Flat versus simulated mountain trail running: a multidisciplinary comparison in well-trained runners

1This paper compares cardiopulmonary and neuromuscular parameters across three running aerobic speeds in two conditions that differed from a treadmill's movement: flat condition (FC) and unpredictable roll variations similar to mountain trail running (URV). Twenty well-trained male runners (age 33 ± 8 years, body mass 70.3 ± 6.4 kg, height 1.77 ± 0.06 m, V˙O2max 63.8 ± 7.2 mL·kg-1·min-1) voluntarily participated in the study. Laboratory sessions consisted of a cardiopulmonary incremental ramp test (IRT) and two experimental protocols. Cardiopulmonary parameters, plasma lactate (BLa-), cadence, ground contact time (GT) and RPE values were assessed. We also recorded surface electromyographic (sEMG) signals from eight lower limb muscles, and we calculated, from the sEMG envelope, the amplitude and width of peak muscle activation for each step. Cardiopulmonary parameters were not significantly different between conditions (V˙O2: p = 0.104; BLa-: p = 0.214; HR: p = 0.788). The amplitude (p = 0.271) and width (p = 0.057) of sEMG activation peaks did not change between conditions. The variability of sEMG was significantly affected by conditions; indeed, the coefficient of variation in peak amplitude (p = 0.003) and peak width (p < 0.001) was higher in URV than in FC. Since the specific physical demands of running can differ between surfaces, coaches should resort to the use of non-traditional surfaces, emphasizing specific surface-related motor tasks that are normally observed in natural running environments. Seeing that the variability of muscle activations was affected, further studies are required to better understand the physiological effects induced by systematic surface-specific training and to define how variable-surface activities help injury prevention

Effects of Different Training Intensity Distribution in Recreational Runners

Purpose: To compare the impact of two different training intensity distributions in terms of conditional and performance parameters and spent time to training in recreational athletes. Methods: Two different training intensity distribution model were performed for 8 weeks by 38 recreational runners. Runners recruited were randomly assigned to 2 different training models based on HR intensity detected with maximal test. The percentage distribution splitted in zone 1, 2 and 3 were by 77/3/20 and 40/50/10 in polarized endurance training group (PET) and focused endurance training (FOC) group respectively. Programs were balanced for total training impulse (TRIMP). To evaluate effects of training, before and after treatment were performed a maximal exercise test to determine Maximal Oxygen Uptake (V'O2max), Ventilatory Threshold (VT), respiratory-compensation point (RCT) Running Economy (RE) and 2 Km performance. To investigate the effects of training on muscular performance were performed one repetition maximum (1RM), squat jump (SJ) and counter movement jump (CMJ). Results: Both groups significantly improved their velocity at V'O2max (3.2% and 4.0%), at VT (4.0% and 3.2%), RCT (5.7% and 3.4%), the average velocity in 2 Km performance (3.5% and 3.0%) and RE (-5.3% and -8.7%) for PET and FOC respectively for each variable. No differences were found between the groups on any parameter investigated except about the total training time (PET = 29.8 3.1h and FOC = 24.8 2.0 h). Conclusion: Focused Endurance Training obtains similar improvements than Polarized Endurance Training saving 17% of training time in recreational runners

"Running with cancer": A qualitative study to evaluate barriers and motivations in running for female oncological patients

Nowadays, it is widely acknowledged that low physical activity levels are associated with an increase in terms of both disease recurrence and mortality in cancer survivors. In this light, deciphering those factors able to hamper or facilitate an active lifestyle is crucial in order to increase patients' adherence to physical activity. The purpose of this study was to explore barriers and motivations in a sample of female oncological patients, practising running using the ecological model and compare them with healthy controls. Focus group interviews were conducted at Verona University. Participants were 12 female cancer survivors and 7 matched healthy controls who had participated at "Run for Science" project. The interviews were transcribed verbatim and analyzed using content analysis. Transcripts were categorized according to the ecological model, identifying barriers and motivations as themes. About motivations, three sub-themes were included: personal, interpersonal and environmental/organizational factors. Regarding barriers, another sub-theme was recognized: community/policy factors. Compared to healthy controls, survivors expressed motivations and barriers specifically related to their oncological disease. Running was a challenge with their cancer and a hope to give to other patients. Main barriers were represented by treatment-related side effects, inexperienced trainers and external factors, e.g. delivery of incorrect information. Running programs dedicated to oncological patients should consider intrinsic obstacles, related to cancer and its treatment. The interventions should offer a personalized program performed by qualified trainers, together with a motivational approach able to improve participants' adherence to an active lifestyle

Reliability of point-of-care shoulder ultrasound measurements for subacromial impingement in asymptomatic participants

