The characterization of thermal perception in recreational surfers wearing wetsuits.

The purpose of this study was to characterize the perception of heat loss, comfort, and wetness in recreational surfers wearing wetsuits, to compare these data with changes in skin temperature reported in prior studies, and to examine the impact of wetsuit thickness, zipper location, and accessory use on thermal sensation and comfort. Following their surf session, nine-hundred and three male (n = 735) and female (n = 168) recreational surfers responded to a series of questions regarding thermal comfort/sensation, wetsuit characteristics, and surfing history. Average whole body thermal sensation rating was 0.8 ± 3.6 on a scale of -10 to +10 and average whole body thermal comfort rating was 1.5 ± 1.2, midway between "just comfortable" and "comfortable." Overall, surfers felt coldest in their feet, hands, and head. Under their wetsuits, surfers felt the coldest, wettest, and least comfortable in their chest, lower legs, lower arms, and upper back. Wetsuit accessory use had the greatest impact on regions identified as coldest, least comfortable, and wettest. These data suggest that wetsuit design should focus on optimizing water access points and improving accessories for the feet, hands, and head.

Heart Rate Response and Locomotor Activity of Female Skateboarders, BIPOC Skateboarders, and Non-skateboard Users During a Typical Session at a Community Skatepark.

Prior research has demonstrated that male adults and youth engaged in skateboarding at community skateparks achieve heart rates that meet or exceed recommendations for exercise by the CDC. However, these studies do not adequately evaluate other non-traditional or ethnically diverse users who may differ in how they utilize the skatepark and in their cardiovascular response. The purpose of this experiment was to measure heart rate response and locomotor movement in three lesser studied groups that frequently utilize community skateparks, and to compare these results with those reported previously in male adult and youth skateboarders. Fifty-six skatepark users were analyzed, including thirty female and BIPOC skateboarders, and twenty-six non-skateboard users. All participants were instrumented with a HR monitor with GPS capability and asked to engage in their preferred activity with no duration specified. Average heart rate and time spent at high and moderate levels of heart rate intensity were not statistically different among the groups studied here, nor were they different from those reported previously for male adult and youth skateboarders. Distances traveled, average, and peak velocities were also not statistically different among the groups studied here, but all were significantly lower than values previously reported for adult male skateboarders. While some differences in distances traveled and velocity were noted, all groups met or exceeded CDC guidelines for cardiovascular fitness. These data suggest that skateparks can help a community achieve health outcomes, particularly among diverse users.

Heart Rate Response, Duration, Grip Strength, and Anthropometric Characteristics in Recreational Indoor Rock Climbers.

ABSTRACT: Smetanka, RG, Armenta, RF, Nessler, JA, and Newcomer, SC. Heart rate response, duration, grip strength, and anthropometric characteristics in recreational indoor rock climbers. J Strength Cond Res 36(3): 832-837, 2022-Despite the growing popularity of recreational indoor rock climbing, there is a lack of research on cardiovascular responses to rock climbing. In addition, although the importance of body composition and grip strength has been established in elite climbers, their effect on recreational climbing is unknown. Therefore, the purpose of this study was to characterize the physiological and anthropometric characteristics of indoor climbers engaging in climbing at a recreational or noncompetitive setting. We hypothesized that heart rates and climbing durations would meet the standards set by the American College of Sports Medicine (ACSM) and Center for Disease Control and Prevention (CDC) for eliciting health benefits and that grip strength would decrease over the course of a typical climbing session. One hundred twenty-one male and female adult recreational climbers participated in this study. Following informed consent, subjects were instrumented with a heart rate monitor (Polar V800) which recorded heart rate and duration. Preclimb and postclimb grip strength were evaluated using a hand grip dynamometer and used to calculate fatigue. Subjects were 30.9 ± 8.3 years old and had participated in climbing for 5.6 ± 6.5 years. The average heart rate during climbing sessions was 122.3 ± 14.5 b·min-1, and session duration was 90.6 ± 31.3 minutes. Mean grip strength was 49.9 ± 11.2 kg, whereas the strength to mass ratio was 0.71 ± 0.14, and fatigue was 13.1 ± 11.6%. Results from the current study suggest that recreational indoor climbing elicits exercise heart rates and durations that are consistent with the CDC and ACSM's recommendations for cardiovascular health. Grip strength data suggested that forearm muscle fatigue may limit climbing durations.

