Associations of body composition with physical activity, nutritional intake status, and chronotype among female university students in Japan.

BACKGROUND: Having higher muscle mass in early adulthood is an important factor in preventing sarcopenia. However, university students undergo lifestyle changes compared to their high school years, which may lead to changes in body composition, such as an increase in body fat and a decrease in muscle mass. The study aimed to investigate the association between body composition and lifestyle behaviors, including chronotype, among Japanese female university students, due to the prevalence of underweight among young females in the country. METHODS: The physical activity level (PAL), daily dietary intake status, morningness-eveningness questionnaire (MEQ) score, and body composition of 230 students were assessed in this cross-sectional study. Body composition was measured using a multifrequency bioelectrical impedance analyzer, and body mass index (BMI), body fat percentage (%BF), and skeletal muscle mass index (SMI) were determined. RESULTS: Individuals who were evening type (ET) had a higher %BF and lower SMI than those who were non-ET, but no differences in body weight or BMI were found. Although ET individuals had lower total energy intake, protein intake, and PALs than non-ETs, the differences were small. However, multiple regression analyses showed that SMI was significantly positively associated with MEQ and PAL, and %BF was significantly negatively associated with MEQ and PAL. CONCLUSION: These results suggest that female university students with lateness of chronotype and low physical activity have a body composition imbalance resulting in higher body fat and lower muscle mass. Therefore, young females may need to take chronotype-specific measures (especially ET individuals) to help them maintain an appropriate body composition.

Gait Improvement by Alerted Push-Off via Heating of Insole Tip.

This study investigated the change in the joint angles of the lower limb during gait by heating the tip of the insole to make a conscious push-off with the warm part. Fifteen healthy males performed treadmill walking under three different conditions: CONTROL walked as usual, INST was instructed to extend the stride with a push-off from the ball of foot to the toe, and HEAT was asked to walk while attempting to push off the warm area, which was attached to the disposable warmer to the area from the ball of foot to the toe of the insole. A 3D-motion capture system with infrared cameras was used to analyze the gait. The hip joint angle increased significantly under the INST and HEAT. Although the ankle dorsi-flexion at heel strike did not differ significantly for these conditions, ankle plantar-flexion significantly increased at toe-off under the INST and HEAT. Especially, effect size (d) in increased plantar-flexion was large in HEAT (=1.50), whereas it was moderate in INST (=0.68). These results suggest that a heated stimulus during gait enhanced the consciousness of push-off and increased leg swing and ankle plantar-flexion during the terminal stance phase, which may increase the stride length.

Association between Normal Weight Obesity and Skeletal Muscle Mass Index in Female University Students with Past Exercise Habituation.

This study investigated the relationship between normal weight obesity (NW-O) and skeletal muscle mass index (SMI) in 120 female university students who participated in sporting activities during junior and senior high school. The current physical activity level (PAL) was estimated by a factorial method using 24-h physical activity recall. The body mass index (BMI) of the participants ranged from 18.5 to 24.9 kg/m2; their body fat (BF) was classified as NW-O if above the 75th percentile (28.9% BF), normal weight and lean (NW-L) if below the 25th percentile value (21.0%BF), and all others were normal weight (NW). PAL was significantly lower in NW-O than in NW-L. SMI was significantly lower in NW-O than in NW and NW-L, and 60% of NW-O had Low-SMI (<6.3 kg/m2). Although lower limb muscle mass was significantly lower in NW-O than in NW and NW-L, no significant differences were found in the upper limbs. These results suggest that the current PAL is associated with NW-O, and NW-O is associated with a lower SMI, even in young females with past exercise habits. Therefore, the prevention of NW-O in young females is important for the prevention of not only lifestyle-related diseases, but also future sarcopenia.

The CLOCK 3111T/C polymorphism is associated with hour-by-hour physical activity levels only on weekends among Japanese male and female university students.

