Mirjana Milić

Vertical- vs. Horizontal-oriented Drop Jump Training: Chronic Effects on Explosive Performances of Elite Handball Players

Abstract Dello Iacono, A, Martone, D, Milic, M, and Padulo, J. Vertical- vs. horizontal-oriented drop jump training: chronic effects on explosive performances of elite handball players. J Strength Cond Res 31(4): 921–931, 2017—This study aimed to assess the chronic effects of vertical drop jump (VDJ)– and horizontal drop jump (HDJ)–based protocols on neuromuscular explosive abilities, such as jumping, sprinting, and changes of direction (COD). Eighteen elite male handball players (age 23.4 ± 4.6 years, height 192.5 ± 3.7 cm, weight 87.8 ± 7.4 kg) were assigned to either VDJ or HDJ group training twice a week for 10 weeks. Participants performed 5–8 sets × 6–10 repetitions of vertical alternate (VDJ) or horizontal alternate (HDJ) 1-leg drop jumps, landing from the top of a platform 25 cm in height. Before and after training, several performance, kinetic, and kinematic variables were assessed. The HDJ led to greater improvement of the sprint time (−8.5% vs. −4%, p ⩽ 0.05) and COD performance in comparison with the VDJ (−7.9% vs. −1.1%, p ⩽ 0.05), whereas the VDJ caused greater improvement in the vertical jump compared with the HDJ (+8.6% vs. +4.1%, p ⩽ 0.05). Moreover, the VDJ regimen compared with the HDJ induced greater changes in the kinetic variables associated with vertical jumping performance, such as peak ground reaction forces (+10.3% vs. +4.3%), relative impulse (+12.4% vs. +5.7%), leg spring stiffness (+17.6% vs. +4.6%), contact time (CT) (−10.1% vs. −1.5%), and reactive strength index (+7.2% vs. +2.1%); all comparisons with p ⩽ 0.05. Conversely, the HDJ regimen was able to improve the short-distance and COD performances by increasing the step length (+3.5% vs. +1.5% with p ⩽ 0.05) and reducing the CT on COD (−12.1% vs. −2.1% with p ⩽ 0.05) more than the VDJ. This investigation showed the crucial role that specific plyometric regimens play in optimizing similar biomechanical featured functional performances, such as jumping, sprinting, and COD.

Game-profile-based Training in Soccer: A New Field Approach

Abstract Dello Iacono, A, Martone, D, Cular, D, Milic, M, and Padulo, J. Game profile–based training in soccer: a new field approach. J Strength Cond Res 31(12): 3333–3342, 2017—The aim of the study was to profile and compare the time-motion, physiological, and neuromuscular responses of both National Youth League (NYL) and UEFA Youth League (UYL) matches with those of an experimental game profile–based training (GPBT) protocol. Time-motion traits and physiological, perceptual, and neuromuscular responses were investigated in 24 male soccer players across 14 matches and 6 GPBT training sessions, for a total of 420 samples. The GPBT had a greater influence on time-motion traits and perceptual responses than the NYL and UYL matches (all p < 0.001). No significant GPBT vs. match differences were found for mean heart rate or blood lactate (F = 1.228, p = 0.304, and F = 0.978, p = 0.385, respectively). Finally, the GPBT protocol led to greater impairment of the neuromuscular explosive performances when compared with those of the postmatch scores (squat jump: F = 19.991, p < 0.001; countermovement jump: F = 61.703, p < 0.001). Results identified the GPBT protocol as characterized by relatively greater high-intensity workloads than official NYL and UYL matches, requiring increased demanding efforts. In light of these outcomes, the GPBT protocol can be considered an advantageous training method for elite soccer players, capable of stimulating the physical effort and physiological capabilities required during a match. This approach is favorable when designing a training intervention according to the principle of sport specificity, as it is based on the specific metabolic demands.

Herbal medicine for sports: a review

The use of herbal medicinal products and supplements has increased during last decades. At present, some herbs are used to enhance muscle strength and body mass. Emergent evidence suggests that the health benefits from plants are attributed to their bioactive compounds such as Polyphenols, Terpenoids, and Alkaloids which have several physiological effects on the human body. At times, manufacturers launch numerous products with banned ingredient inside with inappropriate amounts or fake supplement inducing harmful side effect. Unfortunately up to date, there is no guarantee that herbal supplements are safe for anyone to use and it has not helped to clear the confusion surrounding the herbal use in sport field especially. Hence, the purpose of this review is to provide guidance on the efficacy and side effect of most used plants in sport. We have identified plants according to the following categories: Ginseng, alkaloids, and other purported herbal ergogenics such as Tribulus Terrestris, Cordyceps Sinensis. We found that most herbal supplement effects are likely due to activation of the central nervous system via stimulation of catecholamines. Ginseng was used as an endurance performance enhancer, while alkaloids supplementation resulted in improvements in sprint and cycling intense exercises. Despite it is prohibited, small amount of ephedrine was usually used in combination with caffeine to enhance muscle strength in trained individuals. Some other alkaloids such as green tea extracts have been used to improve body mass and composition in athletes. Other herb (i.e. Rhodiola, Astragalus) help relieve muscle and joint pain, but results about their effects on exercise performance are missing.

