본 연구는 우리나라 성인 남성 3721명과 여성 379명을 대상으로 종단적인 연구를 통해서 연령별(20대, 30대, 40대, 50대, 60대), BMI, %BF 집단별(Group, A, B, C, D)로 구분하여 신체구성, 체력 수준의 차이와 상관성을 분석하였으며, 심폐체력 수준이 낮은 집단과 정상 집단을 구분하여 로지스틱 회귀분석을 실시하여 다음과 같은 결론을 얻었다.

1. 연령에 따른 신체구성과 체력 비교

연령별 집단에서는 신체구성(BMI, WHR, %BF, BFM)과 체력(VO2max, Lt Grip Strength, Rt Grip Strength, Sit-Up, Push-Up, sit and Reach, Sargent Jump, Side Step, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion)에서 모두 통계적으로 유의한 차이(P<.000)가 나타났다. 체중은 30-40대까지 유지되다가 점진적으로 감소되었으며, BMI는 50대까지 증가하다 감소하는 것으로 나타났다. WHR, %BF는 연령이 증가될수록 비례적으로 증가되었으며 BFM은 30대까지 증가하다가 40대 이후로 비슷한 수준으로 감소하는 것으로 나타났다. VO2max, Sit-Up, Push-Up, sit and Reach, Sargent Jump, Side Step, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion 모두 20대 가장 높게 나타났으며 Lt Grip Strength, Rt Grip Strength는 40대에 가장 높게 나타났다.

2. BMI, %BF와 체력과의 상관성

BMI, %BF와 체력의 상관분석을 실시한 결과 대부분의 변인에서 통계적으로 유의한 부적 상관성(P<.000)이 나타났으며, BMI와 Grip Strength, Sargent Jump, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion는 통계적으로 유의한 정적 상관성(P<.000)이 나타났다. 남성의 체력과 BMI는 Lt Grip Strength, Rt Grip Strength, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion 모두 통계적으로 유의한 정적 상관성이 나타났으며, VO2max, Sit-Up, Push-Up, Sit and Reach, Sargent Jump, Side Step은 부적 상관성(P<.000)이 나타났다. %BF는 대부분의 체력 변인에서 부적 상관성(P<.000)이 나타났으며, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion는 통계적으로 유의한 정적 상관성(P<.000)이 나타났다. 여성의 체력과 BMI는 Lt Grip Strength, Rt Grip Strength에서 낮은 정적 상관성(P<.05)이 나타났으며, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion은 높은 정적 상관성이 나타났다(P<.000). 그리고 Sit-Up과 낮은 부적 상관성(P<.05)이 나타났으며 VO2max, Sargent Jump, Side Step은 높은 부적 상관성이 나타났다(P<.000). %BF는 VO2max, Sit-Up, Sargent Jump, Side Step과 높은 부적 상관성(P<.000)이 나타났으며 Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion과 낮은 정적 상관성(P<.05)이 나타났다.

3. 집단(BMI, %BF)에 따른 신체구성과 체력 비교

BMI, %BF의 집단을 구분하여 Group A는 BMI <25kg/m2, %BF <25%(남성)와 %BF <30%(여성)로 BMI, %BF 모두 정상집단, Group B는 BMI ≥25kg/m2로 비만집단, %BF <25%(남성)와 %BF <30%(여성)로 정상집단, Group C는 BMI <25kg/m2로 정상집단, %BF ≥25%(남성)와 %BF ≥30%(여성)로 비만집단, Group D는 BMI ≥25kg/m2, %BF ≥25%(남성)와 %BF ≥30%(여성)로 나누어 체력 수준을 비교하였다. 실험 결과 연령, 신장은 Group B에서 가장 높게 나타났으며(P<.000), 체중, BMI, WHR, %BF, BFM은Group D에서 가장 높게 나타났다(P<.000). 체력 변인 중 VO2max, Sit and Reach, Side Step은 Group A에서 가장 높게 나타났으며(P<.000), Lt Grip Strength, Rt Grip Strength, Group, Sit-Up, Push-Up, Sargent Jump, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion은 Group B에서 가장 높게 나타났다(P<.000).

