Immediately Postexercise Research Articles

Hormonal and Metabolic Responses to Endurance Exercise in Children With Prader–Willi Syndrome and Non-Syndromic Obesity

ObjectiveExcess adiposity affects endocrine and metabolic function at rest and during exercise. This study evaluated the endocrine and metabolic responses to exercise in syndromic (Prader–Willi syndrome) and non-syndromic pediatric obesity. Materials/methodsEleven PWS (10.9±1.6y, 45.4±9.5% body fat), 12 lean (9.4±1.2y, 17.5±4.6% body fat), and 12 obese (9.2±1.2y, 39.9±6.8% body fat) children completed ten two-minute cycling exercise bouts, separated by one-minute rest. Blood samples were obtained at rest pre-exercise (PRE), immediately post-exercise (IP), and 15, 30 and 60minutes into recovery. Samples were analyzed for hormones and metabolites. ResultsGrowth hormone increased in response to exercise in lean and obese but not PWS (IP>PRE; IP: lean>obese). Epinephrine increased with exercise in lean (IP>PRE), while norepinephrine increased in lean and obese (IP>PRE) but not PWS; no differences were observed between lean and obese groups at IP. No other significant hormonal group interactions existed. Glucose, lactate, free fatty acid, glycerol and ketone responses were similar among groups. ConclusionPWS children exhibited altered stress hormone responses to exercise. However, glucose-regulating hormones and metabolic responses to exercise appeared normal.

Repeated bouts of eccentrically biased endurance exercise stimulate salivary IgA secretion rate.

To determine the salivary secretory immunoglobulin A (sIgA) response to repeated bouts of unaccustomed, downhill running (eccentrically biased) and examine potential protective immunological adaption from a repeated bout effect. Eleven active but untrained males (age: 19.7±0.4 years; VO2peak: 47.8± 3.6 ml · kg−1 · min −1) performed two 60 min bouts (Run 1 and Run 2) of downhill running (−13.5% gradient), separated by 14 days, at a speed eliciting 75% of their VO2peak on a level grade. Saliva samples were collected before (baseline), immediately post exercise (IPE), and every hour for 12 h and every 24 h for 6 days after each run. Salivary sIgA concentration was measured and sIgA secretion rate was calculated. Results were analysed using repeated measures ANOVA (12 h period: 2x14; 24 h intervals: 2x7; p ≤ 0.05) with Tukey post-hoc tests where appropriate. Results are reported as means ± SE. There was a significant (p < 0.0001) interaction effect for sIgA secretion rate, IPE, with higher values after Run 2, as well as a significant (p < 0.01) time effect with elevated levels IPE and between 24 h and 144 h. There was a run effect (p < 0.0001), with the sIgA secretion rate significantly higher after Run 2. Repeated bouts of unaccustomed, eccentrically biased exercise induced alterations in the salivary sIgA secretion rate. This may serve as a protective mucosal adaptation to exercise-induced tissue damage.

The Effects of High Intensity Short Rest Resistance Exercise on Muscle Damage Markers in Men and Women

Within and between sexes, universal load prescription (as assigned in extreme conditioning programs) creates extreme ranges in individual training intensities. Exercise intensity has been proposed to be the main factor determining the degree of muscle damage. Thus, the purpose of this study was to examine markers of muscle damage in resistance-trained men (n = 9) and women (n = 9) from a high intensity (HI) short rest (SR) (HI/SR) resistance exercise protocol. The HI/SR consisted of a descending pyramid scheme starting at 10 repetitions, decreasing 1 repetition per set for the back squat, bench press, and deadlift, as fast as possible. Blood was drawn pre-exercise (pre), immediately postexercise (IP), 15 minutes postexercise (+15), 60 minutes postexercise (+60), and 24 hours postexercise (+24). Women demonstrated significant increases in interleukin 6 (IL-6; IP), creatine kinase (CK; +24), myoglobin (IP, +15, +60), and a greater relative increase when compared with men (+15, +60). Men demonstrated significant increases in myoglobin (IP, +15, +60, +24), IL-6 (IP, +15), CK (IP, +60, +24), and testosterone (IP, +15). There were significant sex interactions observed in CK (IP, +60, +24) and testosterone (IP, +15, +60, +24). Women completed the protocol faster (women: 34:04 ± 9:40 minutes, men: 39:22 ± 14:43 minutes), and at a slightly higher intensity (women: 70.1 ± 3.5%, men 68.8 ± 3.1%); however, men performed significantly more work (men: 14384.6 ± 1854.5 kg, women: 8774.7 ± 1612.7 kg). Overall, women demonstrated a faster inflammatory response with increased acute damage, whereas men demonstrated a greater prolonged damage response. Therefore, strength and conditioning professionals need to be aware of the level of stress imposed on individuals when creating such volitional high intensity metabolic type workouts and allow for adequate progression and recovery from such workouts.

