The present study aimed to investigate whether daily steps in male college students have actually decreased in the last decade. If the decline in steps is found, we additionally aimed to examine whether the decline in steps is attributed to a reduction of exercise or, rather, to a reduction of non-exercise activity. A serial cross-sectional study was performed from 2003 to 2012 at the Osaka Institute of Technology. A total of 1,215 male college freshmen were analyzed. Every year, scores of the physical activity levels were evaluated by a questionnaire, and we measured daily steps of participants using a pedometer during usual 1 week. Daily behavior record was also analyzed (n = 69). There were no significant trends or differences in characteristics of participants and the scores of physical activity levels throughout the 10 years. However, interestingly, significant decreasing trends were observed in the steps of average and weekend. In addition, daily behavior record analyses indicate that a cell-phone or a PC usage increased significantly in both weekday and weekend and that playing video games increased significantly in weekday. Therefore, these data support the view that daily steps have actually reduced in the last decade. Our findings also raise the possibility that the decline in steps may be related to the decline in non-exercise activity associated with the increase in a cell-phone or a PC usage and playing the video games.

The present study aimed to examine the effects of Internet addiction on daily steps. A cross-sectional study was performed at the Osaka Institute of Technology. A total of 334 male college freshmen were analyzed. The participants were assigned to five groups according to Internet addiction levels. Internet addiction levels were assessed by Diagnostic Questionnaire, which has been reported by Young (1998), and we measured daily steps of the participants using a pedometer during usual 1 week. There were no significant trends or differences among five groups in physical characteristics of the participants, sleep duration, frequency of eating breakfast, and walking during commute time. However, with the level of Internet addiction increasing, daily steps showed a statistically significant decreasing trend. Therefore, Internet addiction levels might be related to reductions in steps in a dose-response manner. To clarify this point, further investigations will be required after considering confounding factors.

The present study aimed to examine the effects of community-based intervention on cognitive function and hand finger dexterity in older adults at different levels of time to go out. Forty men and women (age, 73 ± 1 years) participated in supervised group activity and seated exercise for 60 min per session, once each week during an 8-week intervention. The participants wore an activity monitor for 1 week to determine baseline values and for the 8 weeks of intervention. Mini-mental state examination (MMSE) and pegboard test, which is related to cognitive function, were assessed before and after the intervention. Based on the total time to go out at baseline, the participants were assigned to Control group (> 60 min/day, n = 18) or Short group (≦ 60 min /day, n = 22), and then analyzed. After the 8 weeks of intervention, the Control and Short groups improved physical fitness parameters such as handgrip strength. Although MMSE in the both groups did not reach statistically significant level, these values tended to increase slightly from the baseline. Interestingly, two-way repeated-measures analysis of variance indicated significant interaction of pegboard test, and the score significantly increased only in the Short group. Total physical activity and moderate-vigorous physical activity in the both groups did not change significantly between the baseline and intervention periods. Therefore, these results suggest that the trainability of pegboard test, which is an index of hand finger dexterity and is related to cognitive function, would differ depending on the time to go out at baseline in older adults.

This study aimed at clarifying the effects of a lifestyle intervention using an activity monitor with game functions on daily physical activity. A 12-week randomized crossover study was conducted in 23 healthy volunteers (31 ± 11 yrs). The subjects were randomly assigned to Group A (a 6-week game intervention and then a 6-week normal intervention) and Group B (a 6-week normal intervention and then a 6-week game intervention). In the game intervention period (G), the subjects wore two different activity monitors, namely a normal activity monitor (Lifecorder EX) and an activity monitor with game functions (Yuuhokei). On the other hand, in the normal intervention period (N), the subjects wore only a normal activity monitor. Daily steps were significantly higher in the G than in the N (G: 10417 ± 2358 vs. N: 8744 ± 2180 steps/day, P < 0.001). Amount of physical activity (i.e., daily total METs · hour = Ex/day) at the intensity of 3 METs or more was significantly higher in the G than in the N (G: 3.1 ± 0.9 vs. N: 2.4 ± 0.8 Ex/day, P < 0.001). Our results indicate that the lifestyle intervention using an activity monitor with game functions would more effectively increase daily physical activity such as steps and physical activity amount, than a normal intervention using an activity monitor. These findings therefore have important implications for reaching more easily the goals (i.e., 23 Ex/week or 10,000 steps/day) and the use of an activity monitor with game functions in the field of exercise or physical activity instructions.

