The Effect of Pubertal Status on Post-activation Performance Enhancement in Young Soccer Players

Abstract

Post-activation performance enhancement (PAPE) occurs when performance improves after intense contractile stimulation. This study examined the effect of pubertal status on PAPE after a maximal cardiopulmonary exercise test (CPET) in 48 male soccer players aged 10–18 years. Additionally, we investigated the relationship between maximal aerobic speed (MAS) and lower limb strength. They were classified as pre-pubescent (n=13), pubescent (n=15), and post-pubescent (n=20). The participants performed three countermovement jumps (CMJ) before and after a maximal CPET. The PAPE was estimated by calculating the difference between pre- and post-exercise CMJ height at five minutes of recovery after CPET. The CPET was performed on a treadmill using a ramp protocol to determine the maximal oxygen consumption (VO₂ max) and MAS. CMJ height was significantly greater after the CPET for all groups. Post-pubescent participants had significantly greater PAPE than both pre-pubescents and pubescents. Pre-pubescents had significantly lower CMJ height, VO₂ max, and MAS compared to pubescent and post-pubescents. Finally, a positive relationship was observed between MAS and CMJ height. In conclusion, PAPE after maximal CPET was observed in all pubertal cohorts of young soccer players. However, it was greater in post-pubescent children. Finally, MAS was positively correlated with lower limbs strength.

Keywords

aerobic performance - lower limbs strength - countermovement jump - football - maturity

Introduction

Soccer is regarded as the world’s leading sport with respect to practitioners, licenses, spectators, financial resources, and revenues [1], with millions of players in professional soccer academies around the world [2]. The sport is characterized by the combination of high-intensity activities, including sprinting, running, jogging, accelerating, jumping, and changing direction, intertwined with low-intensity activities, such as stopping or walking [3]. Additionally, soccer performance involves a multidisciplinary approach which involves not only physical parameters but also technical-tactical, maturational, and psychological factors [4].

Post-activation performance enhancement (PAPE) is a phenomenon in which neuromuscular performance characteristics are improved after intense contractile stimulation [5]. The term PAPE has been recently introduced for utilization by Cuenca-Fernandez et al. [6] in cases where high-intensity voluntary conditioning contractions result in improved voluntary muscular performance in subsequent tests without confirmed evidence of classical post activation potential (i. e., twitch contraction). PAPE is caused by the phosphorylation of the myosin regulatory light chain, which increases the rate of cross-bridge formation, leading to an increase in both the magnitude of force and rate of force development for submaximal activation [7]. PAPE manifests as an increase in voluntary muscle force, occasionally maximal voluntary contraction, with a unique duration of action compared to other types of potentiation, typically spanning from 4 to 15 minutes [8]. If PAPE can be triggered by a conditioning contraction and applied during explosive activities, it can potentially enhance mechanical power, improve physical performance, and amplify the training stimulus [9].

Strength and power production are crucial for athletic performance in various activities such as sprinting, jumping, throwing, kicking, and changing direction [10]. A maximal or near-maximal muscular contraction can increase strength and power production in subsequent exercises [11]. Similarly, cardiorespiratory fitness is a crucial factor to determine performance in several sports, including soccer [12]. Therefore, trainers and athletes are interested in strategies to enhance aerobic performance, as well as strength and power production. Considering the role of PAPE in the high level of enhancement in athletic performance, several training strategies have been developed to generate PAPE and optimize athletic performance, including improving explosive power [13] and endurance [14].

Interestingly, pubertal status can have a significant impact on the physical abilities of youth athletes, particularly in terms of strength and speed-related performance [15]. As players mature, their muscles may grow larger and stronger, which can improve their ability to generate force and power on the field [16]. Additionally, pubertal development can impact performance through changes in the fiber-type composition of muscles. Different types of muscle fibers have different properties, such as their ability to generate force quickly or sustain effort over time, affecting their overall performance [17].

Previous studies have documented that muscle twitch force can increase through a preceding dynamic conditioning stimulus [5] [11] [18]. However, there is little research regarding the effects of aerobic exercise on subsequent neuromuscular performance in young soccer players. Thus, this study assessed the effect of pubertal status on PAPE after maximal cardiorespiratory exercise test in young soccer players. Secondly, we aimed to examine the relationship between maximal aerobic speed (MAS) and lower limb strength.