BACKGROUND: CLOCK 3111T/C has been shown to be closely associated with morningness-eveningness, such as sleep-wake rhythms in healthy humans. However, previous studies examined the physical activity (PA) in a single day, and no study has investigated the relationships between CLOCK 3111T/C polymorphism and PA for an entire week. It was hypothesized that the CLOCK 3111T/C polymorphism might be associated with diurnal PA patterns, especially on the weekends. METHODS: Eighty-one university students (male, n = 14; female, n = 67; age, 20.4 ± 2.9 years) wore a digital accelerometer for 7 successive days, including the weekend, to collect hour-by-hour objectively-measured PA. CLOCK 3111T/C polymorphism was assessed using the oral mucosa. During the study, participants recorded their wake time and bedtime each day. Furthermore, lifestyle-related variables (i.e. morningness-eveningness, habitual meal and sleep timings) were collected using questionnaires. Linear mixed-effects models assessed the association of polymorphism (TT carriers vs. TC+CC carriers) with wake time and bedtime as well as daily PA throughout the week (time). RESULTS: TT carriers had an earlier wake time (weekly mean: 44 min [95% CI, -82 to -5 min], time interaction: p = 0.026) and bedtime (weekly mean: 30 min [95% CI, -61 min to - 15 s], time interaction: p = 0.048) than TC+CC carriers. Furthermore, TT carriers' wake time and bedtime on Saturday were significantly later than on other days (gene interaction: all p < 0.05). On Saturday, the hour-by-hour PA in TT carriers was significantly greater than that in TC+CC carriers (hourly mean 1.7 min [95% CI, 0.2 to 3.4 min], time: p < 0.001, group: p = 0.028, interaction: p = 0.155). CONCLUSIONS: CLOCK 3111T/C polymorphism may be associated with objectively measured hour-by-hour PA only on Saturday. Academic/social obligations may mask the genetically determined biological rhythm of PA on weekdays.

An association between the physical activity level and skeletal muscle mass index in female university students with a past exercise habituation.

OBJECTIVES: This study aims to investigate the association between skeletal muscle mass index (SMI) and physical activity among female university students who had exercise habituation in junior and high school. METHODS: The body composition of 120 Japanese female students was measured using the bioelectrical impedance analysis (BIA) method, and their physical activity level (PAL) was measured using a factorial method. Based on the 'Dietary Reference Intakes for Japanese' (DRIs-J), according to the Ministry of Health, Labour and Welfare, PAL (24-h energy consumption/basal metabolic rate) classifications were defined as low-PAL (PAL < 1.6), moderate-PAL (1.6 ≤ PAL < 1.9), and high-PAL (1.9 ≤ PAL < 2.2), respectively. RESULTS: Individuals with low-PAL had a significantly lower SMI, especially for the lower limb muscles, than individuals with moderate-PAL or higher. More than 50% of the individuals with currently low-PAL corresponded or tended to correspond to the SMI cut-off value defined by the Asian Working Group for Sarcopenia or the 2017 National Health and Nutrition Survey of Japan. Therefore, more than half of the female students with currently low-PAL, even those with an exercise habituation in the past, corresponded to the cut-off value for muscle loss in sarcopenia diagnosis, particularly in the lower limbs. CONCLUSIONS: These results suggest that it is important to maintain a moderate or higher level of physical activity in the DRIs-J classification, even for young women who used to exercise in the past, to maintain muscle mass accordingly.

Immediate after-effects of shapes of clothing worn on tandem gait performance.

PURPOSE: This study investigated the immediate after-effects of clothing shape on tandem gait performance. METHODS: Nineteen healthy men (21.8 ± 1.8 years) performed tandem gait tests while blindfolded under three clothing conditions: only half or short tights, a cotton cloth wrapped around the waist and draped to the middle point of the lower leg (DC), and tracksuit bottoms (TS). Participants performed pre- and post-gait tests at their fastest possible speed while wearing tights. Between the pre- and post-tests, participants practiced the same tandem gait, but at their own chosen speed while wearing DC or TS. RESULTS: The practice with the DC increased gait speed and decreased lateral shift during the post-gait test compared to the pre-gait test. The practice while wearing the TS also reduced lateral shift but did not increase gait speed. CONCLUSIONS: These results suggest that some clothing shapes are more effective for motor learning of balance control during tandem gait by enhancing the feedback for body orientation. Clothing that has a certain amount of space between the material and the body and that makes contact with the body as it moves may be more effective.

