High-intensity interval training (HIIT) research has drastically increased globally in the last decade. This might be owing to the application of HIIT in various fields such as among cardiovascular ...disease and cancer populations, and its increasing popularity in the media and fitness industries. It is crucial to realize the substantial benefits of HIIT, keeping safety in mind, for these target groups. In this narrative review, HIIT is discussed from multifaceted perspectives. First, I describe the rationale behind the improvement in aerobic and metabolic capacity with HIIT requiring less time compared to moderate-intensity continuous training, as well as the enjoyable and affective factors and the broad applicability of HIIT due to the “relative” high-intensity training. Second, I describe ways to maximize the effects of HIIT, which include optimising a potential genetic factor in HIIT responder, decreasing non-responders by attaining a targeted intensity, and adhering to the exercise intensity and unsupervised long-term participation. Recent development of HIIT/sprint interval training protocols and several unique clinical studies in the world have helped overcome the barriers against high adherence. Finally, safety and potential risks were only discussed briefly due to insufficient available data. In conclusion, to utilise the benefits of HIIT effectively and safely for unfit subjects with lifestyle-related and chronic diseases, optimising HIIT protocols to include high adherence to exercise intensity and long-term participation should be considered.
Young, D, Malone, S, Beato, M, Mourot, L, and Coratella, G. Iidentification of maximal running intensities during elite hurling match-play. J Strength Cond Res 34(9): 2608-2617, 2020-The current ...study aimed to describe the duration-specific running intensities of elite hurling players during competition with respect to position using a rolling average method. Global positioning systems (10-Hz Viper; STATSport, Viper, Newry, Northern Ireland) were used to collect data from 36 elite hurling players across 2 seasons. Players were categorized according to playing positions (full-backs, half-backs, midfielders, half-forwards, and full-forwards). A total of 230 full match samples were obtained from 22 competitive games for analysis. The velocity-time curve was analyzed using a rolling average method, in which the maximum relative total distance (TD; m·min), high-speed running distance (HSR; m·min), and sprint distance (SD; m·min) intensities were calculated across 10 different rolling time durations (1-10 minutes) within each game. There were large to very large (effect sizes ES = 0.66-4.33) differences between 1 minute rolling averages and all other durations for TD, HSR, and SD. However, pairwise comparisons between 6 and 10 minutes for TD, HSR, and SD were smaller and more variable (ES = 0.07, trivial to ES = 0.85, moderate). Half-backs, midfielders, and half-forwards achieved a higher maximal relative TD and HSR in all duration-specific fields when compared with full-backs and full-forwards. No positional difference was observed in 1- and 2-minute durations for SD. Because the rolling average duration increased the maximum TD, HSR and SD running intensities decreased across all positions. These data provide knowledge of the peak running intensities of elite hurling competition and can be used to design training activities to sufficiently prepare players for these "worst-case scenarios."
To optimize the recovery phase between heats in ski-mountaineering sprint competitions, this study investigated whether an active recovery protocol on an ergocycle could improve subsequent ...performance compared with a self-selected recovery strategy.
Thirteen elite ski mountaineers (9 men and 4 women) performed 3 sprints with 2 different recovery conditions (Ergo vs Free) in a randomized order. The Ergo condition involved a 10-minute constant-intensity exercise on an ergocycle performed at 70% of maximum heart rate. For the Free condition, the athlete was asked to self-select modality. At the end of the third sprint, a passive recovery (seated) was prescribed for both protocols. Sprint performance (time) and physiological parameters (lactate concentration La, heart rate HR, and rating of perceived exertion RPE) were recorded from each sprint and recovery phase.
In the Ergo vs Free protocols, sprint times (177 24 s vs 176 23 s; P = .63), recovery average HR (70% 2.9% vs 71% 5.2% of maximal HR), and RPE (16.7 1.5 vs 16.8 1.5; P = .81) were not significantly different. However, La decreased more after Ergo (-2.9 1.8 mmol·L-1) and Free (-2.8 1.8 mmol·L-1) conditions compared with passive recovery (-1.1 1.6 mmol·L-1; P < .05).
