Min Post Exercise Research Articles

PL - 035 Effects of lactate infusion on the molecular response to resistance exercise in men and women

PL - 035 Effects of lactate infusion on the molecular response to resistance exercise in men and women

Working Dogs Drinking a Nutrient-Enriched Water Maintain Cooler Body Temperature and Improved Pulse Rate Recovery After Exercise.

Exercise-related physiological changes were evaluated in hydrated, exercise-conditioned working dogs with free access to tap water (TW) with or without a nutrient-enriched water supplement (NW). Physiological samples and measures were collected before and after work-related field tasks in a warm and moderately humid ambient environment. In a cross-over design study, 12 dogs (age range 8–23 months) were evaluated on 3 separate occasions within each period with exercise bouts up to 30 min, on days −4, 3, and 11. Dogs were offered either ad libitum TW or portion-controlled NW daily plus ad libitum TW. Prior to and serially after exercise, pulse rate (PR), core (BTcore) and ear (BTear) temperature were recorded. Urine was collected first thing in the morning, whereas blood samples collected and body weight (BW) recorded pre- and immediately post exercise. Ambient temperature was above 21.7°C (71°F) and relative humidity ranged from 36 to 76%. Activity parameters, AM urine measures, post-exercise percent change of BW, resting PR and resting BTcore did not differ between treatment groups on any exercise day. At the completion of exercise, mean BTcore for all dogs ranged from 104.8 to 105.6°F. Immediate post-exercise BTear was always lower compared to BTcore and means ranged from 103.3 to 104.0°F. The effect of time was highly significant (P < 0.001) for both BT measures with both BTcore and BTear recovering to resting levels by 60 min post exercise. PR and several blood values showed a significant main effect of time. Over the recovery period, dogs in the NW group had lower mean BTear and PR by 0.6°F and 3.4 bpm, respectively. Daily ingestion of a NW in combination with free access to TW can reduce the post-exercise-related BTcore and BTear hyperthermia, and improve pulse rate recovery following exercise in this population of working dogs undergoing 30 min bout of exercise.

The Influence of Body Composition and Skinfold Thickness on Skin Temperature Changes after Resistance Exercise

Resistance exercise leads to an increase in skin temperature (T) in the area of the exercised muscle. Non-contact infrared thermography seems to be applicable to identify these primary used functional muscles with measuring T changes. In previous studies, lean men showed homogenous T patterns after standardized exercise protocols. Purpose: To examine the influence of body fat percentage (BF%) and skinfold thickness on T patterns after resistance exercise. Methods: 38 male subjects (19-32 years, BMI 20.4-55.2 kg/m2) participated. Means (min-max) of BF% and skinfold thickness of biceps brachii were 19.2 % (6.2-51.5) and 9 mm (2-36) respectively. After 15 min of acclimatization, the participants completed three sets with ten repetitions of unilateral biceps curl with 50 % of the individual one-repetition- maximum (two min rest between the sets). T of the exercised biceps was measured at rest (Trest), immediately following set 1, 2 and 3 (TS1, TS2, TS3) and up to 30 min post exercise (T1-T30) with an infrared camera. For statistical analysis, [INCREMENT]-values to Trest for every measuring time point, as well as Tmax, [INCREMENT]Tmax (=Tmax-Trest) and time to Tmax (min after the final set) were calculated. Results: One-way ANOVA detected a time effect on the T-values Trest to T30 (Eta2=0.64, p<0.001). Means (min-max) of Trest, Tmax , [INCREMENT]Tmax and time to Tmax were 32.3 °C (28.0-34.6), 34.0 °C (29.7-36.8), 1.7 °C (-0.3-2.8) and 8 min (2-30) respectively. BF% and skinfold thickness showed a negative correlation with Trest, Tmax, [INCREMENT]Tmax and time to Tmax (r>-0.52, p<0.001). A negative correlation between BF% and skinfold thickness with the [INCREMENT]-values to Trest was found from TS2 to T10 (for BF%: r>-0.49, p<0.001; for skinfold thickness: r>-0.66, p<0.001). All subjects up to a skinfold thickness of 10 mm showed a homogeneous T pattern in reaction to the exercise with a minimum [INCREMENT]Tmax of 1.3 °C and a time to Tmax between 2 and 9 min. The T patterns in subjects with a higher skinfold thickness were heterogeneous and some of these subjects did not respond to the resistance exercise with an increase of T. Conclusion: A higher BF% and a higher skinfold thickness is associated with delayed and lower increases in T after resistance exercise. In contrast to lean subjects, identifying the primary used functional muscles by infrared thermography in obese subjects seems to be challenging.

