Vagal modulation of the heart and central hemodynamics during dynamic handgrip exercise and forearm occlusion following forearm exercise training

The purpose was to examine the cardiovascular response to an acute bout of handgrip exercise before and after non-dominant arm exercise training. 19 people participated in 16 sessions of exercise training and 16 participants acted as controls (age: 20±1yrs). Blood flow measurements were taken at rest and following 3-min of forearm occlusion (RHBF) using plethysmography. Pneumotachometer, ECG, and blood pressure data were continuously collected during three testing conditions (spontaneous breathing (SB1: 5min), handgrip exercise (0.5hz) at 60%MVC with 50mmHg of pressure on the arm (H60+50mmHg: 5 min), and forearm occlusion (FAO: 3min)). Data were analyzed for respiratory rate, mean R-R interval, standard deviation of normal RR intervals (SDNN), normalized units of low- (0-0.15 hz) frequency power (LFnu), and mean arterial pressure (MAP). There was no main effect of group or arm. There was a main effect of test condition such that respiratory rate (+3.10±5.40breaths/min), LFnu (+19.06±14.73%), and MAP increased (+24.51±21.15mmHg) and mean R-R (-247.11±129.70msec) and SDNN (-45.16±40.65msec) decreased significantly during H60+50mmHg (non-dominant arm; p\u3c0.05). Respiratory rate (-0.10±4.84breaths/min), SDNN (-9.50±57.14msec), and LFnu (-1.64±18.34%) recovered to SB1 levels during. Mean R-R (46.11±106.57msec) and MAP (16.65±15.84mmHg) remained elevated above SB1 (p\u3c0.05). There were positive linear associations between forearm circumference and Mean R-R and MAP during H60+50mmHg; and MAP during FAO. There was a negative linear association with forearm circumference and Mean R-R during FAO. There was no significant main effect or interaction with handgrip exercise training on any of the variables. There was a decrease in vascular resistance during RHBF (0.80±1.08 mmHg/ ml/100ml/min, p\u3c0.05) in the arm that underwent exercise training. In conclusion, we found elevated MAP during FAO, which is indicative of significant EPR activity during exercise. Uniquely, we found linear associations between forearm circumference and the cardiovascular response to H60+50mmHg and FAO suggesting variation in the predominant mechanism of cardiovascular control. We did not see an attenuation of cardiovascular responses to H60+50mmHg and FAO with exercise training. However, we did see a decrease in forearm vascular resistance during the reactive hyperemia condition in the exercise-trained arm

A comparison of owner perceived and measured body condition, feeding and exercise in sport and pet dogs

Dog obesity is a significant problem in the US and elsewhere. The purpose was to evaluate factors contributing to pet obesity in sport and pet dog owners. Owners were recruited over social media to answer a questionnaire regarding demographics, health, body condition, feeding, exercise and dog related expenses. Owners identified as pet or sport dog owners. We asked owners to measure the pelvic circumference and hock to stifle length in their dogs in order to calculate percent fat. Owners reported that their dogs were in “ideal” body condition. However, percent fat calculated from owner measurements was significantly different between groups (Sport: 16 ± 10%fat; Pet: 24 ± 10% fat; p < 0.05) and revealed that over 50% of the dogs were over fat. Owners reported feeding dogs a range of 413 to 1,133 Kilocalories (Kcal) per day that correlated well with dog size (R = 0.58; p < 0.05). The size of the treats fed was smaller in the Sport dogs (treat was pinky nail to thumbnail sized) than in Pet dogs (treat was bigger than thumb to larger than palm). Owners reported walking their dogs on leash every day for 15–45 min per session. Overall, owners did a poor job in identifying correct body condition of their dogs. This is concerning because 50% of the dogs were over fat. Better understanding of correct body condition and feeding for the level of physical activity is still a critical issue in controlling obesity in pet dogs

Protein Supplementation Throughout 10 Weeks of Progressive Run Training Is Not Beneficial for Time Trial Improvement

