will also deal with the effects on the metabolic factors linked to obesity in the second part. At the end of this article, mistakes not to commit in order to avoid exercise-related adverse effects will be discussed.
Keywords: Energy balance; physical activity; obesity; weight loss; endurance
... Moreover, the PEDro scale is probably one of the most frequently used scales in the literature, helping to make comparisons between meta-analyses. According to cut-off scores, the methodological quality was rated as 'poor' (<4), 'fair' (4)(5), 'good' (6)(7)(8) and 'excellent' (9)(10) in some subfields, however, it is not possible to satisfy all scale items in some areas of physiotherapy practice [53]. ...
Background: The notion that specific exercises reduce localized adipose tissue depots (i.e., targeted fat loss) and modify fat distribution is commonly termed spot reduction. According to this long-held popular belief, exercising a limb would lead to greater reduction in the adjacent adipose tissue in comparison to the contralateral limb. Aside from popular wisdom, scientific evidence from the 20th and 21th century seems to offer inconclusive results. Objective: To summarize the peer-reviewed literature assessing the effects of unilateral limb training, compared to the contralateral limb, on the localized adipose tissue depots on healthy participants, and to meta-analyse its results. Methods: We followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We searched PubMed, Web of Science, and SCOPUS electronic databases, using several relevant keywords combinations. Independent experts were contacted to help identify additional relevant articles. Following a PICOS approach, we included controlled studies that incorporated a localized exercise intervention (i.e., single-limb training) to cohorts of healthy participants (i.e., no restriction for fitness, age, or sex), compared to a control condition (i.e., contralateral limb), where the main outcome was the pre-to-post intervention change of localized fat. The methodological quality of the studies was assessed using the Physiotherapy Evidence Database scale. Pre- and post-intervention mean ± standard deviation for fat-related outcome from the trained and control groups (limbs) were converted to Hedges’ g effect size (ES; with 95% confidence intervals [CI]), using a random-effects model. The impact of heterogeneity was assessed using the I2 statistic. The risk of reporting bias was explored using the extended Egger’s test. The statistical significance threshold was set at p < 0.05. Results: From 1,833 search records initially identified, 13 were included in the meta-analysis, involving 1,158 male and female participants (age, 14-71 years). The 13 studies achieved a high methodological quality, and results with low heterogeneity (I2 = 24.3%) and no bias (Egger’s test p = 0.133). The meta-analysis involved 37 comparisons, with 17 of these favouring (i.e., greater reduction of localized fat) the trained limb, and 20 favouring the untrained limb, but the ES ranged between -1.21 to 1.07. The effects were consistent, with a pooled ES = -0.03, 95% CI -0.10 to 0.05, p = 0.508, meaning that spot reduction was not observed. Conclusion: Localized muscle training has no effect on localized adipose tissue depots, i.e., no spot reduction, regardless of the characteristics of the population and of the exercise program. The popular belief on spot reduction is probably derived from wishful thinking, and convenient marketing strategies, such as influencers seeking increased popularity and procedures’ sellers interested in increasing advertising.
... [19], hypothesized that exercise on specific muscles may induce "spot lipolysis" via an increased blood flow and release of fatty acids in the SAT nearby the contracting muscle regardless of exercise intensity. However, most of the studies found conflicting conclusions: some authors found a positive effect of spot reduction on localized lipolysis [20][21][22], while others were inconclusive [23][24][25][26]. The discrepancy between results can be found on the several exercise modalities employed, on the different body areas examined and, on the technique used for measuring SAT [27]. ...
Accumulation of adipose tissue in specific body areas is related to many physiological and hormonal variables. Spot reduction (SR) is a training protocol aimed to stimulate lipolysis locally, even though this training protocol has not been extensively studied in recent years. Thus, the present study sought to investigate the effect of a circuit-training SR on subcutaneous adipose tissue in healthy adults.
Methods:
Fourteen volunteers were randomly assigned to spot reduction (SR) or to a traditional resistance training (RT) protocol. Body composition via bioimpedance analysis (BIA) and subcutaneous adipose tissue via skinfold and ultrasound were measured before and after eight weeks of training.