β-Hydroxy-β-methylbutyrate (HMB)-free acid attenuates circulating TNF-α and TNFR1 expression postresistance exercise

The purpose of this study was to examine the effect of β-hydroxy-β-methylbutyrate-free acid (HMB-FA) and cold-water immersion (CWI) on circulating concentrations of TNF-α and monocyte TNF-α receptor 1 (TNFR1) expression. Forty resistance-trained men (22.3 ± 2.4 yr) were randomized into four groups [placebo (PL), HMB-FA, CWI, and HMB-FA-CWI] and performed an acute, intense exercise protocol (four sets of up to 10 repetitions of the squat, dead lift, and split squat). Participants also performed four sets of up to 10 repetitions of the squat at 24 and 48 h following the initial exercise bout. Blood was sampled before exercise (PRE), immediately postexercise (IP), and 30 min, 24 h, and 48 h postexercise (30P, 24P, and 48P, respectively). Circulating TNF-α was assayed, and TNFR1 expression on CD14+ monocytes was measured by flow cytometry. The exercise protocol significantly elevated TNF-α in only PL (P = 0.006) and CWI (P = 0.045) IP. Mean percent changes show that TNF-α significantly increased from PRE to IP for only PL and CWI groups (P < 0.05), whereas the percent change of TNF-α for HMB-FA and HMB-FA-CWI was not significant. TNFR1 expression was elevated in PL (P = 0.023) and CWI (P = 0.02) at 30P compared with PRE, whereas both HMB-FA-treated groups did not increase significantly. In conclusion, HMB-FA attenuated circulating TNF-α IP and TNFR1 expression during recovery compared with PL and CWI. HMB-FA supplementation may attenuate the initial immune response to intense exercise, which may reduce recovery time following intense exercise.

Triphasic multinutrient supplementation during acute resistance exercise improves session volume load and reduces muscle damage in strength-trained athletes

We hypothesized that triphasic multinutrient supplementation during acute resistance exercise would enhance muscular performance, produce a more favorable anabolic profile, and reduce biochemical markers of muscle damage in strength-trained athletes. Fifteen male strength-trained athletes completed two acute lower-body resistance exercise sessions to fatigue 7 days apart. After a 4-hour fast, participants consumed either a multinutrient supplement (Musashi 1-2-3 Step System, Notting Hill, Australia) (SUPP) or placebo (PLA) beverage preexercise (PRE), during (DUR), and immediately postexercise (IP). Session volume loads were calculated as kilograms × repetitions. Lower-body peak power was measured using unloaded repeated countermovement jumps, and blood samples were collected to assess biochemistry, serum hormones, and muscle damage markers at PRE, DUR, IP, 30 minutes postexercise (P30), and 24 hours postexercise (P24h). The SUPP demonstrated increased glucose concentrations at DUR and IP compared with at PRE (P < .01), whereas PLA demonstrated higher glucose at P30 compared with at PRE (P < .001). Session volume load was higher for SUPP compared with PLA (P < .05). Cortisol increased at DUR, IP, and P30 compared with at PRE in both treatments (P < .05); however, SUPP also displayed lower cortisol at P24h compared with at PRE and PLA (P < .01). The total testosterone response to exercise was higher for PLA compared with SUPP (P < .01); however, total creatine kinase and C-reactive protein responses to exercise were lower for SUPP compared with PLA (P < .05). These data indicate that although triphasic multinutrient supplementation did not produce a more favorable anabolic profile, it improved acute resistance exercise performance while attenuating muscle damage in strength-trained athletes.

