The impact of exercise modality on exercise-induced gastrointestinal syndrome and associated gastrointestinal symptoms

ObjectivesThis study aimed to determine the impact of running and cycling exercise modalities on the magnitude of exercise-induced gastrointestinal syndrome (EIGS) and associated gastrointestinal symptoms (GIS).DesignParallel group trial design.MethodsTwenty-eight endurance athletes (male n = 14, female n = 14) completed 2 h running at 55 % of maximal oxygen uptake or cycling at 55 % of maximal aerobic power in T_amb 35 °C and 22 % RH. Pre- and post-exercise blood samples were collected and analysed for markers of intestinal epithelial integrity perturbations (i.e., plasma intestinal fatty acid protein (I-FABP), soluble (s)CD14, and lipopolysaccharide binding protein (LBP)) and systemic inflammatory cytokines (i.e., plasma IL-1β, TNFα, IL-10, and IL-1ra). GIS were assessed pre-exercise and every 10 min during exercise.ResultsExercise-associated Δ for plasma I-FABP (191 and 434 pg?ml^?1) and LBP (?1228 and 315 ng?ml^?1) did not differ between running and cycling, respectively; however for sCD14 was higher (p = 0.030) on cycling (116 ng?ml^?1) vs running (96 ng?ml^?1). There were no differences in absolute pre- and post-exercise systemic inflammatory cytokine concentration, with large individual variation observed. Exercise-associated plasma TNF-α, (p = 0.041) and IL-10 (p = 0.019) responses were greater in running than cycling, but did not lead to a greater systemic inflammatory response profile (p = 0.305) between running (5.0arb.units) and cycling (?2.5arb.units). Although greater GIS incidence occurred in running (44 %) compared with cycling (25 %), there was no difference between groups for GIS severity.ConclusionsWhen running and cycling exercise is performed with similar duration, intensity, ambient conditions, and with confounder control, the exercise modality does not substantially impact the magnitude of EIGS or associated GIS severity.     

The effects of hydration status and ice-water dousing on physiological and performance indices during a simulated soccer match in the heat

ObjectivesTo assess the effects of hydration status and ice-water dousing on physiological and performance parameters.DesignRandomized, crossover.MethodsTwelve athletes (mean[M] ± standard deviation[SD]; age, 20 ± 1 years; height, 174 ± 8 cm; body mass, 72.1 ± 11.0 kg; VO_2max 53.9 ± 7.3 mL⋅kg⁻¹⋅min⁻¹) completed four trials (euhydrated without dousing, hypohydrated without dousing, euhydrated with dousing, and hypohydrated with dousing), which involved intermittent treadmill running (five 15-minute bouts) in the heat (M ± SD; ambient temperature, 34.7 ± 2.1 °C; relative humidity, 46 ± 3%; wet-bulb globe temperature, 28.0 ± 0.4 °C). Participants also completed four cognitive, power, agility, reaction time, and repeated sprint performance tests throughout each trial. Heart rate (HR) and rectal temperature (T_rec) were measured continuously. Repeated measures ANOVAs were performed to assess differences between physiological and performance variables. Alpha was set at ≤0.05, a priori. Data are reported as mean difference ± standard error (MD ± SE).ResultsHR was significantly lower in euhydrated trials compared to hypohydrated trials, irrespective of dousing (8 ± 2 bpm; p = 0.001). Dousing did not significantly impact HR (p = 0.455) and there was no interaction between hydration and dousing (p = 0.893). T_rec was significantly lower in euhydrated trials compared to hypohydrated trials (0.39 ± 0.05 °C, p < 0.001), with no effect from dousing alone (p = 0.113) or the interaction of hydration and dousing (p = 0.848). Dousing resulted in improved sprint performance (11 ± 3 belt rotations, p = 0.007), while hydration status did not (p = 0.235).ConclusionsAthletes should aim to maintain euhydration during exercise in the heat for improved physiological function and cooling with ice-water dousing elicits additional performance benefits.     

