The Unsuitability of Energy Expenditure Derived From Microtechnology for Assessing Internal Load in Collision-Based Activities

2017 ◽  
Vol 12 (2) ◽  
pp. 264-267 ◽  
Author(s):  
Jamie Highton ◽  
Thomas Mullen ◽  
Jonathan Norris ◽  
Chelsea Oxendale ◽  
Craig Twist

This aim of this study was to examine the validity of energy expenditure derived from microtechnology when measured during a repeated-effort rugby protocol. Sixteen male rugby players completed a repeated-effort protocol comprising 3 sets of 6 collisions during which movement activity and energy expenditure (EEGPS) were measured using microtechnology. In addition, energy expenditure was estimated from open-circuit spirometry (EEVO2). While related (r = .63, 90%CI .08–.89), there was a systematic underestimation of energy expenditure during the protocol (–5.94 ± 0.67 kcal/min) for EEGPS (7.2 ± 1.0 kcal/min) compared with EEVO2 (13.2 ± 2.3 kcal/min). High-speed-running distance (r = .50, 95%CI –.66 to .84) was related to EEVO2, while PlayerLoad was not (r = .37, 95%CI –.81 to .68). While metabolic power might provide a different measure of external load than other typically used microtechnology metrics (eg, high-speed running, PlayerLoad), it underestimates energy expenditure during intermittent team sports that involve collisions.

2020 ◽  
Vol 45 ◽  
pp. 36-45
Author(s):  
Eser Çalı ◽  
Utku Alemdaroğlu

The aim of the present study was to examine the relationships between internal training loads (TL) (Banister, Edwards Training-Impulse (TRIMP), session RPE (s-RPE)) and external TL (Total distance (TD), high speed distance (HSD), high metabolic distance (HMD) in amateur soccer players. Nine male amateur soccer players (age = 28.74±5.2 years; height 173.74± 8.04 cm; weight 72.73±5.5 kg) voluntarily participated in the study. Individual field-based training sessions were monitored over 8 weeks. The results showed that there were moderate and very large correlations between s-RPE and both Edwards and Banister’s TRIMP (respectively, r = 0.42-0.86; r= 0.45-0.85). Additionally, from large to nearly perfect correlations were observed between the HR-based methods (r= 0.58-0.98). We also found moderate to very large correlations between s-RPE and HMD and large to nearly perfect correlations between HR-based TL methods and HMD. Correlations between internal load and external load parameters was weaker in HSD than TD. In the light of the results of the current study, internal and external loads should not be used interchangeable and HMD seems to be appropriate to monitor TL in soccer players because its equations include both speed and acceleration values.


2016 ◽  
Vol 11 (6) ◽  
pp. 853-858 ◽  
Author(s):  
Shane Malone ◽  
Kieran D Collins ◽  
Dominic A Doran

The current study examined the extent to which pitch dimensions can influence the physical and estimated energetic demands of hurling small-sided games. Training data ( n = 990) were collected from 24 (age 25.5 ± 3.2 years; height 178.9 ± 3.2 cm; body mass 78.5 ± 4.5 kg) hurling players using 4-Hz global positioning system technology (VX Sport, Lower Hutt, New Zealand). Total distance (m), high-speed running distance (m; ≥ 17 km/h), very high-speed running distance (m; ≥ 22 km/h), total accelerations ( n), acceleration distance (m), peak and mean velocity (km/h) were considered. In addition changes in velocity were analysed by assessing the acceleration actions during SSG. This allowed for the assessment of estimated energy expenditure (kJ/kg) and the equivalent distance covered a different metabolic power thresholds. The main findings show that traditional speed-based data increased as pitch dimensions were increased ( p = 0.002; d = 4.53 ± 0.46; very large). Furthermore, as relative player area increased there was an increase in estimated energy expenditure ( p = 0.004; d = 2. 16 ± 0.20; very large) and average metabolic power metrics ( p = 0.002; d = 1.13 ± 0.46; moderate). Distances covered at metabolic power categories (TP) increased with small-sided games pitch dimension ( p = 0.002; d = 0.3 ± 0.06; small). The study enables coaches to better understand the physical demands imposed on players during specific hurling small-sided games pitch dimensions, and highlights that traditional speed-based data underestimate the running demands of small-sided games.


