European Journal of Sport Science

Strafford, Ben William; Davids, Keith; North, Jamie Stephen; Stone, Joseph Antony

doi: 10.1080/17461391.2021.1891295pmid: 33583349

Parkour speed-runs require performers (known as Traceurs) to negotiate obstacles with divergent properties such as angles, inclinations, sizes, surfaces, and textures in the quickest way possible. The quicker the run, the higher the performer is ranked. Performance in Parkour speed-runs may be regulated through Parkour Traceurs’ functional movement skill capacities given the physical requirements of the event. This study examined what functional movement skills correlate with Parkour speed-run performance. Nineteen male Parkour Traceurs undertook a physical testing battery inclusive of: agility T-test, maximal grip strength test, and maximal vertical and horizontal jumps across several jump modalities. For the speed-run, Parkour Traceurs navigated an indoor Parkour installation. Pearson’s correlation analyses (r) revealed that agility T-test performance showed a significant positive correlation with Parkour speed-run performance, whereas standing long jump and counter movement jump (with and without arm swing) were significantly negatively correlated with Parkour speed-run performance. Concurrent with the intrinsically-linked building blocks in the Athletic Skills Model, the data from the present study suggest that performance in Parkour-speed-runs are underpinned by functional movement skills (jumping, running; arm swinging) and conditions of movement (agility), all of which encapsulate elements of basic motor properties (speed; strength). From a practical perspective, the agility T-test, standing long jump, and counter movement jump with and without arm swing can form a basic battery to evaluate the physical effects of Parkour speed-run interventions on functional movement skills. Highlights As Parkour speed-runs could be implemented to improve functional movement skills in different domains (indoors, outdoors, collectively as members of a team or individually), it was important to explore what composition of a battery of standardised athletic tests for functional movement skills correlated to Parkour speed-run performance (time to completion). In line with the intrinsically-linked building blocks in the Athletic Skills Model, the data from the present study suggest that performance in Parkour-speed-runs are underpinned by functional movement skills (jumping, running; arm swinging) and condition of movement (agility), all of which encapsulate elements of basic motor properties (speed; strength). Testing batteries examining the effects of Parkour speed-run interventions should include the following: agility T-test, CMJ jumps without arm swing using both feet and the dominant and the non-dominant foot, SLJ, and CMJ jumps with an arm swing component using both feet and the dominant and the non-dominant foot.

Kordi, Mehdi; Galis, Gert; Erp, Teun van; Terra, Wouter

doi: 10.1080/17461391.2021.1891296pmid: 33590804

Elite level cycling events are performed at speeds in excess of 50 km/h. At these speeds, over 90% of the resistance forces come from aerodynamic resistance (CDA). Recently bicycle-mounted pitot tubes, such as the Notio Konect (NK) have become more commercially available making CDA easier to measure. Its reliability and sensitivity would be useful for riders and coaches to be able to understand what constitutes as a change in CDA. Accordingly, the aim of this study was to establish the intra- and inter-effort reliability and sensitivity of the CDA measures of the NK. Seven elite level track riders were used in this study which was broken into two parts: (1) Reliability and (2) Sensitivity. For both parts of the experiment, riders performed identical efforts, riding at ∼50 km/h for six laps of a 250 m indoor velodrome. For reliability, the riders performed six efforts without any changes in position or resistance. For sensitivity, they performed the efforts with a rod with discs of a known diameters attached at each end to vary the CDA by a known amount. For the reliability assessment, low coefficient of variation of intra – (0.47%) and inter-effort (0.9%) reliability were measured. With regards to sensitivity, the smallest changes in resistance (from 5 – 6 cm, i.e. 1.2% or 0.002 m2) was identified by the NK. The data in this experiment suggests that the NK is a highly reliable in measuring CDA can detect changes up to at least 1.2% in an indoor velodrome using elite level track riders. Highlights The Notio Konect showed high levels of inter- and intra-effort reliability. The Notio Konect could detect a change as small as 1.2% in aerodynamic drag. The findings suggest that the Notio Konect is suitable for detecting small changes in aerodynamic drag in a velodrome setting.