This study aimed to examine a new walking method to fulfill the Physical Activity Reference for Health Promotion in Japan in a shorter time, which can be performed as a non-exercise activity (NEA) such as walking during commuting. Eleven healthy subjects performed normal walking (NW) and knee-up walking (KU) for eight minutes without load (0%) and with loads of 5, 10, and 20% of body mass in a backpack carried on the back (NW-0, 5, 10, and 20; KU-0, 5, 10, and 20) on a treadmill at a speed of 5 km/h at 0% tilt. Oxygen uptake, blood lactate levels, and ratings of perceived exertion (RPE) were measured in the last two minutes of each walking stage. Metabolic equivalents (METs) were also calculated from the resultant oxygen uptake. METs in NW-20 and all weight conditions of KUs were significantly greater (P < 0.01) than those in NW-0 (3.8 ± 0.1 METs). RPE in both KU-10 and KU-20 was above 15 (i.e., indicating Hard). Blood lactate levels in the KU-20 (4.5 ± 0.7 mmol/L) were above the Onset of Blood Lactate Accumulation. On the other hand, NW-20, KU-0, and KU-5 were physical activity level of moderate- to vigorous- intensity that could be performed as a NEA. These data suggest that our new walking methods such as NW-20, KU-0, and KU-5 can satisfy the Physical Activity Reference in a shorter time rather than normal walking, and could be continuously performed in daily life.

This study aimed to clarify the effects of a lifestyle intervention by the concurrent use of an activity monitor and Twitter on daily physical activity. Twenty-one healthy males and females (37 ± 13 yrs) were randomly assigned to Normal intervention group (N group, n = 10) or Twitter intervention group (T group, n = 11). In both groups, the intervention period was 6 weeks. Participants in N group wore an activity monitor (Lifecorder EX). Meanwhile, participants in T group were asked to tweet about their daily steps or physical activity in addition to wearing an activity monitor, and also an observer read through the tweet from each participant and commented about physical activity. There were no significant differences in daily physical activity (i.e., steps and amount of physical activity (PA)) at week 1 between both groups. In addition, no significant time-course changes in steps and amount of PA were observed in N group. In contrast, steps in T group were gradually increased from week 1 8,542 ± 3,158 steps/day to week 6 12,700 ± 3,935 steps/day (P < 0.01). Amount of PA in T group was also gradually increased from week 1 2.5 ± 1.2 METs·hour/day to week 6 4.6 ± 2.3 METs·hour/day (P < 0.01). Therefore, these findings indicate that the lifestyle intervention by the concurrent use of an activity monitor and Twitter could effectively induce an increase in daily physical activity compared with the intervention using only an activity monitor.

This retrospective observational study aimed to examine the effects of playing Pokémon GO on daily steps of male college students. Twenty-five Japanese male college students (20 ± 1 years) were assigned to Control group (C, n = 11) or Pokémon GO group (P, n = 14) based on their playing Pokémon GO or not. Daily step levels were obtained from the health care app of Apple iPhone from September 2016 to October 2016. In P group, the data for the 4 weeks to determine baseline values and for the 4 weeks of playing Pokémon GO were analyzed. The steps data of C group were also analyzed in the same period of the total 8 weeks. There were no significant differences in steps at baseline level between both groups. In addition, no significant time-course changes in steps were observed in C group. In contrast, steps in P group significantly increased from baseline 8,368 ± 544 steps/day to week 1 10,028 ± 617 steps/day (P < 0.01). The changes in steps from baseline to week 1 were significantly greater in P group than in C group (1,671 ± 345 vs. -81 ± 582, P < 0.01). However, the increased steps returned to baseline level by week 2, and the values did not increase again. Therefore, our findings indicate that playing Pokémon GO increases daily steps only during one week in Japanese male college students.