BackgroundRehabilitation is the key to management of patients with subacromial impingement syndrome to prevent disability and loss of function. While point-of-care musculoskeletal ultrasound aids clinical diagnosis of subacromial impingement syndrome, many patients do not demonstrate the classic findings of dynamic supraspinatus tendon impingement beneath the acromion on ultrasound. The objective of this study was to establish the most reliable shoulder ultrasound measurements for subacromial impingement, by evaluating the intra-rater and inter-rater reliability of measurements in asymptomatic participants.MethodsEighteen participants (9 women, 9 men, mean ± standard deviation: 34.6 ± 7.9 years of age) underwent bilateral shoulder ultrasound evaluations with measurements for subacromial impingement (acromiohumeral distance, acromion-greater tuberosity distance, supraspinatus tendon, subacromial-subdeltoid bursa, and subacromial-subdeltoid bursal fluid thickness) performed by two sports medicine physicians. Intra-class coefficients were calculated to determine the intra- and inter-rater reliability of shoulder ultrasound images and measurements.ResultsIntra-rater reliability for acromiohumeral distance (0.76–0.79), supraspinatus tendon (0.91–0.95), subacromial-subdeltoid bursa (0.76–0.84), and subacromial-subdeltoid bursal fluid thickness (0.75–0.81) was found to be good to excellent, whereas inter-rater reliability ranged from poor to moderate.ConclusionsAcromiohumeral distance in neutral position and short axis ultrasound measurements of supraspinatus tendon, subacromial-subdeltoid bursa, and subacromial-subdeltoid bursal fluid thickness in the modified Crass position were the most reliable for subacromial impingement in asymptomatic participants. We recommend validation of these measurements in a symptomatic population to aid diagnosis and direct rehabilitation of patients with suspected subacromial impingement, and to increase point-of-care ultrasound uptake, availability, and training among rehabilitation professionals across health systems

Prolonged visual reaction time after strenuous endurance exercise: higher increment in male compared to female recreational runners

Purpose: This project aimed to evaluate the simple visual reaction time (SVRT) changes in runners of both sexes before and after a 21.1 km run. Methods: 20 male (age 35.3 ± 17.1 years, BMI 23.5 ± 3.3 kg/m2) and 20 female (age 32.2 ± 14.3 years, BMI 24.8 ± 4.2 kg/m2) amateur runners were evaluated 30 min before and after a half-marathon run under competing conditions. Subjects were asked to push an electronic switch at the lighting of a lamp for 11 trials randomly divided to one another between 1 and 10 s. Effort-perception data were collected through a Borg CR100 scale and SVRT data using an electronic chronometric device. A two-way RM ANOVA assessed the effects of exercise and biological sex on SVRT. Results: Borg effort data were similar (M: 82.4 ± 3.9 vs W: 84.7 ± 4.9 AU, p = 0.68). SVRT was lower in men than women before (M: 234.05 ± 3.33 vs F: 239.47 ± 6.1 ms, p < 0.05) but not after the race (M: 249.9 ± 7.18 vs F: 252.09 ± 16.93 ms, p = 0.7). Exercise lengthened the SVRT (M: + 7%; F: + 5%; p < 0.05). Response accuracy was greater in men both before and after exercise. Conclusion: Previous studies suggested exercise lengthened SVRT due to an exercise intensity-related reduced post-exercise cerebral oxygenation that decreases cognitive processes efficiency. In our results, this reduction seemed higher in men. The sex-related response accuracy might be due to different estrogen effects in brain areas implicated in information processing, motor performance, and attention and to different processing and attention focus strategies between the sexes or anticipatory strategies in females. © 2019, Springer-Verlag Italia S.r.l., part of Springer Nature

Estimating the best performance in RunForScience half marathon by laboratory and field evaluations

To evaluate the predictor capacity of 2 and 10 km maximal field test, in order to estimate the half-marathon best performance and its relation with the classical physiological variables related to endurance performance (V0O2max, aerobic and anaerobic thresholds) obtained in a cardiopulmonary laboratory test (CPET)

Attentional bias to emotions after prolonged endurance exercise is modulated by age

Physical exercise has an impact in biasing attention to positive or negative emotional stimuli. While attentional shift to emotions varies with age, evidence is lacking on the effect of prolonged endurance exercise on age-related attentional bias to emotions. This study aims at filling this knowledge gap, by applying a dot-probe task to measure attentional bias to emotions before and after a half-marathon in healthy participants of different ages (age range 21-65 years). State anxiety, positive and negative affect were also assessed. Younger adults showed attentional bias towards anger and away from sadness after the race, supporting the hypothesis of the congruency between the high-arousing task and the associated emotion (anger) in the modulation of attention. Conversely, older adults showed a bias away from anger, likely representing an attempt to maintain an optimal emotional level after the competition. This study sheds new light on how age impacts on emotional mechanisms involved in prolonged endurance exercise and suggests that regulatory processes in response to stress may be involved differently, depending on age

Kinematic and mechanical changes during a long half-marathon race: males and females at uphill/downhill slopes

