The effect of strength and resistance training on

changes in total fat, body mass index and serum

leptin as well as their correlation in obese sedentary

employees

Amir Falahnezhad Mojarad

and Nematolah Nemati

MA in Exercise Physiology

Assistant Professor, Islamic Azad University of Damghan Department of Physical Education, Faculty of

Human Sciences, Islamic Azad University of Damghan Damghan, Iran

ABSTRACT

This study aims to investigate the effect of strength and resistance training on changes in total fat, body mass index (BMI), and serum

leptin as well as correlation between serum leptin and BMI in obese sedentary employees. Research variables include total fat, serum

leptin, body mass index, and strength training protocol for a month and in 3 sessions per week, each session lasts for 84 minutes as

well as 60 to 70 percent of maximum heart rate. The strength training protocol lasts for one month and the weight training for 3 times

per week, 60 to 75% for 1 repetition maximum (1RM) and the total exercise lasts for 70 minutes per session. In this study, the research

method is experimental. 30 out of 110 obese employees are randomly selected as the statistical sample. The sample is categorized into

three groups, including control (n = 10), resistance (n = 10), and strength (n = 10). In pre-test, demographic and physical characteristics

of the sample are measured and recorded. In the post-test and after the course of the training protocol, the previous measurements are

repeated. Statistical methods to compare training groups in the test process include repeated measures ANOVA, the Bonferroni post hoc

test whenever a signi cant difference between three or more sample means has been revealed by an analysis of variance (ANOVA), and

Pearson correlation coef cient to investigate the relationship between variables. Spss version 19 software is used to analyze the data and

the error rate in all cases is ( = 0.5 %). The  ndings of the study include: 1) for both groups, the resistance training has no signi cant

effect on serum leptin level, 2) endurance training has a signi cant effect on body mass index, but strength training has no signi cant

effect on body mass index, 3) Strength and resistance training have a signi cant effect on total fat, 4) for the group with resistance train-

ing, there is a positive correlation between the variables of leptin and body mass index, 5) for the group with strength training, there is

a positive correlation between the variables of leptin and body mass index. These changes are associated with an increase in the level of

readiness for participants in both training protocol groups. Perhaps by increasing the statistical population, the intensity, and duration

of exercise activities, there will be a different effect on changes of variables and their signi cance.

KEY WORDS: TOTAL FAT, BODY MASS INDEX, SERUM LEPTIN OBESE SEDENTARY EMPLOYEES

105

ARTICLE INFORMATION:

*Corresponding Author: amirfalah.sport@gmail.com

Received 12

Jan, 2017

Accepted after revision 18

March, 2017

BBRC Print ISSN: 0974-6455

Online ISSN: 2321-4007

Thomson Reuters ISI ESC and Crossref Indexed Journal

NAAS Journal Score 2017: 4.31 Cosmos IF : 4.006

reserved.

Online Contents Available at: http//www.bbrc.in/

Biosci. Biotech. Res. Comm. Special Issue No 1:105-111 (2017)

106 THE EFFECT OF STRENGTH AND RESISTANCE TRAINING ON CHANGES BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS

Amir Falahnezhad Mojarad and Nematolah Nemati

Table 1. Mean and standard deviation of age, height and weight of the

participants in three groups

Group

Age (year) Body weight (kg) Height (m)

Mean

standard

deviation

Mean

standard

deviation

Mean

standard

deviation

Resistance 27.1 3.87 94.29 5.38 1.8 0.046

Strength 26.4 3.71 91.5 7.48 1.76 0.036

Control 26.1 4.25 99.3 8.79 1.81 0.069

Total 26.53 3.83 95.03 7.82 1.79 0.054

INTRODUCTION

Obesity is considered as a major risk factor for diseases

such as diabetic and coronary heart diseases. Levels of

the hormone leptin are associated with body fat mass

and can be regulated by hunger, eating a meal, insulin

and many other factors. Exercise is one of the strat-

egies to reduce the obesity (Jockehovel et al. 1997).

