11 research outputs found
Acute effects of a 60‑min time trial on power‑related parameters in trained endurance runners
Background: The advent of power meters for running has raised the interest of athletes and coaches in new ways of
assessing changes in running performance. The aim of this study is to determine the changes in power-related variables
during and after a strenuous endurance running time trial.
Methods: Twenty-one healthy male endurance runners, with a personal record of 37.2 ± 1.2 min in a 10-km race,
completed a 1-h run on a motorized treadmill trying to cover as much distance as they could. Before and after the
time trial the athletes were asked to perform a 3-min run at 12 km h−
1. Normalized mean power output, step frequency,
form power and running effectiveness were calculated using the Stryd™ power meter. Heart rate (HR) and
rating of perceived exertion (RPE) were monitored, and data averaged every 5 min.
Results: Despite high levels of exhaustion were reached during the time trial (HRpeak = 176.5 ± 9.8 bpm;
RPE = 19.2 ± 0.8), the repeated measures ANOVA resulted in no significant differences (p ≥ 0.05), between each
pair of periods for any of the power-related variables. The pairwise comparison (T test) between the non-fatigued
and fatigued constant 3-min runs showed an increase in step frequency (p = 0.012) and a decrease in form power
(p < 0.001) under fatigue conditions, with no meaningful changes in normalized mean power output and running
effectiveness.
Conclusions: Trained athletes are able to maintain power output and running effectiveness during a high demanding
extended run. However, they preferred to reduce the intensity of vertical impacts under fatigue conditions by
increasing their step frequency
Is There a Relationship between the Morphology of Connective Tissue and Reactivity during a Drop Jump? Influence of Sex and Athletic Performance Level
The influence of the morphologic characteristics of connective tissue, which plays an
essential role during sports activities, on sporting tasks needs further research given the controversial
findings reported in the literature. This study aimed at examining the relationship between lower
limb connective tissue morphology and drop jump reactivity and determining the influence of
sex and athletic performance level. A total of 30 men and 14 women, runners, executed 6 drop
jumps (3 20 cm and 30 cm height respectively) and their thickness and cross-sectional area were
recorded for Achilles and patellar tendons and plantar fascia. No significant results were found in the
relationship between the morphology of the connective tissue and reactivity strength index for both
sexes. Significant sex differences were found, while women showed greater values (p < 0.005) for
Achilles tendon and plantar fascia; men showed greater values for reactivity strength index and drop
jump performance (p < 0.001). The present study shows a limited relationship between connective
tissue morphology and drop jump reactivity. Additionally, women showed greater normalized
values for Achilles tendon and plantar fascia, and men showed greater reactivity strength index and
jumping performance values. No relationships between athletic performance level and connective
tissue were found
Effects of a neuromuscular training program on physical performance and asymmetries in female soccer
Introduction: Women’s football require optimal neuromuscular system
development for injury prevention and performance optimization. Standardized
neuromuscular training programs have shown promising results in reducing
injuries and functional asymmetries, but evidence on their impact on
performance is limited.
Methods: This research examined the effects of a 10-week neuromuscular
training program on physical performance and asymmetries in female football
players. Thirty-eight female players from two Spanish Second Division women’s
football teams participated in the study. The physical performance tests used
were: ankle dorsiflexion, bilateral and unilateral horizontal jump, bilateral and
unilateral vertical countermovement jump, 40 m sprint including partial times at
10, 20 and 30 m and the 505 test for change of direction evaluation. For 10 weeks,
players in the experimental group performed three weekly 24-min neuromuscular
training sessions. Participants in the control group completed their normal 24-min
strength and conditioning program.
Results: The main results were that maximal linear velocity and change of
direction skills showed the most notable improvements [effect size (ES), 0.46
to 0.59] after implementation of the training program, ankle dorsiflexion and
jumping skills, also improved although, to a lesser extent (ES, <0.35) while
asymmetries between limbs were reduced. Maximal running speed improved in
the intervention group (p < 0.001) with a mean ES −0.59.