4. 로지스틱 회귀분석을 통한 심폐체력 수준 비교

심폐체력(VO2max) 수준이 정상인 집단(Normal CRF)과 낮은 집단(Low CRF)을 구분하여 집단 간 차이와 로지스틱 회귀분석을 실시하였으며 연령은 Normal CRF 집단이 통계적으로 유의하게 높게 나타났으며(P<.000) 체중, BMI, WHR, %BF, BFM은 Low CRF 집단이 통계적으로 유의하게 높게 나타났다(P<.000). 체력의 경우 VO2max, Lt Grip Strength, Rt Grip Strength, Sit-Up, Push-Up, sit and Reach, Sargent Jump, Side Step, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion 모두 Normal CRF 집단이 통계적으로 유의하게 높게 나타났다(P<.000). 체중이 1증가할 때 심폐체력이 Low CRF 집단으로 속하게 될 확률은 통계적으로 유의하게 1.358배 증가하였다(P<.000). WHR이 1증가할 때 심폐체력이 Low CRF 집단으로 속하게 될 확률은 통계적으로 유의하게 6.705E30배 증가하였으며(P<.000), %BF가 1증가할 때 심폐체력이 Low CRF 집단으로 속하게 될 확률은 통계적으로 유의하게 .422배 감소하였다(P<.000). 체력에서는 VO2max가 1증가할 때 심폐체력이 Low CRF 집단으로 속하게 될 확률은 통계적으로 유의하게 .114배 감소하였다(P<.000).

위와 같은 결과로 볼 때 신체구성 중 비만과 관련된 수준은 연령이 증가될수록 지속적으로 증가하며 체력 수준의 경우 20대 이후로 지속적으로 감소한다고 볼 수 있다. BMI, %BF는 체력 수준과 높은 관련성이 있는 것으로 나타났으며, BMI가 근력 수준과 높은 정적 상관성이 있는 것으로 나타났으며 %BF는 모든 체력 변인에 부적 상관성이 나타났다. 따라서 근력이 높을 경우 BMI 수준이 높을 수 있으며 비만을 평가하는데 있어서 BMI는 다른 비만관련 변인들과는 독립적인 해석일 필요할 것으로 판단된다. 또한 체중과 체지방의 감소 또는 체력 증가를 시키는 것이 심폐체력을 증가시키기 위한 중요한 수단이 될 수 있으며 BMI, %BF와 부적 관련성이 있는 체력 수준을 높이는 것이 비만 해소에 도움이 될 수 있을 것으로 사료된다. 따라서 본 연구를 토대로 성인의 체력수준과 비만을 적절하게 분석할 수 있도록 관련 변인에 대한 지속적인 연구와 연령의 증가에 따른 체력 수준의 관리, 체지방 감량을 위한 구체적이고 체계적인 프로그램이 필요할 것으로 생각된다.

This study analyzed difference and correlation between body composition and fitness level by dividing it into age-based(20s, 30s, 40s, 50s, 60s) and BMI & %BF group-based(Group, A, B, C, D) through a longitudinal study targeting 3721 men and 379 women in adults of our country, divided cardiorespiratory fitness into the low group and the normal group, and carried out logistic regression analysis. And then the following conclusions were obtained.

1. A comparison between body composition and fitness according to age


In the age-based group, the statistically significant difference(P<.000) was shown in all of body composition(BMI, WHR, %BF, BFM) and fitness(VO2max, Lt Grip Strength, Rt Grip Strength, Sit-Up, Push-Up, sit and Reach, Sargent Jump, Side Step, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion). Weight was maintained until the 30s-40s, and then was gradually reduced. BMI was indicated to increase up to the 50s and then to decrease. WHR and %BF were grown proportionally in the more rise in age. BFM was indicated to increase up to the 30s and then to decrease following the 40s at the similar level. All of VO2max, Sit-Up, Push-Up, sit and Reach, Sargent Jump, Side Step, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion were indicated to be the highest in the 20s. Lt Grip Strength, Rt Grip Strength were indicated to be the highest in the 40s.

