The Effects of Acute Anaerobic Exercise on the Cardiovascular and Metabolic Response to the Cold Pressor Test in Healthy Adult Males

International Journal of Exercise Science 13(3): 1729-1740, 2020. Little is known about the physiological response to the cold pressor test (CPT) when in a clinically-induced state of autonomic nervous system (ANS) imbalance, despite its utility in various disease- and injury-states. To date, research in this area is limited to acute aerobic and isometric exercise, with a paucity of research investigating the effects of anaerobic exercise on the physiological response to the CPT. Therefore, the purpose of our study was to assess the effects of the Wingate anaerobic cycle test (WAT) on cardiovascular (CV) and metabolic recovery following the CPT in a group of healthy adult males. A pre-post intervention study was conducted, whereby 10 healthy adult males (age = 29 ± 4 years, height = 182 ± 7 cm, mass = 83 ± 9 kg) completed a baseline cold pressor test (CPT-only) and a follow-up cold pressor test preceded by a Wingate anaerobic exercise test (WAT+CPT). Recovery slopes for various CV and metabolic variables, including heart rate (HR), blood pressure (BP), and relative oxygen consumption (O2) were analyzed using single-subject analysis, with celeration line slopes calculated for all participants in the CPT-only and WAT+CPT testing sessions. Celeration line slopes were compared between testing sessions using paired t-tests. No differences were identified for recovery slopes for HR (p = .295), diastolic BP (p = .300), and relative O2 (p= .176) when comparing CPT-only and WAT+CPT testing sessions. Our results suggest that the CPT elicits a CV and metabolic response beyond that elicited solely by an acute bout of anaerobic exercise. As such, the CPT may be able to serve as a surrogate test for anaerobic exercise for individuals where high-intensity exercise may be contraindicated. Future research is warranted however, as the specific physiological mechanisms governing the observed responses have yet to be elucidated

Effects of Creatine Supplementation on Brain Function and Health

While the vast majority of research involving creatine supplementation has focused on skeletal muscle, there is a small body of accumulating research that has focused on creatine and the brain. Preliminary studies indicate that creatine supplementation (and guanidinoacetic acid; GAA) has the ability to increase brain creatine content in humans. Furthermore, creatine has shown some promise for attenuating symptoms of concussion, mild traumatic brain injury and depression but its effect on neurodegenerative diseases appears to be lacking. The purpose of this narrative review is to summarize the current body of research pertaining to creatine supplementation on total creatine and phophorylcreatine (PCr) content, explore GAA as an alternative or adjunct to creatine supplementation on brain creatine uptake, assess the impact of creatine on cognition with a focus on sleep deprivation, discuss the effects of creatine supplementation on a variety of neurological and mental health conditions, and outline recent advances on creatine supplementation as a neuroprotective supplement following traumatic brain injury or concussion

Anti-Inflammatory and Anti-Catabolic Effects of Creatine Supplementation: A Brief Review

It is well established that creatine supplementation, primarily when combined with resistance training, significantly increases measures of muscle mass and performance (primarily strength). Emerging research also indicates that creatine supplementation may have favorable effects on measures of bone biology. These anabolic adaptations may be related to creatine influencing cellular hydration status, high-energy phosphate metabolism, growth factors, muscle protein kinetics, and the bone remodeling process. Accumulating research also suggests that creatine supplementation has anti-inflammatory and anti-catabolic properties, which may help create a favorable environment for muscle and bone accretion and recovery from exercise. Creatine supplementation has the ability to decrease markers of inflammation and possibly attenuate cancerous tumor growth progression. From a musculoskeletal perspective, there is some evidence to show that creatine supplementation reduces measures of muscle protein catabolism (primarily in males) and bone resorption when combined with resistance training. The purpose of this brief review is to summarize the current body of literature examining the potential anti-inflammatory and anti-catabolic effects of creatine supplementation across various research populations

Caffeine Alters Blood Potassium and Catecholamine Concentrations but not the Perception of Pain and Fatigue with a 1 km Cycling Sprint

Background: Caffeine has been used by some athletes to improve short-term high-intensity exercise performance; however, the literature is equivocal. Objectives: The objective of this study was to investigate the effects of caffeine on plasma potassium and catecholamine concentrations, pain and fatigue perception, to determine whether potassium ion handling and altered perception related to the central nervous system are associated with enhanced performance during a 1 km cycling time trial.  Methods: Thirteen well trained men with a mean age of 27 ± 6 yrs (body mass: 76.4 ± 6.4 kg, height: 180 ± 7 cm, and max: 57.5 ± 4.6 ml·kg-1·min-1) were recruited.  Participants were randomized to a caffeine (5 mg·kg-1) or a placebo condition using a double blind, cross over design.  Results: Caffeine had no significant effects on the 1 km time-trial performance indicators of time (82.1 ± 2.4 vs. 81.9 ± 3.9s), peak (633.0 ± 83.6 vs. 638.7 ± 110.1 watts) or average power (466.0 ± 37.3 vs. 467.5 ± 59.9 watts; caffeine and placebo conditions respectively).  In addition, caffeine had no significant effect on oxygen consumption () (4.11 ± 0.24 vs 4.06 ± 0.29 L),the perception of pain (5.6 ± 2.4 vs. 5.5 ± 2.6) or fatigue (7.1 ± 1.8 vs.7.1 ± 1.8: caffeine and placebo conditions respectively).  There was a significantly greater increase in post-exercise blood lactate (p0.05) and catecholamines (p0.05) as well as a lower pre-exercise blood potassium concentration (p0.05) in the caffeine condition. Conclusions: The results suggest that caffeine can enhance certain metabolic parameters, but these changes were unable to augment short-distance (1km), high-intensity cycling performance.Keywords: ergogenic, anaerobic exercise, performance, oxygen consumptio

