Comparison of BMI Body Fat Percentage and Lean

Comparison of BMI, Body Fat Percentage and Lean body weight of National Level Teenage Swimmers and Non-Swimmers in Sri Lanka. Suranga Dassanayake Allied Health Sciences Unit, Faculty of Medicine, University of Colombo Sri Lanka August 2016

INTRODUCTION • Swimming is a popular sport all over the world. • It is a full body exercise that can be both fun and competitive which ranges from school level to international championships. • Swimming is becoming more popular due to direct and indirect health benefits caused on an individual’s health and body composition

OBJECTIVES This study was conducted with the objectives to • Assess the Body Mass Index (BMI), body fat percentages and the lean body mass • Compare the BMI, body fat percentages and the lean body mass • of national level female teenage swimmers and age and geographical area matched non athletic non swimmers in Sri Lanka

METHODOLOGY Study Population Teen age Female Swimmers and Non swimmers Sample: Controls Teenage female swimmers who qualify for the School Nationals Meet Age and geographical area matched Female Non- athletes/non swimmers Sample size: 90 4

METHODOLOGY Ethical Clearance: Ethics review Committee, FM, Uo. P Consent Recruitment Data collection Data recording and Analysis: Printed Sheets computer SPSS 5

Results • Age, body weight, height and BMI of female swimmers and controls • Age range 13 – 19 years with mean 15± 1. 8 years. • Range of body weight 42. 0 - 61. 0 kg. with mean 51. 4± 4. 3 kg. • Range of height 142 - 176. 3 cm with mean 164± 5. 5 cm. • BMI Range 14. 1 - 22. 8 kg/m 2. with mean 19± 1. 5 kg/m 2 • • The female controls too had a mean age of 15 ± 1. 8 yrs. Mean weight 52. 6± 3. 7 kg. Range 42. 0 - 59. 5 kg. Mean height 153. 0± 8. 3 cm. Range 133. 6 - 166. 5 cm Mean BMI 22. 5± 2. 2 Range 18. 2 - 28. 1 kg/m 2.

Results • A statistically significant difference was observed in the means of • Weight • Height • BMI (p=0. 05) (p=0. 0001) (p= 0. 0001) • Of female swimmers

Age, body weight, height and BMI female swimmers and controls (n =90) Weight (kg) Height (cm) BMI (kg/m 2) Group Mean SD Swimmers 51. 4 4. 3 Controls 52. 6 3. 7 Swimmers 164. 0 5. 5 Controls 153. 0 8. 3 Swimmers 19. 0 1. 5 Controls 22. 5 2. 2 Minimum Maximum 42. 0 61. 0 42 59. 5 142. 0 176. 3 133. 6 166. 5 14. 1 22. 8 18. 2 28. 1 p 0. 05 0. 0001

Results • LBW, Fat weight and Fat percentage of female swimmers and controls • In swimmers • The mean LBW was 42. 0± 3. 7 and the minimum and maximum values were 34. 7 kg and 51. 8 kg. • Mean FW were 9. 4± 1. 9 kg while the minimal and maximum values were 5. 2 kg and 16. 6 kg • Mean fat percentage was 18. 2± 3. 4% • In controls • The mean LBW was 39. 3± 2. 2 kg and minimum and maximum values were 34. 3 kg and 44. 9 kg • The mean FW was 13. 3± 2. 2 kg and respective Minimum and maximum values were 7. 5 kg and 17. 9 kg • The mean fat percentage was 25. 1± 3. 1% for female controls and the minimum and maximum values were 17. 8 and 32. 4 kg.

Results • A statistically significant difference was observed in the means of • LBW : • Fat%: p=0. 0001. • of female swimmers

Results Group LBW Female swimmers (kg) Female controls Fat % Female swimmers Female controls n Mean SD 90 42. 0 3. 7 90 39. 3 2. 2 90 9. 4 1. 9 90 13. 3 2. 2 90 18. 2 3. 4 90 25. 1 3. 1 Min Max 34. 7 51. 8 34. 3 44. 9 5. 2 16. 6 7. 5 17. 9 12. 1 28. 6 17. 8 32. 4 p 0. 0001

DISCUSSION • The measurements considered in the study were – Body weight, – Height, – Skin fold thickness at seven different sites • Chest, mid axillary, triceps, sub scapular abdominal, supra iliac and thigh). • The parameters which were calculated were – – Body mass index Fat weight Fat percentage Lean body weight

DISCUSSION • Difference of mean body weight, height and the BMI of female swimmers and non swimmers the were statistically significant. • Therefore the female non swimmers in the study were heavier, shorter and with higher BMI than the female swimmers.