Fluid Loss in Recreational Surfers.

Surfing offers unique challenges to thermoregulation and hydration. The purpose of this study was to quantify fluid loss in recreational surfers, and to analyze the effects of water temperature, air temperature, exercise intensity, duration, and garment thickness on the total amount of fluid lost during a surf session. A total of 254 male and 52 female recreational surfers were recruited from San Diego, Costa Rica, and Australia to participate in the study. Participants' hydration status was assessed by comparing nude body mass pre- and post-surf session. Heart rate (HR), used as an index of exercise intensity, was measured throughout the session. Environmental conditions and surf characteristics were recorded. The difference between average pre-mass (73.11 ± 11.88 kg) and average post-mass (72.51 ± 11.78) was statistically significant (0.60 ± 0.55, p < 0.001). Surfers experienced a 0.82 ± 0.73% reduction in body mass. In multivariable linear regression, session duration and body mass index (BMI) were significantly associated with fluid loss. For every 10-minute increase in session duration, there was a 0.06 kg (SE = 0.001; p < 0.001) increase in fluid loss, and for every two unit increase in BMI, fluid loss increased by 0.05 kg (SE = 0.03; p = 0.02). Results suggest that prolonged surfing at high environmental temperatures in participants with high BMI's resulted in significant body water deficits. Since there is no opportunity to rehydrate during a surf session, surfers must properly pre-hydrate before surfing in order to avoid the detrimental effects of dehydration.

Energetics of Swimming With Hand Paddles of Different Surface Areas.

ABSTRACT: Crocker, GH, Moon, JF, Nessler, JA, and Newcomer, SC. Energetics of swimming with hand paddles of different surface areas. J Strength Cond Res 35(1): 205-211, 2021-Hand paddles are one of the most common training aids used by the competitive swimmer, yet little is known regarding how hand paddle surface area affects the metabolic cost of transport (COT) while swimming. The purpose of this study was to determine how altering hand paddle size affects energy use during submaximal, front-crawl (i.e., freestyle) swimming. Twenty-six proficient, adult swimmers (13 men and 13 women) completed six 3-minute trials in a flume at a constant pace (102 cm·s-1; 1:38 per 100 m). Trials were performed in random order, using 1 of 5 pairs of hand paddles of different sizes or no paddles at all. Paddle surface areas were 201, 256, 310, 358, and 391 cm2 per hand. Without paddles, COT, arm cadence, and distance per stroke were 7.87 ± 1.32 J·kg-1·m-1, 29.4 ± 4.9 min-1, and 2.13 ± 0.34 m, which corresponded to a rate of oxygen consumption (V̇o2) of 23.3 ± 3.7 ml·kg-1·min-1 and a heart rate (HR) of 118 ± 17 b·min-1. The use of larger hand paddles decreased COT, cadence, V̇o2, and HR and increased distance traveled per stroke (all p < 0.001). However, the magnitude of the change of COT decreased as paddle size increased, indicating diminishing marginal return with increasing paddle surface area. The largest sized paddles increased COT per stroke compared with swimming without paddles (p = 0.001). Therefore, results from this study suggest that an optimal hand paddle size exists (210-358 cm2) for proficient, adult swimmers, which reduces COT without increasing COT per stroke.

Characterization of Heart Rate Responses, Duration, and Distances Traveled in Youth Participating in Recreational Skateboarding at Community Skateparks.