The ratio of leptin to fat mass is relatively constant

during the period of sexual maturity. However, the

reason for obesity in youth is resistance against leptin

through changing hypothalamic leptin receptor iso-

forms due to mutations of the coding region of leptin

receptor long isoform. It can be said circulating leptin

concentrations have a positive correlation with body

fat stores. Leptin plays an important role as a signal

in the regulation of adipose tissue and body weight.

Performance of Leptin is controlling food intake and

stimulating energy consumption. However, leptin as

the circulating signal is effective in attenuating appe-

tite. There are many questions related to the effect of

physical activity (exercise) on the concentration of lep-

tin. Physical activity (exercise) is in effective in reduc-

tion of obesity. A study has shown that serum leptin

concentration is related to body mass index. Among

employees, the issue of an appropriate physical norm

and overweight is important. In Iran, if the employee

is overweight his / her next promotion is delayed until

reaching the ideal weight. Therefore, investigating the

effectiveness of exercise in reducing the risk factors of

obesity can help the employees. Given that the effects

of strength training on serum leptin concentration and

body mass index are less important. Knowledge in this

area, in particular, its effects on endocrine system still

remain somewhat unknown. In most studies, compar-

ing the two groups of strength and resistance is used

without control group and assessment inside the group.

This study aims to investigate the Effect of strength

and resistance training on changes in total fat, body

mass index (BMI), and serum leptin as well as correla-

tion between serum leptin and BMI in obese sedentary

employees.

METHODOLOGY

PARTICIPANTS

A public call for the voluntary participation in research

design was used and 52 out of 110 people announced

their readiness based on completed questionnaires,

clinical examination, not having an orthopedic injury

history, lack of medicine consumption, not 28 k/m2.

After brie ng session and  lling out the consent form,

Physical Activity Readiness Questionnaire (PAR-Q), and

Health History Questionnaire, those who had no history

or symptoms of infection from a month ago, cardiovas-

cular disease, thalassemia, diabetes, arthritis, and res-

piratory disorders, insulin resistance, and other disease

statuses, medicine consumption and ergogenic supple-

ments were removed from the research. Finally, a total

of 22 people dropped out or were forced to quit and 30

people remained. According to the classi cation by one

of the colleagues, these 30 people were randomly cat-

egorized into three groups in terms of body mass index,

age, and the fat content determined by body composi-

tion analyzer. The groups include control (n = 10), resist-

ance (n = 10), and strength (n =10). The selected people

were requested to take the commitment to regularly par-

ticipate in the research plan in due time and the control

group was requested not to do any exercise but attend

the exercises. Statistical description of characteristics for

participants in terms of central tendency and dispersion

are given in Table 1.

MEASURING INSTRUMENTS AND METHODS

As scheduled in coordination with blood samples, the

participants were requested to take the pre-test. Then,

according to program, leptin levels of both the experi-

mental group and the control group were measured by

the relevant specialist and his assistant in the labora-

tory through Leptin ELISA Kit manufactured by the

German company sensitivity 0.1 ng per milliliter. Next,

they attended the sport conference center and height

and weight were measured without shoes on the device

BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS THE EFFECT OF STRENGTH AND RESISTANCE TRAINING ON CHANGES 107

Amir Falahnezhad Mojarad and Nematolah Nemati

(Seca weighing scale, model 220, the accuracy of 0.1

kg, and with height measuring rod). The participants

were standing on two legs in order to divide the weight

equally and their look was parallel to the horizon after a

normal expiration. In this way, the horizontal ruler was

placed on the man’s head and the end of the ruler was

on the graded tape. Body mass index and body fat per-

centage were measured by Body Composition Analyzer

(model GAIA 359 PLUS). 1-Mile Walking Test was used

to determine Vo2Max and 1 repetition maximum (1RM).