Menting, Stein Gerrit Paul; Hanley, Brian; Elferink-Gemser, Marije Titia; Hettinga, Florentina Johanna

doi: 10.1080/17461391.2021.1893828pmid: 33634744

The current study analysed the pacing behaviour of athletes competing in the middle-long track event finals of the IAAF Under 18 and Under 20 World Championships between 2015 and 2018. Official finishing times, 1000-m split times and positioning data of 116 female and 153 male athletes, competing in the middle-long distance running (3000 m, 5000 m and 10,000 m) and race walking (5000 m and 10,000 m) events, were gathered. Repeated measures analysis of variance, with 1000-m speed as within-subjects factor and final ranking (medallist, Top 8 or Top 12, rest of the field) as between-subjects factor, was performed to compare the pacing behaviour between athletes. Positioning of the athletes was analysed by Kendall tau-b (Tb) correlation between the intermediate position and final position. Overall, medallists increased their speed throughout a race, with the exception of the 5000 m running event, in which a parabolic pacing behaviour was exhibited. The 1000-m segment in which a significant (P > 0.05) difference in speed was exhibited between differently ranked athletes coincided with a strong (Tb  > 0.7) correlation between intermediate and final positioning. These combined results point towards a separation between the athletes during the race, as the Top 8 or Top 12 and the rest of the field are unable to match the speed of the medallists. The distance, discipline, sex, age category and behaviour of competitors all influence the pacing behaviour of young track athletes during international level competition, emphasising the importance and complexity of developing adequate pacing behaviour in track athletes. Highlights The distribution of effort over an exercise task (i.e. pacing) is an important factor in endurance exercise competition. The pacing behaviour of athletes is determined by many aspects, such as the biomechanical characteristics of the task, the exercise environment and the age of the athlete Sport specific competition data from youth athlete sports events can provide insight into the pacing behaviour of developing athletes. These insights could assist in the optimalisation of the development of pacing behaviour of young athletes in the future. The current study analysed the 1000-m split times and positioning data of athletes competing in the running (3000 m, 5000 m and 10,000) and racewalking (5000 m and 10,000m) finals of the U18 and U20 IAAF world-championship. The difference in final ranking impacted the pacing behaviour of the athletes, with the medallists increasing their speed throughout the race and the other athletes separating from the medallists either early (rest of field) or later in the race (Top 8 or Top 12 athletes).

Okumura, Fumihiro; Yokoyama, Keiko; Yamamoto, Yuji

doi: 10.1080/17461391.2021.1905077pmid: 33739228

This study analyzed the global state of groups formed by cyclists competing in three different points races and considered the behaviour of individual cyclists in those races. We measured the time difference between the front cyclist and the other cyclists when they crossed the centrelines of home and back straights in order to quantify the global configuration of cyclists in terms of their density and features of states, extracted using principal components analysis (PCA). We examined whether the group separation and group density that characterize the cycling race can be extracted by PCA. We interpreted the PCA results to explain the separation and density of the group using the first and second principal components. Then, we defined the state of configuration of the cyclists in each lap in the plane of the first and second principal components. Subsequently, the state transition probabilities were obtained. States 1, 2, 3, and 4 corresponded to the third, second, first, and fourth quadrants, respectively. State 1 represented a state comprising one dense group, state 2 represented one stretched group, state 3 represented a divided group, and state 4 represented an escape group far from a single dense group. Highlights An approach to understand the collective behaviour of cycling points races through principal component analysis was effective for quantifying the configuration of the cyclists. Principal component analysis of the global configuration of the cyclists in the points races revealed the fission-fusion dynamics was characterized by two components. The density of a group and number of groups, and transitions among four states was defined by these two components. State transition probabilities indicate that the group separation states were more frequent in the latter half of the sprint interval, and it was difficult to re-combine the separated groups into one. The riders and coaches need to be aware of the stretching and separation of the group, even if it does not occur immediately before the sprint as the positioning of a cyclist in the group would be important at that time.

Takahashi, Katsuki; Kamibayashi, Kiyotaka; Wakahara, Taku

doi: 10.1080/17461391.2021.1907450pmid: 33749535

Muscle hypertrophy can occur non-uniformly in athletes who repetitively perform particular movements, presumably leading to a unique muscle size distribution along the length. The present study aimed to examine if sprinters have unique size distributions within the gluteus and posterior thigh muscles. Nineteen male sprinters and 20 untrained males participated in the present study. T1-weighted magnetic resonance images of the hips and right thigh were obtained in order to determine whole and regional (proximal, middle, and distal) volumes of the gluteus maximus and individual posterior thigh muscles. The results showed that the volumes of all the examined muscles relative to body mass were significantly larger in sprinters than in untrained males (all P < 0.001, d = 1.40–3.29). Moreover, the magnitude of the difference in relative volume between sprinters and untrained males was different between the regions within the gluteus maximus (P = 0.048, partial η 2 = 0.187), semitendinosus (P = 0.004, partial η 2 = 0.331), and adductor magnus (P = 0.007, partial η 2 = 0.322), but not within the other posterior thigh muscles (P = 0.091–0.555, partial η 2 = 0.025–0.176). The magnitude of the difference in relative volume between the sprinters and untrained males was greatest in the distal regions within the gluteus maximus and semitendinosus, while the proximal region within the adductor magnus. These findings indicate that sprinters have unique size distributions within the gluteus maximus, semitendinosus, and adductor magnus, which may be attributed to their competitive and training activities. Highlights Sprinters showed larger gluteus maximus and individual posterior thigh muscles than untrained males. The magnitude of difference varied within the gluteus maximus, semitendinosus, and adductor magnus. The greatest difference was found in distal regions within the gluteus maximus and semitendinosus, while proximal region within the adductor magnus.