Author(s):  
David García-Santos ◽  
José Pino-Ortega ◽  
Javier García-Rubio ◽  
Alejandro Vaquera ◽  
Sergio J. Ibáñez

(1) Background: The use of advanced technology to study the energy demands of sport participants during actual sport competition is an important current research direction. The purpose of this study was to identify the physiological, internal, and external demands placed on basketball referees using ultra-wideband (UWB) technology, in relation to the period of the game. (2) Methods: The sample was comprised of nine international referees, and the data collection took place during the Women’s EuroBasket Sub-16 championship. Internal and external load were assessed through the inertial device WIMU PROTM, using UWB technology in order to quantify the effort exerted by each referee. The internal load was examined in relation to each individual’s heart rate (HR). The external load included the kinematic variables accelerations (Acc), decelerations (Dec), Acc/min, Dec/min, distance covered, steps, maximum speed (Vmax), average speed (Vavg), and speed zones, as well as the neuromuscular variables impacts (Imp), PlayerLoadTM (PLTM), PLTM/min, Metabolic Power (PMet), and PMet/min. (3) Results: The results exposed that referees work around 62% HRmax and spend more than 80% of the match at intensities between 0–12 km/h. The first period was the period in which the greatest work demand was experienced in relation to these neuromuscular outcomes (11.92 PL; 3.61 Met; 277 Impacts). The results revealed a diminishment of internal and external demands on the referees over the course of the game. (4) Conclusions: The results highlight the importance of monitoring and quantifying the workload of basketball officials, because doing so would allow for the establishment of individualized performance profiles that could be designed with the purpose of benefiting referee performance during games. The use of inertial devices allows for the objective quantification of referee workload under competitive circumstances.


2018 ◽  
Vol 39 (08) ◽  
pp. 581-587 ◽  
Author(s):  
Pietro di Prampero ◽  
Cristian Osgnach

AbstractTeam sports are characterised by frequent episodes of accelerated/decelerated running. The corresponding energy cost can be estimated on the basis of the biomechanical equivalence between accelerated/decelerated running on flat terrain and constant speed running uphill/downhill. This approach allows one to: (i) estimate the time course of the instantaneous metabolic power requirement of any given player and (ii) infer therefrom the overall energy expenditure of any given time window of a soccer drill or match. In the original approach, walking and running were aggregated and energetically considered as running, even if in team sports several walking periods are interspersed among running bouts. However, since the transition speed between walking and running is known for any given incline of the terrain, we describe here an approach to identify walking episodes, thus utilising the corresponding energy cost which is smaller than in running. In addition, the new algorithm also takes into account the energy expenditure against the air resistance, for both walking and running. The new approach yields overall energy expenditure values, for a whole match,≈14% smaller than the original algorithm; moreover, it shows that the energy expenditure against the air resistance is≈2% of the total.


2018 ◽  
Vol 39 (08) ◽  
pp. 588-595 ◽  
Author(s):  
Cristian Osgnach ◽  
Pietro di Prampero

AbstractA previous approach to estimate the time course of instantaneous metabolic power and O2 consumption in team sports has been updated to assess also energy expenditure against air resistance and to identify walking and running separately. Whole match energy expenditure turned out ≈14% smaller than previously obtained, the fraction against the air resistance amounting to ≈2% of the total. Estimated net O2 consumption and overall energy expenditure are fairly close to those measured by means of a portable metabolic cart; the average difference, after a 45 min exercise period of variable intensity and mode, amounting to ≈10%. Aerobic and anaerobic energy yields, metabolic power, energy expenditure and duration of High (HI) and Low (LI) intensity bouts can also be estimated. Indeed, data on 497 soccer players during the 2014/2015 Italian "Serie A" show that the number of HI efforts decreased from the first to the last 15-min periods of the match, without substantial changes in mean metabolic power (≈22 W·kg−1) and duration (≈6.5 s). On the contrary, mean metabolic power of the LI decreased (5.8 to 4.8 W·kg−1), mainly because of a longer duration thereof, thus underscoring the need for longer recovery periods between HI.


2017 ◽  
Vol 20 (10) ◽  
pp. 957-961 ◽  
Author(s):  
Chelsea L. Oxendale ◽  
Jamie Highton ◽  
Craig Twist

2017 ◽  
Vol 12 (s2) ◽  
pp. S2-136-S2-141 ◽  
Author(s):  
Darren J. Burgess

Research describing load-monitoring techniques for team sport is plentiful. Much of this research is conducted retrospectively and typically involves recreational or semielite teams. Load-monitoring research conducted on professional team sports is largely observational. Challenges exist for the practitioner in implementing peer-reviewed research into the applied setting. These challenges include match scheduling, player adherence, manager/coach buy-in, sport traditions, and staff availability. External-load monitoring often attracts questions surrounding technology reliability and validity, while internal-load monitoring makes some assumptions about player adherence, as well as having some uncertainty around the impact these measures have on player performance This commentary outlines examples of load-monitoring research, discusses the issues associated with the application of this research in an elite team-sport setting, and suggests practical adjustments to the existing research where necessary.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yeram Park ◽  
Deunsol Hwang ◽  
Hun-Young Park ◽  
Jisu Kim ◽  
Kiwon Lim