According to this test, the participants in the experimen-

tal group of resistance walked a distance of a mile as

fast as they could. The distance time and heart rate were

recorded after  nishing walking. By adding weight and

age to these factors, Vo2Max was calculated through the

following equation:

Vo2 Max = (6965.2 + 20.02 (Body weight in kg)) -

25.7  (Age in years) + 595.5  (1) -224.00  (Test time

in minutes) -11.5 (Heart rate per minute)/ (Body weight

in kg)

Weights of  tness equipment (manufactured by

IMPLUS) were recorded for the experimental group of

strength. The experimental groups did their own exer-

cises at speci ed dates and times (9 to 11 am). After

completion of the training period, height, weight, body

mass index, fat percentage, and maximum oxygen con-

sumption were re-measured in the post-test. In addition,

previous blood tests in the laboratory were repeated in

due date. The amount of blood serum in the posttest

was sent to the hormone laboratory for the analysis of

changes in levels of leptin. Furthermore, all participants

in the pre-test (24 hours before exercise) and in the post-

test (24 hours after exercise) attended the laboratory for

blood sampling at 9 am after fasting for 12 hours. Before

going to the laboratory, participants were announced

by a guide about the main points on the nutrition (24-

hour dietary recall questionnaire in three days), physical

activities, and disease before and after 4 weeks of physi-

cal exercises in order to be careful about the mentioned

points. In the laboratory, blood samples of 30 ml were

taken from a vein in the right arm and blood was slowly

poured into the test tube. When blood was clotted, the

tubes were balanced. Then, the tubes were placed into

Hettich centrifuge. Next, serum was separated from

blood clots and was frozen for testing leptin.

TRAINING PROTOCOLS

In this study, the protocol of aerobic exercise (resistance)

included two months, 3 sessions per week, 84 minutes

in each session, at 2 stations (stationary bike and tread-

mill), 2 sets of four-minute, training intensity by 60 to 70

percent for the maximum heart rate. To follow the prin-

ciple of overload, a half minute per session was added

to the training time in order that the aerobic exercise

time reaches 96 minutes in the last session. Forasmuch

as participants did not regularly the exercises, 12 min-

utes for rest time between two sets and 20 minutes for

rest time between two stations were considered as the

duration of the break in aerobic exercise. The strength

training protocol included Two months for weight train-

ing, the 3 session exercise per week, 9 stations, 8 to

12 repetitions in three sets, 60 -75% of one repetition

maximum with 45 seconds for the rest time between

sets and 1.5 minutes between stations. In the strength

training protocol, the total exercise time was 70 minutes

per session. The one repetition maximum test was given

for the principle of overload at the end of each session.

The strength training program was designed according

to 60-75 percent of the one repetition maximum test

after three training sessions. Statistical methods to com-

pare training groups in the test process include repeated

measures ANOVA, the Bonferroni post hoc test whenever

a signi cant difference between three or more sample

means has been revealed by an analysis of variance

(ANOVA), and Pearson correlation coef cient to investi-

gate the relationship between variables. Spss version 19

software is used to analyze the data and the error rate in

all cases is ( = 0.5 %).

RESULTS

Table 2 shows changes of scores from pre-test to post-

test for all groups based on their BMI, hormone leptin,

and total fat.

The  rst null hypothesis: there is no signi cant dif-

ference for the leptin level between the training groups

(resistance, strength and control). A 2x3 repeated meas-

ures ANOVA was used to investigate the data obtained

from the effects of exercise on hormone leptin. The results

of the Shapiro–Wilk test showed that the blood leptin

Table 2. Mean and standard deviation of the variables in pre-test and post-test

Variables Body mass index Hormone leptin Total fat

Groups pre-test post-test pre-test post-test pre-test post-test

Resistance 29.08±0.704 28.59±0.875 16.6±4.25 12.69±2.38 46.26±2.08 45.15±1.86

Strength 29.25±1.27 29.2±1.16 14.71±2.91 13.59±2.13 44.01±1.29 44.22±1.18

Control 30.06±1.23 30.02±1.27 13.4±3.91 13.13±3.88 44.94±0.88 44.93±0.84

Amir Falahnezhad Mojarad and Nematolah Nemati

108 THE EFFECT OF STRENGTH AND RESISTANCE TRAINING ON CHANGES BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS

level has a normal distribution for all training groups

in pre-test and post-test sessions (p>0.05). According to

Table 3, the Levin test shows that there is homogeneity

of variance between the scores of the training group in

the pre-test and post-test (p>0.05).