Concentric not eccentric cycling sprint intervals acutely impair balance and jump performance in healthy active young adults: A randomized controlled cross-over study

IntroductionModerate aerobic, high-intensity and sprint running or cycling training can transiently impair postural control. However, the acute effects of modified sprint interval training (mSIT) at different muscle working modes have not yet been examined. Thus, this study aimed at investigating acute effects of time-matched eccentric (ECC) versus concentric mSIT cycling session (CON) on jumping and functional balance performance.MethodsTwenty-five healthy and active males (30.0 ± 6.0 years; 80.1 ± 9.1 kg; V̇O_2max: 64.2 ± 7.9 mL kg⁻¹ min⁻¹) were enrolled in this acute randomized controlled crossover trial. Counter-Movement-Jump (CMJ) and functional balance testing (Y-Balance-Test composite score [YBT_CS]; Posturomed total distance: Posturomed_TD) were assessed as primary outcomes before, and immediately after cessation of ECC and CON (10 × 10 s maximum sprints and 50 s of active recovery).ResultsA significant mode × time interaction effect for CMJ (F = 9.620, p = 0.005, η_p² = 0.29) was observed. Subsequent post-hoc testing revealed significant moderate reductions in jumping height after CON (0.31 ± 0.06 vs. 0.27 ± 0.06m; p = 0.004, SMD = 0.59), whilst ECC remained unchanged. YBT_CS (mode × time interaction: F = 6.880, p = 0.015, η_p² = 0.22) showed small but significant balance impairments after CON (0.964 ± 0.068 vs. 0.960 ± 0.063 AU; p = 0.009, SMD = 0.28) and did not significantly change after ECC. Although large significant interaction effects (p = 0.029, η_p² = 0.18) were observed for Posturomed_TD, follow up post-hoc testing did not reveal relevant pre-post differences, neither for ECC nor CON.ConclusionBoth functional balance and jumping performance are deteriorated after acute concentric but not eccentric mSIT cycling. Although higher pedal forces at lower perceived efforts and heart rates during eccentric mSIT were observed, it seems that the cardiocirculatory demanding CON session elicited more pronounced balance and jump performance impairments than eccentric cycling.     

Noon is the best time to perform a dual task while cognitive performance may be boosted by concurrent performance of a physical task

BackgroundDual-task is the concurrent performance of two independent single tasks (ST) that have distinct goals. Daily variations in performance of singular cognitive or motor tasks are reported in the literature.Research questionTo investigate whether performance of a dual-task (DT) varies based on the time of day and whether there is interference between the motor and cognitive aspect of DT.MethodsParticipants performed a 10 Meter Walk Test (10MWT) for motor and a Stroop Test for cognitive task. The DT activity combined both STs. All participants performed three trials for all three conditions at three different times of the day (morning, noon, afternoon), on separate testing days.ResultsData were collected on 42 participants. Most participants were female (28/42), average age of 27.95 ± 9.28 years, and BMI of 25.58 ± 4.49 Kg/m2. Walking velocities in ST were consistently faster than in DT, p < .0005. In DT conditions, the participants walked faster at noon (1.21 ± 0.13 m/s) compared to the morning (1.16 ± 0.15 m/s, p = 0.01) or the afternoon (1.16 ± 0.18 m/s, p = 0.04). The participants’ score on the DT-Stroop test were only different at noon (11.43 ± 2.28) when compared to morning (10.67 ± 1.34, p = 0.006). The percentage DT-Cognitive interference effect was 26.1 % in the morning, 11.8 % at noon and 13.4 % in the afternoon. The Motor interference was −14.6 % in the morning, −12.2 % at noon and −13.8 % in the afternoon.SignificanceNoon is the best time to perform a dual task condition. Noon consistently exhibited the least motor or cognitive interference. Conversely, the maximum boost in cognitive performance was observed in the mornings.     

Effects of a school-based physical activity program on retinal microcirculation and cognitive function in adolescents

ObjectivesTo investigate the effect of combined aerobic and coordinative exercise on retinal microcirculation and its association with changes in cognitive performance in healthy adolescents.DesignUsing cluster-randomization (on class-level), 36 participants were allocated to an exercise group (EX) performing a 20-min aerobic and coordinative exercise session on each school day over a period of 8 weeks or a control group, which was encouraged to have social interactions (CON).MethodPrior to and following the intervention period, central retinal arteriolar (CRAE) and venular diameters (CRVE) were assessed by use of a static vessel analyzer. Additionally, a computer-based version of the Stroop Color-Word task was administered to assess inhibitory control.ResultsThe statistical analysis revealed that EX compared to CON showed higher CRAE at post-test, when pre-test values were accounted for, F(1,32) = 4.92, p = 0.036, η² = 0.130. In contrast, no such effect was reported for CRVE. With regard to cognitive performance, a greater reduction of reaction time on the Stroop task was observed in EX relative to CON, F(1,30) = 8.58, p = 0.006, η² = 0.222. The increase in CRAE was significantly correlated with a decrease of reaction time on trials demanding inhibitory control, even after adjusting for covariates, r(31) = −0.438, p = 0.011.ConclusionsA structured exercise program leads to a widening of retinal arteriolar diameters, which is associated with improvements in inhibitory control. Consequently, daily exercise sessions performed during the school break-time can be recommended for promoting both cardiovascular and cognitive health in adolescents.     