Effect Of Progressive Fatigue On Session Rpe

INTRODUCTION: The Session Rating of Perceived Exertion (sRPE) is an accepted surrogate measure of exercise intensity. The purpose of this study was to examine the effect of progressive fatigue from heavier than normal training on sRPE. METHODS: Twelve moderately fit college age students completed 30-min or 60-min interval workouts on a cycle ergometer, with the sequence of sessions designed to test the hypothesis that sRPE for a given exercise bout would increase with progressive fatigue, whether from a longer bout, or from successive days of harder than usual bouts. The workouts were Monday through Thursday for two weeks. The first week was three 30-min sessions (e.g. normal training) followed by a 60-min session (30-min session repeated 2x) (e.g. heavier than usual training). The second week was three 60-min sessions followed by a 30-min session. sRPE was measured 30-min post exercise, and RPE and HLa were measured at 10 min intervals during exercise. RESULTS: The 30-min sessions in week 1 had sRPE that was significantly less than the 60-min session (4.3+1.7, 4.3+1.4, 4.5+1.7 & 5.3+1.8). During week 2 the 60-min sessions became progressively harder, before the recovery 30- min session on day 4 (5.3+1.4, 5.9+1.6, 6.0+2.1 & 4.5+1.6). The mean RPE/HLa during the exercise bouts, a potential index of glycogen depletion mediated fatigue, followed a relatively constant course in week 1 (0.7+0.2, 0.9+0.4, 0.8+0.4 & 0.9+0.4) and an increasing course in week 2 (0.8+0.4, 0.9+0.4, 1.0+0.4 & 0.9+0.4). CONCLUSION: The results suggest that in addition to being a surrogate of exercise intensity, sRPE reflects accumulated fatigue during periods of increased training.

Differences in Autonomic Recovery Following Maximal Resistance Exercise in Young and Older Adults

Aging is associated with negative changes in autonomic function and an increased risk of cardiovascular disease. The risk of a sudden cardiovascular event is elevated during and immediately following vigorous exercise, potentially due to increased sympathetic dominance. Because resistance exercise provides a large hypertensive stimulus and young adults show reduced cardiac vagal control during recovery, further exploration of the effects of an acute bout of resistance exercise on autonomic function and recovery in older adults is required.PurposeTo evaluate the effects of high‐intensity lower body resistance exercise on autonomic modulation in young (YA) and older adults (OA).MethodsThirty‐five YA (17 female, 26±5 years, BMI: 23.8±3.2 kg/m2) and 25 OA (14 female, 60±6 years, BMI: 29.9±5.4 kg/m2) completed 3 sets of 10 repetitions of maximal isokinetic knee flexion/extension on a force dynamometer in a semi‐recumbent position. Throughout the protocol, participants were instrumented with a 3‐lead ECG and finger‐photoplethysmography for continuous heart rate and blood pressure recordings. Time and spectral components of heart rate (HRV) and blood pressure variability (BPV), non‐invasive indices of autonomic function, were analyzed using five‐minute segments at baseline and 5‐minutes post‐resistance exercise.ResultsAt baseline, OA had higher systolic and mean blood pressure, as well as lower root mean square of successive differences (RMSSD), low‐frequency (LF) RRI, high‐frequency (HF) RRI, and baroreceptor sensitivity (BRS) (p&lt;0.05). At 5‐minutes post‐exercise, LF/HF ratio and LF systolic blood pressure increased (p&lt;0.05). RMSSD, HF RRI, and BRS, were greater at baseline for YA and all variables decreased at 5‐min, while older adults did not change over time (interactions, p&lt;0.05).ConclusionsThese results suggest YA exhibited parasympathetic withdrawal 5‐minutes post‐exercise, whereas OA either did not exhibit parasympathetic withdrawal or had already recovered at 5 min post exercise, but this cannot be distinguished from our data. Both groups appear to have elevated sympathetic modulation at 5‐min, as indicated by RRI, LF/HF and LF BPV. Further investigation of the response during exercise is required. However, there are clear differences in autonomic recovery following maximal resistance exercise in OA.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The effect of aerobic walking and lower body resistance exercise on serum COMP and hyaluronan, in both males and females.