According to Table 4, the results of the repeated

measures ANOVA show that the effect of the test is sig-

effect (Test * Group) was signi cant, the paired sample

t-test was used to compare the pre-test and post-test.

The results of the paired sample t-test showed that there

is a signi cant difference between the pre-test and post-

test in the resistance training group (t=4.960, p= 0.001)

but there is no signi cant difference between the pre-

test and post-test in other groups.

The second null hypothesis: there is no signi cant

difference for the Body mass index between the training

groups (resistance, strength and control). A 2x3 repeated

measures ANOVA was used to investigate the data

obtained from the effects of exercise on hormone lep-

tin. The results of the Shapiro–Wilk test showed that the

blood leptin level has a normal distribution for all train-

Table 3. Evaluation of homogeneity of variance between the

training groups in the pre-test and post-test (Levin test)

Test/statistics Levin statistics df1 df2 Sig.

pre-test 0.621 2 27 0.545

post-test 2.569 2 27 0.95

Table 4. The repeated measures ANOVA to compare the groups in the pre-test and

post-test

Indexes® Sources of

Variation¯

Sum of

squares

Degrees of

freedom

Mean

Square

Intragroup

Test 37.763 1 37.763 23.901 0.000

Test * group 25.658 2 12.829 8.12 0.002

Error 42.659 27 1.589

Intergroup

Group 13.773 2 6.887 0.330 0.721

Error 562.71 27 20.841

Table 5. Evaluation of homogeneity of variance between the

training groups in the pre-test and post-test (Levin test)

Test/statistics Levin statistics df1 df2 Sig.

pre-test 1.005 2 27 0.379

post-test 0.339 2 27 0.716

Table 6. The repeated measures ANOVA to compare the groups in the pre-test and

post-test

Indexes® Sources

of Variation¯

Sum of

squares

Degrees of

freedom

Mean

Square

Intragroup

Test 0.574 1 0.574 7.352 0.012

Test * group 0.663 2 0.332 4.246 0.025

Error 2.109 27 1.078

Intergroup

Group 15.181 2 7.591 3.179 0.05

Error 64.468 27 2.388

Table 7. Evaluation of homogeneity of variance between

the training groups in the pre-test and post-test (Levin

test)

Test/statistics Levin statistics df1 df2 Sig.

pre-test 5.97 2 27 0.007

post-test 2.249 2 27 0.012

ni cant. In other words, there is a signi cant difference

between the pre-test and post-test regardless of the type

of training. In addition, the interaction effect is signif-

icant. However, the results show that the main effect

of the group is not signi cant. It means that there is

a signi cant difference between the different training

groups regardless of the type of training. Hence, the null

hypothesis is con rmed. Forasmuch as the interaction

ing groups in pre-test and post-test sessions (p>0.05).

According to Table 3, the Levin test shows that there

is homogeneity of variance between the scores of the

training group in the pre-test and post-test (p>0.05).

According to Table 6, the results of the repeated meas-

ures ANOVA show that the effect of the test is signi cant.

In other words, there is a signi cant difference between

the pre-test and post-test regardless of the type of train-

Amir Falahnezhad Mojarad and Nematolah Nemati

BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS THE EFFECT OF STRENGTH AND RESISTANCE TRAINING ON CHANGES 109

ing.. Hence, the null hypothesis is rejected. Because of

differences between groups Bonferroni post hoc test was

used to determine the location of difference. The results

showed that there was a signi cant difference between

resistance and control groups. Forasmuch as the inter-

action effect (Test * Group) was signi cant, the paired

sample t-test was used to compare the pre-test and post-

test. The results of the paired sample t-test showed that

there is a signi cant difference between the pre-test and

post-test in the resistance training group (t=2.985, p=

0.015) but there is no signi cant difference between the

pre-test and post-test in other groups.

The third null hypothesis: there is no signi cant differ-

ence for the total fat between the training groups (resist-

ance, strength and control). A 2x3 repeated measures

ANOVA was used to investigate the data obtained from

the effects of exercise on hormone leptin. The results

of the Shapiro–Wilk test showed that the blood leptin

level has a normal distribution for all training groups

in pre-test and post-test sessions (p>0.05). According to

Table 3, the Levin test shows that there is homogeneity

of variance between the scores of the training group in

the pre-test and post-test (p>0.05).