Beneficial effects of habitual resistance exercise training on coagulation and fibrinolytic responses

BackgroundA sedentary lifestyle is a major risk factor for cardiovascular and thrombotic complications. While habitual endurance activity will reduce the risk of these adverse events, the influence of habitual resistance exercise is less clear. This study examined coagulation and fibrinolytic responses to an acute exhaustive resistance exercise test (AERET) in both resistance-trained (RT, min 2yr, 5 men and 5 women) and untrained (UT, 5 men and 5 women) subjects. MethodsThe AERET consisted of six sets of 10 repetitions of squats at 80% of 1-repetition maximum. Venous blood was collected pre-exercise, immediate post exercise (IP), and +15, +60, and +120minutes post exercise. ResultsCompared to UT, RT exhibited a lower capacity to form a clot as seen by activated partial Thromboplastin time (aPTT) integrated area under the curve over time (iAUC) levels, lower pre-exercise and 120min post-exercise plasminogen activator inhibitor −1 (PAI-1) activity, and higher tissue plasminogen activator (tPA) activity immediately post-exercise. There were no significant differences between RT and UT for fibrinogen, prothrombin fragment 1+2 (PTF 1+2), and thrombin-antithrombin complexes (TAT). ConclusionThese results suggest that habitual resistance exercise training may provide an enhanced fibrinolytic state.

Continuous and intermittent walking alters HDL2-C and LCATa

PurposeThe purpose of this study was to determine if exercise, whether continuous (CE: completed all in one session) or intermittent (completed in either two (IE 2) or three (IE 3) exercise sessions) expending the same number of calories alters reverse cholesterol transport or low density lipoprotein (LDL) particle size. MethodsSixteen healthy (22±2.1 year old) men (VO2 max=37.0±3.3mL/kg/min) randomly completed three exercise trials, CE, IE 2 and IE 3, expending 450 calories. Blood samples were drawn immediately post-exercise (IPE) and 24 and 48h following exercise and analyzed for total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C) and subfractions (HDL2-C, HDL3-C). Samples were also analyzed to determine LDL-C particle size, lecithin cholesterol acyl transferase activity (LCATa) and cholesterol ester transfer protein activity (CETPa). ResultsHDL2-C increased significantly 48h post-exercise in the CE and IE 2 groups. Additionally, the IE 3 group had significant increases in HDL2-C at 24 (39%) and 48h post-exercise by 66%. This change in HDL2-C was significantly and positively correlated (r=0.62; p<0.05) to the changes in LCATa which increased compared to baseline at 48h post-exercise in the CE and IE 3 groups. No significant changes in LDL particle size or alterations in CETPa were seen. ConclusionsThe results of this study indicate that whether the exercise is continuous or intermittent, keeping calorie expenditure the same, causes significant changes in the HDL2-C subfraction, which was augmented by an increase in LCATa.

Effects of Immediate Postexercise Carbohydrate Ingestion With and Without Protein on Neutrophil Degranulation

The purpose of the study was to determine the effects of carbohydrate (CHO) intake, with and without protein (PRO), immediately after prolonged strenuous exercise on circulating bacterially stimulated neutrophil degranulation. Twelve male runners completed 3 feeding interventions, 1 week apart, in randomized order after 2 hr of running at 75% VO2max. The feeding interventions included a placebo solution, a CHO solution equal to 1.2 g CHO/kg body mass (BM), and a CHO-PRO solution equal to 1.2 g CHO/kg BM and 0.4 g PRO/kg BM (CHO+PRO) immediately postexercise. All solutions were flavor and water-volume equivalent (12 ml/kg BM). Circulating leukocyte counts, bacterially stimulated neutrophil degranulation, plasma insulin, and cortisol were determined from blood samples collected preexercise, immediately postexercise, and every 30 min until 180 min postexercise. The immediate postexercise circulating leukocytosis, neutrophilia, and lymphocytosis (p < .01 vs. preexercise) and the delayed lymphopenia (90 min postexercise, p < .05 vs. preexercise) were similar on all trials. Bacterially stimulated neutrophil degranulation decreased during recovery in control (23% at 180 min, p < .01 vs. preexercise) but remained above preexercise levels with CHO and CHO+PRO. In conclusion, CHO ingestion, with or without PRO, immediately after prolonged strenuous exercise prevented the decrease in bacterially stimulated neutrophil degranulation during recovery.

