Medicine and Science in Sports and Exercise, May 1, 2017
Pokémon Go! is a downloadable video game for use on an internet-connected cellular telephone (cel... more Pokémon Go! is a downloadable video game for use on an internet-connected cellular telephone (cell phone). The game encourages the player to traverse real-world locations (e.g., neighborhoods) and tracks the player, via GPS, as they move through these locales. The purpose of the game is to find computerized characters as the player moves through the real-world locations. Because the game requires players to move through real-world locales, it may promote physical activity. PURPOSE: The purpose of this study was to assess self-reported walking and sedentary behavior in young adults before and after downloading Pokémon Go!. METHODS: A sample of 238 (19.5 ± 1.7 years old, n = 119 females) college students who had downloaded Pokémon Go! on their cell phone for a minimum of two weeks were surveyed for weekly walking and sedentary behavior via the International Physical Activity Questionnaire. Participants reported their walking and sedentary behavior at three time points: the week immediately preceding their download of Pokémon Go!, the first week after downloading the game and currently. Differences in self-reported physical activity and sedentary behavior across the three time points were compared via repeated-measures analyses of variance. RESULTS: There was a significant main effect of time (f ≥ 38.4, p ≤ 0.001) for walking and sedentary behavior. Participants reported greater (t ≥ 7.4, p ≤ 0.001) daily walking during the first week after downloading Pokémon Go! (206 ± 138 min) and currently (191 ± 202 min) versus the week before downloading (105 ± 101 min). There was no difference (t = 1.1, p = 0.27) between the first week after downloading and current walking behavior. Participants reported greater (t ≥ 6.5, p ≤ 0.001) daily sedentary behavior during the week before downloading (329 ± 219 min) versus both the first week after downloading (242 ± 181 min) and currently (256 ± 152 min). There was no difference (t = 1.5, p = 0.15) between the first week after downloading and current sitting behavior. CONCLUSIONS: Use of the popular, physically-interactive cell phone game, Pokémon go!, had favorable effects upon self-reported physical activity (96% to 82% increase) and sedentary behavior (26% to 22% decrease). Such games hold promise as technology that may promote physical activity and discourage sedentary activity.
Medicine and Science in Sports and Exercise, Jun 1, 2019
Low cardiorespiratory fitness and accumulated fat mass have been widely associated with impaired ... more Low cardiorespiratory fitness and accumulated fat mass have been widely associated with impaired cognitive performance in children, however, their influence on creativity remains unclear. The creativity is a component of cognition and is defined as the process of identifying the difficulty, formulating hypotheses about the deficiencies and solving the problems. Actually, the creativity has become an element key to cognition because contribute to personal and professional success of the subject. PURPOSE: Here, we compare creativity in children with different levels of cardiorespiratory fitness (CF) and fat mass (FM), as well as their relationship. METHODS: In this cross-sectional study, 73 children with age ranging from 10.1 to 11.5 participated while attending two testing sessions. On the first testing session, all children had general anthropometric assessments and completed a graded shuttle run test to estimate cardiorespiratory fitness (VO 2 max). On the second session, they perform the Children's Figural Creativity Test, scholar performance test and have the fat mass (FM) measured by the Dual-energy X-ray Absorptiometry. Children were divided in two groups (Lower x Higher) separated by the median value of CF and FM. Creativity was compared between groups by a paired t test and unpaired Mann-Whitney (P<0.005). Pearson or Spearman correlations were used to compare the associations between the variables. The results demonstrate no significant differences on creativity between VO 2 max (p= 0.75) and FM (p= 0.56) levels. In addition, no correlation was identified between creativity with CF (r=-.031; p=.828) and FM (r=.174; p=.218). CONCLUSIONS: In conclusion, creativity is similar in children with different VO 2 and FM level and there is not relationship between these variables. However, are necessary more studies with a robust creativity measurement technique, based in neurobiological markers (NIRS, fMRI).
