Scott Lyons

Exercise Intensity and Lymphocyte Subset Apoptosis

This investigation assessed the lymphocyte subset response to increasing intensity. Participants completed an exertion test (VO(2max)), and later performed a 10-min run at 76% VO(2max), 5-min at 87%, and run to exhaustion at 100% intensity. Blood was sampled at rest, following each intensity, and 1-h post. Cell concentration, apoptosis (annexin V) and migration (CX₃CR1) were evaluated in CD4+, CD8+, and CD19+ subsets. Relative data were analyzed using 1-way ANOVA with significance at P≤0.05. Absolute changes from rest (Δ baseline) were calculated for exercise conditions. CX₃CR1 displayed relative changes 1-h post, (CD8+ Pre=58%, Post=68%, 1 h-Post=37%, P=0.04) (CD19+ Pre=1.9%, Post=3.2%, 1 h-Post=5.2%, P=0.02). No relative changes were noted for subsets and annexin V. Absolute changes revealed that CD4+/annexin V+ and CD8+/annexin V+ significantly increased at 76%,(P<0.01). Significant absolute increases were observed in CD4+/CX₃CR1 at 87% VO2max, and at 87% and 100% VO2max in CD8+/CX₃CR1 (P<0.01). Subsets respond differently with intensity with respect to cell count, and markers of apoptosis and cell migration. CD4+ and CD8+ appear to be prone to apoptosis with moderate exercise, but significant increases in migration at higher intensities suggests movement of these cells from the vasculature in postexercise measurements.

Does aerobic exercise intensity affect health-related parameters in overweight women?

The aim of this study was to compare the effect of a cycling training programme performed at intensity corresponding to the lowest value of the respiratory quotient (RQ) versus at intensity corresponding to the ventilatory threshold (VT), on body composition and health‐related parameters in overweight women. Thirty‐two sedentary obese women (27–42 years old) were studied in a randomized trial of either RQ (n = 17) or VT (n = 15). RQ and VT training sessions were equalized by time (60 min) and performed in a cycloergometer. Anthropometry, body composition, lipid profile, glucose, basal metabolic rate (BMR) and fitness (maximal oxygen uptake) were evaluated before and after 12 weeks of intervention. Body weight, body mass index, fatness and fitness were improved in both groups (P<0·001). Triglycerides (TG) levels decreased only in response to RQ (P<0·001) and fat‐free mass (FFM) to VT (P = 0·002). No differences were observed between groups. Both exercise intensities seem to be effective for improving health in overweight women. However, low‐intensity compared with the high‐intensity exercise training appears to have additional benefits on TG levels and to maintenance of FFM.

Finger-stick Blood Sampling Methodology for the Determination of Exercise-induced Lymphocyte Apoptosis

Exercise is a physiological stimulus capable of inducing apoptosis in immune cells. To date, various limitations have been identified with the measurement of this phenomenon, particularly relating to the amount of time required to isolate and treat a blood sample prior to the assessment of cell death. Because of this, it is difficult to determine whether reported increases in immune cell apoptosis can be contributed to the actual effect of exercise on the system, or are a reflection of the time and processing necessary to eventually obtain this measurement. In this article we demonstrate a rapid and minimally invasive procedure for the analysis of exercise-induced lymphocyte apoptosis. Unlike other techniques, whole blood is added to an antibody panel immediately upon obtaining a sample. Following the incubation period, red blood cells are lysed and samples are ready to be analyzed. The use of a finger-stick sampling procedure reduces the volume of blood required, and minimizes the discomfort to subjects.

Cognitive awareness of carbohydrate intake does not alter exercise-induced lymphocyte apoptosis