Cardiac autonomic response to aerobic exercise with different levels of blood flow restriction in pre-hypertensive men

Purpose

Cardiovascular safety of aerobic exercise with blood flow restriction (BFR) has been little studied in clinical populations. This study investigated the effects of different levels of BFR on cardiac autonomic response during and after walking tasks in pre-hypertensive men.

Methods

Twelve pre-hypertensive men performed three randomly assigned experimental sessions: (1) 20 min of walking at 40% of peak running velocity (V_peak) without BFR (CON); (2) 20 min of walking at 40% of V_peak with BFR sets at 40% of the maximum cuff pressure that fully interrupted blood flow (BFR40); and (3) 20 min of walking at 40% of V_peak with BFR sets at 80% of the maximum cuff pressure that fully interrupted blood flow (BFR80). The HR and HRV measurements were taken at rest, during exercise, and during the recovery period after constant load sessions.

Results

Heart rate was higher throughout the BFR80 session when compared to the CON condition (p?<?0.05). The time constant of heart rate recovery was higher in both BFR80 (73.2?±?28.8 s) and BFR40 (49.8?±?16.1 s) compared to CON (24.3?±?7.8 s; p?<?0.01). In addition, the cardiac vagal modulation during recovery was lower in the BFR80 than CON (p?<?0.05), but there was no significant difference between BFR40 and CON or between BFR80 and BFR40 (p?>?0.05).

Conclusions

Restricting blood flow imposes additional cardiovascular stress during and after exercise in pre-hypertensive men, with apparently greater stress as the level of BFR increases.

     

Men's lacrosse protective equipment increases strain during exercise in the heat

ObjectivesThe purpose of this study was to determine thermoregulatory and cardiovascular effects of wearing men's lacrosse protective equipment during simulated lacrosse activities in the heat.DesignWe conducted a randomized, controlled, crossover study.MethodsThirteen healthy men (22 ± 3 y, 76.2 ± 8.9 kg, 181 ± 6 cm, 16.06 ± 6.16% body fat) completed two matched exercise trials in the heat (WBGT: 25.5 ± 0.8 °C). In randomized order, participants donned full men's lacrosse equipment (helmet, shoulder/elbow pads, and gloves) in one trial while the other included no equipment. Participants completed a topography body scan to determine specific body surface area covered with equipment. Rectal temperature (T_re), heart rate (HR), and mean weighted skin temperature (T_sk) were measured throughout trials. Whole body sweat rate was assessed for trial comparisons.ResultsThe equipment covered 32.62 ± 2.53% body surface area in our participants. Post-exercise T_re was significantly greater with equipment (39.36 ± 0.04 °C) compared to control (38.98 ± 0.49 °C; p = .007). The overall rate of rise of T_re was significantly greater with equipment (0.043 ± 0.015 °C·min⁻¹) compared to control (0.031 ± 0.008 °Cmin⁻¹; p = .041). Regardless of time point, HR and T_sk were significantly elevated with equipment compared to control trial (p ≤ .026). Sweat rates were elevated with equipment (1.76 ± 0.74 L·h⁻¹) compared to shorts and t-shirt (1.13 ± 0.26 L·h⁻¹), but this difference was not significant (p = .058).ConclusionsOur data indicate impairments in heat dissipation and increased cardiovascular strain imposed by men's lacrosse equipment.     