OBJECTIVE To assess self-reported walking and sedentary behavior in young adults before and after... more OBJECTIVE To assess self-reported walking and sedentary behavior in young adults before and after downloading "Pokémon Go!". MATERIALS AND METHODS In September 2016, a sample of 358 (19.8 ± 2.1 years old, n = 187 females) college students who had downloaded "Pokémon Go!" on their cellular telephones (i.e., cell phones) were surveyed for weekly walking and sedentary behavior via the International Physical Activity Questionnaire. A single interview was administered to participants who estimated their walking and sedentary behavior at three time points: the week immediately preceding their download of "Pokémon Go!" (Baseline), the first week after downloading the game (Time 1), and the week the survey was completed (Time 2). Differences in self-reported physical activity and sedentary behavior across the three time points and across the two genders were compared via analyses of variance. RESULTS There was a significant main effect of time (F ≥ 49.3, P ≤ 0.001) for walking and sedentary behavior. Participants reported greater (t ≥ 9.5, P < 0.001) daily walking during Time 1 (218.6 ± 156.3 minutes) and Time 2 (182.7 ± 172.1 minutes) versus the baseline (108.5 ± 110.8 minutes). Walking behavior was also significantly greater (t = 4.1, P < 0.001) at Time 1 versus Time 2. Participants reported greater (t ≥ 6.5, P < 0.001) daily sedentary behavior during baseline (346.6 ± 201.3 minutes) versus both Time 1 (261.7 ± 172.4 minutes) and Time 2 (284.3 ± 175.4 minutes). Sedentary behavior was also significantly greater (t = 2.6, P = 0.03) at Time 2 versus Time 1. There were no effects of gender (F ≤ 1.8, P ≥ 0.17). CONCLUSION Playing "Pokémon Go!" was associated with increased self-reported walking and decreased sedentary behavior. Such games hold promise as technology that may promote physical activity and discourage sedentary behavior.
Medicine and Science in Sports and Exercise, Jul 1, 2020
PURPOSE: To examine the effects of environmental condition and body fat percentage on metabolic e... more PURPOSE: To examine the effects of environmental condition and body fat percentage on metabolic efficiency during cycling exercise. METHODS: Recreationally active men consisting of 4 low-fat (LF; 10.9% + 2.5; 23.8 + 3.1yrs; 182.6 + 7.1cm; 80.7 + 4.5kg; 4.03 + 0.34L•min-1) and 4 high-fat (HF; 15.9% + 2.2; 23.3 + 1.9yrs; 180.9 + 4.3cm; 79.6 + 5.9kg; 3.63 + 0.13L•min-1) completed 2 experimental trials in 5°C/20% RH (LT) and 22°C/45% RH (MT) in a counterbalanced fashion. Participants completed 60-min of cycling at 60% VO2max. Metabolic efficiency was calculated during cycling at 3min, 15min, 30min, 45min, and 60min. Data were analyzed using a three-way repeated measures mixed-design ANOVA. RESULTS: A time x BF interaction was observed (F=4.147; p<0.001). Post hoc analysis indicated a main effect of time in LF (F=11.983; p<0.001) and HF (F=24.086; p<0.001) individuals. Specifically, significant decreases in metabolic efficiency were observed at 15min, 30min, 45min, and 60min compared to 3min (p < 0.05) in LF individuals, with no further reductions observed at 45min (p=0.732) and 60min (p=0.598) compared to 30 min. In HF individuals, significant decreases in metabolic efficiency were observed at 15min, 30min, 45min, and 60min compared to 3min (p < 0.05), with further reductions observed at 45min (p=0.021) and 60min (p < 0.001) compared to 15min, and at 60min compared to 30min (p=0.005) and 45min (p=0.002). Furthermore, a condition x time interaction (F=3.351; p=0.026) was observed. A main effect of time was observed for the LT condition (F=22.436; p<0.001) and MT condition (F=20.850, p<0.001), with significant decreases at 15min, 30min, 45min, and 60min compared to 3min (p < 0.05) during both the LT and MT conditions. Furthermore, paired samples t-test indicated significantly lower metabolic efficiency in the MT condition compared to the LT condition at 45min (MT; 19.17 + 1.6%; LT; 20.2 + 1.6%; p=0.20) and 60min (MT; 18.88 + 0.63%; LT; 19.16 + 0.68% p=0.49). CONCLUSIONS: Data suggests that individuals with a higher % BF may experience greater decreases in metabolic efficiency throughout prolonged cycling exercise at moderate intensity. Additionally, metabolic efficiency appears to decrease throughout cycling exercise, with cold environments resulting in greater efficiency compared to MT conditions.