Effect of acute high-intensity interval exercise on postexercise biventricular function in mild heart failure

We studied the acute effect of high-intensity interval exercise on biventricular function using cardiac magnetic resonance imaging in nine patients [age: 49 ± 16 yr; left ventricular (LV) ejection fraction (EF): 35.8 ± 7.2%] with nonischemic mild heart failure (HF). We hypothesized that a significant impairment in the immediate postexercise end-systolic volume (ESV) and end-diastolic volume (EDV) would contribute to a reduction in EF. We found that immediately following acute high-intensity interval exercise, LV ESV decreased by 6% and LV systolic annular velocity increased by 21% (both P < 0.05). Thirty minutes following exercise (+30 min), there was an absolute increase in LV EF of 2.4% (P < 0.05). Measures of preload, left atrial volume and LV EDV, were reduced immediately following exercise. Similar responses were observed for right ventricular volumes. Early filling velocity, filling rate, and diastolic annular velocity remained unchanged, while LV untwisting rate increased 24% immediately following exercise (P < 0.05) and remained 18% above baseline at +30 min (P < 0.05). The major novel findings of this investigation are 1) that acute high-intensity interval exercise decreases the immediate postexercise LV ESV and increases LV EF at +30 min in patients with mild HF, and this is associated with a reduction in LV afterload and maintenance of contractility, and 2) that despite a reduction in left atrial volume and LV EDV immediately postexercise, diastolic function is preserved and may be modulated by enhanced LV peak untwisting rate. Acute high-intensity interval exercise does not impair postexercise biventricular function in patients with nonischemic mild HF.

Effects Of Acute Exercise On Opiate And Cigarrette Craving In Methadone Patients

Acute aerobic exercise has been shown to reduce craving for cigarettes in smokers. Over 80% of patients enrolled in methadone maintenance treatment (MMT) programs for opiate addiction are smokers. Many MMT counselors believe that regular physical exercise helps their patients to be successful in the program; however, some MMT patients believe that they will need to increase their daily methadone dose if they initiate an exercise program. PURPOSE: To determine if acute aerobic exercise changes opiate and cigarette craving in MMT patients. METHODS: 7 MMT patients (4 men, 3 women; Age = 45±2 years; BMI=27.5±1.9) completed 3 randomly applied experimental trials immediately before receiving their daily methadone dose. Subjects abstained from smoking for 6 hours prior to experimental trials. Experimental trials consisted of 20 minutes of rest, moderate aerobic exercise (65% predicted maximal heart rate), or vigorous aerobic exercise (80% predicted maximal heart rate). Craving for opiates, cigarettes, and sweets was recorded before, immediately post exercise (IPE), and 10 minutes after exercise (10 post). Subjects also completed the Subjective Opiate Withdrawal Scale (SOWS) before and 10 post. RESULTS: Craving for opiates was reduced (p<0.05) as a result of vigorous exercise at IPE (-26.8+6.9%) and 10 Post (-5.5+0.5%); however, craving for opiates was unchanged following moderate exercise. Craving for cigarettes was reduced (p<0.05) following both moderate (IPE=-37.9+6.1%; 10 Post=-13.1+9.1%) and vigorous (IPE=-37.1+7.1%; 10 Post=-8.8+9.2%) exercise. Craving for sweets and the SOWS was unchanged as a result of exercise. CONCLUSIONS: The results of this investigation suggest that craving for opiates and cigarettes in patients participating in a MMT program may be influenced by acute aerobic exercise.

Improved time to exhaustion following ingestion of the energy drink Amino Impact.

BackgroundThe purpose of this study was to examine the effect of a commercially available energy drink on time to exhaustion during treadmill exercise. In addition, subjective measures of energy, focus, and fatigue were examinedMethodsFifteen subjects (9 men and 6 women; 20.9 ± 1.0 y; 172.1 ± 9.1 cm; 71.0 ± 9.4 kg; 16.9 ± 9.7% body fat) underwent two testing sessions administered in a randomized, double-blind fashion. Subjects reported to the laboratory in a 3-hr post-absorptive state and were provided either the supplement (SUP; commercially marketed as Amino Impact™) or placebo (P). During each laboratory visit subjects performed a treadmill run (70% VO2 max) to exhaustion. Mean VO2 was measured during each endurance exercise protocol. Subjects were required to complete visual analog scales for subjective measures of energy, focus and fatigue at the onset of exercise (PRE), 10-mins into their run (EX10) and immediately post-exercise (IP).ResultsTime to exhaustion was significantly greater (p = 0.012) during SUP than P. Subjects consuming the supplement were able to run 12.5% longer than during the placebo treatment. Subjects consuming SUP reported significantly greater focus (p = 0.031), energy (p = 0.016), and less fatigue (p = 0.005) at PRE. Significant differences between groups were seen at EX10 for focus (p = 0.026) and energy (p = 0.004), but not fatigue (p = 0.123). No differences were seen at IP for either focus (p = 0.215), energy (p = 0.717) or fatigue (p = 0.430).ConclusionsResults of this study indicate that the supplement Amino Impact™ can significantly increase time to exhaustion during a moderate intensity endurance run and improve subjective feelings of focus, energy and fatigue.

