The Effect of Psychomotor Performance, Cerebral and Arterial Blood Saturation Between African-American and Caucasian Males Before, During and After Normobaric Hypoxic Exercise

International Journal of Exercise Science 10(5): 655-665, 2017. To further elucidate physiological and cognitive performance differences between African-American (AA) and Caucasian individuals (CAU) before, during or after hypoxic and normoxic exercise. Twelve college aged (18-25) apparently healthy African-American (six volunteers) and Caucasian (six subjects) males took part in two trials consisting of normobaric normoxia and normobaric hypoxia (12% oxygen). Each subject cycled at 50% of their altitude adjusted VO2max (-26% of normoxia VO2max) for one hour after a two-hour baseline. Subjects were monitored for cerebral and arterial O2 saturation, as well as the Trail Making Test A and B (TMT) psychomotor performance. Arterial saturation proved to be significantly higher in AA (86.0±4.7) compared to CAU (79.5±4.8) during the first 60 minutes of exposure to hypoxia at rest (p=0.039), but not during exercise. However, cerebral oxygenation to the left frontal lobe was decreased near the conclusion and in 30 minutes after normoxic exercise. TMT B data revealed that CAU (79±12.7) had faster scores than the AA subjects (98±25.1) at all time points and was significantly different at the 115-minute time point of the hypoxic trial (p=0.024). The data suggests that before, during and after normobaric normoxia and hypoxia trial there is a differential response between AA and CAU in regards to arterial and cerebral oxygenation, as well as psychomotor tests

Ingestion of oxygenated water enhances lactate clearance kinetics in trained runners

Abstract Background Drinks with higher dissolved oxygen concentrations have in recent times gained popularity as a potential ergogenic aid, despite a lack of evidence regarding their efficacy. The aim of this study was to assess effects of ingestion of an oxygen supplement (OS) on exercise performance and post-exercise recovery in a group of trained runners. Methods Trained male runners (n = 25, mean ± SD; age 23 ± 6 years, mass 70 ± 9 kg, BMI 21.9 ± 2.7 kg.m−2 VO2max 64 ± 6mL.kg−1.min−1), completed a randomised double blinded, crossover study to assess the effect of ingestion of OS solution on exercise performance and recovery. Trials consisted of a 30min rest period, 5min warm-up, a 5000m treadmill time-trial, and a 30min passive recovery. Participants ingested 6x15mL of either OS or a taste matched placebo during the trials (3 during the rest phase, 1 during exercise and 2 during the recovery). Muscle tissue O2 saturation was measured via near infrared spectroscopy. Blood lactate concentrations were measured prior to, mid-way and directly after the finish of the 5000m time trials and every 3-min during the post-exercise recovery. Results Ingestion of OS did not improve exercise performance. No significant differences were observed for muscle tissue O2 saturation at any time-points. However, lactate clearance was significantly improved during recovery in the OS trials. Both AUC (109 ± 32 vs. 123 ± 38 mmol.min, P < 0.05, d = 0.40) and lactate half-life (λ) (1127 ± 272 vs. 1223 ± 334 s, P < 0.05, d = 0.32) were significantly reduced. Conclusions Despite no evidence of improved exercise performance, ingestion of OS did enhance post-exercise recovery via increased lactate clearance

Physiological differences before, during and after hypoxic exercise between African-American and Caucasian males