The use of an ergocycle between heat sprints in ski mountaineering does not provide additional benefits compared with a recovery strategy freely chosen by the athletes. However, active conditions provide a faster La reduction compared with passive recovery and seem to be a more suitable strategy between multiple-heat sprints.
Calderón Pellegrino, G, Paredes-Hernández, V, Sánchez-Sánchez, J, García-Unanue, J, and Gallardo, L. Effect of the fatigue on the physical performance in different small-sided games in elite football ...players. J Strength Cond Res 34(8): 2338-2346, 2020-Football players need to be able to perform high-intensity efforts of short duration with brief recovery periods. The aim of this study was to analyze the influence of the pitch dimension on high-intensity actions and the effect of a repeated sprint ability (RSA) test on the physical performance in different 4-against-4 (4v4) small-sided games (SSG) dimensions. Sixteen U-18 elite football players performed an RSA test between two 4v4 SSGs (pre and post) to induce fatigue and compare physical data. Speed, sprint number, accelerations, sprint distance, total distance covered, and total distance covered of the players at different intensities were evaluated in 3 different SSGs (125, 150, 250, and 300 m). Results revealed a significant detriment of physical performance in the 125-m SSG after RSA, mostly in number of sprints (-6.56; confidence interval CI 95%: -10.13 to -3.00; effect size ES: 1.13 p < 0.001), accelerations (-2.69; CI 95%: -5.13 to -0.24; ES: 0.68; p = 0.032), and sprint distance (-65.44 m; CI 95%: -103.73 to -27.16; ES: 1.20; p = 0.001). In bigger SSGs (250 and 300 m), higher distance at high intensity was covered and Vmax, Vmean, and sprint distance were greater. In summary, accelerations, sprint number, and fatigue were higher in smaller pitches, and higher velocities were reached in bigger SSGs. Football players should be aware that changes in pitch size can modify the physical performance on high-intensity actions in SSGs.
The direction of inter-limb asymmetries and the change of direction (COD) deficit are two aspects that have increased in recent years. The main objective of the present study was to assess the ...magnitude of neuromuscular asymmetries in an elite youth female team-sports sample and determine its directionality. Secondary objectives were to evaluate the relationship between COD deficit, linear speed and COD time performance. Elite female youth basketball and handball players (n = 33, age = 16 ± 1.17 y) performed the Single Leg Countermovement Jump in vertical (SLCJ-V), horizontal (SLCJ-H), and lateral (SLCJ-L) directions, the COD and the 10-m sprint. Results showed statistical differences between limbs in all the neuromuscular tests (p < 0.001). The Kappa coefficient showed poor to fair levels of agreement between tasks (K range = -0.087 to 0.233), indicating that asymmetries rarely favoured the same limb between skills. Additionally, small and non-significant correlations were found between the linear sprint capacity and the COD ability. The findings of the present study highlight the independent directionality of asymmetries across tests. The COD deficit does not appear to be much more advantageous than COD total time to measure asymmetry. Practitioners are encouraged to use a fitness testing battery to detect existing side differences and each ability should be specifically trained with functional tasks.
Warm-up is commonly performed by track-and-field athletes before performing maximal sprinting activities. Whilst some warm-up strategies may enhance athletes' physical and mental readiness, less is ...known about the current athletes' behaviors and warm-up practices in track and field. Therefore, this study aimed to identify the warm-up practices in a population of athletes performing in sprinting disciplines.
A cross-sectional exploratory study was performed in which track-and-field athletes, performing in athletics at a competitive level in disciplines requiring maximal acceleration and sprinting were recruited. We collected, using an online survey, information about 1) "General and Anthropometric data;" 2) "Athletics training practices" questioning the level of practices and the training frequency; and 3) "Athletics warm-up practices before maximal sprinting" questioning warm-up structure, duration and specific content.