ABSTRACT: Furr, HN, Nessler, JA, and Newcomer, SC. Characterization of heart rate responses, duration, and distances traveled in youth participating in recreational skateboarding at community skateparks. J Strength Cond Res 35(2): 542-548, 2021-Recreational skateboarding continues to gain popularity in youth within the United States and abroad. Surprisingly, there is a paucity of research regarding the cardiovascular responses of youth participating in recreational skateboarding. Therefore, the purpose of this study was to test the hypothesis that skateboarding would elicit heart rates and durations consistent with the American College of Sports Medicine (ACSM) and Center for Disease Control and Prevention (CDC) recommendations for cardiovascular fitness in youth. Seventy-one recreational skateboarders (boys: 63 and girls: 8) between the ages of 6 and 17 years participated in this study. Data were acquired at 9 skateparks in the local community. After parental consent, subjects completed a questionnaire and were instrumented with a heart rate monitor (Polar V800 GPS Sports Watch), which recorded heart rate, duration, and distance traveled. Subjects were instructed to engage in typical skateboarding activities, with the duration and intensity of activity determined by the individual. Subjects were 10.6 ± 2.9 years old and had participated in skateboarding for 3.1 ± 2.4 years. On average, subjects skateboarded 55.5 ± 28.4 minutes, at an average heart rate of 140.4 ± 16.1 b·min-1, and traveled an average distance of 2.65 ± 1.87 km. Results from this study suggest that youth participating in recreational skateboarding at community skateparks attain exercise intensities and durations that are comparable with the ACSM's and CDC's exercise recommendations for cardiovascular fitness in youth. These findings may hold implications for city planners considering the impact of community skateparks on physical activity in youth and overall public health.

Characterization of Adult Heart Rate Responses During Recreational Skateboarding at Community Skateparks.

Youth participating in recreational skating at community skate parks attain exercise intensities and durations that are comparable with the CDC's exercise recommendations for cardiovascular fitness for their age group. However, it is currently unclear if adults who skateboard in the same environment also achieve the recommended intensities and durations for cardiovascular fitness. Therefore, the purpose of this study was to test the hypothesis that skateboarding would elicit heart rates and durations consistent with the CDC's recommendations for cardiovascular fitness in adults. Fifty-five subjects between ages 18-55 were recruited from six community skateparks for this study. Subjects completed a questionnaire and were instrumented with a Polar V800 heart rate receiver on the left wrist and an H7 Bluetooth heart rate transmitter around the chest below the pectoralis major. Participants were instructed to engage in a typical skateboarding session on their own board with the duration and intensity of activity to be determined by the participant. The mean age of the participants was 27.4 ± 8.5 years, and participants reported skateboarding at a community skate park a mean of 3.1 ± 1.8 days/week. Participants had a mean heart rate of 138.2 ± 21.9 beats per minute (71.7% of age predicted maximum), skated for 65.5 ± 36.2 minutes, and traveled 4.56 ± 4.5 kilometers. Subjects spent 70% of their total duration at moderate-intensity or above and 30% within the low, and below low-intensity range. Results from this study suggest that adults participating in recreational skateboarding in community skateparks achieve the CDC's exercise recommendations for cardiovascular fitness. These findings may have implications for community skatepark design and professional training programs for adult skateboarding athletes.

Impact of Velcro Cuff Closure on Forearm Skin Temperature in Surfers Wearing a 2 mm and 3 mm Wetsuit.

Surfing is a worldwide sport that often requires participants to wear a wetsuit to assist in thermoregulation. In a recent study, forearm skin temperature decreased by approximately 3°C while wearing a wetsuit during recreational surfing. The purpose of this study was to test the hypothesis that reducing water flow in and out of the wetsuit by cuffing the wetsuit at the wrist, with a novel cuff closure system (Velcro cuff), would result in greater forearm skin temperature while surfing. One hundred and twelve (94 male, 18 female) recreational surfers between the ages of 18-50 participated in this study. Forearm skin temperature was measured at 1-minute intervals across the surf session in both arms with four wireless iButton thermal sensors located two inches from the styloid process (wrist) and olecranon process (elbow). Following instrumentation, all subjects had one of their wrists randomly cuffed with a one-inch wide Velcro cuff that was tightened to 2 cm less than the circumference of the wrist plus wetsuit. Subjects were then instructed to engage in regular recreational surfing activities for a minimum of 30 minutes at seven beaches in North San Diego County from October to April. No significant differences were found between the average cuffed wrist skin temperature and the average uncuffed wrist skin temperature (p = 0.06). However, average cuffed forearm skin temperature was significantly higher than average uncuffed forearm skin temperature (p = 0.01). Results from this study suggest that cuffing the wrist of wetsuits is a simple technique that can be utilized by surfers to significantly improve forearm skin temperature during surfing. These findings may also have an implication on future wetsuit designs.