Effects of simulated domestic and international air travel on sleep,performance, and recovery for team sports

The present study examined effects of simulated air travel on physical performance. In a randomized crossover design, 10 physically active males completed a simulated 5‐h domestic flight (DOM), 24‐h simulated international travel (INT), and a control trial (CON). The mild hypoxia, seating arrangements, and activity levels typically encountered during air travel were simulated in a normobaric, hypoxic altitude room. Physical performance was assessed in the afternoon of the day before (D ? 1 PM) and in the morning (D + 1 AM) and afternoon (D + 1 PM) of the day following each trial. Mood states and physiological and perceptual responses to exercise were also examined at these time points, while sleep quantity and quality were monitored throughout each condition. Sleep quantity and quality were significantly reduced during INT compared with CON and DOM (P < 0.01). Yo‐Yo Intermittent Recovery level 1 test performance was significantly reduced at D + 1 PM following INT compared with CON and DOM (P < 0.01), where performance remained unchanged (P > 0.05). Compared with baseline, physiological and perceptual responses to exercise, and mood states were exacerbated following the INT trial (P < 0.05). Attenuated intermittent‐sprint performance following simulated international air travel may be due to sleep disruption during travel and the subsequent exacerbated physiological and perceptual markers of fatigue.     

Effects of graduated compression socks on ankle inversion proprioception of half-marathon runners at different running distances

ObjectivesTo determine the effect of graduated compression socks on ankle proprioception and the relationship between fatigue and ankle proprioception measures in half-marathon runners at successive 7 km intervals during a 21-km run.DesignRepeated measures study.MethodsTwenty well-trained half-marathon runners (mean ± SD: age 38.6 ± 11.3 y, weekly volume 42.3 ± 21.1 km, training experience 4.7 ± 3.5 y) performed two 21 km running trials on a treadmill wearing either graduated compression socks or looser, standard non-compression running socks. Each running trial was divided into three self-paced 7 km blocks, repeated at the same pace for each trial, heart rate was not controlled, but after each block, heart rate, blood lactate, rating of perceived exertion, and ankle inversion proprioception were measured, the latter by using the active movement extent discrimination apparatus.ResultsThere was no differences between the graduated compression sock and non-compression running sock conditions in rating of perceived exertion scores (F = 0.524, p = 0.478), heart rate (F = 0.001, p = 0.975) and blood lactate (F = 0.004, p = 0.951). Overall, wearing graduated compression socks was associated with significantly better ankle proprioception after 21 km of running (p = 0.024, 95% CI = ?0.066, ?0.005). Heart rate, rating of perceived exertion and blood lactate were not correlated with ankle proprioception sensitivity in the graduated compression sock and non-compression running sock conditions at any point during the run (all p > 0.05).ConclusionsWearing graduated compression socks provides a positive effect on proprioceptive control of the ankle joint only after 21 km and may therefore reduce the possibility of injury associated with proprioceptive ability diminishing over time during exercise.     

Two years of regular exercise decreases blood pressure and improves motor skills in early childhood

Purpose

Today’s children experience an increasing deficiency in physical activity accompanied by increasing evidence of cardiovascular risk factors such as overweight and elevated blood pressure. Therefore, 3-year-old children were included in a controlled prospective study to assess the efficacy of a preventive regular exercise program on blood pressure (BP) regulation and motor skills.

Methods

160 children (INT) in 17 nursery schools participated in a regular exercise program. 105 comparable individuals served as controls (CON). BP was measured at rest and during standardized ergometric exercise. Motor testing included jumping, running, and balance skills.

Results

Prior to intervention, both groups were comparable in all measurements. After 2 years, both groups improved in all tests with significant differences between the two groups. Diastolic BP (dBP) was significantly lower in INT when compared with CON at rest and during standardized exercise (62?±?11 vs. 68.8?±?11 mmHg). After 2 years, dBP decreased during exercise in INT when compared with dBP at rest. In contrast, there was an increase in dBP during exercise in CON. INT came off better in balance (195 vs. 139 cm; p?<?0.001), jumping (103.9 vs. 83.7 cm; p?<?0.001), and 6-m running (2.2 vs. 2.62 s; p?<?0.001).

Conclusions

In very young children, 2 years of regular exercise had beneficial effects on BP at rest and BP regulation during exercise and motor skills. Therefore, children should be encouraged to exercise regularly to prevent cardiovascular risk factors such as arterial hypertension and morbidity and mortality in later life.