Present study aimed to examine the effects of high-intensity intermittent training on metabolic or circulatory parameters and exercise time during 30s-lasting exhaustive exercise. Six healthy males (22 ± 1yrs) had an intermittent training four days a week for four weeks. The intermittent training consisted of 8 or more sets of 20s exercise bout at an intensity of 170%VO2 max separated by 10-s recovery. Before and after training period, VO2 max and maximal accumulated O2 deficit (MAOD) were determined as indices of metabolic capacity. During 30s-lasting exhaustive exercise, VO2, O2 deficit, and circulatory parameters, such as heart rate, stroke volume, and cardiac output, were also determined every 10s. After the training, VO2 max and MAOD were significantly increased. During 30s-lasting exhaustive exercise, exercise time, stroke volume, and cardiac output were also significantly enhanced. However, no significant differences were observed in VO2 and O2 deficit every 10s during 30s-lasting exhaustive exercise. Therefore, these findings suggest that high-intensity intermittent training enhances exercise time during 30s-lasting exhaustive exercise and that the improvement of exercise performance is closely related to an increase in anaerobic capacity.

Single-tooth sandals under new development have special material and shape characteristics. Exercises with single-tooth sandals can increase pressing stimulus on the soles of the feet, thereby suppressing a decline in medial longitudinal arch and elevating sole surface temperature. This study thus aimed to examine the effects of exercise with single-tooth sandals on medial longitudinal arch and sole surface temperature. Sixteen young adults (23 ± 5 years) participated in 20 min of stepping exercise on the spot. They randomly put on a regular normal sandal (N conditions) or a single-tooth sandal (Z conditions) on each left and right side. Before and after exercise, medial longitudinal arch and sole surface temperature were assessed by digital caliper and straightedge and thermography, respectively. No significant differences in baseline parameters were observed between N and Z conditions. After exercise, arch height and arch height ratio significantly reduced in N conditions, but not in Z conditions. Central sole surface temperature in Z conditions also increased significantly, and the changes in surface temperature were significantly higher in Z conditions than in N conditions. Therefore, these findings suggest that exercise with single-tooth sandals has a positive effect on a suppressing decline in medial longitudinal arch and an elevation in sole surface temperature.

Green tea catechins are well known to be one of polyphenols, and its regular ingestion induces body fat reduction in obese individuals. Cocoa polyphenols of high-cocoa chocolate can also improve arterial stiffness. However, it is unclear whether green tea catechins improve body fat and arterial stiffness even in healthy young adults. Therefore, this study aimed to examine the effects of regular green tea intake on body fat and arterial stiffness in young adults. This randomized, controlled, parallel-group intervention study included 53 Japanese college students (mean age, 21.1 ± 0.1; men, n = 40; women, n = 13). They were randomly divided into three groups: control group (n = 14), intervention I group (n = 19), and intervention II group (n = 20). The participants ingested 500 ml/day of commercially available natural water (0 mg of catechin/day) or green tea (intervention I group, 200 mg of catechin/day; intervention II group, 400 mg of catechin/day) for 4 weeks. After 4 weeks of intervention period, no significant changes in body weight, body mass index, pulse wave velocity, and cardio-ankle vascular index were observed in all groups. However, body fat and carbon dioxide output significantly reduced only in the intervention II group. With the level of catechin concentrations increasing, significant decreasing trends were found in body fat changes and respiratory exchange ratio changes. Therefore, these findings suggest that four weeks of regular green tea intake would reduce body fat, but not arterial stiffness, in young adults.