Skin Temperatures in Females Wearing a 2 mm Wetsuit during Surfing.

The aim of this investigation was to examine regional skin temperatures in recreational female surfers' wearing a 2 mm thick neoprene wetsuit while surfing and to compare these results to previously published data collected in males participating in an identical study. Female surfers (n = 27) engaged in surfing for at least 40 min while wearing a commercially available 2 mm full wetsuit. Skin temperature of eight different anatomical locations were measured with wireless iButton thermal sensors. Regional skin temperatures significantly differed (p < 0.001) across almost all anatomical regions. Furthermore, regional skin temperatures significantly decreased across time at all skin regions throughout an average surfing session (p < 0.001). The greatest reduction in skin temperature was observed in the lower leg (-5.4 °C). Females in the current study exhibited a significantly greater skin temperature decrease in the lower back (-15.2% vs. -10.8%, p = 0.022) and lower arm (-13.6% vs. -10.8%, p < 0.001) when compared to previous data published in males. Overall, results of the current study are consistent with data previously published on male recreational surfers. However, the current study provides preliminary evidence that the magnitude of change in skin temperature may differ between male and female recreational surfers at some anatomical locations.

Electromyographic Analysis of the Surf Paddling Stroke Across Multiple Intensities.

Nessler, JA, Ponce-Gonzalez, JG, Robles-Rodriguez, C, Furr, H, Warner, M, and Newcomer, SC. Electromyographic analysis of the surf paddling stroke across multiple intensities. J Strength Cond Res 33(4): 1102-1110, 2019-Surfers spend a majority of their time in the water paddling. The purpose of this study was to examine activity in 5 muscles that contribute to paddling at different velocities and to characterize oxygen use, paddling cadence, and surfboard motion at each velocity. Twelve recreational surfers completed an incremental paddling test on a short surfboard in a swim flume. Surface electromyography was recorded bilaterally from latissimus dorsi, upper and mid trapezius, and posterior and mid deltoid. Electromyographic activity increased as water velocity increased for all muscles, but the change in activation between endurance and sprint paddling was greatest for latissimus dorsi (p < 0.001). At higher water velocities, the middle deltoid was activated earlier in the paddling stroke (p = 0.005). Oxygen use, paddling cadence, and surfboard roll/yaw increased with increasing water velocity. These data may be useful for athletes, trainers, and equipment designers interested in increasing power and efficiency of the paddling stroke.

Differences in V[Combining Dot Above]O2peak of Surfers When Paddling in Water vs. on a Swimbench Ergometer.

Furr, HN, Warner, ME, Copeland, TL, Robles-Rodríguez, C, Ponce-González, JG, Nessler, JA, and Newcomer, SC. Differences in V[Combining Dot Above]O2peak of surfers when paddling in water vs. on a swimbench ergometer. J Strength Cond Res 33(4): 1095-1101, 2019-The purpose of this study was to test the hypothesis that surfers would achieve a higher V[Combining Dot Above]O2peak when tested in a swim flume vs. on a swimbench ergometer. Forty-eight surfers (male: 38, female: 10) aged 18-45 years participated in the study. Protocol 1 and 2 both measured heart rate, oxygen consumption (V[Combining Dot Above]O2), and respiratory exchange ratio while subjects performed an incremental paddling test both on a swimbench ergometer and in a swim flume. Protocol 2 additionally measured muscle activity and changes in skin temperature. V[Combining Dot Above]O2peak was significantly higher in the swim flume (33.03 ± 1.04 ml·kg·min) vs. on the swimbench ergometer (29.86 ± 1.08 ml·kg·min) (p value < 0.001). There were also significant differences in muscle activation and changes in skin temperature between the flume and ergometer (p-value < 0.05). Surfers significantly increased their V[Combining Dot Above]O2peak in the water suggesting previous reports of V[Combining Dot Above]O2peak likely underestimated surfer's aerobic fitness when measured on a swimbench ergometer. Future research investigating the aerobic fitness of surfers should be conducted while paddling in water or account for the 11% difference in V[Combining Dot Above]O2peak when tested on a swimbench ergometer.