According to Table 6, the results of the repeated meas-

ures ANOVA show that the effect of the test is signi cant.

In other words, there is a signi cant difference between

the pre-test and post-test regardless of the type of train-

ing. Hence, the null hypothesis is rejected. Because of

differences between groups Bonferroni post hoc test was

used to determine the location of difference. The results

showed that there was a signi cant difference between

resistance and control groups. Forasmuch as the inter-

action effect (Test * Group) was signi cant, the paired

sample t-test was used to compare the pre-test and post-

test. The results of the paired sample t-test showed that

there is a signi cant difference between the pre-test and

post-test in the resistance training group (t=4.418, p=

0.02) but there is no signi cant difference between the

pre-test and post-test in other groups.

The fourth null hypothesis: there is no signi cant

relationship between the blood leptin level and body

mass index of the participants in the resistance training

group.

Pearson correlation test was used to examine the rela-

tionship between these two variables. Table 9 shows the

correlation between variables. The results showed that

there is a signi cant positive relationship between two

variables of the blood leptin level and body mass index

in the posttest. Hence, the null hypothesis is rejected.

The  fth null hypothesis: there is no signi cant rela-

tionship between the blood leptin level and body mass

index of the participants in the strength training group.

Pearson correlation test was used to examine the rela-

tionship between these two variables. Table 10 shows the

correlation between variables. The results showed that

there is a signi cant positive relationship between two

variables of the blood leptin level and body mass index

in the posttest. Hence, the null hypothesis is rejected.

DISCUSSION AND CONCLUSION

This study investigated the effect of strength and resist-

ance training on changes in total fat, body mass index

(BMI), and serum leptin as well as correlation between

serum leptin and BMI in obese sedentary employees.

Table 8. The repeated measures ANOVA to compare the groups in the pre-test and

post-test

Indexes®

Sources of Variation¯

Sum of

squares

Degrees of

freedom

Mean

Square

Intragroup

Test 1.368 1 1.368 8.176 0.008

Test * group 5.105 2 2.552 15.288 0.000

Error 4.558 27 0.167

Intergroup

Group 25.193 2 12.597 3.179 0.048

Error 106.973 27 3.962

Table 9. correlation between the variables of blood

leptin level and body mass index in the post-test in the

resistance training group

body mass

index

blood leptin

level

0.675

0.032

blood leptin level

0.675

0.032

body mass index

Table 10. correlation between the variables of blood

leptin level and body mass index in the post-test in the

strength training group

body mass

index

blood leptin

level

0.183

0.613

blood leptin level

0.183

0.613

body mass index

Amir Falahnezhad Mojarad and Nematolah Nemati

110 THE EFFECT OF STRENGTH AND RESISTANCE TRAINING ON CHANGES BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS

Although many researches have done on serum leptin

concentration and its relationship with body mass index,

Factors such as intensity, time, type of training, physical

conditions of the people, their sex and age, and ways

of measuring body mass index lead to different reac-

tions in the body. In addition, there are a few studies on

the effects of strength training on leptin and body mass

index. Strength and resistance training has no signi cant

effect on serum leptin concentrations in obese and over-

weight men. This result can affect the leptin level due

to changes in hormones concentration affecting leptin

such as insulin, cortisol, testosterone, growth hormone,

and catecholamine (Hamedinia et al. 2011). Other studies

showed that lack of reduction in serum leptin in spite of

decreasing the body fat percentage is because of high

cortisol levels and creating conditions for overtraining

due to the exercise protocol in athletes (Noland et al,

2001). In another study, despite a signi cant decrease in

fat mass, and serum testosterone, there was no change in

serum leptin concentrations after six weeks of strength

training in physical education students because of an

increase in serum leptin concentrations in comparison

with body fat mass (Jones et al, 2009). Furthermore, the

results of some studies showed that in spite of a decrease

in percentage of body fat, there was no change in the

serum leptin level resulting from exercises (Thong and

Hudson, 2002; Lau et al, 2010; Kraemer et al, 2002).