Medicine and Science in Sports and Exercise, Jun 1, 2019
(HR) was measured continuously (Polar). Core temperature was measured via a rectal (PROBE-C) ther... more (HR) was measured continuously (Polar). Core temperature was measured via a rectal (PROBE-C) thermistor and an ingestible pill (PILL). Skin temperature (PROBE-S) was measured at the arm, chest, thigh, and calf, and a mean value was calculated (Ramanathan, 1964). Core and skin temps were also estimated from a sensor electronics module located in a vest (VEST, Equivital) worn by each participant. Vest temperatures were calculated according to equations developed previously (Buller et al., 2013). Repeated measures ANOVA, Pearson correlations, and dependent t-tests were used to examine relationships among the various temperature measurement modalities (Alpha = p<0.05). RESULTS: HR averaged 125±25 and 151±18 b/min for the first and second 30 min of exercise, respectively. Likewise, Power averaged 81±22 and 97±22 W. While core temperatures were nearly identical at onset of exercise (~37.3 o C), the three modalities differed after 60 min of cycling 37.9±0.8, PILL; 38.3±0.3, VEST; 38.6±0.4 o C (p<0.05). Skin temperatures differed between PROBE-S and VEST at both beginning (31.2± 1.1 vs 33.8±1.2 o C) and end (32.9± 1.5 vs 37.0±0.6 o C) of exercise (p<0.01). Correlations among the various modalities were significant (p<0.05) and ranged from R=0.51 -0.77, but did not differ from each other. CONCLUSION: The major study finding was that the vest estimated higher core and skin temperatures during exercise compared to traditional temperature measuring devices, overestimating work intensity at study ambient conditions.
Introduction: Eccentric exercise often results in the production of markers of oxidative stress a... more Introduction: Eccentric exercise often results in the production of markers of oxidative stress and an inflammatory response, which leads to delayed onset muscle soreness (DOMS). DOMS is associated with impaired muscular performance. Dietary interventions may reduce inflammation and improve physical performance. The aim of the study was to determine if Açai supplementation reduces muscle soreness and improves muscle function. Methods: Twenty collegiate athletes and non-athletes were counterbalanced into an Açai group or a placebo group. Supplementation started 48 hours prior to a bout of downhill running (DR). Range of motion, muscle soreness perception, agility, and vertical jump were assessed at baseline, immediately after DR, 24, and 48 hours after DR. Results: The Açai group (N = 10) reported significantly less muscle soreness in the quadriceps muscle (p = .011) compared to the placebo group (N = 10). Furthermore, the Açai group showed improvements in range of motion, agility, and vertical jump displacement compared to the placebo group throughout all 4-time periods. Conclusions: Açai appears to be an effective supplement to decrease quadriceps muscle soreness after downhill running. This decrease in soreness may contribute to performance gains also noted in the Açai group.
Medicine and Science in Sports and Exercise, May 1, 2017
To determine if improvements in ventilatory strength with chronic inspiratory muscle training (IM... more To determine if improvements in ventilatory strength with chronic inspiratory muscle training (IMT) improves 20km cycling time trial (TT) performance in hypoxia (F I O 2 = 16.1%). METHODS: Ten highly-trained men were pair-matched based on pre-exercise values of maximal inspiratory pressure (MIP) and randomly placed into either a sham (n = 5, VO 2 max = 61.7 ± 4.1 ml•kg -1 •min -1 ) or an IMT (n = 5, VO 2 max = 61.5 ± 6.8 ml•kg -1 •min -1 ) group. Subjects completed 6 weeks of flow resistive IMT (80% of MIP) or a sham protocol (30% of MIP), with each session consisting of up to 6 sets of 8 MIP maneuvers performed to failure with descending rest intervals 3 times per week. Pre-and posttraining, subjects performed tests of pulmonary function, lung volume, MIP, maximal expiratory pressure (MEP), lung diffusion capacity (DLCO), and a 20km cycling TT in hypoxia (FIO 2 = 16.1%). RESULTS: After 6 weeks of IMT or sham, the IMT group significantly improved MIP (145.3 ± 27.9 cmH 2 O vs 171.7 ± 38.7 cmH 2 O, p < 0.05), while MIP in the sham group remained unchanged. MEP, DLCO, lung volumes, and pulmonary function values remained unchanged in both groups post-training. 20km TT mean ventilation was higher post-IMT (98.9 ± 15.9 l•min -1 vs 109.3 ± 22.4 l•min -1 , p = 0.055) and unchanged in sham (p = 0.65). 20km TT mean breathing frequency was also higher post-IMT (43.5 ± 6.4 b•min -1 vs 47.8 ± 8.0 b•min -1 , p < 0.01) and unchanged in sham (p = 0.46). 20km TT mean VO 2 was higher post-IMT (45.5 ± 6.4 ml•kg -1 •min -1 vs 47.5 ± 7.1 ml•kg -1 •min -1 , p = 0.05) and unchanged in sham (p = 0.65). In the IMT group, 20km TT performance time pre-training was 37:46 ± 4:39 min:sec and post-training was 37:16 ± 4:02 min:sec (-1.2 ± 2.2%, p = 0.14). 20km TT performance time was unchanged in the sham group (+0.2 ± 2.1%, p = 0.90). 20km TT heart rate and SpO 2 were unchanged in both groups posttraining. CONCLUSION: In a small cohort, IMT-induced improvements respiratory muscle strength resulted in greater ventilation and oxygen uptake during a 20km time trial in hypoxia. IMT should be explored as a useful strategy for improving the quality of cycle exercise training and/or endurance exercise performance at altitude.