A total of 114 athletes replied to the survey. They reported a mean weekly training duration of 10.5 (±4.0) hours and a pre-maximal sprint warm-up duration of 40.5 (±13.5) minutes. During warm-up, they were engaged in five principal activities: predominantly moderate jogging (95% participation, 8±3.3 minutes), succeeded by dynamic and/or ballistic stretching (78% participation, 9±4.3 minutes), followed by athletic drills (96% participation, 15±5.4 minutes), culminating in accelerations (100% participation) along with high-speed running (77% participation). Warm-up duration and composition differed across athletes' levels of practice and disciplines.
Most of the participants' warm-up practices were typically structured in a three-phase manner, comprising jogging, stretching, and specific training (athletic drills and accelerations). Most athletes followed scientific-based warm-up recommendations there are some areas where the evidence is limited, and more research is needed to determine the optimal warm-up routine for athletes.
The study estimated lower and upper extremity contributions to whole-body front crawl swimming using semi-tethered load-velocity profiling. Nine female and 11 male (inter)national-level swimmers ...performed 20 m semi-tethered sprints, each with five progressive loads for lower (leg kicking), upper (arm stroke), and whole-body front crawl movements. The theoretical maximal speed (v
0
) and load (L
0
), and active drag (D
a
) were expressed as a percentage of the sum of both extremities for the movements of each extremity to calculate their contributions. The difference of whole-body values minus the sum of both extremities was used to estimate whole-body reserves. Lower (upper) body contributions were 43.8 ± 2.8% (56.2%) for v
0
, 37.3 ± 7.1% (62.7%) for L
0
, and 39.6 ± 5.6% (60.4%) for D
a
. Statistically significant whole-body reserves were found for v
0
(−30.9 ± 3.9%, p < 0.001) and D
a
(−5.7 ± 11.7%, p = 0.04). V
0
reserves correlated very highly with whole-body v
0
in males (r = 0.71, p = 0.014) and moderately in females (r = 0.47, p = 0.21). The lower extremities contribute substantially to front crawl load-velocity profiles of highly trained swimmers. Higher sprint swimming speeds are associated with an efficient speed transfer from lower- and upper- to whole-body movement.
Albuminuria and left ventricular hypertrophy (LVH) are independent predictors of heart failure (HF); however, to the best of our knowledge, their combined effect on the risk of HF has not yet been ...explored. Therefore, we examined the joint associations of albuminuria and electrocardiographic-LVH with incident acute decompensated HF (ADHF), and whether albuminuria/LVH combinations modified the effects of blood pressure control strategy in reducing the risk of ADHF. A total of 8,511 participants from the Systolic Blood Pressure Intervention Trial (SPRINT) were included. Electrocardiographic-LVH was present if any of the following criteria were present: Cornell voltage, Cornell voltage product, or Sokolow-Lyon. Albuminuria was defined as urine albumin/creatinine ratio ≥30 mg/g. ADHF was defined as hospitalization or emergency department visit for ADHF. Cox proportional hazard models were used to examine the association of neither LVH nor albuminuria (reference), either LVH or albuminuria, and both (LVH + albuminuria) with incident ADHF. Over a median follow-up of 3.2 years, 182 cases of ADHF occurred. In adjusted models, concomitant albuminuria and LVH were associated with greater risk of ADHF than either albuminuria or LVH in isolation (hazard ratio 95% confidence interval: 4.95 3.22 to 7.62, 2.04 1.39 to 3.00, and 1.47 0.93 to 2.32, respectively, additive interaction p = 0.01). The effect of intensive blood pressure in reducing ADHF was attenuated in participants with coexisting albuminuria and LVH without any interaction between treatment group assignment and albuminuria/LVH categories (interaction p = 0.26). In conclusion, albuminuria and LVH are additive predictors of ADHF. The effect of intensive blood pressure control in reducing ADHF risk did not vary significantly across albuminuria/LVH combinations.