Results:
SR significantly reduced body mass (p < 0.05) and subcutaneous abdominal adipose tissue (p < 0.05).
Conclusions:
circuit-training SR may be an efficient strategy to reduce in a localized manner abdominal subcutaneous fat tissue depot.
... In addition, studies that tested this hypothesis, such as by Katch and coworkers [71], have refuted it. If one performs sufficient exercise to achieve fat loss, it will come from all over the body, regardless of which parts of it are involved in the exercise. ...
Obesity is a multifactorial disease with increasing incidence and burden on societies worldwide. Obesity can be managed through everyday behavioral changes involving energy intake and energy expenditure. Concerning the latter, there is strong evidence that regular exercise contributes to body weight and fat loss, maintenance of body weight and fat reduction, and metabolic fitness in obesity. Appropriate exercise programs should ideally combine large negative energy balance, long-term adherence, and beneficial effects on health and well-being. Endurance training appears to be the most effective in this respect, although resistance training and high-intensity interval training play distinct roles in the effectiveness of exercise interventions. With weight regain being so common, weight loss maintenance is probably the greatest challenge in the successful treatment of obesity. There is an established association between higher levels of physical activity and greater weight loss maintenance, based on the abundance of evidence from prospective observational studies and retrospective analyses. However, proving a causative relationship between exercise and weight loss maintenance is difficult at present. Exercise has the potential to alleviate the health consequences of obesity, even in the absence of weight loss. All in all, exercise constitutes an indispensable, yet often underestimated, tool in the management of obesity.
... A study done by Frank I. Katch et al reported that the conventional sit up exercises does not preferentially reduce adipose cell size or subcutaneous fat thickness in the abdominal region to a greater extent compared to other adipose sites and significant changes in fat cell size may occur in the absence of changes in fatfolds, girths or total body composition [11]. ...
Background: With urbanization and development there is reduction in physical activity. According to statistics, about 10-20% of children in India are obese. This number increases to upto 30% among adolescents. About 2/3rd of children with obesity continue to be obese in adult life. A number of physical health problems are associated with obesity.
Purpose: To evaluate and compare the effect of 30 days abdominals challenge versus 30 days planks challenge on waist circumference and abdominal skin fold measurements in healthy young individuals.
Materials and Methods: 60 subjects aged between 18 to 30years were included. The subjects were conveniently selected and then divided into 2 groups: 30 days Abdominals challenge and 30 days Planks challenge.Demographic data and waist circumference, hip circumference, waist hip ratio and skin fold measurement at the abdominals was noted pre and post the intervention. Subjects had to follow a set protocol with respective rest periods in between for 30 days.
Results: Post intervention a mean difference of 2.58 ± 1.87 was seen in the waist circumference in the Abdominals group whereas a mean difference of 1.88 ± 1.39 was noted in the waist circumference in the Planks group. The abdominal skin fold measurements showed a mean difference of 5.10 ± 3.32 in the Abdominals group while a mean difference of 4.14 ± 3.14 was seen in the Planks group. There was no statistical significance found between both the groups with p value more than 0.0001.
Conclusion: The 30 days Abdominals challenge and 30 days Planks challenge are equally effective in reduction of waist circumference and abdominal skin fold measurements.
... Abdominal exercises are recommended to patients to reduce waist circumference and abdominal fat. Katch et al. [34] reported that the size of fat cells in abdominal, subscapular and gluteal regions is decreased via progressive 4-week exercise program. Another study revealed that abdominal exercise training was effective in increasing abdominal strength but it was not effective in reducing abdominal fat [35]. ...
Abdominal muscle strength decreases and fat ratio in the waist region increases following cesarean section. Kinesio taping (KT) is an easily applicable method and stimulates muscle activation. The aim of this pilot randomized controlled trial (RCT) was to investigate the effects of KT combined with exercise in women with cesarean section on abdominal recovery compared to the exercise alone.