Caffeine Alters Blood Potassium and Catecholamine Concentrations but not the Perception of Pain and Fatigue with a 1 km Cycling Sprint

Background: Caffeine has been used by some athletes to improve short-term high-intensity exercise performance; however, the literature is equivocal. Objectives: The objective of this study was to investigate the effects of caffeine on plasma potassium and catecholamine concentrations, pain and fatigue perception, to determine whether potassium ion handling and altered perception related to the central nervous system are associated with enhanced performance during a 1 km cycling time trial.  Methods: Thirteen well trained men with a mean age of 27 ± 6 yrs (body mass: 76.4 ± 6.4 kg, height: 180 ± 7 cm, and max: 57.5 ± 4.6 ml·kg-1·min-1) were recruited.  Participants were randomized to a caffeine (5 mg·kg-1) or a placebo condition using a double blind, cross over design.  Results: Caffeine had no significant effects on the 1 km time-trial performance indicators of time (82.1 ± 2.4 vs. 81.9 ± 3.9s), peak (633.0 ± 83.6 vs. 638.7 ± 110.1 watts) or average power (466.0 ± 37.3 vs. 467.5 ± 59.9 watts; caffeine and placebo conditions respectively).  In addition, caffeine had no significant effect on oxygen consumption () (4.11 ± 0.24 vs 4.06 ± 0.29 L),the perception of pain (5.6 ± 2.4 vs. 5.5 ± 2.6) or fatigue (7.1 ± 1.8 vs.7.1 ± 1.8: caffeine and placebo conditions respectively).  There was a significantly greater increase in post-exercise blood lactate (p<0.05) and catecholamines (p<0.05) as well as a lower pre-exercise blood potassium concentration (p<0.05) in the caffeine condition. Conclusions: The results suggest that caffeine can enhance certain metabolic parameters, but these changes were unable to augment short-distance (1km), high-intensity cycling performance. Keywords: ergogenic, anaerobic exercise, performance, oxygen consumptio

The Size and Strength Development in Elite Youth Ice Hockey Players

Background: Ice hockey is a fast, physical sport that requires high levels of muscular strength, muscular endurance and agility. Objectives: This study was conducted to create a profile including: anthropometric measurement, muscular strength, muscular endurance, lower body jump height and distance, and agility characteristics for elite youth hockey players.  Methods: Pre-season off-ice testing results were retrospectively reviewed from a human performance database.  Variables included height, weight, body fat percentage, grip strength, push-ups/bench press, supine rows, the plank test, vertical jump, standing long jump, hip adductor and abductor strength, and the 5-10-5 shuttle, and. One-way ANOVAs (1group x 4 time) and Tukeys post-hoc tests were performed to determine changes in the immediately successive age group (p<0.05). Results: Participants included male Bantam-(age: 13-14) and Midget-(age: 15-17) AAA ice-hockey players (n=260).  Age categories were grouped as 13 years old (yo)(n=75), 14 yo (n=70), 15 yo (n=58), and 16-17 yo (n=57).  Increases between successive age groups were observed in the following variables: weight (13, 14, 15 and 16-17 yo), height (13 and 14 yo), left and right grip strength (13, 14, 15, and 16-17 yo), bench press (15 and 16-17 yo), left and right hip abduction (14, 15, and 16-17 yo), and vertical and standing long jump (13, 14, and 15 yo). Total time for the 5-10-5 shuttle run test decreased from 13 to 14yo, and 14 to 15 yo. Conclusion: Changes with age in off-ice performance variables of elite amateur hockey players should be recognized, followed, and addressed during player development to maximize the potential for elite performance and reduce the risk of injury.   Keywords: Athletic Performance, Training, Physical Fitnes