Medicine and Science in Sports and Exercise, May 1, 2017
Current adverse components of aging include the increase in both cognitive impairment and the inc... more Current adverse components of aging include the increase in both cognitive impairment and the incidence of dementia. Previous studies have shown positive associations between physical activity and the prevention and treatment of cognitive impairment and dementia. The PURPOSE of the present study was to identify correlates among physical activity, physical function, and cognition in independent older adults. METHODS: In 77 older adults (77±7.8 years), self-reported physical activity (Community Healthy Physical Activities Model Program for Seniors, CHAMPS), cognitive function (Addenbrooke's Cognitive Examination-Revised, ACE-R), and physical function (Six Minute Walk Test, 6MWT; Short Physical Performance Battery, SPPB; and Grip Strength) were measured. Partial correlations were run between the variables while controlling for age and sex. Significance was set to p <0.05. The mean values±standard error (SE) for the physical function variables were: CHAMPS: 1202±130 kcal•wk -1 of moderate-to-vigorous physical activity; 6MWT (distance): 417±14 m; and grip strength: 27.0±1.1 kg. The average score on the ACE-R was 91.6±0.5 out of 100 (≤88 = 94% specificity for dementia). Age was correlated with ACE-R (r = -0.59, p < 0.05). When controlling for age and sex, ACE-R was correlated with SPPB performance (r = 0.39, p < 0.05), 6MWT performance (r= 0.33, p <0.05), and grip strength (r= 0.25, p < 0.03). ACE-R was not correlated with self-reported physical activity (r= 0.14, p > 0.05). CONCLUSIONS: Although previous research has shown positive associations between physical activity and cognitive function, our preliminary data do not support these previous findings. However, indices of physical function, as measured by three standard clinical tests, were associated with cognitive function in this population of independent older adults.
Medicine and Science in Sports and Exercise, Jul 1, 2020
Multiple studies from our research group examining American adults have conclusively identified s... more Multiple studies from our research group examining American adults have conclusively identified smartphone use as a sedentary behavior (SB). However, the same work has repeatedly found no relationship between smartphone use and physical activity (PA). Typically, SB is negatively related to PA. This may not be true of smartphones as the device can displace PA (e.g., watching videos, social media) and also promote PA (e.g., fitness apps, mHealth). Thus, different smartphone behavioral patterns should be considered in relationship to PA. Researchers have recently identified problematic smartphone use as a behavioral pattern motivated by the recurrent craving to use a smartphone. It is an addiction-like behavior leading individuals to use their smartphone compulsively in inappropriate situations such as during classroom lectures, while driving a car, or perhaps in environments intended for PA or planned exercise. Therefore, while total use is not associated with PA, problematic smartphone use may interfere with PA. PURPOSE: To assess the relationship between total and problematic smartphone use to PA in a sample of American college students. METHODS: A sample of American college students (N = 471, 21.1 ± 2.8 years old) completed validated surveys assessing total daily smartphone use, PA, SB (both assessed via the International Physical Activity Questionnaire) and problematic smartphone use (assessed via the Mobile Phone Problem Use 10-item scale). Pearson‘s correlations were then performed. RESULTS: As in previous studies, there was a significant, positive relationship between total daily smartphone use and SB (r = 0.31, p < 0.001) and no relationship with PA (r = 0.05, p = 0.32). However, while problematic smartphone use was similarly significantly and positively related to SB (r = .26, p < .001) it was also significantly and negatively related to PA (r = -0.18, p < .001). CONCLUSION: While prior research and the current study has found no relationship between total smartphone use and PA, this is the first study to assess the relationship between problematic smartphone use and PA. Results suggest that, unlike total daily smartphone use, problematic smartphone use may occur at the expense of PA behavior.
