Brian A. Davis

Natural versus commercial carbohydrate supplementation and endurance running performance.

BackgroundWe examined the metabolic, performance and gastrointestinal (GI) effects of supplementation with a natural food product (raisins) compared to a commercial product (sport chews).MethodsEleven male (29.3 ± 7.9 yrs; mean and SD) runners completed three randomized trials (raisins, chews and water only) separated by seven days. Each trial consisted of 80-min (75%VO2max) treadmill running followed by a 5-km time trial (TT). Heart rate (HR), respiratory exchange ratio (RER), blood lactate, serum free fatty acids (FFA), glycerol and insulin, plasma glucose and creatine kinase, GI symptoms and rating of perceived exertion (RPE) were recorded every 20-min. We employed a within-subject two-way analysis of variance (ANOVA) for repeated measures with a Fisher’s post hoc analysis to determine significant differences.ResultsVO2, HR, lactate, glycerol and RPE did not differ due to treatment. Average plasma glucose was maintained at resting levels (5.3 ± 0.4 mmol·L-1) during the sub-maximal exercise bout (5.9 ± 0.6, 5.7 ± 0.6 and 5.5 ± 0.5 mmol·L-1 for chews, raisins and water respectively), and was significantly higher with chews than water only. RER and % of non-protein macronutrient oxidation derived from carbohydrate was highest with chews, followed by raisins and water was the lowest (74.4 ± 6.4, 70.0 ± 7.0 and 65.1 ± 8.7% for chews, raisins and water respectively) during the sub-maximal exercise period. Serum FFA was higher in the water treatment versus both raisins and chews at 80 min of sub-maximal exercise. Serum insulin was higher with the chews than both raisins and water (5.1 ± 2.0, 3.1 ± 0.8, 1.9 ± 0.6 uU·ml-1 for chews, raisins and water respectively). Plasma creatine kinase, corrected for baseline values, for the last 40 min of the sub-maximal exercise bout, was higher with raisins compared to other treatments. The TT was faster for both carbohydrate supplements (20.6 ± 2.6, 20.7 ± 2.5, 21.6 ± 2.7 min for raisin, chews and water respectively). GI disturbance was mild for all treatments.ConclusionRaisins and chews promoted higher carbohydrate oxidation and improved running performance compared to water only. Running performance was similar between the raisins and chews, with no significant GI differences.

Electrodiagnosis in carpal tunnel syndrome

There is currently no gold standard to definitively diagnose carpal tunnel syndrome. It remains a clinical diagnosis supported by characteristic electrodiagnostic abnormalities. Properly performed electrodiagnostic studies should provide the hand surgeon with information regarding severity, progression if a previous study was performed, and a reasonable assurance that concomitant peripheral nervous system abnormalities are not present. Hand surgeons do not need to discern nuances of an electrodiagnostic evaluation; however, the ability to identify state-of-the-art techniques coupled with a thoughtful interpretation by the electrodiagnostician will improve their confidence in using this important diagnostic tool to evaluate carpal tunnel syndrome.

Betalain-Rich Concentrate Supplementation Improves Exercise Performance in Competitive Runners

This study aimed to determine the effects of a betalain-rich concentrate (BRC) of red beets, containing antioxidant and anti-inflammatory properties, on performance and exercise-related muscle damage. Thirteen (25.3 ± 5.4 years) competitive male runners completed two double-blind, cross-over, randomized trials (BRC and control) separated by seven days. Each trial was preceded by six days of supplementation with 100 mg of BRC or control. On the seventh day, exercise trials commenced 150 min after supplementation with 50 mg BRC or control and consisted of 30 min of treadmill running (77 ± 4% VO2max) followed by a 5-km time trial (TT). During exercise at the same intensity, BRC resulted in a 3% lower heart rate, a 15% lower rate of perceived exertion (RPE) and a 14% lower blood lactate concentration compared to the control (p = 0.05). Five-kilometer TT duration (23.0 ± 4.2 versus 23.6 ± 4.0 min) was faster in 10 of the 13 subjects, and RPE was lower (p < 0.05) with the BRC treatment compared to the control. Lactate dehydrogenase, a marker of muscle damage, increased less from baseline to immediately and 30 min after the 5-km TT with the BRC treatment, despite no differences in subjective measures of muscle soreness and fatigue. In summary, BRC supplementation improved 5-km performance time in male competitive runners.