This study compared the differences in acceleration and deceleration demands between three different warm‐up (WU) strategies (Reaction speed exercises with reaction to a stimulus, Run self‐paced ...running, and Speed exercises such as shuttle running or circuits) applied to highly trained soccer players. Nineteen players were monitored for 4 weeks using a 10 Hz Global Positioning System. Accelerations and decelerations magnitudes were classified as low (25%–50%), moderate (50%–75%), and high (>75%) intensities. Additionally, efforts were analyzed according to their respective starting speeds (<5, 5–10, 10–15, 15–20, 20–25, and >25 km h−1). Differences between WU strategies were estimated via paired mean differences along with effect sizes. The three WU strategies led to few efforts starting >15 km h−1 and high‐intensity efforts (<1 effort per minute). Players performed more high‐intensity accelerations during Speed than Reaction Speed (ES: 0.74 90% CI: 0.21, 1.33); more moderate‐intensity accelerations during Reaction Speed than Run (ES: 1.29 90% CI: 0.72, 2.00); more moderate‐intensity decelerations during Reaction Speed than Run (ES: 0.64 90% CI: 0.04, 1.32) and Speed (ES: 0.89 90% CI: 0.37, 1.50); more decelerations started at 20–25 km h−1 during Speed than Reaction Speed (ES: 0.81 90% CI: 0.20, 1.49) and Run (ES: 0.76 90% CI: 0.42, 1.18); and more decelerations started at >25 km h−1 during Speed than Reaction Speed (ES: 3.57 90% CI: 2.88, 4.58). In conclusion, Speed elicited higher acceleration and deceleration demands than the Reaction Speed and Run WU strategies, and this should be considered when designing training sessions.
Highlights
Soccer warm‐ups (WUs) use different training strategies, which should be monitored independently as they elicit different acceleration and deceleration demands.
Speed exercises (such as shuttle running and circuits) may expose players to more high‐speed displacements and high‐intensity accelerations.
Practitioners should choose WUs strategies considering the subsequent activity to avoid under or overloading players.
This study was performed to devise an instructional program for children who were not good at sprinting and to verify the program’s effectiveness for improvement of sprinting ability and motion. The ...participants were 19 upper grade elementary school children who were not good at sprinting. The program included 2 drills with some teaching devices and running on flat markers. The children attended the program for 8 days (2 days per week) and each lesson lasted an hour. In order to validate the program outcome, sprint time (50 m), interval speed (every 10 m), average speed, maximal speed, rate of speed decline, interval and average step frequency and step length were analyzed, and sprint motions were evaluated. The results were as follows: 1) Most of the children’s 50 m times were below the national average. This suggested that their negative feelings toward sprinting resulted from the realization that they were unable to run as fast as other children. 2) The children’s sprint times were improved after the program, and a significant correlation between pre-time and post-pre time was revealed. It was also found that the greater the increase in the children’s step frequency, the faster their sprint times became. These results suggest that sprinting instruction allows low-performing children to increase their step frequency and improve their sprint times. 3) The main aim of the program was to improve children’s sprint motions in the mid sprint phase, and the participants practiced start motions only twice during the program. As a result, speeds from the start to 10 m, 20-50 m, and maximum speed were increased significantly by this practice, suggesting that significant changes of speed led to improvement of the sprint times. 4) Participants became able to swing back their leg under their body and to make contact with the ground with the middle or front of the foot. Therefore it was considered that the drills and running on flat markers with teaching devices were valuable for improving the children’s sprint motions. 5) Although the scissors-like leg motion was not improved by practice with a color board and bells, the kneefolding motion of the swing leg did appear to be improved. Therefore, the children seemed to acquire basic skill in more rapid scissors-like leg motion. These results suggest that our instructional program was effective in enabling children to improve their sprinting ability and motion. However, additional research focusing on aspects such as the relationship between sprinting ability and sprint motion, or individual feelings and motor competency in the context of sprinting, will be needed.
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