     

A survey of glenohumeral joint rotational range and non-specific shoulder pain in elite cricketers

ObjectivesTo determine if a glenohumeral joint internal rotation range of motion difference (IRD) and external rotation difference (ERD) exists between dominant and non-dominant shoulders of cricketers as demonstrated in other overhead sports, and, if present, to establish if differences exist between cricketers with and without a history of gradual onset non-specific shoulder pain.DesignAn observational study.SettingNon-clinical, at national cricket indoor training venues.ParticipantsOne hundred and nine elite male and female cricketers (11–35 years), representing 97% of the England and Wales national and West of England regional Under 13 teams, consented. The final number included for data analysis was 133.Main outcome measuresData relating to playing position, cricket exposure, shoulder pain and demographic details collected using a questionnaire. Passive isolated glenohumeral rotation measured in 90° shoulder abduction using an inclinometer.ResultsCricketers who regularly bowl or throw overarm had significantly less internal (−7.9°, p<0.001) and greater external (8.6°, p<0.001) dominant to non-dominant glenohumeral rotation. Wicket-keepers had tendencies for smaller differences that were still statistically significant [mean IRD −5.9° (p<0.001); ERD 5.0° (p=0.002)]. Cricketers who experienced shoulder pain demonstrated a significantly greater IRD [mean 3.2° (p=0.032)] than those who did not.ConclusionsThe results of this study support measurement of passive glenohumeral joint rotation during musculoskeletal profiling and indicate that a possible link between increased IRD and non-specific shoulder pain warrants further investigation.     

Tissue flossing on ankle range of motion,jump and sprint performance: A follow-up study

ObjectivesPrevious results from our laboratory suggest that band flossing results in increased ankle range of motion (ROM) and jump performance 5-min following application. However, the time-course of such benefits is yet to be examined.DesignParallel group design.SettingUniversity laboratory.Participants69 recreational athletes (32 male/37 female).Main outcome measuresParticipants performed a weight-bearing lunge test (WBLT), a counter-movement jump (CMJ) and a 15 m sprint test (SPRINT) pre and up to 45-min post application of a floss band to both ankles (FLOSS) or without flossing of the ankle joints (CON).ResultsThere was a significant intervention × time interaction in favour of FLOSS when compared to CON for the WBLT (p < 0.05). These results were associated with trivial to small effect sizes at all time points. Small, but non-significant (p > 0.05) benefits were seen for FLOSS when compared to CON for CMJ force (mean ± 90%CI: 89 ± 101 N) and 15 m SPRINT times (−0.06 ± 0.04 s) at 45-min post.ConclusionThere is a trend towards a benefit for the use of floss bands applied to the ankle joint to improve ROM, jump and sprint performance in recreational athletes for up to 45-min following their application.     

The effect of estimation and production procedures on running economy in recreational athletes

ObjectivesRunning economy is an important component in any endurance event. However, the influence of effort perception on running economy has yet to be examined.DesignThe purpose of this study was to assess the oxygen cost of running (running economy) at identical ratings of perceived exertion (RPE) during estimation (EST) and production (PR) procedures, during treadmill exercise.MethodsFourteen, well-trained male participants actively produced (self-regulated) a range of submaximal exercise intensities equating to RPE values 9, 11, 13, 15 and 17, and passively estimated their perception of exertion during an incremental graded-exercise test (GXT). Allometric scaling was used to ensure an appropriate comparison in running economy between conditions.ResultsThe present study demonstrated that the overall running economy between conditions was statistically similar (p > 0.05). A significant interaction was however identified between Conditions and RPE (p < 0.001). The interaction revealed that running economy significantly improved during PR but remained fairly consistent during EST between moderate and high perceptions of exertion (RPE 11–17). Despite similarities in running economy between conditions, physiological (oxygen uptake, heart rate, minute ventilation and blood lactate) and physical (running velocity) markers of exercise intensity were significantly higher during EST for equivalent perceptions of exertion (all p < 0.05).ConclusionsPassive estimation procedures may improve running economy and enhance athletic performance when compared to identical perceptions of exertion elicited during active production procedures. Athletes, coaches and physical trainers should consider the perceptual procedures utilised during training to ensure that an athlete trains at the most effective training intensity.     

Does exertional heat stress impact gastrointestinal function and symptoms?