Materials and methods

Subjects

A total of 48 male soccer players aged 10–18 years (13.8±2.3 years) were divided into three groups: pre-pubescent (n=13, 11.2±1.5 years), pubescent (n=15, 13.1±0.8 years), and post-pubescent (n=20, 15.9±1.3 years). We defined the volunteers as “pre-pubescent, pubescent, and post-pubescent” after examining and comparing their genitalia and pubic hair with standardized images. Pubertal stage was assessed using the Marshall-Tanner criteria and evaluated by physicians who underwent standardized training [19]. Athletes participated in regular systematic training four days a week in addition to competitive matches. This study was carried out in accordance with the principles of the Declaration of Helsinki and was approved in 2023 by the institutional review board, under protocol 74350923.3.1001.5214. All subjects signed the informed consent form according to resolution 466/12 of the National Health Council.

Procedures

Participants underwent a countermovement jump (CMJ) test five minutes before and five minutes after maximal cardiorespiratory exercise test (CPET) to evaluate the PAPE, as described in [Fig. 1]. The PAPE was assessed by calculating the difference between pre- and post-exercise CMJ height. In addition, we evaluated the correlation between CMJ and the MAS reached in the CPET. All jump tests showed excellent relative reliability (ICC>0.948, p<0.001). However, they presented great the dispersion level around the mean (CV<16.2%).

Fig. 1 Schematic view of the procedures protocol. Abbreviations: CMJ, countermovement jump; CPET, cardiopulmonary exercise test.

The jumps were performed on a contact mat (Elite Jump, S2 Sports, São Paulo, Brazil). The obtained flight time (t) was used to estimate the jump height (h) (i. e., h=gt^2/8), where “g” is the gravitational acceleration. In order to perform the CMJ test, participants stood upright with their hands on their hips. Following the command, starting from a standing position, they rapidly flexed their knees (to around 90 degrees) and immediately performed a vertical jump at maximum height. In both types of jumps, the hands remained on the hips to prevent any influence from arm swinging on the jumping performance. From take-off to landing, the knees and ankles were fully extended. The accuracy of the movements was assessed by three researchers. If any of the researchers deemed a movement incorrect, that jump was excluded from the analysis.

The CPET was conducted on a programmable treadmill (ATL; Ibramed Sao Paolo, Brazil) using a ramp protocol to determine maximal oxygen consumption (VO₂ max) and MAS. Gas exchange and ventilatory variables were measured continuously breath-by-breath during the gas exchange test using a metabolic analyser system (Metalyzer 3B; Cortex, Leipzig, Germany). The test was preceded by a 3-minute warm-up. The speed started at 7 km/h with speed increases of 1 km/h every 60 s at 1% of inclination. The participants ran in an indoor facility maintained at standard environmental conditions at 22–24°C and around 40–60% of relative humidity. Volunteers were encouraged to give a maximal effort. The criteria to determine the maximal exertion were as follows: the participant needed to exhibit personal signs of fatigue using the Borg scale, scoring above 18 [20] and either a peak heart rate (HR)≥190 bpm, or a maximal respiratory exchange ratio≥1.0 [21].

Statistical analysis

Normal distribution and homogeneity of variance of the data were tested using the Shapiro-Wilk and Levene’s tests, respectively. Reliability for the jump tests was tested using intraclass correlation coefficients (ICCs) and coefficient of variation (CV). ICC levels greater than 0.75 indicated excellent reliability [22]. One-way ANOVA followed by Tukey’s test was used to verify differences between groups. A repeated measures ANOVA was performed to determine if significant interactions existed between groups (pre-pubescent, pubescent and post-pubescent) and testing times (before and after CPET). A Pearson correlation coefficient was used to evaluate the association between CMJ heights measured before the CPET and the MAS. Statistical analyses were performed using SPSS 22.0 software (IBM, Armonk, NY, USA), with significance set at p<0.05.

Results

Results are presented as mean and standard error of the mean. The characteristics of the participants are listed in [Table 1]. As seen in [Fig. 2] Panel A, pre-pubescent participants presented significantly lower CMJ height compared to pubescent and post-pubescent participants (23.8±2.5 vs. 29.0±3.7 vs. 34.9±5.2, respectively). Additionally, both pre-pubescent and pubescent participants had significantly lower CMJ post-pre levels (1.5±1.7 and 2.2±1.9, respectively) than post-pubescent volunteers ([Fig. 2] Panel B). The repeated measures ANOVA revealed a statistically significant difference in CMJ performance before and after the CPET across pre-pubescent, pubescent, and post-pubescent groups (p<0.03). Regarding the results obtained from the CPET, pre-pubescent participants presented significantly lower MAS values compared to pubescent and post-pubescent, as seen in [Fig. 3] Panel A (12.4±0.9 vs. 14.2±1.9 vs. 16.2±1.4, respectively). Additionally, pre-pubescent players had lower VO₂ max values (48.7±7.3) than the other groups ([Fig. 3] Panel B). However, no significant differences were observed between pubescent and post-pubescent participants (53.2±5.6 vs. 53.9±4.7, respectively). Finally, we found a positive correlation between MAS reached during the CPET and the CMJ heights ([Fig. 4]).