Twenty-four women in between the fourth and sixth postnatal months who had cesarean section were randomly assigned to KT + exercise (n = 12) group or exercise group (n = 12). KT was applied twice a week for 4 weeks on rectus abdominis, oblique abdominal muscles and cesarean incision. All women were instructed to carry out posterior pelvic tilt, core stabilization and abdominal correction exercises. Outcome measures were evaluated with the manual muscle test, sit-up test, abdominal endurance test, Visual Analog Scale (VAS), circumference measurements and Roland Morris Disability Questionnaire (RMDQ). Mann-Whitney U and Wilcoxon tests were used to analyze data. p < 0.05 was considered as statistically significant.
The improvement observed in the KT + exercise group was significantly greater compared to the exercise group in terms of the strength of the rectus abdominis muscle, sit-up test, VAS, measurements of the waist circumference and RMDQ (p < 0.05).
It appears that the addition of KT to abdominal exercises in the postnatal physiotherapy program provides greater benefit for the abdominal recovery in women with cesarean section. Further studies with larger sample sizes and long-term follow-up are needed to verify these results.
... 34 Spot reduction of fat from a specific area being exercised is not effective. 35 ...
... It could be speculated that one mechanism by which endurance exercise reduced RBP4 expression in visceral fat tissue might be related to the reduced adipocyte size and fat mass, which was not measured in the present study. Consistent with our suggestion, previous studies showed that weight loss and exercise led to reduced adipocyte size, which in turn is an important determinant for the secretion of several adipokines [25][26][27] . ...
Aims/IntroductionThe present study was designed to investigate from which tissues the decrease in retinol-binding protein 4 (RBP4) expression could contribute to the improvement of serum RBP4 and insulin resistance (IR) after endurance training. Materials and Methods
Male 7-week-old Wistar rats were randomly assigned into four groups including control (C), trained (T), diabetic control (DC) and trained diabetic (TD). At 8 weeks-of-age, diabetes was induced by a high-fat diet and intraperitoneal injection of low-dose streptozotocin (STZ; 35 mg/kg). Rats in the T and TD groups carried out a 7-week exercise program on a motorized treadmill (15–20 m/min for 20 min/day for 5 weeks), whereas the C and DC remained sedentary in their cages. Tissues gene expression and protein levels of RBP4 were assessed by using real-time polymerase chain reaction and western blot, respectively, while serum RBP4 was measured using an enzyme-linked immunosorbent assay kit. ResultsExercise significantly improved IR and reduced serum concentration of RBP4 in the TD group. This reduction of serum RBP4 was accompanied by decreased RBP4 protein expression in visceral fat tissue. In contrast, exercise had no significant effect on RBP4 expression in liver and subcutaneous fat tissue in the TD group. Exercise also significantly decreased RBP4 gene expression in visceral fat tissue and muscle, whereas the effect of exercise on liver RBP4 messenger ribonucleic acid expression was not significant. Conclusions
The present study showed that the mechanism for RBP4 reducing the effect of endurance training could involve decreased RBP4 messenger ribonucleic acid expression and its protein level in adipose tissue in STZ-induced diabetic rats.
... Several studies have evaluated the effects of specific localized exercise on whole-body and regional tissue composition, with contradicting results. Some studies have reported that after exercise intervention, localized mobilization of subcutaneous fat may be observed (15,18,19,21), whereas others have not found these changes (6,9,10,12,17,23). The conflicting results may be accounted for by the methodology used in the studies cited. ...