The effect of acute and chronic exercise on steroid hormone fluctuations in young and middle-aged men

&NA; The current study examine the effects of combined sprint and resistance training on serum total testosterone (TT), sex‐hormone‐binding globulin (SHBG) and cortisol (C), at rest, and in response to the Wingate Anaerobic‐Test (WAnT) in 21 and 41 years old men. Forty moderately‐trained men were randomly assigned to a young trained (YT), young control (YC), middle‐aged trained (MAT), and middle‐aged control (MAC) group. Before (P1), and after (P2) training, blood samples were collected at rest and after exercise. At P1, higher C and lower TT was observed in middle‐aged groups compared to younger ones (P < 0.05). At P2, basal TT increased significantly (P < 0.05) in MAT and the age‐difference was absent between trained groups (P > 0.05). Basal SHBG decreased significantly in YT at P2 (P < 0.05) but did not change in other groups from before to after training (P > 0.05). Free‐testosterone was significantly (P < 0.05) higher in young compared to middle‐aged groups at P1, but at P2, this age‐related difference disappeared between YT and MAT (P > 0.05). C post‐WAnT increased significantly for MAT only (P < 0.05) at P2, whilst no significant changes were observed in the other three groups (P < 0.05) at P2. In contrast, resting levels of C did not change in all groups at P2 (P > 0.05). The current study demonstrates that this training intervention may help increase steroids hormones in middle‐aged men and counteract the negative effect of age on TT and free testosterone.

The effects of structural and technical constraints on the profiles of football-based passing drill exercises: suggestions for periodization planning and skill development

ABSTRACT Objectives: The aim of this study was to profile the physiological, time motion and technical responses induced by football passing drills and to analyze the influence of structural and technical constraints. Methods: Twenty-two male footballers performed five sets of intermittent passing drill bouts lasting 3 min each, interspersed by 1 min of passive recovery. The experimental protocols consisted of either a triangle-shaped or a Y-shaped drill format, in which the number of players (eight vs. six) and the technical demands (single vs. double pass) were manipulated. The physiological responses (heart rate [HR], rating of perceived exertion [RPE]), external load measures (GPS related) and technical performances (pass speed and accuracy) were analyzed. Results: The results highlighted specific profiles for the experimental protocols: (1) a higher number of players involved led to greater internal and external load responses and higher technical scores and (2) additional technical requirements, such as for the double-pass task, determined lower internal load responses and a greater amount of acceleration and deceleration actions, but trivial or unclear effects on the technical performances. Conclusions: In light of these outcomes, coaches could include passing drill formats with a variable number of players and technical demands, within appropriate long-term programs that address both physical adaptations and skill development.

Seasonal weather conditions affect training program efficiency and physical performance among special forces trainees: A long-term follow-up study

The purpose of the present investigation was to follow-up the effect of specific commandos’ training-cycles (SCTCs) on upper-body strength resistance and running endurance performance, as well as determine whether variation in seasonal parameters has any effect on physical performance. Fourteen SCTCs were held over eight years, involving 466 participants. Participants were assigned to four subgroups according to their distribution over the seasons: summer (n = 124), autumn (n = 145), winter (n = 52) and spring (n = 145). Before and after each SCTC, four tests (maximal pull-up, push-up and sit-up repetitions in 70-seconds for muscle strength resistance) and a 5-km cross-country run (endurance) were performed. Seasonal data were continuously recorded during all SCTCs. Body mass decreased significantly (p<0.05) in all groups following SCTCs. These training-cycles induced a significant increase (p<0.05) in the 70-seconds push-ups, pull-ups and sit-ups and a decrease (p<0.01) in the 5-km cross-country running time among all trainees. The main effect of the season was present in all tests (p<0.01). With regard to the percentage of changes, the results from the 70-seconds push-up, pull-up and sit-up tests were significantly higher in winter and spring (p<0.01) compared with the two other seasons, while 5-km cross-country performance improvements were significantly higher (p<0.01) in spring and summer, compared to the two other seasons. In summary,14-week of SCTCs improved upper-body strength resistance and running endurance performance in the commandos. Improvements in strength resistance performance were greater during cool weather (winter and spring), while improvements in running endurance performance were higher during hotter (spring and summer) seasons.