Fig. 2 Countermovement jump performance before the CPET (Panel A) and CMJ delta values before and after the CPET (Panel B). Values are presented as mean±standard error of the mean. *p≤0.05 vs. pubescent; # p≤0.05 vs. post-pubescent. Abbreviations: CMJ, countermovement jump.

Fig. 3 Maximal aerobic speed (Panel A) and maximal oxygen consumption (Panel B) measured during the cardiopulmonary exercise test. Values are presented as mean±standard error of the mean. *p≤0.05 vs. pubescent; # p≤0.05 vs. post-pubescent. Abbreviations: MAS, maximal aerobic speed; VO₂ max, maximal oxygen consumption.

Fig. 4 Correlation between maximal aerobic speed and countermovement jump. Abbreviation: MAS, maximal aerobic speed.

Table 1 Characteristics of the participants.

Variable	Pre-pubescent (95% CI) (n=13)	Pubescent (95% CI) (n=15)	Post-pubescent (95% CI) (n=20)	Total (95% CI) (n=48)
Age (years)	11.15±1.14ab (10.46, 11.84)	13.13±0.83b (12.67, 13.60)	15.90±1.29 (15.29, 16.51)	13.75±2.27 (13.09, 14.41)
Height (m)	1.46±0.04ab (1.44, 1.49)	1.64±0.11b (1.58, 1.70)	1.73±0.08 (1.70, 1.78)	1.63±0.14 (1.59, 1.67)
Body mass (kg)	42.52±6.18ab (38.79, 46,26)	53.00±8.74b (48.46, 57.84)	65.54±10.22 (60.76, 70.33)	55.39±12.9 (51.65, 59.13)
Body mass index (kg/m2)	19.73±2.58 (18.17, 21.29)	19.56±1.85b (18.53, 20.59)	21.58±2.31 (20.50, 22.67)	20.45±2.42 (19.75, 21.15)
CMJ pre (cm)	23.77±2.46ab (22.21, 25.34)	29.0±3.71b (26.97, 31.08)	34.9±5.16 (32.51, 37.34)	30.20±6.13 (28.40, 32.00)
CMJ post-pre (Δ cm)	1.48±1.71b (0.37, 2.54)	2.19±1.92b (0.31, 3.39)	3.30±1.09 (1.78, 4.54)	2.33±0.91 (1.52, 3.12)
VO2 max (ml/kg/min)	48.65±7.30ab (44.24, 53.06)	53.19±5.56 (50.12, 56.28)	53.93±4.69 (51.74, 56.13)	52.27±6.07 (50.51, 54.04)
MAS (km/h)	12.38±0.86ab (11.86, 12.91)	14.20±1.93b (13.13, 15.27)	16.15±1.38 (15.50, 16.80)	14.52±2.12 (13.90, 15.14)

CI, confidence interval; CMJ, countermovement jump; MAS, maximal aerobic speed; VO₂ max, maximal oxygen consumption; a, significant different compared to pubescent; b, significant different compared to post-pubescent.

Discussion

The present study aimed to investigate the effect of pubertal status on post-activation performance enhancement after maximal cardiopulmonary exercise test in young soccer players. Previous studies have been conducted recently regarding the effect of different PAPE protocols on soccer players [23] [24] [25] [26]. However, to the best of our knowledge, this is the first study to assess the extent to which pubertal status affects PAPE levels in soccer players. Our findings provide valuable insights into the intricate relationship between pubertal development and athletic performance. The results revealed significant differences in various performance metrics among pre-pubescent, pubescent, and post-pubescent participants. Secondarily, we found a positive relationship between maximal aerobic speed and lower limb strength in young soccer players.

The findings from the repeated measures ANOVA underscore the impact of cardiorespiratory fitness on CMJ performance across pre-pubescent, pubescent, and post-pubescent individuals. This suggests a complex relationship between cardiorespiratory fitness and lower-body strength, potentially influenced by chronological age and physiological changes associated with pubertal development [27]. Additionally, we observed that both pre-pubescent and pubescent participants exhibited significantly lower PAPE values compared to post-pubescent individuals. These findings align with previous research that has highlighted the influence of neuromuscular maturation and hormonal changes during puberty on PAPE [28]. In fact, it has been demonstrated that the sudden increase in anabolic hormones such as testosterone and growth hormone during puberty can contribute to increased muscle contractility and power output, potentially explaining the observed improvement in PAPE among post-pubescent players [29]. In this context, our findings are in accordance with a previous investigation that has linked the pubertal growth spurt and associated muscle development to improved jump performance [30]. The significant increase in CMJ height among post-pubescent individuals can be attributed to enhanced muscle strength, coordination, and explosiveness resulting from the interaction of hormonal and neuromuscular changes during puberty.