Heart rate and thermal responses to power yoga.

BACKGROUND: and Purpose: Yoga has grown in popularity and may offer a viable alternative form of physical activity. The purpose of this study was to examine heart rate, hydration, and thermal responses to a power yoga sequence. MATERIALS AND METHODS: Twenty-seven men and women (n = 4/23; Mean ±â€¯SD age = 23.3 ±â€¯3.3 years; BMI = 23 ±â€¯3 kg m-2) underwent ∼45 min of power yoga. Heart rate and skin temperature were recorded. Mass was measured before and after exercise to estimate fluid loss. Time spent in light, moderate, and vigorous heart rate zones was calculated. RESULTS: Heart rate and skin temperature increased (p < 0.0001). Participants spent more time in moderate and vigorous heart rate zones than in light intensity (p < 0.0001). There was a reduction in body mass (-0.28 ±â€¯0.13 kg, p < 0.0001). CONCLUSION: Power yoga may be considered moderate-vigorous intensity exercise, based on heart-rate.

Physiological Profile of Male Competitive and Recreational Surfers.

Furness, J, Hing, W, Sheppard, JM, Newcomer, S, Schram, B, and Climstein, M. Physiological profile of male competitive and recreational surfers. J Strength Cond Res 32(2): 372-378, 2018-Surfing consists of both high- and low-intensity paddling of varying durations, using both the aerobic and anaerobic systems. Surf-specific physiological studies lack adequate group sample sizes, and V[Combining Dot Above]O2peak values are yet to determine the differences between competitive and recreational surfers. The purpose of this study was therefore to provide a comprehensive physiological profile of both recreational and competitive surfers. This multisite study involved 62 male surfers, recreational (n = 47) and competitive (n = 15). Anthropometric measurements were conducted followed by dual-energy x-ray absorptiometry, anaerobic testing and finally aerobic testing. V[Combining Dot Above]O2peak was significantly greater in competitive surfers than in recreational surfers (M = 40.71 ± 3.28 vs. 31.25 ± 6.31 ml·kg·min, p < 0.001). This was also paralleled for anaerobic power (M = 303.93 vs. 264.58 W) for competitive surfers. Arm span and lean total muscle mass was significantly (p ≤ 0.01) correlated with key performance variables (V[Combining Dot Above]O2peak and anaerobic power). No significant (p ≥ 0.05) correlations were revealed between season rank and each of the variables of interest (V[Combining Dot Above]O2peak and anaerobic power). Key performance variables (V[Combining Dot Above]O2peak and anaerobic power) are significantly higher in competitive surfers, indicating that this is both an adaptation and requirement in this cohort. This battery of physiological tests could be used as a screening tool to identify an athlete's weaknesses or strengths. Coaches and clinicians could then select appropriate training regimes to address weaknesses.

Characterisation of regional skin temperatures in recreational surfers wearing a 2-mm wetsuit.

The purpose of this study was to investigate skin temperatures across surfers' bodies while wearing a wetsuit during recreational surfing. Forty-six male recreational surfers participated in this study. Participants were instrumented with eight wireless iButton thermal sensors for the measurement of skin temperature, a Polar RCX5 heart rate monitor and a 2-mm full wetsuit. Following instrumentation, participants were instructed to engage in recreational surfing activities as normal. Significant differences (p < 0.001) in skin temperature (Tsk) were found across the body while wearing a wetsuit during recreational surfing. In addition, regional skin temperature changed across the session for several regions of the body (p < 0.001), and the magnitude of these changes varied significantly between regions. We show for the first time that significant differences exist in skin temperature across the body while wearing a wetsuit during a typical recreational surfing session. These findings may have implications for future wetsuit design. Practitioner Summary: This study investigated the impact of wearing a wetsuit during recreational surfing on regional skin temperatures. Results from this study suggest that skin temperatures differ significantly across the body while wearing a 2-mm wetsuit during recreational surfing. These findings may have implications for future wetsuit design.