Aims. Hypoxic exposure improves glucose metabolism. We investigated to validate the hypothesis that carbohydrate (CHO) oxidation could increase in mice exposed to severe hypoxic conditions. Methods. Seven-week-old male ICR mice (n=16) were randomly divided into two groups: the control group (CON) was kept in normoxic condition (fraction of inspired O2=21%) and the hypoxia group (HYP) was exposed to hypoxic condition (fraction of inspired O2=12%, ≈altitude of 4,300 m). The CON group was pair-fed with the HYP group. After 3 weeks of hypoxic exposure, we measured respiratory metabolism (energy expenditure and substrate utilization) at normoxic conditions for 24 hours using an open-circuit calorimetry system. In addition, we investigated changes in carbohydrate mechanism-related protein expression, including hexokinase 2 (HK2), pyruvate dehydrogenase (PDH), pyruvate dehydrogenase kinase 4 (PDK4), and regulator of the genes involved in energy metabolism (peroxisome proliferator-activated receptor gamma coactivator 1-alpha, PGC1α) in soleus muscle. Results. Energy expenditure (EE) and CHO oxidation over 24 hours were higher in the HYP group by approximately 15% and 34% (p<0.001), respectively. Fat oxidation was approximately 29% lower in the HYP group than the CON group (p<0.01). Body weight gains were significantly lower in the HYP group than in the CON group (CON vs. HYP; 1.9±0.9 vs. −0.3±0.9; p<0.001). Hypoxic exposure for 3 weeks significantly reduced body fat by approximately 42% (p<0.001). PDH and PGC1α protein levels were significantly higher in the HYP group (p<0.05). Additionally, HK2 was approximately 21% higher in the HYP group. Conclusions. Hypoxic exposure might significantly enhance CHO oxidation by increasing the expression of PDH and HK2. This investigation can be useful for patients with impaired glucose metabolism, such as those with type 2 diabetes.


Author(s):  
Alice Iannaccone ◽  
Daniele Conte ◽  
Cristina Cortis ◽  
Andrea Fusco

Internal load can be objectively measured by heart rate-based models, such as Edwards’ summated heart rate zones, or subjectively by session rating of perceived exertion. The relationship between internal loads assessed via heart rate-based models and session rating of perceived exertion is usually studied through simple correlations, although the Linear Mixed Model could represent a more appropriate statistical procedure to deal with intrasubject variability. This study aimed to compare conventional correlations and the Linear Mixed Model to assess the relationships between objective and subjective measures of internal load in team sports. Thirteen male youth beach handball players (15.9 ± 0.3 years) were monitored (14 training sessions; 7 official matches). Correlation coefficients were used to correlate the objective and subjective internal load. The Linear Mixed Model was used to model the relationship between objective and subjective measures of internal load data by considering each player individual response as random effect. Random intercepts were used and then random slopes were added. The likelihood-ratio test was used to compare statistical models. The correlation coefficient for the overall relationship between the objective and subjective internal data was very large (r = 0.74; ρ = 0.78). The Linear Mixed Model using both random slopes and random intercepts better explained (p < 0.001) the relationship between internal load measures. Researchers are encouraged to apply the Linear Mixed Models rather than correlation to analyze internal load relationships in team sports since it allows for the consideration of the individuality of players.


Author(s):  
Eñaut Ozaeta ◽  
Javier Yanci ◽  
Carlo Castagna ◽  
Estibaliz Romaratezabala ◽  
Daniel Castillo

The main aim of this paper was to examine the association between prematch well-being status with match internal and external load in field (FR) and assistant (AR) soccer referees. Twenty-three FR and 46 AR participated in this study. The well-being state was assessed using the Hooper Scale and the match external and internal loads were monitored with Stryd Power Meter and heart monitors. While no significant differences were found in Hooper indices between match officials, FR registered higher external loads (p < 0.01; ES: 0.75 to 5.78), spent more time in zone 4 and zone 5, and recorded a greater training impulse (TRIMP) value (p < 0.01; ES: 1.35 to 1.62) than AR. Generally, no associations were found between the well-being variables and external loads for FR and AR. Additionally, no associations were found between the Hooper indices and internal loads for FR and AR. However, several relationships with different magnitudes were found between internal and external match loads, for FR, between power and speed with time spent in zone 2 (p < 0.05; r = −0.43), ground contact time with zone 2 and zone 3 (p < 0.05; r = 0.50 to 0.60) and power, speed, cadence and ground contact time correlated with time spent in zone 5 and TRIMP (p < 0.05 to 0.01; r = 0.42 to 0.64). Additionally, for AR, a relationship between speed and time in zone 1 was found (p < 0.05; r = −0.30; CL = 0.22). These results suggest that initial well-being state is not related to match officials’ performances during match play. In addition, the Stryd Power Meter can be a useful device to calculate the external load on soccer match officials.


Sign in / Sign up

Export Citation Format

Share Document