The Size and Strength Development in Elite Youth Ice Hockey Players

Background: Ice hockey is a fast, physical sport that requires high levels of muscular strength, muscular endurance and agility. Objectives: This study was conducted to create a profile including: anthropometric measurement, muscular strength, muscular endurance, lower body jump height and distance, and agility characteristics for elite youth hockey players.  Methods: Pre-season off-ice testing results were retrospectively reviewed from a human performance database.  Variables included height, weight, body fat percentage, grip strength, push-ups/bench press, supine rows, the plank test, vertical jump, standing long jump, hip adductor and abductor strength, and the 5-10-5 shuttle, and. One-way ANOVAs (1group x 4 time) and Tukeys post-hoc tests were performed to determine changes in the immediately successive age group (p0.05). Results: Participants included male Bantam-(age: 13-14) and Midget-(age: 15-17) AAA ice-hockey players (n=260).  Age categories were grouped as 13 years old (yo)(n=75), 14 yo (n=70), 15 yo (n=58), and 16-17 yo (n=57).  Increases between successive age groups were observed in the following variables: weight (13, 14, 15 and 16-17 yo), height (13 and 14 yo), left and right grip strength (13, 14, 15, and 16-17 yo), bench press (15 and 16-17 yo), left and right hip abduction (14, 15, and 16-17 yo), and vertical and standing long jump (13, 14, and 15 yo). Total time for the 5-10-5 shuttle run test decreased from 13 to 14yo, and 14 to 15 yo. Conclusion: Changes with age in off-ice performance variables of elite amateur hockey players should be recognized, followed, and addressed during player development to maximize the potential for elite performance and reduce the risk of injury.  Keywords: Athletic Performance, Training, Physical Fitnes

Effects of Omega-3 Supplementation Alone and Combined with Resistance Exercise on Skeletal Muscle in Older Adults: A Systematic Review and Meta-Analysis

Sarcopenia negatively affects skeletal muscle mass and function in older adults. Omega-3 (&omega;-3) fatty acid supplementation, with or without resistance exercise training (RET), is suggested to play a role as a therapeutic component to prevent or treat the negative effects of sarcopenia. A systematic review and meta-analysis were conducted on the impact of &omega;-3 fatty acid supplementation with or without RET on measures of muscle mass and function in older adults (&ge;55 y). The data sources included SPORTDiscus, PubMed, and Medline. All the study types involving &omega;-3 fatty acid supplementation on measures of muscle mass and function in older adults (without disease) were included. The mean differences (MDs) or standardized mean differences (SMDs) with 95% confidence intervals were calculated and pooled effects assessed. Sixteen studies (1660 females, 778 males) met our inclusion criteria and were included in the meta-analysis. &omega;-3 fatty acid supplementation did not impact lean tissue mass (SMD 0.09 [&minus;0.10, 0.28]). Benefits were observed for lower body strength (SMD 0.54 [0.33, 0.75]), timed-up-and-go (MD 0.29 [0.23, 0.35]s), and 30-s sit-to-stand performance (MD 1.93 [1.59, 2.26] repetitions) but not walking performance (SMD &minus;0.01 [&minus;0.10, 0.07]) or upper body strength (SMD 0.05 [&minus;0.04, 0.13]). Supplementing with &omega;-3 fatty acids may improve the lower-body strength and functionality in older adults

Non-Invasive and Minimally-Invasive Cerebral Autoregulation Assessment: A Narrative Review of Techniques and Implications for Clinical Research.

The process of cerebral vessels regulating constant cerebral blood flow over a wide range of systemic arterial pressures is termed cerebral autoregulation (CA). Static and dynamic autoregulation are two types of CA measurement techniques, with the main difference between these measures relating to the time scale used. Static autoregulation looks at the long-term change in blood pressures, while dynamic autoregulation looks at the immediate change. Techniques that provide regularly updating measures are referred to as continuous, whereas intermittent techniques take a single at point in time. However, a technique being continuous or intermittent is not implied by if the technique measures autoregulation statically or dynamically. This narrative review outlines technical aspects of non-invasive and minimally-invasive modalities along with providing details on the non-invasive and minimally-invasive measurement techniques used for CA assessment. These non-invasive techniques include neuroimaging methods, transcranial Doppler, and near-infrared spectroscopy while the minimally-invasive techniques include positron emission tomography along with magnetic resonance imaging and radiography methods. Further, the advantages and limitations are discussed along with how these methods are used to assess CA. At the end, the clinical considerations regarding these various techniques are highlighted

The Quantitative Associations Between Near Infrared Spectroscopic Cerebrovascular Metrics and Cerebral Blood Flow: A Scoping Review of the Human and Animal Literature.

Cerebral blood flow (CBF) is an important physiologic parameter that is vital for proper cerebral function and recovery. Current widely accepted methods of measuring CBF are cumbersome, invasive, or have poor spatial or temporal resolution. Near infrared spectroscopy (NIRS) based measures of cerebrovascular physiology may provide a means of non-invasively, topographically, and continuously measuring CBF. We performed a systematically conducted scoping review of the available literature examining the quantitative relationship between NIRS-based cerebrovascular metrics and CBF. We found that continuous-wave NIRS (CW-NIRS) was the most examined modality with dynamic contrast enhanced NIRS (DCE-NIRS) being the next most common. Fewer studies assessed diffuse correlation spectroscopy (DCS) and frequency resolved NIRS (FR-NIRS). We did not find studies examining the relationship between time-resolved NIRS (TR-NIRS) based metrics and CBF. Studies were most frequently conducted in humans and animal studies mostly utilized large animal models. The identified studies almost exclusively used a Pearson correlation analysis. Much of the literature supported a positive linear relationship between changes in CW-NIRS based metrics, particularly regional cerebral oxygen saturation (rSO2), and changes in CBF. Linear relationships were also identified between other NIRS based modalities and CBF, however, further validation is needed