BACKGROUND: The aim of this study was to compare the running kinematics and the spring mass model mechanics over an entire half-marathon race in male and female athletes on different slopes (- 7%, 0% and +7%). METHODS: 59 recreational runners (39 males and 20 females) participated in this study. Their running steps at own best self-selected speed were video recorded during a half-marathon (i.e. in ecological conditions): the kinematic variables (i.e. running speed, stride length and frequency, contact and flight time) were calculated, as well as the spring-mass characteristics (i.e. leg and vertical stiffness) of their running steps. RESULTS: Males were able to run with greater speeds and lengths compared to females (P < 0.001) but with lower flight times (P < 0.05), and they reached higher values of both leg and vertical stiffness (P < 0.001). During downhill running, step lengths were larger compared to the level and the uphill (+6%) whereas frequencies slightly decreased (-2%), and aerial times were the greatest ones (+17%). During uphill running, contact times were slightly higher compared to other conditions (+3%), and leg stiffness reached the lowest values (-8%). CONCLUSIONS: This study confirmed that there are important alterations in running steps in function of sex and surface slope. Importantly, the response to fatigue (i.e. alterations with the covered distance) does not alter these sex differences and is therefore independent of the sloped conditions

Effects of acute sympathetic activation on the central artery stiffness after strenuous endurance exercise

Purpose Augmented central arterial stiffness (CAS) increases cardiovascular risk. CAS can be augmented by physical exercise and sympathetic activation (SYMP) induced by stressful stimuli. Interestingly, sympathetic vasoconstriction triggered by a sympathetic stimulant is augmented immediately after a strenuous half-marathon compared to at rest. This study assessed whether CAS also augments more post- than pre-half-marathon in response to SYMP. Such assessment takes on relevance considering the growing popularity of strenuous, long-distance endurance exercises.Methods 13 healthy recreational runners (age 46.1 +/- 6.5 years; V'O-2 max 54.23 +/- 9.31 mlO(2)/min/kg) provided the following measurements prior to and within 10 min following a strenuous half-marathon: beat-by-beat aortic pulse wave velocity (aPWV; index of CAS), mean blood pressure, and heart rate assessment. Measures were performed at rest and during a 2 min handgrip-mediated SYMP. The effects of the half-marathon and SYMP were assessed by two-way repeated-measures ANOVA.Results Measurements of the aPWV pre- and post-race were not significantly different (7.5 +/- 0.8 vs 7.8 +/- 0.8 m/s, p = 0.34; pre- vs post-race). 2 min of SYMP increased the baseline aPWV post-race (7.8 +/- 0.8 vs 8.4 +/- 0.8, p= 0.003; rest vs SYMP) but not pre-race (7.5 +/- 0.8 vs 7.9 +/- 0.9, p = 0.21).Conclusion The baseline aPWV assessed 7 to 8 min after a strenuous half-marathon is similar to that pre-race in healthy runners. This agrees with previous studies suggesting CAS being at or below resting values > 5 min following completion of aerobic exercises. The same sympathetic stressor augments CAS to a greater extent 8-10 min post-race than pre-race, suggesting a greater post-exercise stiffening of central artery segments triggered by the same task

Effect of acute sympathetic activation on leg vasodilation before and after endurance exercise

Vascular conductance (VC) regulation involves a continuous balance between metabolic vasodilation and sympathetic vasoconstriction. Endurance exercise challenges the sympathetic control on VC due to attenuated sympathetic receptor responsiveness and persistence of muscle vasodilation, especially in endurance athletes, predisposing them to blood pressure control dysfunctions. This study assessed whether acute handgrip-mediated sympathetic activation (SYMP) restrains sudden leg vasodilation before and after a half-marathon. Prior to, and within the 20 min following the race, 11 well-trained runners underwent two single passive leg movement (SPLM) tests to suddenly induce leg vasodilation, one without and the other during SYMP. Leg blood flow and mean arterial pressure were measured to assess changes in leg VC. Undertaking 60 sec of SYMP reduced the baseline leg VC both before (4.0 ± 1.0 vs. 3.3 ± 0.7 ml/min/mmHg; P=0.01; NO SYMP vs. SYMP, respectively) and after the race (4.6 ± 0.8 vs. 3.9 ± 0.8 ml/min/mmHg; P=0.01). However, SYMP did not reduce leg peak vasodilation immediately after the SPLM either before (11.5 ± 4.0 vs. 12.2 ± 3.8 ml/min/mmHg; P=0.35) or after the race (7.2 ± 2.0 vs. 7.3 ± 2.6 ml/min/mmHg; P=0.96). Furthermore, SYMP did not blunt the mean leg vasodilation over the 60 sec after the SPLM before (5.1 ± 1.7 vs. 5.9 ± 2.5 ml/min/mmHg; P=0.14) or after the race (4.8 ± 1.3 vs. 4.2 ± 1.5 ml/min/mmHg; P=0.26). This data suggest that the release of local vasoactive agents effectively opposes any preceding handgrip-mediated augmented vasoconstriction in endurance athletes before and after a half-marathon. Handgrip-mediated SYMP might improve normal vasoconstriction while athletes are still, but not necessarily while they move, as movements can induce a release of vasoactive molecules