Some studies concluded that the reason for the reduc-

tion of the leptin level is a decrease in percentage of the

body fat (Kraemer et al, 1998). Some others concluded

that the effect of exercise on the leptin level is positive

and independent from changes in the body fat (Gaini

et al, 2000; http://www.ensani.ir/fa/content/303352/

default.aspx). We can say that the apparent differences

in training protocol and type of participants and their

individual characteristics can explain the difference in

the percentage of the body fat and leptin. In a study, it

was concluded that the lack of changes in leptin was the

limitation of the leptin performance (Maestu et al, 2008;

Erikson et al, 2008).

In the present study, the volume of exercises such as

the intensity and duration of exercise was not enough to

affect the leptin level. There may also be another possibil-

ity that explains the lack of changes in the leptin level in

this study. Leptin is either free (possibly active) or pro-

tein bound. The free leptin level is greater in obese people

and concentration of free leptin decreases after weight

loss even more than total leptin concentration (Unal et

al. 2005). Exercise in spite of no reduction in total leptin

is effective in changing in the ratio of free leptin to pro-

tein bound leptin (resulting in changes in leptin activity).

Measuring the amount of leptin binding protein requires

the measurement of leptin receptor in plasma. This issue

was not measured in the present study.

It seems that there are many other factors involved

in the effect of training on the serum leptin level. These

factors include enzymes involved in the biosynthesis

of testosterone as a result of stress caused by exercise

(Nidle et al. 2002), the inhibitory effect of cortisol on

LH receptors in Leydig cells of the testes, and reduc-

tion in the secretion of testosterone (Cooke et al, 1999).

Therefore, high cortisol levels may decrease the secre-

tion of testosterone and LH receptors (Gotshalk et al,

1997). Researches have shown a strong inverse relation-

ship between leptin and testosterone (Dohem and Louis,

1978). Leptin also affects the production and secretion

of cortisol (Lowndes et al, 2008) and cortisol is stimulus

of leptin gene expression. There is a direct correlation

between leptin and cortisol resting levels (Smilios et al,

2003). With regard to the inverse relationship between

cortisol and testosterone, an increase in the hormone

cortisol results in increasing stress (Cooke et al, 1999).

It leads to decreasing testosterone and the emergence

of a factor in line with the lack of a signi cant effect

of the exercises, including strength training and resist-

ance training protocol, on the hormone leptin. Kraemer

et al investigated the effect of the resistance exercises on

cyclists. Glucocorticoids play an important role in the

physiological regulation of leptin and cortisol is simul-

taneously effective in the production and disposal of

leptin (Kraemer et al, 2002).

There was a signi cant difference between differ-

ent groups in relation to the effects of two methods of

exercise training on body mass index. According to the

results of the Bonferroni post hoc test in the present

study, there is a signi cant difference between the con-

trol and resistance groups. It can be concluded that this

change occurs due to an increase in fat oxidation for the

control of body composition in the resistance training

group.

This issue is consistent with the control of the variable

of fat in the present study. According to the reduction

in body mass index in strength and resistance groups in

this research, it seems that the way of training in this

study has the required intensity and energy cost thresh-

old for changing the weight levels of the participants.

Given that there was a signi cant change in body mass

index and height is stable according to the middle age

range of the participants, the weight loss occurred for

the participants. The overall conclusion indicated that

both of the exercises lead to the similar results. Most

changes in body mass index were related to the resist-

ance training.

Therefore, it is suggested that the resistance exercises

are further used to prevent obesity and many diseases

caused by inactivity and obtain the desired effect of

exercises based on physical preparation and reducing

overweight.

Amir Falahnezhad Mojarad and Nematolah Nemati

BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS THE EFFECT OF STRENGTH AND RESISTANCE TRAINING ON CHANGES 111

REFERENCES

Cooke RR, McIntosh JEA, and McIntosh RP. (1999): Is cortisol

an important factor in the serum binding of testosterone? Pro-

ceed Endo Soci Aus, 33: 53-59.

Dohem GL, and Louis TM. (1978): Change in androstendion

`testosterone and protein metabolism as a result of exercise.