Introduction: Protein supplementation is proposed to promote recovery and adaptation following endurance exercise. While prior literature demonstrates improved performance when supplementing protein during or following endurance exercise, chronic supplementation research is limited.Methods: Runners (VO2peak = 53.6 ± 8.9 ml/kg/min) were counter-balanced into a placebo group (PLA; n = 8) or protein group (PRO; n = 9) based on sex and VO2peak, and underwent 10 weeks of progressive endurance training. Prior to training, body composition, blood cell differentials, non-invasive mitochondrial capacity using near-infrared spectroscopy, and a 5 km treadmill time trial (TT) were evaluated. Progressive training then commenced (5–10% increase in weekly volume with a recovery week following 3 weeks of training) whereby PRO supplemented with 25 g of whey protein following workouts and prior to sleep (additional 50 g daily). PLA supplemented similarly with a < 1 g sugar pill per day. Following training, participants were reanalyzed for the aforementioned tests.Results: VO2peak and initial 5 km TT were not significantly different between groups. PRO consumed significantly more dietary protein throughout the training period (PRO = 132 g/d or 2.1 g/kg/day; PLA = 84 g/d or 1.2 g/kg/day). Running volume increased significantly over time, but was not significantly different between groups throughout training. Blood measures were unaltered with training or supplementation. Mitochondrial capacity trended toward improving over time (time p = 0.063) with no difference between groups. PLA increased lean mass 0.7 kg (p < 0.05) while PRO experienced infinitesimal change (−0.1 kg, interaction p = 0.049). PLA improved 5 km TT performance 6.4% (1 min 31 s), while PRO improved only 2.7% (40 s) (interaction p = 0.080).Conclusion: This is the first evidence to suggest long-term protein supplementation during progressive run training is not beneficial for runners

Plasma dipeptidyl peptidase IV activity and measures of body composition in apparently healthy people

Aim: Based on its regulatory action on glucagon-like peptide 1, dipeptidyl peptidase IV (DPP-IV) has increasingly been linked to Type 2 diabetes. However, there is no evidence as to how this normal modulatory enzyme leads to pathology. It is thought that DPP-IV is affected by the development of obesity, which is a common precursor to Type 2 diabetes. Little is known about the relationship between DPP-IV activity in plasma and specific body composition measures. Main methods: In the current study, plasma DPP-IV activity and body composition measures were collected from 111 healthy subjects between the ages of 19 and 70 years old for analysis. Key findings: The mean plasma DPP-IV activity was 35.9U/L ± 12.3, falling within normal reference value range presented by Durinx et al. DPP-IV activity was negatively correlated with absolute body fat mass, but absolute lean mass was positively correlated. Consistent with the findings, DPP-IV activity was also negatively correlated with absolute gynoid fat (p = 0.0047). DPP-IV activity did not have a significant correlation with absolute android fat mass, visceral adipose tissue, BMI, and age. Significance: From these results, it can be concluded that high activity of DPP-IV is not indicative of pathology, and specific body composition components may influence soluble DPP-IV activity in the blood

Data from: Plasma dipeptidyl peptidase IV activity and measures of body composition in apparently healthy people

Aim: Based on its regulatory action on glucagon-like peptide 1, dipeptidyl peptidase IV (DPP-IV) has increasingly been linked to Type 2 diabetes. However, there is no evidence as to how this normal modulatory enzyme leads to pathology. It is thought that DPP-IV is affected by the development of obesity, which is a common precursor to Type 2 diabetes. Little is known about the relationship between DPP-IV activity in plasma and specific body composition measures. Main methods: In the current study, plasma DPP-IV activity and body composition measures were collected from 111 healthy subjects between the ages of 19 and 70 years old for analysis. Key findings: The mean plasma DPP-IV activity was 35.9U/L ± 12.3, falling within normal reference value range presented by Durinx et al. DPP-IV activity was negatively correlated with absolute body fat mass, but absolute lean mass was positively correlated. Consistent with the findings, DPP-IV activity was also negatively correlated with absolute gynoid fat (p = 0.0047). DPP-IV activity did not have a significant correlation with absolute android fat mass, visceral adipose tissue, BMI, and age. Significance: From these results, it can be concluded that high activity of DPP-IV is not indicative of pathology, and specific body composition components may influence soluble DPP-IV activity in the blood