Exercise profile during cycling, and fitness and health level among middle and older adults with a cycling habit / 体力科学

This study evaluated the exercise profile (heart rate, cycling speed and pedal cadence) during 25-30 km cycling and fitness and health level for adults (11 males: 69.6 ± 4.7 yrs; 6 females: 66.3 ± 4.9 yrs) with a recreational cycling habit (27.6 ± 14.8 km/week). Exercise intensity at a constant speed on a flat road during male and female cycling was 71.2 ± 11.5 and 66.8 ± 11.4% heart rate reserved (HRR), respectively. Exercise intensity over 60% HRR occupied 72% of cycling time. Peak intensity during male and female cycling was 89.2 ± 8.9 and 93.1 ± 6.1% HRR, respectively. VO2max and CS (chair stand)-30 test for male and female were 40.3 ± 4.3 and 37.7 ± 2.4 ml/kg/min, and 30.8 ± 3.1 and 30.1 ± 3.2 times, respectively. The muscle cross-sectional area of thigh extensor and flexor measured by MRI were 55.4 ± 6.5 and 58.3 ± 13.3 cm² for male, and 45.5 ± 6.4 and 50.2 ± 5.7 cm² for female, respectively. Blood profile for HDL-C (cholesterol), LDL-C and HbA1c (JDS) for male and female were 65.9 ± 8.2 and 67.9 ± 10.6 mg/dl, 112.3 ± 32.0 and 130.6 ± 12.3 mg/dl, and 4.8 ± 0.4 and 4.7 ± 0.1%, respectively. Fitness level and blood profile results were superior to those of the same aged adults. We concluded that the exercise intensity of cycling by middle and older adults with a recreational cycling habit is high and their fitness and health level are higher than average adults.

PROFILES OF ACTIVITIES OF THIGH MUSCLES DURING SPRINT RUNNING IN TRACK AND FIELD ATHLETES EXPERIENCED HAMSTRINGS (MUSCLE) STRAIN INJURY － DIFFERENCE BETWEEN INJURED AND NON INJURED LEGS － / 体力科学

The present study aimed to investigate the profiles of activities of thigh muscles during 100 m sprint running in track and field athletes experienced hamstrings (muscle) strain injury, with specific emphasis on the difference between injured and non-inured legs. The subjects were 20 track and field athletes who were divided into muscle strain injury group (MS) and non muscle strain injury group (NMS). The electromyograms (EMGs) of five thigh muscles (the biceps femoris, semitendinosus, rectus femoris, vastus lateralis and vastus medialis) and knee joint angles were recorded during 100 m sprint running. For NMS, there were no significant differences between the right and left legs. For MS, the averaged EMG of every muscle,expressed as relative to that during maximum voluntary contraction (%mEMG_MVC), values of the biceps femoris and semitendinosus in the latter phases of takeoff and swing periods were significantly higher in the injured leg than in the non-injured leg. Also, the maximal flexed and extended angles of the knee joint during takeoff and swing period, respectively, for the injured leg were significantly greater than those for non-injured leg. Thus, the present results indicate that track and field athletes experienced hamstrings (muscle) strain injury show by higher EMG activities in the biceps femoiris and semitendinosus of the injured leg at the later phases of swing and takeoff periods during 100 m sprint running. This may be partially related to the running style with a greater extended position of knee joint angles at the corresponding phases.