Can reducing sitting time in the university setting improve the cardiometabolic health of college students?

PURPOSE: The high prevalence of metabolic syndrome (MetS), prediabetes, and increased risk of cardiovascular diseases linked with prolonged sitting has created a need to identify options to limit sedentary behaviors. A potentially simple approach to achieve this goal in the university setting is to provide students the option to stand during courses rather than sit. The purpose of the present study was to examine the effects of standing in the college classroom setting on cardiometabolic risk factors in a cohort of college students. PATIENTS AND METHODS: Healthy college students (n=21) who attended at least two courses per week (a minimum of 5 hours) in a specified university building with standing desks participated in a 7-week intervention that was divided into three phases: 3 weeks of standing, 1 week of washout (sitting), and 3 weeks of sitting. The participants (mean ± SD: age, height, weight, body mass index, and waist-to-hip ratio were 22.7±6.4 years, 174.3±10.0 cm, 70.6±14.3 kg, 23.0±3.0 kg/m2, and 0.76±0.05, respectively) were randomly assigned to the phase of intervention of which they should start (sitting or standing), and all participants engaged in sitting during the washout phase. Cardiometabolic risk factors and metabolic equivalents (METs) were measured at baseline and weekly throughout the intervention. RESULTS: Paired t-tests revealed significant differences (P<0.05) in all cardiometabolic risk factors between the 3 weeks of sitting and 3 weeks of standing time blocks. Moreover, MetS z-score was significantly improved (P<0.05) during the 3 weeks of standing (-5.91±2.70) vs 3 weeks of sitting (-5.25±2.69). The METs were significantly higher (P<0.05) during standing (1.47±0.09) than during sitting (1.02±0.07). Although there was considerable interindividual variability in the ∆ MetS z-score response, there was a 100% (21/21) incidence of a favorable change (ie, responders) in MetS z-score response. CONCLUSION: A standing desk in the classroom paradigm was found to significantly improve cardiometabolic health throughout a short 3 weeks time span. Increasing standing time in the classroom, and therefore lessening weekly sedentary behavior, could be a potential wide-scale, effective strategy for primordial prevention of cardiometabolic diseases.

The Effect of Detraining after a Period of Training on Cardiometabolic Health in Previously Sedentary Individuals.

The purpose of this study was to quantify the time-magnitude changes in cardiometabolic health outcomes that occur with cessation of regular exercise training. All participants (n = 22) performed baseline testing, completed a 13-week exercise program, and completed post-program testing. Upon completion of the 13-week exercise program, participants were randomized to one of the following two treatment groups: (1) the treatment group that continued their exercise for 4 weeks (TRAIN); or (2) the treatment group that discontinued exercise (DETRAIN). Changes from baseline to 13 weeks in both the TRAIN and DETRAIN treatment groups for maximal oxygen consumption (VO2max), body fat percentage, mean arterial pressure, high-density lipoprotein (HDL) cholesterol, and triglycerides were significantly favourable (p < 0.05). VO2max, body fat percentage, and favourable cardiometabolic health adaptations continued to improve (p < 0.05) with an additional one month of exercise training. Upon cessation of exercise, all measures of VO2max and body fat percentage, along with mean arterial pressure, HDL cholesterol, and triglycerides significantly worsened (p < 0.05) in the DETRAIN treatment group. Favourable training adaptations were further enhanced with an additional month of continued exercise training, and cessation of regular exercise rapidly abolished all training adaptations within one month. These novel findings underscore the importance of sustained and uninterrupted exercise training.

Effects of a Custom Bite-Aligning Mouthguard on Performance in College Football Players.

Besides injury prevention, mouthguards can also be employed to improve physical performance. The effects of personalization of mouthguards have rarely been investigated. This 3-armed, randomized, controlled crossover trial investigated the difference of wearing (a) personalized or custom-made (CM, e.g., bite-aligned), (b) standard (BB, boil and bite), and (c) no (CON) mouthguards on general fitness parameters in experienced collegiate football players. A group of 10 upperclassmen (age, 19-22 years; mean ± SD: age = 20.7 ± 0.8 years; body mass = 83 ± 7.4 kg; height = 179.1 ± 5.2 cm; body mass index = 25.9 ± 2.2 kg·cm), National Collegiate Athletic Association Division II football players with at least 2 years of playing experience, were randomly assigned to the 3 mouthguard conditions: a randomized, within-subjects repeated-measures design was applied. All participants were randomly tested on strength and endurance performance V[Combining Dot Above]O2max testing, with Bruce treadmill protocol including (a) time to fatigue, (b) blood lactate concentration in millimoles per liter at stage 2 and (c) at peak fatigue, (d) flexibility, (e) reaction time, (f) squat vertical jump, (g) countermovement vertical jump, and (h) 1 repetition maximum bench press. Repeated-measures analysis of variance showed no significant differences between the 3 conditions for each outcome variable (0.23 < p < 0.94; 0.007 < (Equation is included in full-text article.)< 0.15). These data indicate that CM mouthguards did not superiorly affect general fitness parameters compared with BB and CON. In turn, protective BB or CM mouthpieces did not appear to impair general fitness performance vs. CON. The recommendation of a custom bite-aligning mouthguards for performance enhancement in young Division II football players is questioned. Further studies with larger sample sizes, gender comparison, and (sport) discipline-specific performance testing are needed.