Discussion: We conclude that a 10-week neuromuscular training program can be
a sufficient stimulus to improve football-specific performance variables in highlevel female football players. Therefore, female players and coaches should be
aware that weekly inclusion of strength, power and dynamic balance exercises
following a neuromuscular paradigm is helpful for football-specific performance
improvement
Mechanical Power in Endurance Running: A Scoping Review on Sensors for Power Output Estimation during Running
Mechanical power may act as a key indicator for physiological and mechanical changes
during running. In this scoping review, we examine the current evidences about the use of power
output (PW) during endurance running and the di erent commercially available wearable sensors to
assess PW. The Boolean phrases endurance OR submaximal NOT sprint AND running OR runner
AND power OR power meter, were searched in PubMed, MEDLINE, and SCOPUS. Nineteen studies
were finally selected for analysis. The current evidence about critical power and both power-time and
power-duration relationships in running allow to provide coaches and practitioners a new promising
setting for PW quantification with the use of wearable sensors. Some studies have assessed the
validity and reliability of di erent available wearables for both kinematics parameters and PW when
running but running power meters need further research before a definitive conclusion regarding its
validity and reliability
Relationship between Reactive Strength and Leg Stiffness at Submaximal Velocity: Effects of Age on Distance Runners
Background: Musculotendinous reactive strength is a key factor for the utilization of
elastic energy in sporting activities such as running. AIM: To evaluate the relationship between
musculotendinous reactive strength and lower-limb stiffness during running as well as to identify
age-related differences in both variables. Methods: Fifty-nine amateur endurance runners performed
three 20-cm drop jumps and a constant 3-min easy run on a motorized treadmill. Reactive strength
index and dynamic lower-limb stiffness were calculated with a photoelectric cell system by jumping
and running, respectively. Additionally, sit to stand difference in plantar arch height was assessed as
a static lower-limb stiffness measure. The cluster analysis allows the comparison between younger
and older runners. Results: No significant correlations were found between jumping reactive strength
and running lower-limb stiffness. The younger group performed better at drop jumps (p = 0.023,
ES = 0.82), whereas higher-but-no-significant results were found for reactive strength index and
stiffness-related metrics. Conclusions: Musculotendinous vertical reactiveness may not be transferred
to combined vertical and horizontal movements such as running
Running fatigue assessment with stryd
Analysis of running power-related metrics in amateur long-distance runners over a 60-min near-maximal tes
Estimating Functional Threshold Power in Endurance Running from Shorter Time Trials Using a 6-Axis Inertial Measurement Sensor
Wearable technology has allowed for the real-time assessment of mechanical work employed
in several sporting activities. Through novel power metrics, Functional Threshold Power
have shown a reliable indicator of training intensities. This study aims to determine the relationship
between mean power output (MPO) values obtained during three submaximal running time trials
(i.e., 10 min, 20 min, and 30 min) and the functional threshold power (FTP). Twenty-two recreationally
trained male endurance runners completed four submaximal running time trials of 10, 20, 30, and
60 min, trying to cover the longest possible distance on a motorized treadmill. Absolute MPO (W),
normalized MPO (W/kg) and standard deviation (SD) were calculated for each time trial with a
power meter device attached to the shoelaces. All simplified FTP trials analyzed (i.e., FTP10, FTP20,
and FTP30) showed a significant association with the calculated FTP (p < 0.001) for both MPO and
normalized MPO, whereas stronger correlations were found with longer time trials. Individual
correction factors (ICF% = FTP60/FTPn) of ~90% for FTP10, ~94% for FTP20, and ~96% for FTP30
were obtained. The present study procures important practical applications for coaches and athletes
as it provides a more accurate estimation of FTP in endurance running through less fatiguing,
reproducible tests
Relationship between Connective Tissue Morphology and Lower-Limb Stiffness in Endurance Runners. A Prospective Study
Background: The lower limb behaves like a spring compressing and decompressing
during running, where lower-limb stiffness is one of the most influential factors. This prospective
observational study is aimed at examining the relationship between the connective tissue morphology
and lower-limb stiffness and investigating whether the barefoot/shod condition influences on such
relationship. Methods: 14 male amateur runners (10-km time trial <500
) were included. Data were
recorded over one session, where participants ran 2 trials (i.e., barefoot and shod conditions) of
3 minutes at 12 km/h, where running spatiotemporal parameters and vertical (Kvert) and leg stiffness
(Kleg) were obtained. Prior to testing trials, thickness and cross-sectional area (CSA) were recorded
for Achilles (AT) and patellar tendons (PT) and plantar fascia (PF) with ultrasound. Results: Under
barefoot condition, a positive correlation was found between Kleg and AT-thickness and CSA and
PF-thickness; and between Kvert and AT-thickness and PF thickness. Under shod condition, a
positive correlation was found between Kleg and PT-CSA and PT-thickness, and between Kvert and
PT-CSA and PT-thickness. Conclusions: The results reveal a specificity of the relationship between
the lower-limb stiffness and the morphology of the connective tissue. Greater tendon shows higher
lower-limb stiffness when that tendon is specially demanded by the function
Evaluation of 10-Week Neuromuscular Training Program on Body Composition of Elite Female Soccer Players
(1) Background: This study was conducted to investigate the effects of a 10-week neuromuscular training program (NMT) on the sum of six skinfolds (Σ6S) and body composition variables in elite female soccer players. (2) Methods: Forty-four Spanish elite female soccer players (age: 24.0 ± 4.2 years; height: 164.3 ± 5.5 cm; body mass: 60.4 ± 5.5 kg; body mass index (BMI): 22.4 ± 2.2 kg/m2) were randomly assigned to a control group (CG) or to an experimental group (EG). Participants in the EG completed a specific NMT program of 24 min, three times per week, which included exercises from six different categories (mobility, dynamic stability, anterior chain strength, lumbopelvic control, posterior chain strength, and change of direction). The CG followed their normal strength and conditioning program. Pre- and post-intervention assessments included anthropometric measurements (weight, height, limb circumferences, and bone breadths), and subsequently, body composition factors BMI, Σ6S, body mass, muscle mass, and lean body mass were calculated. Nutrition was standardized by a nutritionist and also load monitored. (3) Results: A two-way mixed analysis of variance (group × time) revealed that there was a significant (p ≤ 0.001) group × time interaction between body mass, fat mass, and Σ6S in favor of NMT. A significant interaction was also observed for body skeletal muscle mass and lean body mass favoring NMT. (4) Conclusions: The application of an NMT program seems to be a useful strategy to improve body composition in elite female soccer players