DISCUSSION • The average of the subjects recruited to the study was 15, which was at the puberty resulting a rapid body growth with increased weight, height and fat deposition. • The physical growth accelerates in the first half of teen age (13 -16 years) which is stimulated by hormonal signals from the brain (Mc. Ardle et al. , 2010) causing the growth, functions, bones, and muscles. (Barrett et al. , 2010). • The maturity of puberty is early in girls (Mc. Ardle et al. , 2010). • The average of the females in our study were close to the puberty completion age and that may be the reason for showing higher body mass and BMI of female non swimmers as female swimmers are involved in their training and are burning their fat.

DISCUSSION • The BMI values fall into the normal range as per WHO cuts offs , though the tendency of getting obese has been observed in the world (Albon et al. , 2008) • our study did not show higher BMI values at least in risk of over weight range but the difference between swimmers and controls were significant statistically. • The regular structured training of swimmers which increased their energy expenditure and the hormonal effect of the pubertal age may be the reasons for this observation.

DISCUSSION • Lack of physical activity is reported to influence BMI ( Russle et al. , 2006, Kumar et al. , 2013). • Our results of the female swimmers support the argument that swimming could be used as a means to reducing the obesity problem prevailing all over the world (Kumar et al. , 2013, Chatwal et al. , 2004, Redzal et al. , 2013).

DISCUSSION • The differences of the mean values of the fat weight and the fat percentages were statistically significant • In females, the difference of LBW is significantly higher in swimmers, even though female controls were significantly heavier than the female swimmers

DISCUSSION • The differences of the fat weight and the fat percentage of both male and female groups were statistically significant according to the analysis • Female swimmers had lower fat weight compared to the female controls

DISCUSSION • Physical activity cause an energy deficit, burning more calories leading to fat mass reduction (Kumar et al. , (2013) Mc. Ardle et al. , 2010). • The above factors are the reasons of our observation that the higher lean body weight of the physically active females.

Discussion • The increase in muscle fiber size is stimulated by an increase in muscle protein synthesis. During intense exercise, protein synthesis appears to decrease and then increase during the recovery period. (Mc. Ardle et al. , 2010 & Barrett et al. , 2010). • Furthermore micro trauma which may result by the regular activity, play a significant role in muscle growth. Therefore, physical activity will increase the muscle mass.

DISCUSSION • Since skeletal muscle is the primary component of lean mass, participation in sport could have not only a direct osteogenic effect, but also an indirect effect by increasing muscle mass and hence the tensions generated on bones during prepubertal years (Rodrigoz et al, 2000). • Therefore swimming as a full body exercise helps the bony growth increasing the lean body mass and the dimensions

DISCUSSION • Swimming may improve physical fitness and therefore fat weight was less in swimmers and further, the training could result in lower fat percentage than in non-athlete children supporting the findings of the results of Schneider et al. , 2005, Lieber et al. , 1999, Russel et al. , 2006, Emslander et al. , 1998 and Kumar et al. , 2013. • The present study is in agreement with the published data supporting that Swimming has a direct influence BMI, LBW and Fat %.

Conclusions • These results generally conclude that swimming may directly influence the BMT, BF% and LBW.

Conclusions • The higher lean body mass and less fat mass can be an advantage to a swimmer and the reason for that can be the intense training as described in the published literature by Zuniga et al. , 2011, Reel et al. , 2001, Knechtle et al. , 2004, Santos et al. , 1998, & Tanda et al. , 2013. • It can be concluded that increased lean body mass may lead to improved performance and to better keeping swimmers with higher lean body mass (less body fat) due to same the reason.

Conclusions • Swimming could keep fat weight at a lower level in female swimmers. • It further emphasizes that swimming could be used as an exercise component of reducing body fat or body composition as suggested by White et al. , (1978) a few decades ago.