ObjectivesExertional-heat stress generates a thermoregulatory strain that exacerbates splanchnic hypoperfusion and sympathetic drive, but the effects on gastrointestinal function are poorly defined. The study aimed to determine the effects of exertional-heat stress on gastric myoelectrical activity, orocecal transit time (OCTT), and gastrointestinal symptoms (GIS).DesignRandomised cross-over study.MethodsEndurance runners (n = 16) completed 2 h of running at 60 % V?O_2max in 35 °C (HOT) and 22 °C (TEMP) ambient conditions. Surface electrogastrography (cEGG) was recorded pre- and post-exercise to determine gastric myoelectrical activity, a lactulose challenge was used to determine OCTT, and GIS were recorded using a modified visual analogue scale tool.ResultsPost-exercise T_re [HOT:38.8(38.5 to 39.0)°C and TEMP:38.1(37.8 to 38.4)°C] and Δ T_re [HOT:2.2(2.0 to 2.4)°C and TEMP:1.5(1.2 to 1.8)°C] was higher on HOT compared to TEMP (p < 0.001). Normal gastric myoelectrical cycle frequency reduced (p = 0.010) on HOT [? 11.7(? 20.8 to ? 2.6)%], but this decrease did not differ (p = 0.058) from TEMP [? 2.7(? 8.3 to 3.0)%]. Bradygastria increased post-exercise on both trials (HOT:11.3(2.3 to 20.4)%, p = 0.030; and TEMP:7.4(2.1 to 12.6)%, p = 0.009). OCTT did not differ between trials (p = 0.864) with transit response classified as very slow on both HOT (99(68 to 131)min) and TEMP (98(74 to 121)min). GIS incidence was higher on HOT (88 %) compared to TEMP (81 %), in accordance with greater total-GIS and upper-GIS severity (p = 0.005 and p = 0.033, respectively).ConclusionsRunning for 2 h at 60 % V?O_2max in either hot or temperate ambient conditions instigates perturbations in myoelectrical activity and OCTT, with GIS incidence and severity greater in hot conditions.     

Simulated games activity vs continuous running exercise: A novel comparison of the glycemic and metabolic responses in T1DM patients

To compare the glycemic and metabolic responses to simulated intermittent games activity and continuous running exercise in type 1 diabetes. Nine patients (seven male, two female; 35 ± 4 years; HbA1c 8.1 ± 0.2%/65 ± 2 mmol/mol) treated on a basal‐bolus regimen completed two main trials, a continuous treadmill run (CON) or an intermittent running protocol (INT). Patients arrived to the laboratory fasted at ～ 08:00 h, replicating their usual pre‐exercise meal and administering a 50% reduced dose of rapid‐acting insulin before exercising. Blood glucose (BG), K⁺, Na⁺⁺, pH, triglycerides, serum cortisol and NEFA were measured at baseline and for 60 min post‐exercise. Interstitial glucose was measured for a further 23 h under free‐living conditions. Following exercise, BG declined under both conditions but was less under INT (INT ?1.1 ± 1.4 vs CON ?5.3 ± 0.4 mmol/L, P = 0.037), meaning more patients experienced hypoglycemia (BG ≤ 3.5 mmol/L; CON n = 3 vs INT n = 2) but less hyperglycemia (BG ≥ 10.9 mmol/L; CON n = 0 vs INT n = 6) under CON. Blood lactate was significantly greater, and pH lower, with a temporal delay in K⁺ under INT (P < 0.05). No conditional differences were observed in other measures during this time, or in interstitial glucose concentrations during the remaining 23 h after exercise. Simulated games activity carries a lower risk of early, but not late‐onset hypoglycemia than continuous running exercise in type 1 diabetes.     

Time of the day of exercise impact on cardiovascular disease risk factors in adults: a systematic review and meta-analysis

ObjectivesTo compare the effect of a single bout of morning vs. evening exercise on cardiovascular risk factors in adults.DesignSystematic review and meta-analysis.MethodsA systematic search of studies was conducted using PubMed and Web of Science from inception to June 2022. Selected studies accomplished the following criteria: crossover design, acute effect of exercise, blood pressure, blood glucose, and/or blood lipids as the study's endpoint, a washout period of at least 24 h, and adults. Meta-analysis was performed by analyzing: 1) separated effect of morning and evening exercise (pre vs. post); and 2) comparison between morning and evening exercise.ResultsA total of 11 studies were included for systolic and diastolic blood pressure and 10 studies for blood glucose. Meta-analysis revealed no significant difference between morning vs. evening exercise for systolic blood pressure (g ∆ = 0.02), diastolic blood pressure (g ∆ = 0.01), or blood glucose (g ∆ = 0.15). Analysis of moderator variables (age, BMI, sex, health status, intensity and duration of exercise, and hour within the morning or evening) showed no significant morning vs. evening effect.ConclusionsOverall, we found no influence of the time of the day on the acute effect of exercise on blood pressure neither on blood glucose.     

