Strength, Endocrine, and Body Composition Alterations across Four Blocks of Training in an Elite 400 m Sprinter

he ability to produce force rapidly has the potential to directly in uence sprinting performance through changes in stride length and stride frequency. This ability is commonly referred to as the rate of force development (RFD). For this reason, many elite sprinters follow a combined program consisting of resistance training and sprint training. The purpose of this study was to investigate the strength, endocrine and body composition adaptations that occur during distinct phases of a block periodized training cycle in a 400 m Olympic level sprinter. The athlete is an elite level 400 m male sprinter (age 31 years, body mass: 74 kg,

a combined program consisting of resistance training and sprint training. The purpose of this study was to investigate the strength, endocrine and body composition adaptations that occur during distinct phases of a block periodized training cycle in a 400 m Olympic level sprinter. The athlete is an elite level 400 m male sprinter (age 31 years, body mass: 74 kg, years of training: 15 and Personal Best (PB): 45.65 s). This athlete completed four distinct training phases of a block periodized training program (16 weeks) with ve testing sessions consisting of testosterone:cortisol (T/C) pro les, body composition, vertical jump, and maximum strength testing. Large uctuations in T/C were found following high volume training and the taper. Minor changes in body mass were observed with an abrupt decrease following the taper which coincided with a small increase in fat mass percentage. Jump height (5.7%), concentric impulse (9.4%), eccentric impulse (3.4%) and power ratio (18.7%) all increased substantially from T1 to T5. Relative strength increased 6.04% from T1 to T5. Lastly, our results demonstrate the effectiveness of a competitive taper in increasing physiological markers for performance as well as dynamic performance variables. Block periodization training was effective in raising the physical capabilities of an Olympic level 400 m runner which have been shown to directly transfer to sprinting performance. Keywords:periodization; sprinter; track and eld; athlete monitoring; endocrine; force plate 1. Introduction The 400 m sprint is a speed endurance event that demands a high level of anaerobic metabolism, buffering capacity and aerobic processes to maintain maximum velocity [1–4]. Although stride frequency and stride length have been shown to in uence sprinting speed, stride length seems to be the more important biomechanical parameter when distinguishing between levels of performance in 400 m races [5]. Elite sprinters have demonstrated the ability to apply greater forces into the ground, resulting in longer stride lengths, faster stride frequencies, and subsequently, faster sprint times compared to less experienced sprinters [6,7]. Although the 400 m race is classi ed as “sprint distance” it is characterized by unique metabolic, neuromuscular, and technical requirements in comparison to 100 and 200

[5]. Elite sprinters have demonstrated the ability to apply greater forces into the ground, resulting in longer stride lengths, faster stride frequencies, and subsequently, faster sprint times compared to less experienced sprinters [6,7]. Although the 400 m race is classi ed as “sprint distance” it is characterized by unique metabolic, neuromuscular, and technical requirements in comparison to 100 and 200 m races [5,8]. J. Funct. Morphol. Kinesiol.2021,6, 25.

J. Funct. Morphol. Kinesiol.2021,6, 25 2 of 17 Agreement exists that, from a bioenergetics/metabolic standpoint, anaerobic capacity is the main factor discriminating 400 m performance [2]. Nevertheless, the need to generate high forces in a small amount of time underscores the importance of qualities such as rate of force development (RFD) and power in developing sprinting speed [9]. Currently, there is very little long term, descriptive, observational research regarding the experience of elite 400 m sprinters who have followed combined resistance and running training programs. In terms of maximizing strength/power adaptations, block periodization and appropriate programming can result in superior strength/power gains [10–14]. Block periodization depends upon “stages”, each containing three tness phases: accumulation, transmutation, and realization [15]. The sequenced order of these phases, along with appropriate programming, allows for early adaptations to further potentiate adaptations in the later blocks, termed phase potentiation [16–18]. For example, the development of work capacity and basic strength during the accumulation phase allows for greater development of maximal strength and power during the later phases of training [11–13,16,17,19–21]. The block model depends upon several levels of programming variation, including the use of heavy and light days, in which intensity and or volume may be increased or decreased through programmatic means such as sets, reps and relative intensities. This type of loading paradigm has the potential to enhance the recovery and adaptation processes, leading to a superior performance [11–14,22]. The combination of resistance training in a block periodized manner and track and eld speci c training resulted in a more ef cient and ef cacious improvement of maximal strength, rate of force development (RFD) and superior fatigue management in comparison to other forms of training. These studies [12,13] are characterized by a high degree of ecological validity and lend support to a combined approach in training, but more research is warranted within elite track and eld settings including 400 m runners. Despite a growing evidence base for the value of a block periodized approach to training [15–18,23,24] there is a need for understanding whether/how elite athletes apply these strategies operate within the real-world annual training/competition