The purpose of this study was to examine the effects of a localized muscle endurance resistance training program on total body and regional tissue composition. Seven men and four women (23±1 years of age) trained with their non-dominant leg during 12 weeks, three sessions per week. Each session consisted of 1 set of 960-1,200 rep (leg press exercise), at 10-30% 1RM. Before and after training, body mass, bone mass, bone mineral density, lean mass, fat mass and fat percentage were determined by dual-emission X-ray absorptiometry. Energy intakes were registered, by using a food recall questionnaire. At the whole body level, body mass, bone mass, bone mineral density, lean mass or body fat percentage were not significantly changed. However, body fat mass significantly decreased by 5.1% (pre 13.5±6.3 kg, post 12.8±5.4 kg; P<0.05). No significant changes in bone mass, lean mass, fat mass or fat percentage were observed in both the control and trained leg. A significant (P<0.05) decrease in fat mass was observed in the upper extremities and trunk (10.2 and 6.9%, respectively, P<0.05). The reduction of fat mass in the upper extremities and trunk was significantly greater (P<0.05) than the fat mass change observed in the trained leg, but not vs. the control leg. No significant changes were observed in energy intake pre and post exercise intervention (2,646±444 kcal•day and 2,677±617 kcal•day, respectively). In conclusion, the training program was effective in reducing fat mass, but this reduction was not achieved in the trained body segment. The present results expand the limited knowledge available about the plastic heterogeneity of regional body tissues when a localized resistance training program is applied.
Background:
The present study tested the possibility of a localized fat mass (FM) reduction by means of training programmes focusing on specific bodily regions.
Methods:
Sixteen physically inactive women (age: 31±4; BMI: 27.5±2.1), randomly allocated to two groups, completed an 8 week training programme. In one group (UpBdResist) training sessions consisted of upper body resistance exercises followed by 30-minute cycling at 50%VO2max, while the other group (LwBdResist) performed lower body resistance exercises followed by 30 minutes on an arm-ergometer. Regional body composition was assessed by DEXA and skin fold measures.
Results:
Regardless of a similar reduction in both groups, UpBdResist training elicited a greater reduction of the upper limbs (UL) FM as compared to the lower limbs (LL) (Δ% UL vs. LL: -12.1±3.4 vs. -4.0±4.7; P=0.02). Conversely, in the LwBdResist group, FM loss was more pronounced in the LL as compared to the UL (Δ% UL vs. LL: -2.3±7.0 vs. -11.5±8.2, P=0.02). Likewise, LwBdResist elicited a larger effect on lean mass (LM) of the LL as compared to UL (Δ% LL vs. UL: +8.4±5.8 vs. -2.7±5.0, P<0.01), yet no differences between upper and lower limb LM changes were detected in UpBdResist group.
Conclusions:
The present data suggest that a training programme entailing localized explosive resistance exercise, prior to an endurance exercise bout, may target specific adipose tissue sites eliciting localised fat mass loss in the upper and lower limbs.
Objective: To determine the effects of a 15-week high-intensity intermittent exercise (HIIE) program on subcutaneous and trunk fat and insulin resistance of young women. Design and procedures: Subjects were randomly assigned to one of the three groups: HIIE (n ¼ 15), steady-state exercise (SSE; n ¼ 15) or control (CONT; n ¼ 15). HIIE and SSE groups underwent a 15-week exercise intervention. Subjects: Forty-five women with a mean BMI of 23.2 ± 2.0 kg m À2 and age of 20.2 ± 2.0 years. Results: Both exercise groups demonstrated a significant improvement (Po0.05) in cardiovascular fitness. However, only the HIIE group had a significant reduction in total body mass (TBM), fat mass (FM), trunk fat and fasting plasma insulin levels. There was significant fat loss (Po0.05) in legs compared to arms in the HIIE group only. Lean compared to overweight women lost less fat after HIIE. Decreases in leptin concentrations were negatively correlated with increases in VO 2peak (r ¼ À0.57, Po0.05) and positively correlated with decreases in TBM (r ¼ 0.47; Po0.0001). There was no significant change in adiponectin levels after training. Conclusions: HIIE three times per week for 15 weeks compared to the same frequency of SSE exercise was associated with significant reductions in total body fat, subcutaneous leg and trunk fat, and insulin resistance in young women.
To determine the effects of a 15-week high-intensity intermittent exercise (HIIE) program on subcutaneous and trunk fat and insulin resistance of young women.
Subjects were randomly assigned to one of the three groups: HIIE (n=15), steady-state exercise (SSE; n=15) or control (CONT; n=15). HIIE and SSE groups underwent a 15-week exercise intervention.