Peng, Hsien-Te; Song, Chen-Yi; Chen, Zong-Rong; Lai, Chien-Ting; Gu, Chin-Yi; Wang, Li-I.

doi: 10.1080/17461391.2021.1915390pmid: 33832386

This study aimed to investigate the effects of the external load of elastic bands attached to the waist and heels to enhance the pre-activation of leg extensor muscles on drop jumps (DJs). Twelve male college athletes volunteered for this study. Eight cameras and two force platforms were used to collect data. Each subject performed DJs with elastic band loads of 0% and 20% body weight (BW) attached to the waist and heels during the airborne and landing phases from 40- and 50-cm drop heights. Repeated measures of two-way analysis of variance were performed with two loads of the elastic bands and two heights of the platform for each dependent biomechanical variable. Jump height, reactive strength index, leg stiffness, hip, knee flexion, and ankle plantarflexion angles at the initial foot contact and ankle dorsiflexion range of motion (ROM) significantly increased with 20% BW loads. The peak ground reaction force of impact, eccentric work, and hip flexion range of motion significantly decreased with 20% BW loads. The use of the elastic bands as accentuated loading during the airborne and landing phases of DJs can induce pre-activation of the joint extensors of the lower extremity to achieve stretch-shortening cycle benefits and performance and reduce the ground impact for the lower extremity. Highlights Attaching elastic bands to the waist and heels enables the following during drop jumps. The joint extensors of the lower extremities act as a counterbalance to the pull from the elastic bands. The performance of the drop jump was improved. The ground impact was reduced.

Bertozzi, Filippo; Porcelli, Simone; Marzorati, Mauro; Pilotto, Andrea M.; Galli, Manuela; Sforza, Chiarella; Zago, Matteo

doi: 10.1080/17461391.2021.1930190pmid: 33980124

Success in sprint kayaking depends on the propulsive power generated by trunk, pelvis, shoulder and lower limb movements. However, no studies have examined whole-body kinematics over a simulated distance. We aimed to study the changes in movement patterns of kayakers performing a 500-m kayak sprint. Eleven young K1 sprint kayakers (three females; age: 16.5 ± 1.9 years, height: 174.1 ± 7.1 cm and weight: 66.1 ± 6.2 kg) performed an incremental test on a kayak ergometer to assess their Peak Oxygen Uptake (V̇O2peak). They then performed a 500-m sprint trial on the same ergometer, and the positions of 40 reflective markers were recorded to assess whole-body kinematics. Joint angles over time were computed for the trunk and right shoulder, hip, knee, and ankle. Changes of joint kinematics during the test were assessed with Statistical Parametric Mapping, calculating at each time node the linear regression between joint angles waveforms and the time of the rowing cycle, p < .05. Cardiometabolic responses confirmed that the participants achieved a maximal effort (V̇O2 and HR reached 99 ± 11% and 94 ± 6% of peak values, respectively). Paddle velocity negatively correlated with sprint time. The shoulder (elevation, rotation and flexion), trunk (lateral flexion and rotation) and hip (abduction) angles significantly changed over time in different phases of the stroke cycle during the simulated sprint. No significant differences over time were found for knee and ankle flexion. A high-intensity sprint may affect the shoulder, trunk and hip kinematics of kayak paddling. The kinematic analysis of kayakers’ paddling during simulated metabolic-demanding tasks can provide useful insights to coaches and athletes.