Influence of tactile sensitivity in the finger on postural control while using the light touch effect.

Providing additional tactile sensory input, such as light finger touch, improves postural control while standing. This phenomenon is called light touch (LT) effect. The present study investigated influences of tactile sensitivity in a finger on the magnitude of improvement in postural sway owing to LT. The participants were 16 healthy men (20-33 years). They performed two upright postures with their eyes closed; their feet 1) comfortably apart (normal stance) and 2) together in a side-by-side stance (Romberg stance). These tasks were performed both with and without LT. The participants let their right index finger lightly touch a fixed surface. The tactile sensitivity in the finger was evaluated using a two-point discrimination test. Although postural sway decreased owing to the LT, the association between tactile sensitivity in the finger and the percentage change in postural sway was not statistically significant, regardless of the difficulty of the upright tasks. These results suggested that the person might not be able to perceive a change in direction in their posture through LT; however, the LT might be recognized as a reference point to detect relative changes in the alignment of the body. Therefore, tactile sensitivity in the finger might not be necessary to achieve the LT effect.

Development and initial validation of the Morningness-Eveningness Exercise Preference Questionnaire (MEEPQ) in Japanese university students.

The aim of this study was to develop a questionnaire to conveniently assess the diurnal preferences of physical activity (PA) in Japanese university students. A total of 219 subjects completed our novel Morningness-eveningness Exercise Preference Questionnaire (MEEPQ). The MEEPQ consisted of 30 items (15 items for the morning and the same 15 items for the evening) rated on a 5-point Likert scale concerning their preference for participating in PA in the morning and evening. The morning score (MS) and evening score (ES) were determined by summing each of the respective 15 items. The internal consistency and construct validity were assessed, and a factor analysis was conducted. To examine the external validity of the MEEPQ, participants wore an accelerometer for seven consecutive days to measure their PA levels objectively. Finally, the test-retest reliability was evaluated at a one-month interval. The MEEPQ showed excellent internal consistency (Cronbach's alpha = 0.896) and construct validity (morning KMO = 0.913, evening KMO = 0.875). A factor analysis showed a three-factor structure involving Physical Wellness (MEEPQ-W), Psychological Well-Being (MEEPQ-P) and Exercise Barrier (MEEPQ-B). The percent of variance was largest for MEEPQ-W in the morning (45.2%) and MEEPQ-P in the evening (40.8%). Test-retest showed that MEEPQ scores had fair repeatability. Significant and positive associations between scores and objectively measured PA levels were found in the MS and 6-9 AM PA and in the ES and 6-9 PM and 9 PM- 0 AM PA (all p<0.05). In summary, the novel MEEPQ showed relatively good agreement and thus can be used for Japanese university student samples. In the MEEPQ, three factors (the physical wellness, psychological well-being and exercise barrier) contributed to a morning or evening PA preference. The summed scores were significantly associated with the objectively measured PA levels in both the morning and evening. Therefore the MEEPQ appears to be a suitable tool for assessing diurnal PA preferences.

Influence of light finger touch on postural stability during upright stance with cold-induced plantar hypoesthesia.