Forty-five women with a mean BMI of 23.2+/-2.0 kg m(-2) and age of 20.2+/-2.0 years.
Both exercise groups demonstrated a significant improvement (P<0.05) in cardiovascular fitness. However, only the HIIE group had a significant reduction in total body mass (TBM), fat mass (FM), trunk fat and fasting plasma insulin levels. There was significant fat loss (P<0.05) in legs compared to arms in the HIIE group only. Lean compared to overweight women lost less fat after HIIE. Decreases in leptin concentrations were negatively correlated with increases in VO(2peak) (r=-0.57, P<0.05) and positively correlated with decreases in TBM (r=0.47; P<0.0001). There was no significant change in adiponectin levels after training.
HIIE three times per week for 15 weeks compared to the same frequency of SSE exercise was associated with significant reductions in total body fat, subcutaneous leg and trunk fat, and insulin resistance in young women.
Two investigators assessed fat cell size from photographs using a digitizer apparatus, a Zeiss Particle Size Analyzer, and by hand measurement. Also, the photographic film was directly projected on the digitizer screen. The mean values derived from the four techniques did not differ by more than 5% and the reliability among techniques was high. The difference between investigators was significant for the Zeiss Particle Size Analyzer and digitizing from the photographs. Since the digitizer/film method is reliable, compares with other methods, reveals no investigator bias, and can rapidly measure numerous cells, it seems the most effective method.
The purpose of this study was to assess the role of exercise in reducing body weight in overweight college women and to compare the effect of two types of exercises, spot and generalized, on the physical contour of the overweight individual. The experimental program which included a uniform diet resulted in a slight but significant reduction of weight. Planimetric measurements of selected areas and linear transverse measures, obtained from preexercise and postexercise photographs, yielded evidence of reduction in body segments where fat accumulations had been most conspicuous, regardless of the type of exercise administered.
Eight severely obese patients with adipose tissue hypercellularity, elevated body cell mass, and a juvenile onset of obesity were subjected to physical training during 6 mo without dietary restrictions. The training program was of 35-min duration three times weekly and followed a fixed schedule individualized to the working ability of each subject, so that the heart rate was 10–15 beats below maximal during three 5-min periods of each training session. Body weight, body cell mass, and body fat showed no significant changes after 3 or 6 mo of training. Fasting plasma insulin decreased after 3 mo of training, but fasting blood glucose was not changed. After 6 mo plasma insulin values were still decreased. Now glucose tolerance had also improved, and plasma triglycerides showed a trend to lower values. The results suggest that the lack of body fat decrease after the long training period might be characteristic for subjects with the type of severe obesity studied, because in a previous study1 a similar, although lighter, training procedure produced a marked body fat decrease in patients without severe obesity.
One-leg exercise of 5 weeks duration in 10 healthy middleaged women resulted in a significant increment of muscle force in the exercising leg and in a less, but at some angular velocities also significant, increase in the nonexercising leg. The thickness of subcutaneous tissue measured by ultrasound and skinfold caliper decreased, while muscle thickness increased in the exercising leg only. The increased thickness of muscle tissue was associated with an increase in the relative number and relative fiber area of type II fibers in the exercising leg. The mean fiber area of type IIB fibers increased significantly as well as the activity of lactate dehydrogenase and myokinase. The decrease of thickness of subcutaneous adipose tissue was not associated with a significant decrease in fat cell size and was probably due to geometrical factors secondary to hypertrophy of the underlying muscle. It is concluded that the relationship between lean and fat components of the human thigh is significantly influenced by changes in the activity of the thigh skeletal muscles, but a local dynamic strength training program can hardly be used for local emptying of the fat depot over the exercising muscles.