To compare the serum cartilage oligomeric matrix protein (COMP) and hyaluronan (HA) response to walking (high-repetition loading) and resistance training exercise (low-repetition loading) in males and females. 15 males (age: 28 ± 6 years; BMI: 24 ± 2; mean ± SD) and 15 females (age: 26 ± 4 years; BMI: 23 ± 2) completed both a 40-min walk at 80% of maximum heart rate and a 40-min lower body resistance training protocol, separated by a minimum of 48h. Serum COMP and HA were determined at rest, immediately post, and 30-min post exercise. Resting femoral cartilage thickness was also measured using ultrasonography. COMP increased following walking (28.9%; P < 0.001) and resistance training exercise (26.0%; P < 0.001), remaining above baseline post-exercise following walking (mean difference: +28.3ng/ml; 95% CI 3.8-52.8ng/ml; P = 0.02). Although the exercise response did not differ for gender, COMP concentrations were higher in males than in females at all time points (all, P < 0.001). In contrast, HA concentrations did not change following either modality of exercise. However, females demonstrated higher HA pre-exercise (37.7 ± 17.8 vs 26.2 ± 12.8ng/ml; P = 0.006) and immediately post exercise (38.0 ± 19.0 vs 28.2 ± 15.5ng/ml; P = 0.033) compared to men. Finally, following adjustment for body size, femoral cartilage thickness was greater in men compared to women (notch: 2.66 vs 1.74mm, P < 0.001). The effect of a single bout of lower body exercise on serum COMP and HA is independent of exercise modality in healthy men and women. Furthermore, having thicker femoral cartilage and higher baseline COMP in males does not appear to influence how the cartilage responds to exercise.

Effects of L-citrulline malate oral supplementation on post-exercise hypotension

Background: L-citrulline malate supplementation promotes an increase in oxide nitric metabolites, which are considered important mediators of peripheral vasodilation. Thus, the supplementation with this substance might maximize the duration and magnitude of post-exercise hypotension. Objectives: To investigate the hypotensive effect of L-citrulline malate supplementation following a single session of aerobic exercise in normotensives. Methods: Forty adults, normotensives, sedentary, were randomly assigned to one of the four experimental groups (control-placebo, control-Lcitrulline, exercise-placebo and exercise-Lcitrulline). All participants ingested a sachet with placebo or L-citrulline with malate (6 grams), both dissolved in water and the ingestion was made 120 minutes before starting the experimental session. The subjects performed 40 minutes of walk/run at 60-70% of reserve heart rate. For the control session, they remained seated in rest during 40 minutes. The blood pressure was taken in rest and every 10 minutes until complete 60 minutes after the experimental session. The ambulatory blood pressure device take the readings every 20 minutes (awake time) and each 30 minutes (sleep time) over the course of 24 hours. Results: L-citrulline malate supplementation associated to aerobic exercise promoted significantly reductions on systolic blood pressure when compared with control-placebo at 20 min (net change[NC]: 9.7 mmHg [P=0.010]), 40 min (NC: 12.7 mmHg [P=0.010]), 50 min (NC: 12.1 mmHg [P=0.012]), 60 min (NC: 9.0 mmHg [P=0.050]) and overall mean (NC: 7.8 mmHg [P=0.018]) post exercise. Conclusion: Acute L-citrulline malate supplementation might potentiate the post-exercise hypotension effects in normotensive subjects.

The Effects of a Botanical Blend on Post-Exercise Mucosal Antimicrobial Proteins

Exercise is a stressor that is known to in some cases suppress antimicrobial protein levels, particularly secretory immunoglobulin type A (IgA). Athletes in the midst of in-season training often demonstrate declining levels of sIgA as well as increased risk for ailments such as upper respiratory tract infections. Therefore, it is important to investigate natural supplements that may enhance post exercise mucosal immune function. Twenty healthy collegeaged males volunteered to participate in the present single blind, repeated measures study. Three treatments were administered (botanical spray, botanical drops, placebo) at the onset of 30 Min of 80% VO2 max cycle ergometer exercise. Secretory IgA and Human Alpha Defensin were quantified in saliva samples 30 Min and 90 Min post exercise. Analysis via repeated measures Anova revealed a significant treatment effect at 30 min (p=0.030) with post hoc testing revealing a difference between the botanical spray and placebo (p=0.027), but by 90 Min there was no differences by treatment (p=0.758). There was no difference by treatment observed at either 30 or 90 Min for human alpha defensin concentrations. Based upon these preliminary data, it appears that a single dose of the tested botanical blend delivered via mouth spray can increase sIgA, one of the primary anti-microbial proteins in the oral cavity, for a short time post exercise.