Endocrine Response Patterns to Acute Unilateral and Bilateral Resistance Exercise in Men

Rehabilitation programs and research experiments use single-arm protocols in which the contralateral arm is not functional or used as a control limb. This study was interested in determining the hormonal signal impacts of such one- versus two-arm exercise responses that might have an impact on adaptational changes with training. The purpose was to examine the acute hormonal responses to a unilateral and a bilateral upper-body resistance exercise (RE) protocol. A balanced randomized treatment intervention with series time frame for blood collections before and after exercise was used as the basic experimental design. Ten recreationally resistance trained men (18-25 years, 20.4 +/- 1.2 years, 175.6 +/- 4.5 cm, 81.7 +/- 9.3 kg) gave informed consent to participate in the investigation. Each subject performed unilateral (dominant arm only) and bilateral upper-body RE protocol separated by 1 week in a balanced randomized fashion. The RE protocol consisted of 3 sets of 10 repetitions of 5 different dumbbell upper-body exercises at 80% of 1-repetition maximum, and blood samples were obtained before and 5, 15, and 30 minutes immediately postexercise (IP). Blood was obtained and analyzed for lactate, immunoreactive growth hormone (iGH), cortisol (C), total testosterone (T), and insulin concentrations. Total volume of work also was determined for the 2 exercise sessions. Total volume of work performed during the unilateral protocol was 52.1% of that for the bilateral protocol. Both RE protocols elicited a significant (p < or = 0.05) increase in lactate and iGH, but the increase for the bilateral condition was significantly greater. Cortisol decreased significantly during recovery for the unilateral condition. Testosterone was not affected by either protocol. Insulin was significantly increased at IP and 5 minutes postexercise for both conditions.These results indicate that the hormonal responses to dominant-arm unilateral RE is blunted compared to that for bilateral RE. This differential endocrine response is likely a result of the difference in volume between the protocols. It is important to pay attention to the amount of muscle mass utilized in a resistance exercise protocol to optimize endocrine signaling.

Does Baseline High Density Lipoprotein Cholesterol Influence Post-exercise Change Associated With Acute Exercise?

PURPOSE: The purpose of this study was to determine if baseline levels of high density lipoprotein cholesterol (HDL) affects the change in HDL levels associated with an acute bout of exercise of varying energy expenditure. METHODS: Two groups of healthy untrained male volunteers participated in this study. Subjects were assigned to one of two groups according to their baseline HDL levels. The LOW HDL group consisted of 13 subjects with clinically low HDL (< 40mg/dl) and the NORMAL HDL group consisted of 14 subjects with normal HDL (≥ 45mg/dl). Age, diet, VO2max and anthropometric data were collected prior to initiation of the experimental protocol and were similar for both groups. Age, height, weight, BMI, VO2max and resting HDL for LOW were 21.9 ± 2.0 yrs, 1.8 ± 0.1 m, 80.9 ± 7.9 kg, 25.2 ± 2.2 kg/m2, 45.8 ± 5.1 ml/kg/min and 35.7 ± 2.7 mg/dl, respectively while characteristics of the NORMAL group were 23.4 ± 7.1yrs, 1.8 ± 0.1 m, 78.6 ± 7.6 kg, 24.3 ± 2.5 kg/m2, 47.5 ± 4.8 ml/kg/min and 53.9 ± 5.8 mg/dl. Subjects completed two nonconsecutive exercise sessions (on separate days) expending 500 and 700 kcals while running on a treadmill at 65% of VO2max. Venous blood was collected pre-exercise, immediately post-exercise (IPE), and 24 hours post-exercise (+24) and analyzed for HDL and subfractions of HDL (HDL2and HDL3) and corrected for any shift in plasma volume. RESULTS: No differences in HDL or HDL subfractions were observed between NORMAL and LOW HDL groups at any post-exercise times. With both groups pooled HDL was significantly increased (p<0.05) by 2.5mg/dl (5.6%) at IPE, but not at +24 when compared to pre-exercise values. The increase in HDL post exercise was due for the most part to increased HDL3 (3.5mg/dl, 13.6%) whereas the HDL2 subfraction remained statistically unchanged. CONCLUSIONS: Baseline HDL status does not appear to affect the magnitude of post-exercise HDL-C alterations in untrained men. Furthermore, post-exercise increases in HDL associated with acute exercise appear due to increased HDL3 and not HDL2 in the subjects of this study.

