Association between different attributes of physical activity and fat massin untrained, endurance- and resistance-trained men

The objective of this cross-sectional study was to assess different attribu tes of physical activity and fitness and their relationship to nutritional state in endurance- and resistance-trained. compared to untrained men. The subjects were 42 men matched for age, of which 13 were untrained [UT, mean age 30.2 years, mean height 180.7 cm, mean body mass 83.6 kg, mean body mas s index (BMI) 25.6 kg(.)m(-2)], 14 were endurance-trained athletes (ET, mea n age 29.6 years, mean height 178.4 cm, mean body mass 74.0 kg, mean BMI 23 .2 kg(.)m(-2)) and 15 were: resistance-trained athletes (RT, mean age 25.4 years, mean height 183.4 cm, mean body mass 94.1 kg, mean BMI 27.4 kg(.)m(- 2)). Fat mass (FM), fat free mass (FFM) muscle mass (MM) and total body wat er (TBW) were assessed using anthropometry and bioelectrical impedance anal ysis. Resting energy expenditure was measured by indirect calorimetry (IC) and total energy expenditure (TEE) by a combination of IC and individually calibrated 24-h heart-rate monitoring. The activity related energy expendit ure (AEE) and the physical activity level were calculated. Movements were a ssessed using pedometry. Aerobic fitness was determined using ergometry, mu scle strength [quadriceps muscle (Fa(max)), ischiocruralis muscle (Fb(max)) , biceps muscle (Fc(max)), triceps muscle (Fd(max))] by computer tensiometr y. Different time domain indexes of heart rate variability (HRV) were exami ned during sleep, rest and the whole;lav as an index of sympathetic nervous system (SNS) activity. When compared with UT and RT, ET had reduced body m asses and FM, but increased percentage TBW (P < 0.05 and P < 0.01, respecti vely). FFM and MM were increased in RT, when compared with UT and ET (P < 0 .01). ET had higher TEE, AEE, pedometry derived activities, oxygen consumpt ion and power during vigorous exercise than RT and UT (P < 0.05 and P < 0.0 1, respectively). Respiratory exchange ratio at moderate exercise intensiti es was increased in RT (P < 0.05). In the 12 time domain indexes of HRV 6 a nd 10 were higher in ET than in RT and UT respectively (P < 0.05 or P < 0.0 1, respectively) suggesting an increased SNS activity in ET. By contrast, F a(max), Fc(max) and Fd(max), were elevated in RT (P < 0.01). FM was negativ ely associated with aerobic fitness, but not with muscle strength. We concl uded that the physiological and metabolic adaptations to exercise and nutri tional state differ between ET and RT subjects. Participation in RT results predominantly in changes in body composition and strength but not in energ y expenditure, movements and SNS activity. The opposite was the case for ET . Aerobic fitness, physical activity, movements and activity of SNS were al l increased but body mass and FM were decreased. The latter finding may sup port the idea that, with regard to possible health benefits, ET is more eff ective than RT.