Effects of 2 Types of Resistance Training, Pyramid and Reverse pyramid training, on IL-4, IL-6, and IFN-γ in Young women

Based on insufficient research on effects of different types of resistance training, the purpose of this study was to investigate effects of pyramid and reverse pyramid training on levels of rest of IL-4, IL-6, and IFN-γ in young women. Thirty participants were accidently assigned into 3 groups: pyramid, reverse pyramid, and control group. Pyramid and reverse pyramid training groups took increasing resistance training for 8 weeks. Before (24 hours before training) and after training (48 hours after training), blood samples were taken from participants. Analysis of Variance (ANOVA) with repeated measures was employed to examine and compare changes of variables. Resistance training resulted in increase of IL-4 and IL-6 and reduction of IFN-γ (p<0.05). However, there was no difference between pyramid and reverse pyramid training (p>0.05). Perhaps resistance training reduces cellular immune response and increases humoral and inflammatory response in young women through reduction of IFN-ã and increase of IL-4 and IL-6. It is possible that the training has been too intensive for participants. Further research on this issue is required.


INTRODUCTION
Resistance training is popular with many people, especially women to improve and maintain their health.Resistance training has different types which may have common and unique effects on physiological systems, especially immune system.Focusing on cytokines can help explain complex issues of immune response to training.Immune system has a role in inflammatory responses, increased sensitivity, and defending body against pathogens (virus and bacterium) (Blotta M et al., 1997;Bruunsgaard, 2005).
.Inflammatory responses are accompanied by production of cytokines including IL-4 and IFN-γ.Cytokines produced by T lymphocytes play a role in development and increase of immune system function against pathogens.Differentiation of T lymphocytes to Th1/ Tc1 (type I) is identified by production of IFN-ã (Maria N et al., 2003).Extracellular pathogens produce humoral immune response which results in differentiation of T lymphocytes to Th2/Tc2 (type II) and production of IL-4 (Hernberg M et al., 1997;Ibfelt T et al., 2002).Another cytokine is IL-6 which has a variety of actions.IL-6 induces acute phase proteins synthesis which improves innate immune and plays a role during systemic inflammation (acute phase).Also, during acquired immune, IL-6 stimulates growth of B lymphocytes which differentiate to antibody producer cells (Kamimura D et al., 2003;Abul K et al., 2007).IL-6 is significantly increased in response to physical activities (up to 100 times) and then decreases (Suzuki K et al., 2002).IL-6 can increase lipolysis and induce production of cortisol and other regulatory cytokines such as IL-10 and IL1ra.Moreover, it suppresses production of preinflammatory cytokine, TNF-γ.Therefore, it reduces resistance to insulin which is an advantage of exercise (Pedersen B et al., 2007).On exercising, IL-6 is increased in muscle fibers.Based on its preinflammatory and anti-inflammatory role and due to being known as a myokine, its increase after exercise can be related to its anti-inflammatory function (Baum M et al., 1999;Suzuki K et al., 2002).The effects of moderate training on increase of levels of muscular have been reported (Fehrenbach E et al., 2005).reported that regular training for 12 weeks results in decrease of production and circulating level of IL-6 (Timmerman K et al., 2008).Generally, the results revealed that regular exercise influences several factors of immune system.In fact, it improves function and number of components of immune system.(Timmerman K et al., 2008;Adam S et al., 2001;Lancaster G et al., 2005).
In years past, it was believed that women cannot benefit much from resistance training due to their hormone differences.Recently, it has been proved that women can benefit from resistance training as men.Nowadays, due to women's tendency to improve their health and keep themselves in shape, they show an interest in resistance training.According to the characteristics of cytokines and effects of resistance training, the purpose of this study was to compare the effects of pyramid resistance training and reverse pyramid resistance training on serum levels of IL-4, IL-6, and IFN-γ in non-athlete young women.

Participants
Thirty active and healthy women (age: 25.43±3.23;height: 166.77±3.71)were purposefully collected and accidently and equally assigned into 3 groups: pyramid resistance training, reverse pyramid resistance training, and control group.Participants had no surgery or illness, took no medicine, were non-smokers and physically healthy, and took training once a week.

Data collection
Study protocol was explained to participants a week before study.Resistance training was introduced to participants.General characteristic of participants were examined.Blood samples were taken from 3 groups.Then participants of pyramid and reverse pyramid resistance training groups performed resistance training for 8 weeks.Control group performed no regular training and had their daily routine.Blood samples were taken from 3 groups 48 hours after last training session.