Diagnosis and management of thoracic and rib pain in rowers

Thoracic and lumbar injuries can dramatically affect a rower’s performance and lead to time lost from practice and competition. Even though the number of injuries encountered by elite and competitive rowers appears to have increased over the past 20 years, rowing-specific research has been very limited in its scope and ability to guide practitioners caring for these athletes. Specifically, case reports relating to rib stress fractures abound, yet very few controlled studies discuss the mechanisms of injury and appropriate management of thoracic injuries. We believe that the identification and treatment of kinetic chain abnormalities in areas distant to the site of injury, such as the lower extremities, pelvis, and lumbar spine, should be an integral part of thoracic injury evaluation and treatment. Simultaneous evaluation of training regimen and equipment is also crucial to the management of rowers suffering from thoracic injuries.

Betalain-rich concentrate supplementation improves exercise performance and recovery in competitive triathletes

We aimed to determine the effects of a betalain-rich concentrate (BRC) of beetroots, containing no sugars or nitrates, on exercise performance and recovery. Twenty-two (9 men and 13 women) triathletes (age, 38 ± 11 years) completed 2 double-blind, crossover, randomized trials (BRC and placebo) starting 7 days apart. Each trial was preceded by 6 days of supplementation with 100 mg·day-1 of BRC or placebo. On the 7th day of supplementation, exercise trials commenced 120 min after ingestion of 50 mg BRC or placebo and consisted of 40 min of cycling (75 ± 5% maximal oxygen consumption) followed by a 10-km running time trial (TT). Subjects returned 24 h later to complete a 5-km running TT to assess recovery. Ten-kilometer TT duration (49.5 ± 8.9 vs. 50.8 ± 10.3 min, p = 0.03) was faster with the BRC treatment. Despite running faster, average heart rate and ratings of perceived exertion were not different between treatments. Five-kilometer TT duration (23.2 ± 4.4 vs 23.9 ± 4.7 min, p = 0.003), 24 h after the 10-km TT, was faster in 17 of the 22 subjects with the BRC treatment. Creatine kinase, a muscle damage marker, increased less (40.5 ± 22.5 vs. 49.7 ± 21.5 U·L-1, p = 0.02) from baseline to after the 10-km TT and subjective fatigue increased less (-0.05 ± 6.1 vs. 3.23 ± 6.1, p = 0.05) from baseline to 24 h after the 10-km TT with BRC. In conclusion, BRC supplementation improved 10-km TT performance in competitive male and female triathletes. Improved 5-km TT performances 24 h after the 10-km TT and the attenuated increase of creatine kinase and fatigue suggest an increase in recovery while taking BRC.

Large Thigh Mass in a Recreational Athlete: A Case Report

opliteal cysts or Baker cysts usually are encapsulated extensions of synovial fluid into the opliteal space. The size of these fluid collections is quite variable, but the location remains onstant. The term Baker cyst is named after Dr. William Baker, who first described it in 872 [1]. They are often, but not always, asymptomatic and identified incidentally. Baker ysts can be associated with various mechanical and inflammatory conditions of the knee. In atients who have a large popliteal mass or a painful mass of any size, diagnostic imaging is ndicated to confirm the diagnosis and treatment plan. Treatment should be directed toward he underlying pathology and includes both nonsurgical and surgical options. This case presentation describes one of the largest Baker cysts reported in the literature to ate. The report will describe the clinical presentation, diagnostic challenges and pitfalls particularly in interpreting imaging findings), a discussion of the differential diagnosis, and presentation of various classical and novel treatment approaches. Further, a literature eview of Baker cysts will be described, highlighting the relatively unusual location of this atient’s Baker cyst.