Prior exercise increases phosphorylation of Akt substrate of 160 kDa (AS160) in rat skeletal muscle

The main purpose of this study was to determine whether the increased glucose transport (GT) found immediately postexercise (IPEX) or 4 h postexercise (4hPEX) is accompanied by increased phosphorylation of Akt substrate of 160 kDa (AS160, a protein regulator of GLUT4 translocation). Paired epitrochlearis muscles were dissected from rats (sedentary or IPEX, 2-h swim) and used to measure protein phosphorylation and insulin-independent GT. IPEX values exceeded sedentary values for GT and phosphorylations of AS160, AMP-activated protein kinase (pAMPK) and acetyl-CoA carboxylase (pACC) but not for AS160 abundance or phosphorylation of Akt serine (pSerAkt), Akt threonine (pThrAkt), or glycogen synthase kinase-3 (pGSK3). AS160 phosphorylation was significantly correlated with GT (R=0.801, P<0.01) and pAMPK (R=0.655, P<0.05). Muscles from other rats were studied 4hPEX along with sedentary controls. One muscle per rat was incubated without insulin, and the contralateral muscle was incubated with insulin. 4hPEX values exceeded sedentary values for insulin-stimulated GT. The elevated pAMPK and pACC found IPEX had reversed by 4hPEX. Insulin caused a significant increase in pSerAkt, pThrAkt, pGSK3, and AS160 phosphorylation with or without exercise. Exercise significantly increased AS160 phosphorylation, regardless of insulin, with unchanged AS160 abundance. Among the signaling proteins studied, insulin-stimulated GT was significantly correlated only with insulin-stimulated pThrAkt (R=0.720, P<0.0005). The results are consistent with a role for increased AS160 phosphorylation in the increased insulin-independent GT IPEX, and the exercise effects on AS160 phosphorylation and/or pThrAkt at 4hPEX are potentially relevant to the increased insulin-stimulated glucose transport at this time.

Alterations in acute-phase reactants (CRP, rheumatoid factor, complement, Factor B, and immune complexes) following an ultramarathon

Objectives. The human body initiates an acute phase response (APR) in response to a wide range of homeostatic disturbances. This complex series of reactions serves to activate repair processes and prevent ongoing tissue damage. An important aspect of the APR is the de novo synthesis of acute phase proteins (APP), many of which have not been thoroughly investigated. Main outcome measures. Alterations in CRP (C-reactive protein), C1est, C3, C4, C6, rheumatoid factor (RF) and Factor B were determined before and after an ultramarathon. Data were analysed using a one-way analysis of variance comparing values to pre-exercise levels. Significance was set at p &lt; 0.05. Design. Venepunctures were performed on athletes participating in an ultramarathon (90 km) 24 hours before, immediately post-exercise (IPE), and 3h, 24h and 72h after the race. Serum was stored at –80°C until analysed. CRP levels in serum were assessed using the N Latex CRP kit. The levels of circulating immune complexes (CIC) were determined using particle-enhanced nephelometry. Complement proteins C1est, C3, C4 and RF were measured using laser nephelometry. C6 and Factor B were determined by radial immunodiffusion. Results. CRP was significantly elevated IPE (58%), 3h post (77%), 24h post (87%) and 72h post (69%). Pre-race CRP levels were above the normative range (5.10 ± 3.08 mg/l), C6 was significantly elevated (p &lt; 0.05) at 24h post (7.8%) and 72h post (8.8%) exercise. Factor B was significantly elevated (p &lt; 0.05) at 72h post exercise (12.8%). RF was significantly elevated at 72h post exercise (6.7%). Conclusion. Significant increases in selected acutephase reactants occur several days after the exercise event. In addition, as indicated by elevated resting levels of CRP, the athletes began the race with some degree of inflammation, presumably as a result of the cumulative training and racing mileage in preparation for the ultramarathon. SA Sports Medicine Vol.16(2) 2004: 17-21

Alterations in acute-phase reactants (CRP, rheumatoid factor, complement, Factor B, and immune complexes) following an ultramarathon