Medicine and Science in Sports and Exercise, May 1, 2017
Pokémon Go! is a downloadable video game for use on an internet-connected cellular telephone (cel... more Pokémon Go! is a downloadable video game for use on an internet-connected cellular telephone (cell phone). The game encourages the player to traverse real-world locations (e.g., neighborhoods) and tracks the player, via GPS, as they move through these locales. The purpose of the game is to find computerized characters as the player moves through the real-world locations. Because the game requires players to move through real-world locales, it may promote physical activity. PURPOSE: The purpose of this study was to assess self-reported walking and sedentary behavior in young adults before and after downloading Pokémon Go!. METHODS: A sample of 238 (19.5 ± 1.7 years old, n = 119 females) college students who had downloaded Pokémon Go! on their cell phone for a minimum of two weeks were surveyed for weekly walking and sedentary behavior via the International Physical Activity Questionnaire. Participants reported their walking and sedentary behavior at three time points: the week immediately preceding their download of Pokémon Go!, the first week after downloading the game and currently. Differences in self-reported physical activity and sedentary behavior across the three time points were compared via repeated-measures analyses of variance. RESULTS: There was a significant main effect of time (f ≥ 38.4, p ≤ 0.001) for walking and sedentary behavior. Participants reported greater (t ≥ 7.4, p ≤ 0.001) daily walking during the first week after downloading Pokémon Go! (206 ± 138 min) and currently (191 ± 202 min) versus the week before downloading (105 ± 101 min). There was no difference (t = 1.1, p = 0.27) between the first week after downloading and current walking behavior. Participants reported greater (t ≥ 6.5, p ≤ 0.001) daily sedentary behavior during the week before downloading (329 ± 219 min) versus both the first week after downloading (242 ± 181 min) and currently (256 ± 152 min). There was no difference (t = 1.5, p = 0.15) between the first week after downloading and current sitting behavior. CONCLUSIONS: Use of the popular, physically-interactive cell phone game, Pokémon go!, had favorable effects upon self-reported physical activity (96% to 82% increase) and sedentary behavior (26% to 22% decrease). Such games hold promise as technology that may promote physical activity and discourage sedentary activity.
Medicine and Science in Sports and Exercise, Jun 1, 2019
Low cardiorespiratory fitness and accumulated fat mass have been widely associated with impaired ... more Low cardiorespiratory fitness and accumulated fat mass have been widely associated with impaired cognitive performance in children, however, their influence on creativity remains unclear. The creativity is a component of cognition and is defined as the process of identifying the difficulty, formulating hypotheses about the deficiencies and solving the problems. Actually, the creativity has become an element key to cognition because contribute to personal and professional success of the subject. PURPOSE: Here, we compare creativity in children with different levels of cardiorespiratory fitness (CF) and fat mass (FM), as well as their relationship. METHODS: In this cross-sectional study, 73 children with age ranging from 10.1 to 11.5 participated while attending two testing sessions. On the first testing session, all children had general anthropometric assessments and completed a graded shuttle run test to estimate cardiorespiratory fitness (VO 2 max). On the second session, they perform the Children's Figural Creativity Test, scholar performance test and have the fat mass (FM) measured by the Dual-energy X-ray Absorptiometry. Children were divided in two groups (Lower x Higher) separated by the median value of CF and FM. Creativity was compared between groups by a paired t test and unpaired Mann-Whitney (P<0.005). Pearson or Spearman correlations were used to compare the associations between the variables. The results demonstrate no significant differences on creativity between VO 2 max (p= 0.75) and FM (p= 0.56) levels. In addition, no correlation was identified between creativity with CF (r=-.031; p=.828) and FM (r=.174; p=.218). CONCLUSIONS: In conclusion, creativity is similar in children with different VO 2 and FM level and there is not relationship between these variables. However, are necessary more studies with a robust creativity measurement technique, based in neurobiological markers (NIRS, fMRI).