Wearing an Inflatable Vest Alters Muscle Activation and Trunk Angle While Paddling a Surfboard.

Low back pain is a commonly reported problem among recreational surfers. Some individuals report that wearing a vest with an inflatable bladder that alters trunk angle may help to alleviate pain. The purpose of this study was to determine whether such a vest has an effect on muscle activation and extension of the lower back. Twelve recreational surfers completed 12 paddling trials at 1.1 m/s in a swim flume on both a shortboard and a longboard on 2 separate days. Three conditions of no vest, vest uninflated, and vest inflated were presented to participants in random order. Surface EMG and trunk angle were acquired via wireless sensors placed over the right erector spinae, mid-trapezius, upper trapezius, and latissimus dorsi. Wearing the inflated vest affected muscle activation: erector spinae and mid-trapezius demonstrated a significant decrease in activation relative to wearing no vest (12% and 18% respectively, p < .05). Trunk extension was also significantly reduced when the vest was inflated (18% reduction, p < .05). Results were similar for both the short and longboard, though this effect was greater while paddling the larger board. These results suggest that a properly inflated vest can alter trunk extension and muscle activity while paddling a surfboard in water.

Increasing surfboard volume reduces energy expenditure during paddling.

The purpose of this study was to investigate how altering surfboard volume (BV) affects energy expenditure during paddling. Twenty surfers paddled in a swim flume on five surfboards in random order twice. All surfboards varied only in thickness and ranged in BV from 28.4 to 37.4 L. Measurements of heart rate (HR), oxygen consumption (VO2), pitch angle, roll angle and paddling cadence were measured. VO2 and HR significantly decreased on thicker boards [VO2: r = -0.984, p = 0.003; HR: r = -0.972, p = 0.006]. There was also a significant decrease in pitch and roll angles on thicker boards [Pitch: r = -0.995, p < 0.001; Roll: r = -0.911, p = 0.031]. Results from this study suggest that increasing BV reduces the metabolic cost of paddling as a result of lower pitch and roll angles, thus providing mechanical evidence for increased paddling efficiency on surfboards with more volume. Practioner Summary: This study investigated the impact of surfboard volume on energy expenditure during paddling. Results from this study suggest that increasing surfboard volume reduces the metabolic cost of paddling as a result of lower pitch and roll angles, thus providing mechanical evidence for increased paddling efficiency on surfboards with more volume.

Characterization of Activity and Cardiovascular Responses During Surfing in Recreational Male Surfers Between the Ages of 18 and 75 Years Old.

Participation in surfing has evolved to include all age groups. Therefore, the purpose of this study was to determine whether activity levels and cardiovascular responses to surfing change with age. Surfing time and heart rate (HR) were measured for the total surfing session and within each activity of surfing (paddling, sitting, wave riding, and miscellaneous). Peak oxygen consumption (VO2peak) was also measured during laboratory-based simulated surfboard paddling on a modified swim bench ergometer. VO2peak decreased with age during simulated paddling (r = -.455, p < .001, n = 68). Total time surfing (p = .837) and time spent within each activity of surfing did not differ with age (n = 160). Mean HR during surfing significantly decreased with age (r = -.231, p = .004). However, surfing HR expressed as a percent of age-predicted maximum increased significantly with age. Therefore, recreational surfers across the age spectrum are achieving intensities and durations that are consistent with guidelines for cardiovascular health.

Heart Rate Responses of High School Students Participating in Surfing Physical Education.