Regulation of oxygen saturation in retinal blood vessels in response to dynamic exercise.

To evaluate the impact of dynamic exercise on retinal vessel oxygen saturation in healthy individuals. Twenty-six healthy participants underwent moderate dynamic exercise (modified Master's two-step exercise). In all subjects, intraocular pressures (IOP), systolic and diastolic blood pressures (SBP and DBP), retinal vessel calibres and retinal arterial and venous oxygen saturation were measured at baseline, immediately following exercise and 15min postexercise. Moderate dynamic exercise increased SBP and DBP immediately postexercise (SBP: 116 (±13) mmHg to 150 (±21) mmHg; p<0.001 and DBP: 69 (±10) mmHg to 74 (±10); p<0.001), while IOP decreased by an average of 2mmHg (baseline: 13 (±3) mmHg)) immediately postexercise (11 (±2) mmHg). Oxygen saturation in retinal arteries remained unchanged (baseline=93±8%; immediately postexercise=94±9% and 15min postexercise=96±8%; p=0.069), but increased in retinal veins immediately postexercise and did not return to baseline values within 15min postexercise (baseline=54±12%; immediately postexercise=56±15%; 15min postexercise=57±12%; p=0.036). There is a mild increase in retinal venous oxygen saturation and there is a trend towards an increase in arterial saturation in otherwise healthy individuals following dynamic exercise.

Physiological response to an experimental 100 m flying pace race in Icelandic horses and effect of rider

This study evaluated the physiological response to an experimental 100 m flying pace race (EPR) in Icelandic horses with pace-competition experience, and whether there was an effect of rider. A cross-over design with nine horses and two riders was used. The EPR was performed twice (once with each rider) with four days of rest in-between. The EPR consisted of two runs (I and II), of which at least 100 m was in pace at full speed according to international competition rules. Plasma lactate concentration increased and was greater after pace run II than I (18.5±1.3 vs 11.9±0.7 mmol/l; P&lt;0.001). Heart rate was higher during pace run I than II (207±3 vs 205±3; P=0.02). Heart rate and Lact had not recovered 30 min post exercise but Hct was back to resting level after 30 min recovery. Speed did not differ between riders and pace runs (pooled mean ± standard deviation of pace runs: 10.4±0.7 m/s, range 9.2-12.1 m/s) but HR and Lact were higher from warm-up and until 30 min recovery with rider 1 than 2 (P&lt;0.001). There was a negative correlation between post EPR Lact with rider 1 and previous best record (r2=0.72, P=0.032). To conclude, a 100 m flying pace race in the Icelandic horse is a high-intensity exercise and anaerobic metabolism is crucial for performance. The rider had an effect on the physiological response but it is unclear if it was due to body weight, riding style or both. The practical relevance of the differences observed between riders remains to be proven but our results indicate that they may have limited impact on single day competitions since the speed was the same with the two riders.

The Acute Arterial Stiffness Response to Interval vs. Continuous Exercise in Postmenopausal Women

High Intensity Interval Exercise (HIIE) has been associated with greater reductions in cardiovascular disease (CVD) risk factors when compared to continuous moderate exercise. Arterial stiffness (AS) is an independent risk factor for CVD that increases exponentially in women following menopause. PURPOSE: The current research was designed to investigate the acute AS response to a single bout of HIIE versus a single bout of moderate continuous endurance exercise (MCE) in postmenopausal women. METHODS: A total of 13 women (age = 60.85 ± 4.41 years) completed the study. Subjects completed both a HIIE and a MCE treadmill protocol on separate occasions. Time of the MCE intervention was adjusted to match for the average number of heart beats obtained during the HIIE intervention. Pulse wave velocity (PWV), augmentation index (AIx), central systolic blood pressure (CSBP), and central diastolic blood pressure (CDBP) were measured pre exercise, 15 min post exercise, and 30 min post exercise to assess arterial stiffness. RESULTS: No significant interaction (p > .05) between exercise intervention and time was determined for PWV, AIx, CSBP, or CDBP. No change in PWV was found from pre to post exercise (p = .109). A trend was found for a greater decrease in AIx following HIIE compared to the decrease in AIx following MCE (p = .086). A significant decrease in AIx was found from pre exercise to 15 min post exercise (p = .002; Mpre = 33.91, M15post = 27.40) and from pre exercise to 30-min post exercise (p = .035; Mpre = 33.91, M30post = 28.67). CONCLUSION: The results of this study indicate that whether postmenopausal women perform MCT or HIIE, the acute response of central arterial stiffness does not differ. No change in PWV from pre to post exercise was found for either exercise intervention.