Omental fat cells were 30% smaller than those in subcutaneous regions. In omental fat cells with a mean diameter of 95 mu, the basal cAMP concentration was 50% lower, but the basal rate of glycerol release was three times as rapid as in subcutaneous (epigastric) fat cells of identical size. Added at maximal effective concentration, noradrenaline increased the level of cAMP and the rate of glycerol release more markedly in the omental than in the subcutaneous adipocytes, whereas the response to isopropyl noradrenaline was similar. Before starvation the lipolytic effects of noradrenaline and isopropyl noradrenaline, respectively, were identical in the two regions of subcutaneous adipose tissue investigated (femoral and hypogastric). The findings were well related to the tissue levels of cAMP induced by the two agents. During starvation noradrenaline and isopropyl noradrenaline increased the cAMP level and the rate of lipolysis in fat cells obtained from the hypogastric region, whereas noradrenaline decreased these parameters in femoral adipocytes. Starvation was associated with a more prominent inhibitory effect of phenylephrine on basal and isopropyl-noradrenaline-induced lipolysis in femoral than in hypogastric adipose tissue. In conclusion, differences exist between different regions of adipose tissue in their lipolytic responsiveness to noradrenaline, which seems related to the balance between alpha- and beta-adrenergic receptor response.
The viability of the “spot reduction” hypothesis was evaluated by investigating the anthropometric and densitometric effects of two types of exercise programs in a 10-week study using 56 college women. The 27 women assigned to the localized exercise regimen performed calisthenic-type activities concentrated on the abdomen, hips, and thighs while the generalized exercise group (n = 29) participated in a variety of typical aerobic activities. Exercise sessions for both groups were conducted 3 days per week for 30 minutes. The intensity of exercise was equated on the basis of exercise pulse rates. A total of 12 skinfold, girth, densitometric, and derived variables were assessed before and after the experimental period. Application of multivariate and univariate ANOV As revealed significant pre- to posttest changes; however, there was not a significant difference between groups. Therefore, the results indicate that although either general aerobic or localized exercises are effective in altering the anthropometric and densitometric characteristics of females, neither exercise regimen was shown to be more effective.
Rat and human isolated adi-pocyte sizes were determined by both the measurement of their diameter on photomicrographs and by electronic counting of osmium-fixed cells. The average cell size was 0.348 and 0.353 μg of lipid/cell, respectively. The agreement between the two methods was excellent over a wide range of cell sizes (0.15-0.09 μg of lipid/cell). The photomicrographic method was applied to a morphological study of epididymal adipose tissue in Wistar rats fed a high-fat diet for either 1 or 10 months. The enlargement of the adipose depot induced by 1 month of the high-fat diet was achieved by an increase of fat cell size only. Ten months of high-fat feeding induced either a moderate obesity with only hypertrophy of the adipocytes or a severe obesity with apparent hyper-trophic-hyperplastic changes.
Twenty-eight obese women were divided after arbitrary statistical guidelines obtained from control studies into hyperplastic (increase in fat cell number) (n equal to 10), hypertrophic obesity (increase in average fat cell size) (n equal to 11), and a remaining group (n equal to 7). All these subjects were treated on an outpatient basis with an energy-reduced diet (1,100 kcal/day) until weight decrease failure occurred. The fat cells of the femoral and gluteal regions were larger than in the abdominal region in hypertrophic obese subjects. This regional fat cell size profile was found also in middle-aged and young controls. The hyperplastic obese subjects on the other hand had larger fat cells in the abdominal site. At failure of therapy enlarged fat cells in either of the two obesity groups had decreased to the size of fat cells of controls. Fat cell number remained unchanged. Thus the hypertrophic obese patients ended up with a normal body fat while hyperplastic obese subjects had a pronounced remaining obesity. The results suggest that when the fat cell size in different regions of an individual are known, as well as the total fat cell number, the success of an energy-reduced dietary regimen might be approximately predicted both in terms of remaining total body fat and in regional fat depot decrease.
The degree of filling of adipose tissue associated with a close caloric balance was examined by measuring adipose tissue fat cell size in three groups of weight-stabile, physically active men. These groups consisted of men who had survived a myocardial infarction and had reached weight-stability on a supervised physical training program during periods up to 18 months, a group of middle-aged active endurance athletes, and a group of young athletes. Appropriate controls for these three groups were the myocardial infarction patients before training, middle-aged randomly selected men, and young sedentary men, respectively.