Despite the nation's rising epidemic of childhood obesity and diabetes, schools struggle to promote physical activities that help reduce risks for cardiovascular disease. Emerging data suggest that adopting novel activities into physical education (PE) curriculum may serve as an effective strategy for increasing physical activity in children. The purpose of this investigation was to characterize activity in the water and heart rates (HRs) of high school students participating in surf PE courses. Twenty-four male (n = 20) and female (n = 4) high school students (mean age = 16.7 ± 1.0 years) who were enrolled in surf PE courses at 2 high schools participated in this investigation. Daily measurements of surfing durations, average HR, and maximum HR were made on the students with HR monitors (PolarFT1) over an 8-week period. In addition, HR and activity in the water was evaluated during a single session in a subset of students (n = 11) using a HR monitor (PolarRCX5) and a video camera (Canon HD). Activity and HR were synchronized and evaluated in 5-second intervals during data analyses. The average duration that PE students participated in surfing during class was 61.7 ± 1.0 minutes. Stationary, paddling, wave riding, and miscellaneous activities comprised 42.7 ± 9.5, 36.7 ± 7.9, 2.9 ± 1.4, and 17.8 ± 11.4 percent of the surf session, respectively. The average and maximum HRs during these activities were 131.1 ± 0.9 and 177.2 ± 1.0 b·min, respectively. These data suggest that high school students participating in surf PE attained HRs and durations that are consistent with recommendations with cardiovascular fitness and health. In the future, PE programs should consider incorporating other action sports into their curriculum to enhance cardiovascular health.

Gestational exercise protects adult male offspring from high-fat diet-induced hepatic steatosis.

BACKGROUND & AIMS: Mounting evidence indicates that maternal exercise confers protection to adult offspring against various diseases. Here we hypothesized that maternal exercise during gestation would reduce high-fat diet (HFD)-induced hepatic steatosis in adult rat offspring. METHODS: Following conception, pregnant dams were divided into either voluntary wheel running exercise (GE) or wheel-locked sedentary (GS) groups throughout gestation (days 4-21). Post-weaning, offspring received either normal chow diet (CD; 10% fat, 70% carbohydrate, 20% protein) or HFD (45% fat, 35% carbohydrate, and 20% protein) until sacrificed at 4- or 8-months of age. RESULTS: GE did not affect offspring birth weight or litter size. HFD feeding in offspring increased weight gain, body fat percentage, and glucose tolerance test area under the curve (GTT-AUC). Male offspring from GE dams had reduced body fat percentage across all ages (p<0.05). In addition, 8-month male offspring from GE dams were protected against HFD-induced hepatic steatosis, which was associated with increased markers of hepatic mitochondrial biogenesis (PGC-1α and TFAM), autophagic potential (ATG12:ATG5 conjugation) and hepatic triacylglycerol secretion (MTTP). CONCLUSIONS: The current study provides the first evidence that gestational exercise can reduce susceptibility to HFD-induced hepatic steatosis in adult male offspring.

Effect of High-Calcium Diet on Coronary Artery Disease in Ossabaw Miniature Swine With Metabolic Syndrome.

BACKGROUND: Calcium is a shortfall essential nutrient that has been a mainstay of osteoporosis management. Recent and limited findings have prompted concern about the contribution of calcium supplementation to cardiovascular risk. A proposed mechanism is through the acceleration of coronary artery calcification. Determining causality between calcium intake and coronary artery calcification has been hindered by a lack of sensitive methodology to monitor early vascular calcium accumulation. The primary study aim was to assess the impact of high calcium intake on coronary artery calcification using innovative calcium tracer kinetic modeling in Ossabaw swine with diet-induced metabolic syndrome. Secondary end points (in vitro wire myography, histopathology, intravascular ultrasound) assessed coronary disease. METHODS AND RESULTS: Pigs (n=24; aged ≈15 months) were fed an atherogenic diet with adequate calcium (0.33% by weight) or high calcium (1.90% from calcium carbonate or dairy) for 6 months. Following 5 months of feeding, all pigs were dosed intravenously with (41)Ca, a rare isotope that can be measured in serum and tissues at a sensitivity of 10(-18) mol/L by accelerator mass spectrometry. Kinetic modeling evaluated early coronary artery calcification using (41)Ca values measured in serial blood samples (collected over 27 days) and coronary artery samples obtained at sacrifice. Serum disappearance of (41)Ca and total coronary artery (41)Ca accumulation did not differ among groups. Secondary end points demonstrated no treatment differences in coronary artery disease or function. CONCLUSION: There was no detectable effect of high calcium diets (from dairy or calcium carbonate) on coronary artery calcium deposition in metabolic syndrome swine.