The present study investigated the influence of light finger touch on postural stability during an upright stance with or without cold-induced plantar hypoesthesia. Participants were 21 healthy right-handed men (20-33 years), randomly assigned to a normal temperature group (NML-group; n = 11) or cold-induced plantar hypoesthesia group (COLD-group; n = 10). Participants performed two standing tasks with their eyes closed: 1) stand upright with the feet comfortably apart (normal standing); and 2) with the feet together in a side-by-side stance (Romberg standing). The order of the tasks was randomized across participants. After a rest period, they were asked to perform each standing task and let their right index finger lightly touch the fixed surface. Before the each task, participants in the COLD group were conducted a plantar intermediate hypothermic exposure. Postural sway was decreased by providing additional haptic sensory input through the light touching regardless of standing task difficulty with a normal plantar temperature. Although postural sway under plantar hypoesthesia is decreased by light touching, the effect was greater during the difficult posture task. These results suggest that, when the sensory information from the plantar surface is decreased, additional haptic input from the hand or finger might provide supplementary information about the relative changes in one's own body orientation. Therefore, sensory information provided by touching became relatively more important to maintaining postural control during the relatively difficult postural task performed under the reduced plantar sensitivity condition.

Effect of haptic sensory input through a fluttering cloth on tandem gait performance.

This study investigated the effects of haptic sensory input through a fluttering cloth on balance control during locomotion. Twenty-one healthy men performed a tandem gait test for 4m with their eyes closed under two different conditions: (1) wearing only half or short tights (HT-condition), or (2) wearing a fluttering cloth that was wrapped around the waist and extended to the lower leg (CLOTH-condition). Participants performed two trials with a 3-min rest period. The first trial involved the HT-condition, whereas the second trial involved either the CLOTH-condition (n=11), or the HT-condition again (n=10). The gait time and double support phase were significantly lower in the CLOTH-condition than in the HT-condition, and the relationship between the change in these two parameters was significant (r=0.74, P<0.01). Further, the relationship between the change in gait time and subjective walking sensation (evaluated through a visual-analogue scale) was significant in the CLOTH-condition (r=0.82, P<0.01). Therefore, if the participant demonstrated improved gait performance while wearing a fluttering cloth, it was accompanied by an improvement in subjective walking sensation. These results suggest that wearing a fluttering cloth can provide a haptic sensory cue to enhance the individuals' perception of their body orientation, which contributes to better balance control during locomotion. Therefore, locomotive ability may improve depending on the shape of the garment.

Effect and immediate after-effect of lightly gripping the cane on postural sway.

BACKGROUND: This study investigated the effect and after-effect of lightly touching a real cane on postural sway and ankle muscle activity. METHOD: Participants performed a single-leg stance (SLS) task with their eyes closed for 30 s under three tasks. In the first and third tasks, the participants performed a normal SLS. In the second task, the participants in light-grip group (n = 11) were asked to perform SLS while lightly gripping a cane with their hand. The participants in depend-on-cane group (n = 11) were asked to support their own body with a cane. RESULTS: Postural sway during a single-leg stance is decreased by light gripping and is accompanied by decreased co-contraction of the ankle-joint muscles. If a participant lightly gripped a cane, postural sway decreased not only during the light gripping but also immediately after the withdrawal of the cane. Although postural sway and co-contraction in the depend-on-cane group were significantly decreased during the second task compared to the first task, they were not significantly changed between the first and third tasks. CONCLUSION: These results suggest that lightly gripped cane provides a haptic sensory cue that can be used to assist postural control mechanisms due to enhanced perception of self-motion through sensory interaction with the environment through the cane. Further, the haptic sensory cue during postural maintenance might be promoted as a practice effect of postural control.

The Effect of Lightly Gripping a Cane on the Dynamic Balance Control.

The purpose of the current study was to investigate the effect of lightly gripping a cane on the Functional Reach Test (FRT) to evaluate dynamic balance. 21 healthy men (19±1 years) were asked to perform the FRT three times. The standard FRT was performed in the first and third trials. In the second trial, participants in a light-grip group (n = 11) were told to lightly grip (but to not apply force for mechanical support) the cane during the FRT. Participants in a depend-on-cane group (n = 10) were told to perform the FRT while supporting their weight with the cane. FRT is improved by not only supporting a person's own weight with a cane but also just lightly gripping the cane. These findings would be helpful in the development of a useful application to improve the human movement using a haptic sensory supplementation for activities of daily living.

Effects of light finger touch to the upper legs on postural sway and muscle activity during quiet standing.