Objectives. The human body initiates an acute phase response (APR) in response to a wide range of homeostatic disturbances. This complex series of reactions serves to activate repair processes and prevent ongoing tissue damage. An important aspect of the APR is the de novo synthesis of acute phase proteins (APP), many of which have not been thoroughly investigated. Main outcome measures. Alterations in CRP (C-reactive protein), C1est, C3, C4, C6, rheumatoid factor (RF) and Factor B were determined before and after an ultramarathon. Data were analysed using a one-way analysis of variance comparing values to pre-exercise levels. Significance was set at p &lt; 0.05. Design. Venepunctures were performed on athletes participating in an ultramarathon (90 km) 24 hours before, immediately post-exercise (IPE), and 3h, 24h and 72h after the race. Serum was stored at –80°C until analysed. CRP levels in serum were assessed using the N Latex CRP kit. The levels of circulating immune complexes (CIC) were determined using particle-enhanced nephelometry. Complement proteins C1est, C3, C4 and RF were measured using laser nephelometry. C6 and Factor B were determined by radial immunodiffusion. Results. CRP was significantly elevated IPE (58%), 3h post (77%), 24h post (87%) and 72h post (69%). Pre-race CRP levels were above the normative range (5.10 ± 3.08 mg/l), C6 was significantly elevated (p &lt; 0.05) at 24h post (7.8%) and 72h post (8.8%) exercise. Factor B was significantly elevated (p &lt; 0.05) at 72h post exercise (12.8%). RF was significantly elevated at 72h post exercise (6.7%). Conclusion. Significant increases in selected acutephase reactants occur several days after the exercise event. In addition, as indicated by elevated resting levels of CRP, the athletes began the race with some degree of inflammation, presumably as a result of the cumulative training and racing mileage in preparation for the ultramarathon. SA Sports Medicine Vol.16(2) 2004: 17-21

Non-allergic activation of eosinophils after strenuous endurance exercise

Objective. To determine the effect of prolonged endurance exercise on the serum concentrations of eosinophil cationic protein (ECP), immunoglobulin E (IgE) and upper respiratory tract symptoms (URTS). Design. In 11 healthy, experienced volunteers (6 males, 5 females, age 43 ± 9.8 years) the serum concentrations of ECP and IgE were measured, 24 hours prior to projected finishing time, immediately post exercise (IPE), and 3 h, 24 h, and 72 h after an ultramarathon (90 km). Self-reported URTS were also recorded for 14 days after the race. ECP was measured using radioimmunoassay and IgE using the Alastat Microplate Total IgE kit. The after-exercise values were corrected for plasma volume changes, which were calculated from haematocrit and haemoglobin values. Serum concentrations of ECP and IgE were analysed using an analysis of variance (ANOVA) comparing values with before-exercise levels. Level of significance was set at p ≤ 0.05. Results. ECP was significantly elevated at 72 hours (+52%), whilst IgE was not significantly altered after the ultramarathon. There were no reported URTS for the 14 days after the race. Conclusion. The eosinophil is a pro-inflammatory leukocyte involved in bronchial hyperreactivity and allergic inflammation of the airways. IgE is associated with allergic diseases such as asthma and rhinitis. Serum ECP is a sensitive marker of eosinophil activation. The result provides evidence for the non-allergic activation of blood eosinophils during prolonged endurance exercise. Whether this indicates exercise or environmentally induced airway inflammation, or a role for ECP in muscle /tissue repair, are hypotheses that require additional research. SA Sports Medicine Vol.16(2) 2004: 12-16

Non-allergic activation of eosinophils after strenuous endurance exercise

Objective. To determine the effect of prolonged endurance exercise on the serum concentrations of eosinophil cationic protein (ECP), immunoglobulin E (IgE) and upper respiratory tract symptoms (URTS). Design. In 11 healthy, experienced volunteers (6 males, 5 females, age 43 ± 9.8 years) the serum concentrations of ECP and IgE were measured, 24 hours prior to projected finishing time, immediately post exercise (IPE), and 3 h, 24 h, and 72 h after an ultramarathon (90 km). Self-reported URTS were also recorded for 14 days after the race. ECP was measured using radioimmunoassay and IgE using the Alastat Microplate Total IgE kit. The after-exercise values were corrected for plasma volume changes, which were calculated from haematocrit and haemoglobin values. Serum concentrations of ECP and IgE were analysed using an analysis of variance (ANOVA) comparing values with before-exercise levels. Level of significance was set at p ≤ 0.05. Results. ECP was significantly elevated at 72 hours (+52%), whilst IgE was not significantly altered after the ultramarathon. There were no reported URTS for the 14 days after the race. Conclusion. The eosinophil is a pro-inflammatory leukocyte involved in bronchial hyperreactivity and allergic inflammation of the airways. IgE is associated with allergic diseases such as asthma and rhinitis. Serum ECP is a sensitive marker of eosinophil activation. The result provides evidence for the non-allergic activation of blood eosinophils during prolonged endurance exercise. Whether this indicates exercise or environmentally induced airway inflammation, or a role for ECP in muscle /tissue repair, are hypotheses that require additional research. SA Sports Medicine Vol.16(2) 2004: 12-16