OBJECTIVE To assess self-reported walking and sedentary behavior in young adults before and after... more OBJECTIVE To assess self-reported walking and sedentary behavior in young adults before and after downloading "Pokémon Go!". MATERIALS AND METHODS In September 2016, a sample of 358 (19.8 ± 2.1 years old, n = 187 females) college students who had downloaded "Pokémon Go!" on their cellular telephones (i.e., cell phones) were surveyed for weekly walking and sedentary behavior via the International Physical Activity Questionnaire. A single interview was administered to participants who estimated their walking and sedentary behavior at three time points: the week immediately preceding their download of "Pokémon Go!" (Baseline), the first week after downloading the game (Time 1), and the week the survey was completed (Time 2). Differences in self-reported physical activity and sedentary behavior across the three time points and across the two genders were compared via analyses of variance. RESULTS There was a significant main effect of time (F ≥ 49.3, P ≤ 0.001) for walking and sedentary behavior. Participants reported greater (t ≥ 9.5, P < 0.001) daily walking during Time 1 (218.6 ± 156.3 minutes) and Time 2 (182.7 ± 172.1 minutes) versus the baseline (108.5 ± 110.8 minutes). Walking behavior was also significantly greater (t = 4.1, P < 0.001) at Time 1 versus Time 2. Participants reported greater (t ≥ 6.5, P < 0.001) daily sedentary behavior during baseline (346.6 ± 201.3 minutes) versus both Time 1 (261.7 ± 172.4 minutes) and Time 2 (284.3 ± 175.4 minutes). Sedentary behavior was also significantly greater (t = 2.6, P = 0.03) at Time 2 versus Time 1. There were no effects of gender (F ≤ 1.8, P ≥ 0.17). CONCLUSION Playing "Pokémon Go!" was associated with increased self-reported walking and decreased sedentary behavior. Such games hold promise as technology that may promote physical activity and discourage sedentary behavior.
Medicine and Science in Sports and Exercise, Jul 1, 2020
PURPOSE: To examine the effects of environmental condition and body fat percentage on metabolic e... more PURPOSE: To examine the effects of environmental condition and body fat percentage on metabolic efficiency during cycling exercise. METHODS: Recreationally active men consisting of 4 low-fat (LF; 10.9% + 2.5; 23.8 + 3.1yrs; 182.6 + 7.1cm; 80.7 + 4.5kg; 4.03 + 0.34L•min-1) and 4 high-fat (HF; 15.9% + 2.2; 23.3 + 1.9yrs; 180.9 + 4.3cm; 79.6 + 5.9kg; 3.63 + 0.13L•min-1) completed 2 experimental trials in 5°C/20% RH (LT) and 22°C/45% RH (MT) in a counterbalanced fashion. Participants completed 60-min of cycling at 60% VO2max. Metabolic efficiency was calculated during cycling at 3min, 15min, 30min, 45min, and 60min. Data were analyzed using a three-way repeated measures mixed-design ANOVA. RESULTS: A time x BF interaction was observed (F=4.147; p<0.001). Post hoc analysis indicated a main effect of time in LF (F=11.983; p<0.001) and HF (F=24.086; p<0.001) individuals. Specifically, significant decreases in metabolic efficiency were observed at 15min, 30min, 45min, and 60min compared to 3min (p < 0.05) in LF individuals, with no further reductions observed at 45min (p=0.732) and 60min (p=0.598) compared to 30 min. In HF individuals, significant decreases in metabolic efficiency were observed at 15min, 30min, 45min, and 60min compared to 3min (p < 0.05), with further reductions observed at 45min (p=0.021) and 60min (p < 0.001) compared to 15min, and at 60min compared to 30min (p=0.005) and 45min (p=0.002). Furthermore, a condition x time interaction (F=3.351; p=0.026) was observed. A main effect of time was observed for the LT condition (F=22.436; p<0.001) and MT condition (F=20.850, p<0.001), with significant decreases at 15min, 30min, 45min, and 60min compared to 3min (p < 0.05) during both the LT and MT conditions. Furthermore, paired samples t-test indicated significantly lower metabolic efficiency in the MT condition compared to the LT condition at 45min (MT; 19.17 + 1.6%; LT; 20.2 + 1.6%; p=0.20) and 60min (MT; 18.88 + 0.63%; LT; 19.16 + 0.68% p=0.49). CONCLUSIONS: Data suggests that individuals with a higher % BF may experience greater decreases in metabolic efficiency throughout prolonged cycling exercise at moderate intensity. Additionally, metabolic efficiency appears to decrease throughout cycling exercise, with cold environments resulting in greater efficiency compared to MT conditions.