The purpose of the present study was to investigate the effects of light finger touch (LT) to one's own body on postural sway and ankle muscle activity during quiet standing. In the first part of the present study, 24 healthy men (19 ± 1 years) stood upright with their eyes closed on a pneumatic balance disk under 3 different conditions. In the first condition, the participants kept their hands in loose fists, and contact between the fingers/palms and the legs was avoided. In the second condition, the participants touched the lateral sides of upper legs lightly (without applying force for mechanical support) with all fingers. In the third condition, the participants again held their hands in loose fists. Postural sway was significantly decreased during second condition compared to first condition. Further, it also tended to decrease in third condition (P = 0.08). The second part of the present study was designed to investigate the mechanisms underlying the association between postural sway and LT by analyzing electromyographic data. Data were obtained from 12 healthy men (20 ± 1 years). During quiet stance on the stable surface, soleus activity did not significantly change by LT. However, tibialis-anterior activity significantly decreased with LT. These results suggest that LT to the upper part of one's own legs decreases postural sway (during and after touching) during a still stance by decreasing co-activation of the ankle muscles.

Gender difference of aerobic contribution to surface performances in finswimming: analysis using the critical velocity method.

PURPOSE: Finswimming is a speed competition sport practiced on the surface or underwater, by using monofins or two fins. In surface events (SF), competitors should surface within 15 m after the start and any turns. The aim of this study was to investigate the gender differences in the aerobic contribution to SF performances in finswimming, using the critical velocity (CV) concept in the analysis. METHODS: The participants were sixteen monofin swimmers (eight males and eight females; 24±6 years). During a two-day period, participants performed maximal effort swimming at five test distances (100 m, 200 m, 400 m, 800 m and 1500 m), and mean swimming velocity (V) of each distance was calculated. CV was calculated as the slope of the regression line between time and distance in the 400 and 800 m SF tests. RESULTS: Although CV was significantly correlated with V800 m and V1500 m for males, it was significantly correlated with V200 m, V400 m, V800 m and V1500 m for females. CONCLUSION: The present results suggest that although the aerobic performance might contribute to SF performance for events from medium distance (i.e. 200m) to long distance (i.e. 1500m) in female participants, it might contribute to the long distance SF performances in male participants.

Association of force steadiness of plantar flexor muscles and postural sway during quiet standing by young adults.

This study was conducted to assess the relations of force fluctuations during isometric plantar-flexion and postural sway during quiet standing. Twelve healthy men (M age = 21 yr., SD = 1) performed unilateral plantar flexion measured by a strain gauge force transducer. Participants performed force-matching tasks; sustained plantar flexion for 20 sec. at levels corresponding to 10% and 20% of maximum voluntary contraction with the visual feedback. Also, participants were asked to stand quietly with their eyes open, and then the center of mass displacement and velocity in the anteroposterior were measured. In analysis, postural sway was associated with force fluctuation at only 10% of maximum voluntary contraction. The statistically significant correlation between variables was found only at corresponding contraction intensities for plantar-flexor muscles. From this one may infer neural strategies in plantar-flexor muscles during quiet standing may be characteristics similar to those controlling the plantar-flexion force in young adults.

Low-frequency force steadiness practice in plantar flexor muscle reduces postural sway during quiet standing.

The purpose of this study was to assess the effect of low-frequency force steadiness practice in the plantar flexor muscles on postural sway during quiet standing. Healthy young 21 men (21±1 yrs) were randomly assigned to a practice group (n=14) and a nonexercising control group (n=7). Practice groups were divided by frequency of practice: 7 participants practiced once a week, and the other 7 twice a week, for 4 weeks. Steadiness practice required practice group to 5 sets of 60-s contraction at levels corresponding to 10% and 20% maximal voluntary contraction (MVC) in the plantar flexor muscles. The 4-week-long practice period reduced the force fluctuations (assessed as the standard deviation (SD) of the outputted force during steady isometric plantar flexion) and postural sway (assessed as SD of the center of mass velocity during quiet standing). However, these practice effects were not significantly affected by the practice frequencies (1 vs. 2 sessions per week) examined in this study. Further, a linear regression analysis revealed the association between prepractice postural sway and the relative change in postural sway by the practice (r=-0.904) in the practice group. These results suggest that the steadiness practice in plantar flexor muscles improves postural stability during quiet standing, even though the practice is low-frequency (once a week) and low-intensity (within 20% MVC). These practice effects are dependent on prepractice postural stability. Further, the present results have provided the functional significance of force fluctuation in lower limb muscles.