The three sedentary groups had more body fat and larger fat cells than corresponding physically active men. Fat cell size in the gluteal region of the latter was found within a narrow range (0.2-0.5 µgm), apparently independent of age and body fat of these men. This small fat cell size was associated with low fasting plasma triglyceride and insulin values. Fasting blood glucose apparently did not follow this pattern. Cholesterol was low in the athletes, but not in the training myocardial infarction patients.
It was suggested that the degree of adipose tissue filling (fat cell size) may in certain connections be a more meaningful way to define obesity than the amount of body fat, because of its associations with carbohydrate and lipid metabolism.
This study was designed to determine if the skinfold measurements on an exercised arm would decrease as a result of regular weight training with that arm. Thirty-two subjects completed three sets of 7-RM curls and three sets of 7-RM triceps extensions on either a daily or an alternate day schedule for a period of 6 weeks. The nonexercised arm was measured to establish the specificity of the spot reduction on the exercised arm. The results indicate that hard exercise in a specific area of the arm will result in a reduction of the subcutaneous adipose tissue in that area.
Sit-up exercises performed by four male subjects revealed the presence of initial lumbar "hollowing" (lumbar curvature), or trunk hyperextension, or both prior to trunk flexion. Maximum muscular moment developed at the hip joint, which varied with sit-up exercise, was of moderate order of magnitude. Intraesophageal pressure, cardiopulmonary response, and metabolic response to a commonly used sit-up exercise (curl-up) reveals it to be a light exercise which stresses the muscles of the lower limbs as well as those of the trunk, especially the abdominal muscle group.
Regional adipose cell size was assessed in 18 males ranging in age from 20 to 36 years. These measures were correlated to total body fat determined by hydrostatic weighing. Adipose samples were removed from the gluteal, abdominal, and subscapular regions using a needle aspiration technique. The tissue was incubated in collagenase to release individual cells that were immediately photographed under a microscope. To establish the reliability of adipose cell size assessment over time, fat biopsies were secured on 2 separate days. No significant difference was found for any region between day 1 and 2 adipose cell measures. Gluteal cell diameter (90.3 mu) was significantly larger than the abdominal (81.0 mu) and subscapular (78.6 mu) cell diameter (90.3 mu) was significantly larger than the abdominal (81.0 mu) and subscapular (78.6 mu) cell diameters. Total body fat correlated highest with gluteal cell size (r = 0.76) compared with the abdominal (r = 0.67) or subscapular (r = 0.70) regions. This study also examined the number of adipose cells required to subscapular (r = 0.70) regions. This study also examined the number of adipose cells required to obtain a reliable and representative mean value of adipose cell size. Using a sequential estimation analysis it was found that adipose cell diameters of the abdominal, gluteal, or subscapular regions can be reliably estimated with fewer than 100 cells.
James S. Skinner and Thomas M. McLellan begin this section with a discussion of the transition from aerobic to anaerobic metabolism. Discrepancies are identified in activities being defined as anaerobic and the relative importance and meaning of lactate concentration in the blood. Skinner and McLellan propose a hypothetical model to more accurately explain anaerobic activities. The second article, by Frank Katch and Victor Katch, contains a review of sources of error in body composition assessment by laboratory and field methods. Katch and Katch describe problems occurring in the use of hydrostatic weighing, residual air volume, skinfolds, and circumferences. In addition, the importance of statistical considerations is stressed, with an emphasis on the proper use of multiple regression techniques in conducting studies of the measurement of body composition.
Thirty women, aged 18 through 45, living in Iowa City, Iowa, were the subjects for this study. Following a regime of six isometric abdominal contractions held for 6 sec. each, significant reductions were obtained in girth and subcutaneous fat at the waistline and the umbilical level of the abdomen. The exercises were done daily for a period of four weeks, with no additional abdominal or conditioning exercises, and no appreciable change in weight. These results represent some evidence to support the claims made by authors of articles in popular magazines and brochures on isometrics.