Metabolomic Responses to Acute Aerobic and Anaerobic Exercise Bouts

PURPOSE: To explore the acute serum metabolomic responses following single bouts of aerobic and anaerobic exercise in differentially-trained subjects. METHODS: Subjects (N = 40) were equally distributed into one of 4 groups (n = 10) based on a combination of sex [male (M) or female (F)] and training history [endurance (E) or resistance (R) trained] (M = 24 + 4 y, 160.5 + 17.2 kg, 12.8 + 5.7 %BF; F= 22 + 2 y 135.5 + 15.8 kg, 23.3 + 4.8 %BF). On separate days, 45 min aerobic (A) or weight-training (W) exercises were performed. Serum was collected pre, 0 & 60 min post exercise (T0, T1 & T2), and analyzed via UHPLC/MS for identification of 754 biochemicals. Principle components analysis (PCA) was used to define metabolite profiles. RMANOVA’s for sex, training status, exercise type, and time were run with significance set at P < .05. RESULTS: Both A and W increased glycolysis (A = 3.5 + .7 fold; W = 3.9 + 1.0 fold; P<.05), with a significantly greater activation for RW, P<.05. TCA activity (AVG = 1.5 + 0.3 & 1.9 + 0.3 fold; P<.05) also increased. Downstream TCA intermediates (succinate, fumarate, & malate) were increased at T1, particularly for succinate in E (P<.05), and returned to baseline by T2. During exercise, A increased fat metabolism as evidenced by elevation of multiple FFAs and acylcarnitines (i.e., palmitate increased 2.0 + 0.4 v 1.0 + 0.1 fold in A v W) and elevated ketone bodies at T1 in RA & EA. Across exercise conditions, E showed relatively lower FFA and BCAA catabolism than R at T2 (E v R changes from baseline: stearate =1.4 + 0.3 v 1.4 + 0.2 fold; 3-hydroxyisobutyrate = 1.8 + 0.2 v 2.2 + 0.1, P<.05) and generally faster returns towards baseline for all metabolites. Sex-dependent differences in global metabolite profiles were more pronounced in E than R groups, including elevated FFA’s and muted TCA intermediate levels and BCAA catabolism in FE during both A and W. CONCLUSION: The biological response to exercise is dictated by the metabolic demand of the exercise and the physiology of the exerciser, allowing exercise type and individual variation to alter the exercise metabolome. Data support greater TCA capacity in E and greater glycolytic power in R leading to differential fuel selection during exercise, particularly with matched mode. Females displayed lower TCA activity, yet higher FFA oxidation with sex differences most apparent in the E groups.

Acute Effects of Blood Flow Restriction Resistance Exercise in a Head-down Tilt Position on Growth Hormone and Insulin-like Growth Factor-I Release