Training program
Training program included 3 sessions per week, each session lasting 45 minutes.The first 10 minutes in each session was for warm up, then the next 30 minutes for exercise and the last 5 minutes for cooling down.Resistance training was planned in a circular path and pyramid and reverse pyramid.Trainings were performed in 6 stations: chest press, foot press, front of arms, front of feet, back of arms, and back of feet.Each exercise included 3 sets of 10 repetitions.After each set and between exercises they had a break of 1 and 2 minutes, respectively.Each session included a circuit.The pyramid group performed their first set of ten repetitions at 50% of 10 RM, the second set of ten at 75% of 10 RM, and the third set of ten at the 100% of 10 RM.Also, the reverse pyramid group performed their sets the reverse: 100% of 10 RM, 75% of 10 RM, and 50% of 10 RM.

Blood sampling and analysis of cytokines
Blood samples of 5 cc were taken from basilic vein.Collected samples were placed in sterilized tubes containing K3EDTR.Heparin and EDTR tubes were placed in ice and kept in ambient temperature for a few minutes.Then they were centrifuged for 10 minutes at RPM 3500.All frozen samples were kept in -20 p C until being test at laboratory.IL-4, IL-6, and IFN-ã were assayed through ELISA kits from eBioscience.

Statistical methods
Values of variables were described using mean and standard deviation.To investigate normal distribution and use of parametric and nonparametric tests, Kolmogorv-Smirnov test was employed.The results revealed that data distribution was normal.To compare changes of variables in 3 groups, Analysis of Variance (ANOVA) with repeated measures was used in a 3×2 plan (3 groups and 2 times)(P=0.05).SPSS (version 16) was used to do statistical calculations.

RESULTS AND DISCUSSION
Statistical description of weight, BMI, and serum level of IL-4, IL-6, and IFN-γ are represented in table 1.The values are reported using mean and standard deviation.Also, the results of ANOVA with repeated measures were used to compare variables changes in 3 groups (Table2, 3, 4, 5, and 6).There was no significant difference among 3 groups in weight changes and BMI (respectively P=0.18 and P=0.087).Also, no significant difference was observed among 3 groups in IL-4 and IL-6 changes (respectively P=0.12 and P=0.10).However, there was a significant difference among these 3 groups in pattern of changes of IFN-γ (P=0.02);IFN-γ decreased in pyramid and reverse pyramid resistance training groups but increased slightly in control group.The results of Tukey's test revealed that only the difference between control and reverse pyramid resistance training group was significant (Table 7)(P=0.024).

DISCUSSION
The results revealed that there was not a significant difference among these 3 groups in pattern of changes of IL-4 and IL-6.IL-4 and IL-6 Physical activity has a dual effect on immune system; intensive and long-term physical activities result in decrease of function of immune system so that possibility of inflammation and infection increases (Fish D et al., 2003) .Inflammation of tissues is an immune response to infection or injury which includes complex reactions of immune cells and soluble proteins including cytokines ( Findings on pyramid and reverse pyramid resistance trainings are limited and further studies are required to reach a firm conclusion.This study reported increased IL-4 and IL-6 and decreased IFN-γ in resistance trainings; however there was no difference between pyramid and reverse pyramid resistance trainings.

CONCLUSIONS
The results revealed that an eight-week period of resistance training results in increase of IL-4 and IL-6 and decrease of IFN-γ in young women.However, there was no difference between pyramid and reverse pyramid resistance trainings.Perhaps resistance trainings results in decreased cellular immune response and increased humoral and inflammatory immune response in young women through decrease of IFN-γ and increase of IL-4 and IL-6.It is possible that these trainings have been too intensive for the participants.Further studies are required to investigate the issue.Also, probably there is no difference between pyramid and reverse pyramid resistance trainings in terms of their effects on levels of cytokines.

Table 3 : Statistical results of ANOVA with repeated measures to compare changes of BMI in 3 groups Observed Power Effect Size P F Mean Square df Sum of Square Factor
* The mean difference is significant at the 0.05 level

Table 6 : Statistical results of ANOVA with repeated measures to compare changes of IFN-? in 3 groups
* The mean difference is significant at the 0.05 level

Table 7 : Results of Tukey's test to determine point of difference of IFN-ã
Pd"0.05*The mean difference is significant at the