Medicine and Science in Sports and Exercise, Jun 1, 2019
(HR) was measured continuously (Polar). Core temperature was measured via a rectal (PROBE-C) ther... more (HR) was measured continuously (Polar). Core temperature was measured via a rectal (PROBE-C) thermistor and an ingestible pill (PILL). Skin temperature (PROBE-S) was measured at the arm, chest, thigh, and calf, and a mean value was calculated (Ramanathan, 1964). Core and skin temps were also estimated from a sensor electronics module located in a vest (VEST, Equivital) worn by each participant. Vest temperatures were calculated according to equations developed previously (Buller et al., 2013). Repeated measures ANOVA, Pearson correlations, and dependent t-tests were used to examine relationships among the various temperature measurement modalities (Alpha = p<0.05). RESULTS: HR averaged 125±25 and 151±18 b/min for the first and second 30 min of exercise, respectively. Likewise, Power averaged 81±22 and 97±22 W. While core temperatures were nearly identical at onset of exercise (~37.3 o C), the three modalities differed after 60 min of cycling 37.9±0.8, PILL; 38.3±0.3, VEST; 38.6±0.4 o C (p<0.05). Skin temperatures differed between PROBE-S and VEST at both beginning (31.2± 1.1 vs 33.8±1.2 o C) and end (32.9± 1.5 vs 37.0±0.6 o C) of exercise (p<0.01). Correlations among the various modalities were significant (p<0.05) and ranged from R=0.51 -0.77, but did not differ from each other. CONCLUSION: The major study finding was that the vest estimated higher core and skin temperatures during exercise compared to traditional temperature measuring devices, overestimating work intensity at study ambient conditions.
Introduction: Eccentric exercise often results in the production of markers of oxidative stress a... more Introduction: Eccentric exercise often results in the production of markers of oxidative stress and an inflammatory response, which leads to delayed onset muscle soreness (DOMS). DOMS is associated with impaired muscular performance. Dietary interventions may reduce inflammation and improve physical performance. The aim of the study was to determine if Açai supplementation reduces muscle soreness and improves muscle function. Methods: Twenty collegiate athletes and non-athletes were counterbalanced into an Açai group or a placebo group. Supplementation started 48 hours prior to a bout of downhill running (DR). Range of motion, muscle soreness perception, agility, and vertical jump were assessed at baseline, immediately after DR, 24, and 48 hours after DR. Results: The Açai group (N = 10) reported significantly less muscle soreness in the quadriceps muscle (p = .011) compared to the placebo group (N = 10). Furthermore, the Açai group showed improvements in range of motion, agility, and vertical jump displacement compared to the placebo group throughout all 4-time periods. Conclusions: Açai appears to be an effective supplement to decrease quadriceps muscle soreness after downhill running. This decrease in soreness may contribute to performance gains also noted in the Açai group.
Medicine and Science in Sports and Exercise, May 1, 2017
To determine if improvements in ventilatory strength with chronic inspiratory muscle training (IM... more To determine if improvements in ventilatory strength with chronic inspiratory muscle training (IMT) improves 20km cycling time trial (TT) performance in hypoxia (F I O 2 = 16.1%). METHODS: Ten highly-trained men were pair-matched based on pre-exercise values of maximal inspiratory pressure (MIP) and randomly placed into either a sham (n = 5, VO 2 max = 61.7 ± 4.1 ml•kg -1 •min -1 ) or an IMT (n = 5, VO 2 max = 61.5 ± 6.8 ml•kg -1 •min -1 ) group. Subjects completed 6 weeks of flow resistive IMT (80% of MIP) or a sham protocol (30% of MIP), with each session consisting of up to 6 sets of 8 MIP maneuvers performed to failure with descending rest intervals 3 times per week. Pre-and posttraining, subjects performed tests of pulmonary function, lung volume, MIP, maximal expiratory pressure (MEP), lung diffusion capacity (DLCO), and a 20km cycling TT in hypoxia (FIO 2 = 16.1%). RESULTS: After 6 weeks of IMT or sham, the IMT group significantly improved MIP (145.3 ± 27.9 cmH 2 O vs 171.7 ± 38.7 cmH 2 O, p < 0.05), while MIP in the sham group remained unchanged. MEP, DLCO, lung volumes, and pulmonary function values remained unchanged in both groups post-training. 20km TT mean ventilation was higher post-IMT (98.9 ± 15.9 l•min -1 vs 109.3 ± 22.4 l•min -1 , p = 0.055) and unchanged in sham (p = 0.65). 20km TT mean breathing frequency was also higher post-IMT (43.5 ± 6.4 b•min -1 vs 47.8 ± 8.0 b•min -1 , p < 0.01) and unchanged in sham (p = 0.46). 20km TT mean VO 2 was higher post-IMT (45.5 ± 6.4 ml•kg -1 •min -1 vs 47.5 ± 7.1 ml•kg -1 •min -1 , p = 0.05) and unchanged in sham (p = 0.65). In the IMT group, 20km TT performance time pre-training was 37:46 ± 4:39 min:sec and post-training was 37:16 ± 4:02 min:sec (-1.2 ± 2.2%, p = 0.14). 20km TT performance time was unchanged in the sham group (+0.2 ± 2.1%, p = 0.90). 20km TT heart rate and SpO 2 were unchanged in both groups posttraining. CONCLUSION: In a small cohort, IMT-induced improvements respiratory muscle strength resulted in greater ventilation and oxygen uptake during a 20km time trial in hypoxia. IMT should be explored as a useful strategy for improving the quality of cycle exercise training and/or endurance exercise performance at altitude.