ecological validity and lend support to a combined approach in training, but more research is warranted within elite track and eld settings including 400 m runners. Despite a growing evidence base for the value of a block periodized approach to training [15–18,23,24] there is a need for understanding whether/how elite athletes apply these strategies operate within the real-world annual training/competition calendar. Several methods exist to better understand physical adaptations to a combined, peri- odized training plan including the isometric midthigh pull and vertical jump testing. The isometric midthigh pull (IMTP) is a commonly used method to monitor changes in perfor- mance potential through quanti cation of peak force (PF), force at a variety of epochs, and the RFD. The diagnostic ability of these measures may be of importance when considering time-constrained tasks within sports, such as jumping, sprinting, and change of direc- tion [25,26]. Large negative correlations have been observed between PF, RFD and impulse (IP) and 0–5 m split time performance in highly trained sprinters [27]. Contrary, Healy et al. (2019) [28] found no statistically signi cant (but moderate to strong) relationships between IMTP peak force and relative peak force and sprint performance over 40 m with 10 m splits, among a group of twenty-eight national and international level sprinters. However, the authors did not measure 0–5 m or fully diagnose the force–time curve, examining measures of strength such as RFD or impulse. In regards to the maximal power capabilities and for identifying high-velocity power spectrum changes, the countermovement jump (CMJ) is primarily used. A substantial relationship between 400 m performance and average height of 30 s repeated CMJs was noted, but this relationship was not noted for a single CMJ height performance [4,29]. The lack of association between jump height (JH) and 400 m performance may be due to the fact that athletes may employ varying movement strategies (such as increasing the time of force application) to achieve a desired outcome (e.g., jump height) and therefore jump performance may be in uenced by a variety of factors [30,31]. Undoubtedly the importance of a sprinter's ability to produce high

jump height (JH) and 400 m performance may be due to the fact that athletes may employ varying movement strategies (such as increasing the time of force application) to achieve a desired outcome (e.g., jump height) and therefore jump performance may be in uenced by a variety of factors [30,31]. Undoubtedly the importance of a sprinter's ability to produce high forces in a brief time period is paramount as elite sprinters have demonstrated foot contact times around 90 ms [6,7]. Comprehensive insight into athletes' neuromuscular function can be gained through detailed analyses using force plates.

J. Funct. Morphol. Kinesiol.2021,6, 25 3 of 17 Particularly important is the taper/peaking strategy utilized towards the end of the macrocycle in an effort to allow the athlete to express their cumulative adaptations and increase the potential of success on the day of competition. Much of the conceptual framework of the tness–fatigue paradigm and peaking for a speci c competition deals with the alterations and uctuations of an athlete's preparedness across many blocks of training [32]. Force–time characteristics (underpins power expression) may be in uenced by alterations in hormonal status which may be strongly affected by training variables: volume and intensity. Testosterone (T), cortisol (C) and the T/C ratio are often used as valuable tools for the evaluation of athlete preparedness [11,13,32,33]. The high-volume training typically observed in the accumulation block generally decreases T/C ratio as indicative of accumulated fatigue and training stress, whereas the decreased volume load observed in the transmutation and realization phases can result in pattern rebound and augments the T/C ratio, promoting preparedness [11,13,25,34]. This rebound effect has been associated with a greater ability to generate maximal forces, and explosive strength (rate of force development) [13,33–36]. Additionally, the T/C ratio may have an effect on the development of hypertrophy and tissue repair, which play a role in strength development. Increases in the size of a muscle from resistance training have been well established. However, little is known about the extent and time course of the changes in muscle hypertrophy as a result of resistance training combined with relatively high volume loads of speci c 400 m training. Despite the importance of monitoring physiological/performance adaptation and the growing popularity of using force plates [37] in monitoring strength/power capabilities in athletes, there are no (to our knowledge) studies related to 400 m sprinters. Therefore, understanding the magnitudes and direction of adaptations using case studies of elite level athletes can provide better insight into individual responses, serve as a better communica- tion tool with coaches, and can also contribute to generating hypotheses for future research questions [38]. Thus, the purpose of this study was to examine the time course

related to 400 m sprinters. Therefore, understanding the magnitudes and direction of adaptations using case studies of elite level athletes can provide better insight into individual responses, serve as a better communica- tion tool with coaches, and can also contribute to generating hypotheses for future research questions [38]. Thus, the purpose of this study was to examine the time course of the physiological and performance changes in an elite level 400 m male sprinter throughout four resistance training phases in combination with a sport-speci c running program over a 16-week training period. 2. Methods Subject (Athlete) The athlete was an elite level 400 m male sprinter (age 31 years, body mass: 74 kg, years of training: 15 and Personal Best (PB): 45.65 s. He was a 400 m Relay Indoor World Record holder from 2018 (3:01:77) and nal participant of 4 400 m race in 2016 Olympics (Rio de Janeiro). Currently, he is part of the national team program preparing for the Tokyo Olympics. These data arose from the monthly monitoring program in which each athlete's (from the National Team) physiological and motor abilities are routinely measured over the course of the season. The study was approved by the Institute of Sport Committee of Ethics, and written informed consent was obtained. The subject was informed of the bene ts and risks of the investigation prior to signing an institutionally approved informed consent document to participate in the study. The study conformed to the recommendations of the Declaration of Helsinki. 3. Training Program and Testing Timeline This study was a comparison of pre- and postblock testing results from four speci c training phases throughout a single macrocycle leading up to a control indoor competi- tion. The rst testing session was held two weeks after the 2019 IAAF World Athletics Championships (after active recovery period). Testing dates corresponded to the start of a new block of training. The training program followed a single-factor block periodized design. The three periodization blocks consisted of four distinct training blocks. The initial training block (Accumulation 1: T1–T2) consisted of four weeks of high volume and