Muscular atrophy is common among astronauts while in spaceflight. Growth Hormone (GH) and IGF-I are key hormones with regards to the preservation and growth of skeletal muscle tissue. Low intensity blood flow restriction (BFR) resistance exercise is a newer training modality employed to various populations to enhance muscle growth, yet has not been thoroughly explored in the astronaut population. PURPOSE: To determine the effects of low intensity BFR in a head-down tilt position on the acute release of GH and IGF-I. METHODS: Twelve college-aged males with resistance exercise experience were included in the study. The first of three sessions consisted of informed consent, demographic measurements, and 3RM testing. The two experimental sessions consisted of subjects resting in a -6 deg head-down tilt position for 2 hr. Upon rest completion, while tilted, subjects performed the exercise protocol at 30% of estimated 1RM for the following exercises: close-grip bench press, dumbbell bicep curls, and dumbbell triceps extensions. Exercises were performed with or without BFR (160 mmHg) to the upper arms in a counterbalanced order. Venus blood draws (15 mL) occurred 10 min prior to tilt, 10-15 min post exercise protocol, and 24 hr post exercise protocol and were assayed in duplicate. Two 2 x 2 Factorial ANOVAs with repeated measures were utilized for statistical analysis of the dependent variables (GH, IGF-I). Alpha levels were set at p < 0.05. RESULTS: A significant interaction was found between exercise condition and time for GH (p < .05). No significant interaction was found between exercise condition and time for IGF-I (p > .05). No significant mean difference was observed between BFR and no BFR for IGF-I (p >.05). A significant mean difference was observed pre to post exercise protocol for IGF-I (p < .05). CONCLUSION: A low intensity BFR exercise protocol in a head-down tilt position elicited a large increase in systemic GH concentrations from pre to post exercise. Post exercise GH levels were elevated to a much greater extent with BFR compared to no BFR. A low intensity BFR modality may be beneficial to employ to astronauts while in spaceflight or post spaceflight to help promote muscular tissue growth.

Postexercise Hemodynamics in Patients With Type 2 Diabetes: Effect of Exercise Intensity and Duration

Background: For individuals with type 2 diabetes (T2D), the hemodynamic response to regular exercise is critical for regulating blood glucose, protecting vascular function, and reducing cardiovascular disease risk, but the hemodynamic responses to differing doses of acute exercise in T2D are unclear. We aimed to compare postexercise (PE) hemodynamics in patients with T2D in response to 4 doses of dynamic exercise.Methods: Eight subjects with well-controlled T2D (42–64 years old.; hemoglobin A1c: 6.6% ± 0.9%) participated in 4 study days, during which they exercised on a cycle ergometer at 4 different combinations of exercise duration and intensity: 30 min at 40% V˙O2peak (30@40), 30 min at 60% V˙O2peak (30@60), 60 min at 40% V˙O2peak (60@40), and 60 min at 60% V˙O2peak (60@60). Heart rate, arterial pressure, and femoral blood flow (Doppler ultrasound) were measured pre-exercise and every 15 min through 120 min PE. Femoral vascular conductance was calculated as flow/pressure.Results: Compared with pre-exercise baseline, femoral blood flow and femoral vascular conductance were higher through at least 105 min of recovery in all conditions (all P &amp;lt; .05), except for the 30@40 trial. Compared with the pre-exercise measures, systolic blood pressure was lower through at least 75 min of recovery in all conditions (all P &amp;lt; .05), except for the 30@40 trial.Conclusion: These results suggest that exercise must be at least moderate in intensity or prolonged in duration (&amp;gt;30 min) to promote sustained PE elevations in skeletal muscle blood flow and reductions in systolic blood pressure in patients with T2D.

Mouthpiece use during heavy resistance exercise affects serum cortisol and lactate

Recent reports suggest the use of mouthpieces may be beneficial at improving aerobic and anaerobic exercise performance. However, the mechanisms of these reported improvements have yet to be elucidated. The purpose of this study was to explore the possible mechanisms of improved performance using the ArmourBite® mouthpiece. Using a within subject randomized treatment design, 15 experienced resistance trained males (19–26 years of age) performed 6 sets of 10 repetitions of free weight back squats at 80% of 1RM with and without a mouthpiece. Blood samples were collected before exercise, after 3 sets (Mid), immediately post (Post), 30 min post (Post-30), 60 min post (Post-60) and 120 min post (Post-120) exercise. Samples were analyzed for lactate and ELISA was used to determine cortisol. Mouthpiece use resulted in more repetitions completed without assistance (54.36 ± 0.61 vs. 53.27 ± 0.79, p = 0.046) and fewer assisted repetitions (6.73 ± 0.79 vs. 5.64 ± 0.61 repetitions, p = 0.046) compared to the ...

Moderate rest intervals are superior to short intervals for improving PAI-1 following exhaustive exercise in recreational weightlifters.