INTRODUCTION: Hypoxia is a potent stimulus that induces neuropsychological and physical impairments in humans. It is documented that ethnic differences exists across various physiological parameters. There appears to be a varying metabolic response across ethnicities, specifically African-Americans and Caucasians. Purpose: To further elucidate physiological and cognitive performance differences between African-American (AA) and Caucasian individuals (CAU) before, during or after hypoxic and normoxic exercise. Methods: Twelve college aged (18-25) apparently healthy African-American (six volunteers) and Caucasian (six subjects) males took part in two trials consisting of normobaric normoxia and normobaric hypoxia (12% oxygen). Each subject cycled at 50% of their altitude adjusted VO2max (-26% of normoxia VO2max) for one hour after a two-hour baseline. Subjects were monitored for cerebral and arterial O2 saturation, as well as the Trail Making Test A and B (TMT) psychomotor performance. Results: Arterial saturation proved to be significantly higher in AA (86.0±4.7) compared to CAU (79.5±4.8) during the first 60 minutes of exposure to hypoxia at rest (p=0.039), but not during exercise. Cerebral oxygenation to the left frontal lobe was decreased near the conclusion and 30 minutes after normoxic exercise. TMT B data revealed that CAU (79±12.7) had faster scores than the AA subjects (98±25.1) at all time points and was significantly different at the 115 minute time point of the hypoxic trial (p=0.024). Conclusion: Data suggests that before, during and after normobaric normoxia and hypoxia trial there is a differential response between AA and CAU in regards to arterial and cerebral oxygenation and psychomotor tests

Blood Flow Restriction and Various Intensity Exercise in the Upper Extremity

PURPOSE: To determine changes in strength and tendon size with Blood Flow Restriction (BFR) with low-load exercise compared to a high-load exercise without BFR. METHODS AND MATERIALS: Forty-three participants (15 M, 28 F; 2 left-handed, 41 right-handed; age range 18-27 years) were randomly assigned to either the treatment group (BFR) or the control group (high-load exercise). The protocol was twice a week exercise for 7 weeks. Pre-, mid-, and post-participation ultrasound imaging was done of the dominant distal biceps brachii tendon. There was a pre- and post-participation 1 repetition maximum (1RM) of elbow flexion. The BFR group performed bicep curls with the cuff (Smart Tools) placed at the deltoid tuberosity and limb occlusion set to medium intensity. Both groups performed 4 sets of bicep curls with a 30 second break between sets. BFR was at 40% and the control group at of 80% of their 1RM. RESULTS: A within subjects effect was found for both strength (p=\u3c0.001) and tendon size (p=\u3c0.001). There was no significant interaction of group and strength or tendon size. CONCLUSIONS: Both groups demonstrated increased tendon size and strength over the 7-week protocol. High-load exercise did not induce a greater increase in tendon size or strength when compared to the BFR with low-load exercise. Using low-load exercise with BFR can induce similar effects to a high-load exercise program which can be beneficial to those who cannot participate in high-load exercises such as post-surgical patients. Further research is needed on this topic in injured populations

Blood Flow Restriction Cuff Location and the Achilles Tendon

PURPOSE: (1) Assess differences in discomfort between blood flow restriction (BFR) cuff placements, (2) determine if low-load BFR can increase Achilles tendon size, and (3) compare changes in Achilles tendon size between the BFR cuff placements. SUBJECTS: Eighteen participants (15 F, 3 M; all right leg dominant; age 20-25yoa) METHODS AND MATERIALS: Participants were randomly assigned to either BFR with cuff at the proximal thigh (THIGH) or lower extremity (LE) at 50% limb occlusion pressure. Exercise protocol was twice a week for 6 weeks. Pre-, mid-, and post- ultrasound imaging was performed on the Achilles tendon. Exercises were straight knee (SK) and bent knee (BK) calf raises on a step. Participants completed 4 sets of exercises with 1 minute rest between sets and 3-minute rest between exercise. ANALYSES: Ultrasound measurements were analyzed by repeated measures ANOVA. RESULTS: A significant within-subject effect was found for Achilles tendon hypertrophy for both pre- vs mid- ultrasound (p = \u3c0.001) and pre- vs post- ultrasound (p = \u3c0.001). No significant between groups effects (p = 0.522). THIGH group reported greater soreness on the VAS scale before and after exercise sessions compared to the LE group. CONCLUSIONS: Both groups showed increased tendon size over 6 weeks with neither group showing greater gains comparatively. Using low-load BFR at either THIGH or LE may be beneficial to increase Achilles tendon size especially in patients who cannot do high-load resistance training such as post-surgery. Additionally, placing the cuff below the knee may be less painful compared to the proximal thigh