two weeks after the 2019 IAAF World Athletics Championships (after active recovery period). Testing dates corresponded to the start of a new block of training. The training program followed a single-factor block periodized design. The three periodization blocks consisted of four distinct training blocks. The initial training block (Accumulation 1: T1–T2) consisted of four weeks of high volume and

J. Funct. Morphol. Kinesiol.2021,6, 25 4 of 17 low-to-moderate relative intensities, termed a Strength-Endurance Phase (SE). The second block of training (Accumulation II: T2–T3) consisted of four weeks of moderate volumes at higher intensities, termed a Maximal Strength Phase. The third block (Transmutation) termed Strength–Speed consisted of 4 weeks of low volumes, and high intensities com- bined with more velocity dominant exercises. The emphasis within this phase of training is to move relatively heavy loads quickly to enhance RFD characteristics [17,39]. The nal block (Realization) of training consisted of 4 weeks of complex training where the primary exercises were combined with plyometric-type exercises which place greater emphasis on the high velocity end of the force-velocity spectrum while maintaining strength qualities (Speed–Strength phase). Each training session was completed within 1.5 h. The basic structure of the block periodized training program is presented in Table. Testing occurred at the beginning of the week 1 (T1), and after completion of week 4 (T2), 8 (T3), 12 (T4), 16 (T5). Table 1.Training program structure. Block Week Sets Repetitions Intensity/Day Monday Tuesday Wednesday Thursday Friday Saturday Strength Endurance 1 3 10 * M Running ML Running L Running 2 3 10 * MH Running M Running L Running 3 3 10 * H Running MH Running ML Running 4 3 5 * M Running M Running L Running Max Strength Phase 5 3 5 * H Running MH Running M Running 6 3 5 * H Running H Running M Running 7 3 5 * VH Running H Running MH Running 8 3 5 * ML Running L Running L Running Strength–Speed 9 3 3 * Running H Running MH Running Running 10 3 3 * Running VH Running H Running Running 11 3 3 * Running VVH Running M Running Running 12 3 3 * Running ML Running L Running Running Speed–Strength 13 3 3 * Running MH Running L Running Running 14 3 3 * Running H Running M Running Running 15 3 3 * Running VH Running MH Running Running 16 3 3 * Running L Running L Running Running Note: SE

* Running VVH Running M Running Running 12 3 3 * Running ML Running L Running Running Speed–Strength 13 3 3 * Running MH Running L Running Running 14 3 3 * Running H Running M Running Running 15 3 3 * Running VH Running MH Running Running 16 3 3 * Running L Running L Running Running Note: SE = Strength—Endurance, SP = Strength—Power, VL = very light (65–70%), L = light (70– 75%), ML = medium light (75–80%), M = medium(80–85%), MH = medium heavy (85–90%), H = heavy (90–95%), VH = very heavy (95–100%). Intensities are based off a set-rep best system [14,40]. * represent a single drop set at approximately 60% of the working sets. Following baseline testing, the athlete completed both resistance (RT) and running programs on alternating days. RT was completed on Mondays, Wednesdays, and Fridays, whereas a rudimentary running program was completed on Tuesdays, Thursdays and Saturdays. At the onset of T2, RT frequency was reduced to 2 day/week while running frequency was increased to 4 day/week. RT was completed on Tuesdays and Thursdays while running training was completed on Mondays, Wednesdays, Fridays and Saturdays. Resistance training loads were prescribed using relative intensities for a given set and repetition range [14,17,19]. This approach has been shown to produce superior performance adaptations when compared to traditional loading methods such as repetition maximum zones [14]. Exercises employed in each block are presented in Table. Running training intensity was based on a distribution of training into 7 speci c intensities zones presented in Table. It should be added that this running training method has been used since 1994 when the head coach became the Polish national 400 m relay male team's coach. This method helped the Polish 400 m relay team reach the world record for the fth time in history (2:58:00 Uniondale, New York, Goodwill Games) and achieve the Indoor World Record in 2018. The average lactate and RPE values in each training mean are presented based on more than 40 years of collecting data on national team athletes. Due to the fact that test

Polish 400 m relay team reach the world record for the fth time in history (2:58:00 Uniondale, New York, Goodwill Games) and achieve the Indoor World Record in 2018. The average lactate and RPE values in each training mean are presented based on more than 40 years of collecting data on national team athletes. Due to the fact that test dates are dictated by resistance training programs, it is reasonable to present running training programs with respect to this. Although this study is primarily concerned with adaptations to resistance training, physical performance potential

This study examines training adaptations in an elite 400 m sprinter over a 16-week period.