OBJECTIVE: The purpose of this investigation was to determine whether cognitive awareness of carbohydrate beverage consumption affects exercise‐induced lymphocyte apoptosis, independent of actual carbohydrate intake. INTRODUCTION: Carbohydrate supplementation during aerobic exercise generally protects against the immunosuppressive effects of exercise. It is not currently known whether carbohydrate consumption or simply the knowledge of carbohydrate consumption also has that effect. METHODS: Endurance trained male and female (N  =  10) athletes were randomly assigned to one of two groups based on either a correct or incorrect cognitive awareness of carbohydrate intake. In the incorrect group, the subjects were informed that they were receiving the carbohydrate beverage but actually received the placebo beverage. Participants completed a 60‐min ride on a cycle ergometer at 80% VO2peak under carbohydrate and placebo supplemented conditions. Venous blood samples were collected at rest and immediately after exercise and were used to determine the plasma glucose concentration, lymphocyte count, and extent of lymphocyte apoptosis. Cognitive awareness, either correct or incorrect, did not have an effect on any of the measured variables. RESULTS: Carbohydrate supplementation during exercise did not have an effect on lymphocyte count or apoptotic index. Independent of drink type, exercise resulted in significant lymphocytosis and lymphocyte apoptosis (apoptotic index at rest  =  6.3±3% and apoptotic index following exercise  =  11.6±3%, P<0.01). CONCLUSION: Neither carbohydrate nor placebo supplementation altered the typical lymphocyte apoptotic response following exercise. While carbohydrate supplementation generally has an immune‐boosting effect during exercise, it appears that this influence does not extend to the mechanisms that govern exercise‐induced lymphocyte cell death.

Exercise Order Influences Number of Repetitions and Lactate Levels But Not Perceived Exertion During Resistance Exercise in Adolescents

The purpose of this study was to analyze the effects of resistance training (RT) order on number of repetitions, total training volume, ratings of perceived exertion (RPE), and the lactate response in male adolescents. Twelve adolescents (age: 15.7 ± 1.4 yrs) completed two RT sessions in a counterbalanced crossover design: one with exercises for smaller muscle groups followed by larger muscle groups (SM-LM), whereas the other session was performed in the opposite sequence (LM-SM). The exercise order for SM-LM was standing triceps extension (TE), dumbbell biceps curl (BC), bench press (BP), and seated row machine (RM), while the order for LM-SM was the opposite. Subjects performed three sets of a predetermined 10 repetition maximum for each exercise. Total repetitions completed for each exercise and RPE were assessed after each set, and blood lactate (BL) was measured before RT, 1 m after the first exercise, 1 m after the third exercise, and 10 m after each RT session. Blood lactate (BL) was higher for the LM-SG compared with SM-LM 10 m after exercise (7.4 ± 1.8 versus 6.5 ± 2.1 mmol/L; p < 0.05). More repetitions were completed on the TE and BC in the SM-LM compared with LM-SG (24.9 ± 3.4 and 16.2 ± 3.2 versus 16.3 ± 4.2 and 14.6 ± 3.0, respectively; p < 0.02), while more repetitions were completed on the BP and RM following the LM-SM (14.3 ± 2.3 and 23.4 ± 4.5 versus 12.4 ± 4.2 and 13.6 ± 5.1, respectively; p < 0.02). No differences were found for RPE. It may be appropriate to perform multijoint exercises first to improve general coordination and force, while the use of smaller muscle groups first may be interesting to target specific muscle weaknesses.

Effects of a Simulated Tennis Match on Lymphocyte Subset Measurements

Tennis is an activity requiring both endurance and anaerobic components, which could have immunosuppressive effects postexercise. Purpose The purpose of this investigation was to determine the effect of a simulated tennis match on apoptotic and migratory markers on lymphocyte subsets. Method Male high school (n = 5) and college (n = 3) tennis players (M age = 18.9 ± 3.3 years) completed 10 sets of a tennis protocol including serves, forehand strokes, and backhand groundstrokes with 1-min rest periods between sets. Apoptosis antigen 1 receptor (CD95) and chemokine receptor fractalkine (CX3CR1) expression was analyzed on helper T lymphocytes (CD4+), cytotoxic T lymphocytes (CD8+), and B lymphocytes (CD19+) twice, at resting baseline and immediately after all 10 sets of the tennis protocol. Results An increase was observed in each lymphocyte subtype (p < .02, effect size = .41), and comparison of absolute changes revealed increases in CD4+/CD95+, CD8+/CD95+, and CD8+/CX3CR1 lymphocytes following the tennis protocol (p < .01, effect size = .43), but not in CD19+ cells. Conclusions A simulated tennis match has adequate intensity to induce immune modulations in terms of increased cell death and cellular migration in T lymphocyte subsets. Lymphocytopenia following tennis play is influenced by both apoptotic and migratory mechanisms.