SISMES VI NATIONAL CONGRESS

This study examines the effects of Ramadan fasting on various psycho-physiological measures during submaximal exercise, under real-world ecologically valid conditions. Eleven Muslim men performed a 30-min continuous running on a treadmill at intensity 65 % VO_2max in the Ramadan fasted (RAM) and non-fasted (or Control, CON) state, on two separate occasions in a crossover and counter-balanced order. The amount of calories and fluid volume intake of participants’ last pre-exercise main meal, i.e., ~3–4 h prior to CON and ~10–12 h prior to RAM trial, were standardized. To simulate real world scenario, their 24 h pre-trial sleep hours and pattern were typical of the Ramadan and non-Ramadan period. There was no significant difference in total training load for the week prior to the RAM and CON exercise trials. Results showed no differences between RAM and CON trial for both carbohydrate and fat oxidation rate (both p > 0.05; effects size (d) = small and trivial, respectively). Blood glucose in RAM trial was lower at pre-exercise and higher at post-exercise than CON trial (both p < 0.05; d = moderate). Daytime sleepiness and moods state showed no differences between conditions (all p > 0.05; d = trivial). Heart rate throughout run (p = 0.03) and ratings of perceived exertion (p = 0.03, d = small) were higher in RAM. In conclusion, Ramadan fasting has no major impact on substrate utilization and is not an effective ‘fat-burning’ enhancing activity to lose fat mass. Running in the Ramadan fasted state led to a greater psycho-physiological stress compared to the same run in the non-fasted state.     

An integrative test of agility,speed and skill in soccer: Effects of exercise

ObjectivesThe aim of this study was to evaluate the effect of 45 min of soccer-specific exercise in the reactive motor skills test (RMST); a novel test which measures sprint, passing and reactive agility (RAT) performance.DesignA repeated-measures design was used to collect performance data.MethodsForty-two high-level amateur male soccer players (age 18.5 ± 3.5 years) were recruited. Participants were familiarised with the RMST prior to initial testing. Participants undertook 10 repetitions of the RMST before and after 45 min of soccer-specific exercise using the Loughborough Intermittent Shuttle Test. Eighteen of these participants repeated the RMST for test re-test reliability determination. Paired t-tests and effect size statistics were used to determine the effect of 45 min of intermittent exercise on RMST performance. Reliability was assessed using the standard error of measurement.ResultsThe exercise protocol resulted in moderate decreases of sprint (3.0 ± 0.9%, mean ± SD; 1.030 ± 0.09 ES ± 90% Confidence Intervals; p < 0.00001) and RAT performance (1.5 ± 1.1%; 1.015 ± 0.011; p < 0.05), but improved passing task time (?2.7 ± 1.2%; 0.973 ± 0.012; p < 0.001) and passing accuracy (3.6 ± 3.3%; 1.036 ± 0.33). Change in total test time was trivial. The test-retest coefficient of variation for the test was 2.4 ± 0.8%.ConclusionsSoccer-specific exercise decreased sprint and reactive agility performance but improved technical skill performance on a novel, integrative and reliable test of soccer skill performance. Overall RMST performance time was largely unchanged.     

Acute effect of engineered thermoplastic polyurethane elastomer knockoff running footwear on foot loading and comfort during heel-to-toe running

BackgroundBetter midsole materials and comfort have been incorporated into more expensive shoes and are popular with runners. Consequently, knockoff running shoes are currently widely distributed in the Chinese market and and cost only 30%–50% of the total price of genuine branded products.Research questionUncertainty exists concerning the beneficial effects of advanced shoe material application in decreasing foot loading or impact force during running. Additionally, using comfort as a criterion to identify genuine branded running shoes may exclude brand factor.MethodsFifteen healthy male volunteers were asked to perform two different tests, including running and a comfort evaluation. Each participant was asked to identify which footwear was the Adidas brand shoe based on their perception of comfort.ResultsTime to the first peak of the vertical ground reaction force occurred significantly later when subjects wore the genuine branded shoe compared to knockoff shoe 1 (p = 0.003) and knockoff shoe 2 (p = 0.015) footwea. The genuine branded shoe (p = 0.005) and knockoff shoe 1 (p = 0.029) were significantly more comfortable compared to the knockoff shoe 2. Only four subjects selected the genuine branded shoe, whereas six subjects selected both the genuine branded shoe and knockoff shoe 1.SignificanceKnockoff running footwear significantly increases impact loading compared to the genuine branded product, thereby posing greater risk of running injury.