Naharudin, Mohamed Nashrudin; Yusof, Ashril

doi: 10.1080/17461391.2020.1869836pmid: 33357008

An energy-deficit (ED) diet increases lipid mobilisation, while endurance exercise improves lipid profile by promoting formation of high-density lipoproteins (HDLs) among moderately active population. However, it is not clear whether ED with high-intensity exercise training can improve lipid profiles. Therefore, 20 recreationally active males (20.3 ± 2.7 years old with peak oxygen consumption ( O2peak) of 2.8 ± 0.2 L min−1) with HDL concentration of 1.44 ± 0.32 mmol L−1, were evenly allocated to either an ED group (1590 ± 79 kcal day−1: 40% of total caloric omitted at lunchtime) or a control (CON) group (2570 ± 139 kcal day−1). Participants in both groups performed high-intensity cycling at 90% O2peak at a constant workload for 8 min, 2 h after breakfast on day D0, D2, D4, D6, D8 and D10 (Dn is day number), after which blood samples were collected. In ED, compared to D0, triglycerides (TG) decreased on D6-10 (p < .01) while total low-density lipoprotein (LDL), total cholesterol (TC) increased on D2-10, while HDL progressively increased on D6-10 (p = .01) with a final value of 1.67 ± 0.24 mmol L−1. In CON, there were no changes in TG, TC and HDL while LDL was reduced on D8-10 (p = .01). Moreover, the proportions of TC/HDL and LDL/HDL increased in ED on D2-10 and D2-8 (p = .05), respectively, while LDL/HDL in CON was reduced on D8-10 (p = .01). In brief, 10 days of ED and a series of high-intensity exercise sessions show progressive elevation of HDL which suggest longer period is required to observe changes in lipid ratios.

Plaza-Florido, Abel; Amaro-Gahete, Francisco J.; Acosta, Francisco M.; Sacha, Jerzy; Alcantara, Juan M.A.

doi: 10.1080/17461391.2021.1892198pmid: 33591861

This study aimed to examine the association of heart rate (HR) and heart rate variability (HRV) with cardiorespiratory fitness (CRF) in adults. This cross-sectional study included 204 participants: 132 young adults (67% women; 22.3 ± 2.3 years) and 72 middle-aged adults (53% women; 53.2 ± 5 years). HR and HRV were measured using a Polar RS800CX heart rate monitor. CRF was assessed using a metabolic cart during an incremental test. HR was negatively associated with CRF relative to body weight (BW) in young adults adjusting for sex, age, and physical activity (β ranged from −0.200 to −0.195; all P ≤ 0.022). These associations disappeared after including fat mass as a covariate (all P ≥ 0.106) while remained significant after adjusting for fat-free mass (FFM; all P ≤ 0.008). Neither HR nor HRV variables were associated with CRF expressed as absolute values or relative to FFM in young and middle-aged adults after adjusting for the abovementioned covariates (all P ≥ 0.074). Our results suggest that HR rather than HRV is better associated with CRF relative to BW in young adults. However, this association seems to be explained by the inclusion of fat mass in the calculation of CRF relative to BW. Highlights Heart rate and heart rate variability variables have been associated with cardiorespiratory fitness. Our present results, and previous literature, suggest that the “simple” measurement of the heart rate could be easier to obtain and interpret than the heart rate variability variables. The heart rate variable rather than the heart rate variability variables is better associated with cardiorespiratory fitness relative to body weight in healthy young adults.

Martins-Costa, Hugo C.; Lanza, Marcel B.; Diniz, Rodrigo C. R.; Lacerda, Lucas T.; Gomes, Mateus C.; Lima, Fernando V.; Chagas, Mauro H.

doi: 10.1080/17461391.2021.1910346pmid: 33779514

This study investigated the impact of performing two equalized resistance training (RT) protocols for 10 weeks that differ only by repetition duration and number in the force-position and EMG-position relationship. Participants performed an equalized (36 s of time under tension; 3–4 sets; 3 min between sets; 50–55% of one-repetition maximum; 3× week) RT intervention on the bench press and the only different change between protocols was repetition number (RN; 12 vs.6) or duration (RD; 3 s vs. 6 s). Two experimental groups (RN12RD3, n = 12; and RN6RD6, n = 12) performed the RT, while one group was the control (Control, n = 11). Maximal isometric contractions at 10%, 50% and 90% of total bench press range of motion were performed pre- and post-RT, while electromyography was recorded. It demonstrated an increase in isometric force (+14% to 24%, P < 0.001) shifting up the force-position relationship of the training groups after RT, although no difference was between training groups compared to the Control. Neuromuscular activation from pectoralis major presented an increase after training for both RT groups (+44%; P < 0.001) compared to the Control. However, although not significantly different, triceps brachii also presented an increase depending on the protocol (+25%). In conclusion, 10 weeks of an equalized RT with longer RN and shorter RD (or opposite) similarly increases the ability to produce maximal isometric force during the bench exercise across different angles, while neuromuscular activation of the pectoralis major partially explained the shift-up of the force-position relationship after training.