Medicine and Science in Sports and Exercise, May 1, 2017
Current adverse components of aging include the increase in both cognitive impairment and the inc... more Current adverse components of aging include the increase in both cognitive impairment and the incidence of dementia. Previous studies have shown positive associations between physical activity and the prevention and treatment of cognitive impairment and dementia. The PURPOSE of the present study was to identify correlates among physical activity, physical function, and cognition in independent older adults. METHODS: In 77 older adults (77±7.8 years), self-reported physical activity (Community Healthy Physical Activities Model Program for Seniors, CHAMPS), cognitive function (Addenbrooke's Cognitive Examination-Revised, ACE-R), and physical function (Six Minute Walk Test, 6MWT; Short Physical Performance Battery, SPPB; and Grip Strength) were measured. Partial correlations were run between the variables while controlling for age and sex. Significance was set to p <0.05. The mean values±standard error (SE) for the physical function variables were: CHAMPS: 1202±130 kcal•wk -1 of moderate-to-vigorous physical activity; 6MWT (distance): 417±14 m; and grip strength: 27.0±1.1 kg. The average score on the ACE-R was 91.6±0.5 out of 100 (≤88 = 94% specificity for dementia). Age was correlated with ACE-R (r = -0.59, p < 0.05). When controlling for age and sex, ACE-R was correlated with SPPB performance (r = 0.39, p < 0.05), 6MWT performance (r= 0.33, p <0.05), and grip strength (r= 0.25, p < 0.03). ACE-R was not correlated with self-reported physical activity (r= 0.14, p > 0.05). CONCLUSIONS: Although previous research has shown positive associations between physical activity and cognitive function, our preliminary data do not support these previous findings. However, indices of physical function, as measured by three standard clinical tests, were associated with cognitive function in this population of independent older adults.
Medicine and Science in Sports and Exercise, Jul 1, 2020
Multiple studies from our research group examining American adults have conclusively identified s... more Multiple studies from our research group examining American adults have conclusively identified smartphone use as a sedentary behavior (SB). However, the same work has repeatedly found no relationship between smartphone use and physical activity (PA). Typically, SB is negatively related to PA. This may not be true of smartphones as the device can displace PA (e.g., watching videos, social media) and also promote PA (e.g., fitness apps, mHealth). Thus, different smartphone behavioral patterns should be considered in relationship to PA. Researchers have recently identified problematic smartphone use as a behavioral pattern motivated by the recurrent craving to use a smartphone. It is an addiction-like behavior leading individuals to use their smartphone compulsively in inappropriate situations such as during classroom lectures, while driving a car, or perhaps in environments intended for PA or planned exercise. Therefore, while total use is not associated with PA, problematic smartphone use may interfere with PA. PURPOSE: To assess the relationship between total and problematic smartphone use to PA in a sample of American college students. METHODS: A sample of American college students (N = 471, 21.1 ± 2.8 years old) completed validated surveys assessing total daily smartphone use, PA, SB (both assessed via the International Physical Activity Questionnaire) and problematic smartphone use (assessed via the Mobile Phone Problem Use 10-item scale). Pearson‘s correlations were then performed. RESULTS: As in previous studies, there was a significant, positive relationship between total daily smartphone use and SB (r = 0.31, p < 0.001) and no relationship with PA (r = 0.05, p = 0.32). However, while problematic smartphone use was similarly significantly and positively related to SB (r = .26, p < .001) it was also significantly and negatively related to PA (r = -0.18, p < .001). CONCLUSION: While prior research and the current study has found no relationship between total smartphone use and PA, this is the first study to assess the relationship between problematic smartphone use and PA. Results suggest that, unlike total daily smartphone use, problematic smartphone use may occur at the expense of PA behavior.
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Papers by Ellen Glickman