Effect of contact and no-contact small-sided games on elite handball players

ABSTRACT This study aimed to investigate the effect of contact (C-SSG) and no-contact (NC-SSG) handball small-sided games (SSGs) on motion patterns and physiological responses of elite handball players. Twelve male handball players performed 10 C-SSG and 10 NC-SSG while being monitored through the heart rate (HR) and rate of perceived exertion (RPE) as physiological responses and time-motion activities profile using video-match analysis. Both game conditions resulted in similar HR responses (P > 0.05), but the NC-SSG led to a higher RPE scores. The time-motion activity analysis featured NC-SSG with a greater amount of walking (855.6 ± 25.1 vs. 690.6 ± 35.2 m) and backward movements (187.5 ± 12.3 vs. 142.5 ± 8.7 m) combined with fast running (232.3 ± 8.5 vs. 159.7 ± 5.7 m) and sprinting (79.5 ± 4.7 vs. 39.7 ± 3.7 m) activities (P < 0.001). Conversely, C-SSG had a higher percentage of jogging and sideway movements associated with greater frequency of jumping (0.87 ± 0.09 vs. 0.31 ± 0.06 nr) and physical contact (1.82 ± 0.55 vs. 0.25 ± 0.03 nr) events (P < 0.001). No between-regimen differences were found for the number of throws (P = 0.745). In addition, the RPE was significantly correlated with fast running relative distances (r = 0.909, P < 0.001) and sprinting relative distances (r = 0.939, P < 0.001). In conclusion, this investigation showed that both C-SSG and NC-SSG in team handball can effectively represent specifically oriented exercises, according to the sport-task and the performance demands.

Nordic walking versus natural walking: an easy approach to comparing metabolic demands

ABSTRACT The aim of this study was to compare the metabolic demands of Nordic walking (NW) versus natural walking (WK) using a highly reproducible protocol in a natural environment. A total of 14 physically active subjects (3 males and 11 females, 36.6 ± 8.3 years, 63.1 ± 11.4 kg, 1.67 ± 0.06 m) walked at a freely chosen speed along a 2.5-km course in a game reserve, using NW and WK in a random order. They were monitored for speed with a mobile phone global positioning system (GPS) receiver, and for lap average and maximum heart rate (HR) with a belt HR monitor. Analysis of variance (ANOVA) showed significantly higher lap average HR (p = 0.004) and maximum HR (p = 0.004) in NW compared with WK. Due to its increased metabolic load, NW revealed to be an effective means for improving cardiovascular fitness in populations with a low tolerance for exertion. Using this simple and ecological approach promises to be effective for further evaluation of other variables and/or use in other contexts (e.g. high altitude and climbing).

Validity and reliability of the 30-s continuous jump for anaerobic power and capacity assessment in combat sport

Cycling test such Wingate anaerobic test (WAnT) is used to measure anaerobic power (AP), but not anaerobic capacity (AC, i.e., the metabolic energy demand). However, in sports that do not involve cycling movements (Karate), the continuous jump for 30 s (vertical jumps for 30 s) has been extensively used to measure anaerobic performance in all young athletes. Limited information’s are available concerning its validity and reliability especially in children. As such, the current study aimed to test validity and reliability of a continuous jumps test (the CJ30s), using WAnT as a reference. Thirteen female Karate kids (age: 11.07 ± 1.32 years; mass: 41.76 ± 15.32 kg; height: 152 ± 11.52 cm; training experience: 4.38 ± 2.14 years) were tested on three separate sessions. The first and second sessions were used to assess the reliability using Intra-class correlation coefficient (ICC) of CJ30s, whereas on the third session WAnT was administered. Following CJ30s and WAnT, we assessed AP (1/CJ30s, as jump height [JH], fatigue index [FI], and blood lactate [BL]; 2/WAnT, as mechanical power [P], FI, and BL) and AC as the excess post-exercise oxygen consumption (EPOC). Large/highly significant correlations were found between CJ30s and WAnT EPOCs (r = 0.730, P = 0.003), and BLs (r = 0.713, P = 0.009). Moderate/significant correlations were found between CJ30s and WAnT FIs (r = 0.640, P = 0.014), CJ30s first four jumps mean JH and WAnT peak P (r = 0.572, P = 0.032), and CJ30s mean JH and WAnT mean P (r = 0.589, P = 0.021). CJ30s showed excellent and moderate reliability (ICC) for AP (maximal JH 0.884, mean JH 0.742, FI 0.657, BL 0.653) and AC (EPOC 0.788), respectively. Correlations observed especially in terms of AC between CJ30s and WAnT provide evidence that former may adequately assess anaerobic performance for the young combat athlete. CJ30 is a reliable test and allow an easy assessment of AP and AC in karate children.

Letter to the Editor concerning "Validity and reliability of photographic measures to evaluate waistline asymmetry in idiopathic scoliosis" by Matamalas A, Bagó J, D Agata E, Pellisé F (2016) Eur Spine J. 2016 Mar 14 [Epub ahead of print].

In the latest years, some articles investigated the validity and reliability of several devices [3–5] raising several points about them. Recently, we read on the European Spine Journal an article entitled ‘‘Validity and reliability of photographic measures to evaluate waistline asymmetry in idiopathic scoliosis’’ on methodology test–retest assessment [2]. We think that this article promotes an approach surely simple but even worthy of further scientific evaluation. Some points listed in this letter point out what is yet necessary to verify to evaluate properly the effectiveness of this approach. Particularly, the methodological approach shows some severe flaws, which lead to unclear results interpretation. Therefore, this letter aims to help reader better understand the treated matter. Considering the study aims, the following points concern the used methodological approach.