2. Correlation among BMI, %BF, and fitness

As a result of correlation among BMI, %BF, and fitness, the statistically significant negative correlation(P<.000) was shown in most variables. BMI, and Grip Strength, Sargent Jump, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion were shown the statistically significant positive correlation(P<.000). Men''s fitness and BMI were shown the statistically significant positive correlation in all of Lt Grip Strength, Rt Grip Strength, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion. VO2max, Sit-Up, Push-Up, Sit and Reach, Sargent Jump, Side Step were shown the negative correlation(P<.000). %BF was shown the negative correlation(P<.000) in most of fitness variables. Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion were shown the statistically significant positive correlation(P<.000). Women''s fitness and BMI were shown low positive correlation(P<.05) in Lt Grip Strength, Rt Grip Strength. Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion were shown high positive correlation(P<.000). Low negative correlation(P<.05) was shown with Sit-Up(P<.05). VO2max, Sargent Jump, Side Step were shown high negative correlation(P<.000). %BF was shown high negative correlation(P<.000) with VO2max, Sit-Up, Sargent Jump, Side Step. The low positive correlation(P<.05) was shown with Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion.

3. A comparison between body composition and fitness according to group(BMI, %BF)

BMI & %BF group was divided. Group A was divided into normal group in all of BMI, %BF with BMI <25kg/m2, %BF <25%(men) and %BF <30%(women). Group B was divided into the obesity group with BMI ≥25kg/m2 and the normal group with %BF <25%(men) and %BF <30%(women). Group C was divided into the normal group with BMI <25kg/m2 and the obesity group with %BF ≥25%(men) and %BF ≥30%(women). Group D was divided into BMI ≥25kg/m2, %BF ≥25%(men) and %BF ≥30%(women). Then, the fitness level was compared. As a result of experiment, the age and height were indicated to be the highest in Group B(P<.000). Weight, BMI, WHR, %BF, BFM were indicated to be the highest in Group D(P<.000). Out of fitness variables, VO2max, Sit and Reach, Side Step were indicated to be the highest in Group A(P<.000). Lt Grip Strength, Rt Grip Strength, Group, Sit-Up, Push-Up, Sargent Jump, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion were indicated to be the highest in Group B(P<.000).




4. A comparison of cardiorespiratory fitness level through logistic regression analysis

It carried out the group-based difference and logistic regression analysis by dividing VO2max(the cardiorespiratory fitness) into Normal CRF and Low CRF. Age was indicated to be statistically significantly high(P<.000) in Normal CRF group. Weight, BMI, WHR, %BF, BFM were indicated to be statistically significantly high(P<.000) in Low CRF group. In case of fitness, VO2max, Lt Grip Strength, Rt Grip Strength, Sit-Up, Push-Up, sit and Reach, Sargent Jump, Side Step, Rt Knee Extension, Lt Knee Extension, Rt Knee flexion, Lt Knee flexion were all indicated to be statistically significantly high(P<.000) in Normal CRF group. The probability that the cardiorespiratory fitness will belong to Low CRF group when weight increases by 1 grew statistically and significantly by 1.358 times(P<.000). The probability that the cardiorespiratory fitness will belong to Low CRF group when WHR increases by 1 grew(P<.000) statistically and significantly by 6.705E30 times. The probability that the cardiorespiratory fitness will belong to Low CRF group when %BF increases by 1 reduced(P<.000) statistically and significantly by .422 times. The probability that the cardiorespiratory fitness will belong to Low CRF group when VO2max increases by 1 reduced(P<.000) statistically and significantly by .114 times.

Seeing the above results, it can be considered that the obesity-related level out of body composition continuously grows in the more increase in age and to continuously reduce following the 20s in case of fitness level. BMI, %BF were indicated to have high relationship with fitness level. BMI was indicated to have high positive correlation with muscular strength level. %BF was indicated the negative correlation in all fitness variables. Accordingly, when muscular strength is high, BMI level may be high. In evaluating obesity, BMI is judged to likely need independent analysis from other obesity-related variables. Also, what reduces weight and body fat or increases fitness can be an important means for increasing the cardiorespiratory fitness. What increases fitness level, which has negative relationship with BMI, %BF, is considered to be likely conducive to resolving obesity. Hence, based on this study, it is thought to be necessary for a continuous research on relevant variables in order to possibly analyze properly adults'' fitness level and obesity and for a specific and systematic program with the aim of managing fitness level and losing body fact according to a rise in age.