Maximal oxygen consumption is a critical indicator of cardiovascular fitness and is used as a performance factor in several sports, including soccer [31]. Our results demonstrated lower VO₂ max values in pre-pubescent participants, which significantly increased in the pubescent stage and remained stable in the post-pubescent phase. This finding is consistent with previous studies that have reported improvements in VO₂ max during puberty due to enhanced oxygen transport capacity, cardiac output, and muscle oxidative capacity [32] [33], as well as decreased body fat percentage [34]. The lack of significant difference in VO₂ max between pubescent and post-pubescent participants suggests that the cardiovascular system's adaptation may plateau after the initial pubertal changes.

Interestingly, the relationship between MAS and vertical jump heights has long been a topic of interest in sports science and training. In the present study, we observed a positive relationship between MAS and CMJ height. Indeed, MAS, referred to as the ability to sustain high-intensity aerobic efforts, contributes to overall cardiovascular fitness and muscle endurance, which can indirectly impact vertical jump performance by optimizing oxygen delivery to muscles during explosive movements [35]. Additionally, aerobic exercise training can help reduce the accumulation of fatigue-inducing metabolites during repetitive jumps, potentially leading to better vertical jump heights [36]. Athletes and trainers often incorporate cross-training routines that blend aerobic exercises with plyometric and strength training, aiming to achieve a balance that optimizes both attributes. However, while a correlation might exist, it is important to note that vertical jump performance is also influenced by factors like muscle power, neuromuscular coordination, and body composition [37].

The process of physical and physiological maturation has a significant impact on muscle strength and neuromuscular activation [38]. With pubertal development, there is an increase in muscle mass and a higher predominance in muscle fiber type II composition, which are responsible for generating high levels of force and are crucial for anaerobic activities [39]. Additionally, puberty is associated with improvements in neuromuscular coordination, which improves the process of recruiting and synchronizing muscle fibers to produce efficient and powerful movements [40]. Similarly, improved cardiovascular fitness from aerobic training might indirectly benefit vertical jump performance by delaying the onset of fatigue in fast-twitch fibers [41]. The oxidative capacity developed through aerobic training can also aid in the recovery of energy substrates needed for explosive movements [42]. Athletes seeking to improve vertical jump heights might thus integrate aerobic workouts to enhance overall muscle endurance and optimize recovery between jumps.

Pubertal development also plays a huge role in the improvement of glycolytic metabolism in adolescents [19] [21]. As individuals progress through distinct stages of development, their training history and cumulative exposure to various exercise modalities can influence glycolytic metabolism [43]. With age and physical maturity, enzyme activity involved in glycolysis tends to become more efficient and mature individuals may have a higher capacity for glycolysis due to increased enzyme activity [44]. This enables them to convert glucose more effectively into usable energy during intense, short-duration activities.

Finally, our investigation found no difference in VO₂ max between the pubescent and post-pubescent cohorts. On the other hand, the post-pubescent group exhibited superior values to pubescents regarding MAS (16.15 vs. 14.20, respectively) and CMJ height (34.9 vs. 29.0, respectively). Collectively, these findings suggest that, in spite of the similarities between groups regarding VO₂ max, the higher muscular power was the main determinant of MAS in the post-pubescent group instead of the cardiorespiratory capacity.

While our study provides valuable insights, some limitations should be taken into consideration. The cross-sectional design restricts our ability to establish causal relationships between pubertal development and performance metrics. Longitudinal studies tracking individual participants through puberty could provide more robust evidence of the influence of maturation on performance. Additionally, factors such as training history, genetics, and lifestyle could contribute to the observed differences.

Conclusion

Post-activation performance enhancement triggered after maximal CPET was observed in young soccer players at all pubertal status. However, it was greater in post-pubescent children. Therefore, PAPE effect on CMJ performance is associated with maturity in soccer athletes. Finally, we found that maximal aerobic speed was associated with lower limb strength. These findings contribute to the growing body of literature emphasizing the significance of pubertal maturation as a determinant of athletic performance in youth soccer.

Conflict of Interest

The authors declare that they have no conflict of interest.

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Publication History

Received: 04 November 2023

Accepted: 25 June 2024

Article published online:
22 April 2025