Proc Soc Exp Biol Med. 158:622-25.

Eriksson M, Johnson O, Boman K, Hallmans G, Hellsten G, Nils-

son TK,Soderberg S. (2008): “Improved  brinolytic activity dur-

ing exercise may be an effect of the adipocyte – derived hormones

leptin and adiponectin”. Thrombosis research. 122: PP: 701-708.

Gaini, A. A., Rahmani Niya, F., Hosseini, S. M. (2000): The

relationship between aerobic capacity and body size in female

non-athletes students, Research Center of National Olympic

Committee.

Gotshalk LA, Loebel CC, Nindl BC, Putukian M, Sebastianelli

WJ, Newton RU, and Häkkinen K. (1997): Hormonal responses

of multiset versus single-set heavy - resistance exercise proto-

cols. Canad J Appl Physio, 22:244-55.

Hamedinia, M.R., Davarzani, Z., Hosseini Kakhk, S. A. (2011):

The effect of one session of swimming and running on hunger

rate and ghrelin, insulin and cortisol in healthy girls, Journal

of Endocrinology and Metabolism of Iran, 13 (1): 82-89.

Http://www.ensani.ir/fa/content/303352/default.aspx

Jockehovel F , Blum WF , Vogel E , Engalro P , Muller – Wei-

land D , Reinwein D , Rascher W , krone W. (1997): Testoster-

one substitution normal izes elevated serum leptin levels in

hypogonadal males . J. clin Endocrinol Metab. 82: 2510 – 2513.

Jones T, Basilio JL, Brophy PM, McCammon MR, Hickner RC.

(2009): Long-term exercise training in overweight adolescents

improves plasma peptide YY and resistin. Obesity. 17: 1189–1195.

Kraemer R,Hongnun CR, Castracane VD. Leptin and exercise.

Exp Biol Med. (2002): 227:701-8.

Kraemer WJ, Ha¨kinen K, NewtonRU, McCormick M, Nindl BC,

Volek JS, et al. (1998): Acute hormonal responses to heavy

resistance exercise in younger and older men. Eur J Apl Phys-

iol. 7: 206-1.

Lau PWC, Kong Z, Choi C, Yu CCW, Chan DFY, Sung RYT, et

al (2010): Effects of Short-Term Resistance Training on Serum

Leptin Levels in Obese Adolescents. Journal of Exercise Sci-

ence & Fitness; 8(1): 54-60.

Lowndes J, Zoeller RF, Caplan JD, Kyriazis GA, Moyna NM,

Seip RL, et al. (2008): Leptin responses to long-term cardi-

orespiratory exercise training without concomitant weight

loss: A prospective study. J Sports Med Phys Fitness. 48:

391-7.

Maestu J, Jurimae J, Valter J, Jurimae T. (2008): “Increases in

ghrelin and decreases in leptin without altering adiponectin

during extreme weight loss in male competitive bodybuilders”.

Metabolism, 57: PP: 221-225.

Nindle BC, Kraemer WJ, Arciero PJ, Samatalle N. (2002):

Leptin concentratio ons experience a delayed reduction after

resistance in men. Med Sci Sport Exerec. 34: 608-613.

Noland RC, Baker JT, Boudreau SR, Kobe RW, Tanner CJ, Hick-

ner RC, et al. (2001): Effect of intense training on plasma leptin

in male and female swimmers. Medicine and science in sports

and exercise, 33: PP: 227-231.

Smilios I, Pilianidis T, Karamouzis M, Tokmakidis SP. (2003):

Hormonal responses after various resistance exercise proto-

cols. Med Sci Sports Exerc. 35: 644-54.

Thong fsi , Hudson Rahd at al. (2002) Plasma Leptin in mod-

erately obese moles Independent Effects of weight Loss and

Aerobic Exercise AM , ] physiol . Endocrinol, Metab. 279 E

307 – E 313.

Unal M, Unal DO, Baltaci AK, Mogulkoc R. (2005): Investiga-

tion of serum leptin levels and healthy males. Acta Physiol

Hung. 92:173-9.14- Cohen PG.