This study investigated the influence of short and moderate recovery intervals on lipid profiles and plasminogen activator inhibitor-1 (PAI-1) following exhaustive strength exercise in recreational weightlifters. Seven subjects performed two conditions in a randomized order: short, 90% of one maximum repetition (1RM) and 30-sec rest allowed between sets; moderate, 90% of 1RM and 90-sec rest allowed between sets. Total cholesterol (Chol), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triacylglycerol (TAG), Chol/HDL-c ratio and PAI-1 concentrations were assessed at baseline, immediately postexercise, and 15- and 30-min postexercise (post-15 and post-30). The LDL-c concentrations decreased and HDL-c concentrations increased in both conditions but without significant differences (LDL-c: 30 sec: pre, 82.0±19.5 mg/dL, immediately, 73.9±16.4 mg/dL, 90 sec: pre, 75.9±30.8 mg/dL, immediately, 66.2±35.5 mg/dL, P=0.423; HDL-c: 30 sec: pre, 53.5±9.2 mg/dL, immediately, 61.4±11.4 mg/dL; 90 sec: pre, 55.8±11.1 mg/dL, immediately, 84.9±27.8, mg/dL; P=0.146). On the other hand, PAI-1 had a tendency to decrease only in the 90-sec condition (pre, 7,754.9±2,927.7 pg/mL; immediately, 5,313.1±4,637.4 pg/mL; P=0.085). There was a positive correlation between PAI-1 and Chol (30 sec: r=0.83, 90 sec: r=0.91; P<0.05), PAI-1 and fat-free mass in both conditions (30 sec post-15: r=0.79, post-30: r=081, P<0.05; 90 sec immediately: r=0.77, post-15: r=0.81; P<0.05), and PAI-1 and TAG only in 30 sec (r=0.87, P<0.05). Short and moderate intervals of recovery improve lipid profiles after heavy strength exercise but only 90 sec induced greater improved in PAI-1 concentration in recreational weightlifters.

O2score device: analysis of the kinetics of recovery after exercise

Background: The O2Score system was recently developed as a mobile device able to measure the quantity of antioxidants in the body. Since the quantity of antioxidants is modified during effort (to provide a defense system against free radicals [1]) it appears that O2Score system could be used to follow and control the recovery of athletes. However, no known study was conducted to test the relevance of O2Score system.  Purpose: Therefore, the first aim of this preliminary study was to determine the ability of the O2Score to detect different levels of fatigue induced by different training loads. Second aim was to establish a link between perceptive scales and the results obtained with the O2Score.  Methods: 3 subjects were included in this study. Each one performed 3 sessions on a cycle ergometer: at low (mean mechanical work 300 ± 101 kJ), moderate (562 ± 188 kJ) and high (1099 ± 367 kJ) training load. The O2Score index (obtained using capillary blood sample) and Hooper scales ([2] graduated from 0 (good feeling) to 7 (bad feeling)) were used to quantify the recovery from +5 min post exercise to +72 h. Spearman test was used for correlation.  Results: The O2Score index increased until 20 min post-exercise whatever experimental sessions: + 35.3% after high, +25.7% after moderate and +17.7%. A significant correlation was obtained between O2Score index and stress (R2 = 0.343; p <0.01), between O2Score index and torque sleep - stress (R2 = 0.275; p <0.01) and between O2Score index andt he global scale sleep - stress - fatigue- muscle soreness (R2 = 0.162; p <0.05).  Discussion: The O2Score device seemed sensitive to different post exercise training load with 3 distinct curves until 20 min post exercise. The explanation for this response is a difference in oxygen consumption. That is why a proportional increase of free radicals and antioxidant response [3]. However, between 2 and 72 h post exercise, it appears complex to provide a clear interpretation of the data that appear to be influenced by other factors than the training load such as stress, sleep or fatigue. Sure stress was the factor influencing the most the index O2score (R2 = 0.343; p <0.01). This result could be explained by the fact that after intense exercise, the recovery is faster with a lower stress level compared to high level of stress [4]. Another result concerns the significant correlation between the torque stress - sleep and O2Score index (R2 = 0.275; p <0.01). Indeed, the lack of sleep, as well as stress are known to be noxious for the recovery. The work of Milewski et al. (2014) [5] showed that athletes with low sleep time have a higher probability of injury than athletes with an adequate sleep time. A final correlation was obtained between the global scale sleep - fatigue - stress - muscle soreness and O2Score index (p <0.05, R2 = 0.162). An explanation could be that the O2 Score is a system involving all the parameters surrounding the athlete’s environment.  Conclusions: The O2Score seems able to identify different training loads during the first 20 minutes post exercise. Factors significantly influencing O2Score index are stress, torque sleep - stress and all the parameters of the Hooper scales (sleep - stress – fatigue - muscle soreness).