Asymmetry of force fluctuation during low and moderate intensity isometric knee extensions.

The purpose of this study was to investigate the asymmetry of force fluctuation during isometric knee extension at low and moderate intensities. 11 healthy men (M age = 21 yr., SD = 1) performed unilateral force matching tasks; sustained isometric knee extension at 20% and 30% maximal voluntary contraction (MVC). During the tasks, a mechanomyogram was measured by an accelerometer arrangement placed on the vastus lateralis. Although force fluctuation was not significantly different between the two legs at 20% MVC, it was higher in the left (weaker) leg than in the right (stronger) leg at 30% MVC. A significant difference in mean power frequency of the mechanomyographic signal between the two legs was also observed only at 30% MVC. These results suggest that the asymmetry of force fluctuation during isometric knee extension was not statistically significant at low intensity; however, it was significant at moderate intensity. These differences in force fluctuation between intensities might be influenced by different motor-unit firing rates in active muscle.

Relationship between force fluctuation in the plantar flexor and sustainable time for single-leg standing.

The purpose of this study was to investigate the relationships between force fluctuation during isometric plantar flexion and the sustainable time for single-leg standing. Fourteen healthy males (21+/-1 years) performed unilateral (preferred leg) force matching tasks and single-leg quiet standing. Force matching tasks were performed to maintain isometric plantar flexion for 15 s at levels corresponding to 10% and 20% maximal voluntary contraction (MVC) with the visual feedback of force. Force fluctuation during force matching tasks was quantified as the standard deviation of force. Sustainable time for single-leg quiet standing was performed to maintain a single-leg quiet standing barefoot on a platform using the preferred leg with their eyes closed. Force fluctuation was significantly greater in 20% MVC task compared to 10% MVC task. The sustainable time for single-leg quiet standing was strongly correlated with force fluctuation in 20% MVC task (r=-0.56, p=0.04). However, it was not related to force fluctuation in 10% MVC task (r=0.19, p=0.52) or MVC value (r=0.13, p=0.65). These results suggest that a specificity of contraction intensity is observed between force steadiness and the posture stability during single-leg quiet standing; force steadiness during 20% MVC plantar flexion is one of the important components for posture stability during single-leg quiet standing.

Asymmetry of Force Fluctuation During Low Intensity Isometric Contraction in Leg Muscle.

The purpose of this study was to investigate the asymmetry of force fluctuation in the leg muscles during isometric knee extension and flexion. Twenty healthy males (21±2 years) performed the maximal voluntary isometric contraction (MVC) in knee extensor and flexor. On the basis of MVC measurement, the subjects performed sustained isometric knee extension and flexion for 15s at levels corresponding to 10%, 20% and 30% MVC. The main findings of this study were: (1) a greater force fluctuation was found in the stronger MVC limb than in the weaker MVC limb at 30% MVC; (2) no difference was found in the force fluctuation between the stronger and weaker MVC limbs at 10% and 20% MVC; and (3) significant positive correlations were found between the target force values and the force fluctuation at each contraction intensity. These results suggest that: (1) asymmetry of force fluctuation increases with load, (2) asymmetry of the force fluctuation is observed at more than 30% MVC intensity; and (3) if the contraction intensity is same relatively loads (% MVC), force fluctuation is increase with absolute load (target force value). Force fluctuation influence the functional ability of an individual in controlling finger or limb movements in daily life. Further, asymmetry of force fluctuation might influence for more than 30% MVC of daily activities.