Catecholamine responses to high intensity cycle ergometer exercise: Body mass or body composition?

The purpose of this study was to compare the sympathoadrenergic and metabolic responses following 30 s of maximal high intensity cycle ergometry exercise when cradle resistive forces were derived from total-body mass (TBM) or fat-free mass (FFM). Increases in peak power output (PPO) and pedal velocity were recorded when resistive forces reflected FFM (953 +/- 114 W vs 1020 +/- 134 W; 134 +/- 8 rpm vs 141 +/- 7 rpm ; P < 0.05). No differences were observed between mean power output (MPO), fatigue index (FI%), work done (WD) or heart rate (HR) when the TBM and FFM protocols were compared. There were no differences between the TBM and FFM protocols for adrenaline (A), noradrenaline (NA) or blood lactate concentrations ([La-]B) recorded at rest, immediately post or 24 h post exercise. However, increases in blood concentrations of A and NA (P < 0.05) were recorded for both the TBM and FFM protocol immediately post exercise. Significant correlations (P < 0.05) were recorded between PPOs, immediate post- exercise NA and [La-]B for both the TBM and FFM protocols. [La-]B levels were also significantly elevated (P < 0.01) immediately post exercise for both the TBM and FFM protocols. The results from this study suggest that greater peak power outputs are obtainable with no subsequent differences in neurophysiological or metabolic stress as determined by plasma A, NA and [La-]B concentrations when resistive forces reflect FFM and not TBM during loading procedures. The findings also indicate that immediate post exercise concentrations return to resting levels 24 h post exercise.

EFFECT OF VITAMIN C ON FREE RADICALS AND DELAYED ONSET MUSCLE SORENESS FOLLOWING RESISTIVE EXERCISE

An increase in free radical production and serum concentration leads to lipid peroxidation in active tissue following exercise, which may contribute to delayed onset muscle soreness (DOMS). Antioxidant supplementation may reduce free radical levels, thereby attenuating the intensity of DOMS. PURPOSE To determine the effects of Vitamin C supplementation on serum malondialdehyde concentration (MDA) and DOMS following an acute bout of high intensity whole body resistance exercise. METHODS Ten untrained males (20.5 ± 3.2 yr) that did not have resistance exercise experience and did not use supplements in the past year participated in this investigation. Subjects were randomly assigned to a double blind counterbalanced supplementation sequence (Vitamin C and placebo). All subjects completed an eight-exercise circuit resistance exercise protocol consisting of three sets of ten repetitions at 73.5% of 1RM for each exercise under each supplement condition. Blood samples and measures of active and passive muscle soreness were obtained before exercise (BE), immediately post-exercise (IPE), 6hr PE, 24hr PE, and 48hr PE. RESULTS Plasma ascorbic acid (μ mol/L) was higher BE (73.3 ± 29.4 vs. 13.8 ± 7.8, p < 0.01) and 24hr PE (49.6 ± 23.0 vs. 18.5 ± 9.6, p < 0.05) in the Vitamin C supplementation condition. However, there was no difference between the Vitamin C and placebo groups for MDA concentration (μ mol/ml) or DOMS at any time point. At 24hr PE, MDA levels (2.9 ± 0.6) were greater (p < 0.05) than BE levels (2.5 ± 0.5). A time main effect was observed for all measures of muscle soreness. Muscle soreness was greater (p < 0.01) at IPE, 6hr PE, 24hr PE, and 48hr PE compared to BE levels. CONCLUSION This study showed that high intensity whole body resistance exercise significantly increased MDA concentration 24hr PE in untrained males. However, this study showed that Vitamin C supplementation was ineffective at attenuating the rise in MDA concentration and DOMS in untrained males.