Effects of pomegranate extract on blood flow and vessel diameter after high-intensity exercise in young, healthy adults

The effects of pomegranate extract (PE) supplementation were evaluated on high-intensity exercise performance, blood flow, vessel diameter, oxygen saturation (SPO2), heart rate (HR), and blood pressure (BP). In a randomized, crossover design, nineteen recreationally resistance-trained participants were randomly assigned to PE (1000 mg) or placebo (PL), which were consumed 30 min prior to a repeated sprint ability (RSA) test and repetitions to fatigue (RTF) on bench and leg press. The RSA consisted of ten six-second sprints on a friction-loaded cycle ergometer with 30 s recovery. Brachial artery blood flow and vessel diameter were assessed by ultrasound. Blood flow, vessel diameter, SPO2, HR, and BP were assessed at baseline, 30 min post ingestion, immediately post exercise (IPost), and 30 min post exercise (30minPost). With PE, blood flow significantly increased IPost RSA (mean difference = 18.49 mL min−1; P < .05), and IPost and 30minPost RTF (P < .05) according to confidence intervals (CI). Vessel diameter increased significantly 30minPost RSA according to CI and resulted in a significant interaction IPost and 30minPost RTF (P < .05). With PE, according to CI, average and peak power output increased significantly in sprint 5 of the RSA (P < .05). There was no significant difference between PE and PL for bench (P = .25) or leg press (P = .15) repetitions. Acute PE supplementation enhanced vessel diameter and blood flow, suggesting possible exercise performance enhancement from increased delivery of substrates and oxygen. The acute timing and capsule form of PE may be advantageous to athletic populations due to ergogenic effects, taste, and convenience.

Markers of biological stress in response to a single session of high-intensity interval training and high-volume training in young athletes.

The aim of the present study was to compare the effects of high-intensity interval training (HIIT) vs high-volume training (HVT) on salivary stress markers [cortisol (sC), testosterone (sT), alpha-amylase (sAA)], metabolic and cardiorespiratory response in young athletes. Twelve young male cyclists (14±1years; 57.9±9.4mLmin-1kg-1 peak oxygen uptake) performed one session of HIIT (4×4min intervals at 90-95% peak power output separated by 3min of active rest) and one session of HVT (90min constant load at 60% peak power output). The levels of sC, sT, their ratio (sT/sC) and sAA were determined before and 0, 30, 60, 180min after each intervention. Metabolic and cardiorespiratory stress was characterized by blood lactate, blood pH, respiratory exchange ratio (RER) and heart rate (HR), oxygen uptake ([Formula: see text]), ventilation (V E) and ventilatory equivalent (V E/[Formula: see text]). sC increased 30 and 60min after HIIT. However, 180min post exercise, sC decreased below baseline levels in both conditions. sT increased 0 and 30min after HIIT and 0min after HVT. sAA and sT/sC ratio did not change significantly over time in HIIT nor HVT. Metabolic and cardiorespiratory stress, evidenced by blood lactate, HR, [Formula: see text], V E, and V E/[Formula: see text] was higher during HIIT compared to HVT. The metabolic and cardiorespiratory stress during HIIT was higher compared to HVT, but based on salivary analyses (cortisol, testosterone, alpha-amylase), we conclude no strong acute catabolic effects neither by HIIT nor by HVT.

Effects of music and music-video on core affect during exercise at the lactate threshold

The objective of the present study was to examine the effects of music and music-video on core affect during and immediately after stationary cycling at the lactate threshold. A randomized, fully counterbalanced, crossover design with three conditions (music, music-video, and a no-music-video control) was adopted. Twenty-four participants exercised at lactate threshold while exposed to music, music-video, and control conditions. Affective valence and perceived activation were assessed every 2 min during a 20-min exercise bout and every 5 min post exercise over a 20-min period. Results indicated that there was a significant condition x time interaction for affective valence. The music-video condition elicited the highest levels of affective valence followed by the music condition and control. There was a main effect of condition for affective valence, wherein the experimental conditions facilitated significantly higher affective valence than control. Significant main effects of time emerged for both affective valence and perceived activation. Regardless of condition, affective valence decreased during the exercise bout and increased immediately post exercise. Conversely, perceived activation increased during exercise and decreased immediately post exercise. The present findings indicate that music and music-video can enhance core affect during exercise at the lactate threshold and the implications for exercise adherence are expounded.