Critical review of the LTAD models and S&C considerations for youth footballers

The main long-term athlete development models are the Long-Term Athlete Development (LTAD) model (Balyi & Hamilton, 2004) and the Youth Physical Development Model (YPDM) (Lloyd & Oliver, 2012). The YPDM offers a new approach and takes into consideration many biomotor qualities such as fundamental movement skills (FMS), sport specific skills (SSS), mobility, agility, speed, power, strength, hypertrophy, endurance and metabolic conditioning. In contrast, the LTAD model focuses on fewer physical qualities, for example, stamina, speed, strength, skill, suppleness and aerobic development. The LTAD provides a basic framework for the athlete, however this model does not provide a complete holistic approach for the athlete as seen in the YPDM. This article aims to critically review both models and provide strength and conditioning (S&C) recommendations for coaches training youth footballers.

The LTAD model focuses on training certain biomotor’s during “windows of opportunity” through stages of maturation. The YPDM instead targets all physical qualities throughout adolescence, with increased emphases during certain stages of maturation (Figure 1). The windows of opportunity as seen in the LTAD model (Figure 2) aims at training physical qualities before or after an athlete’s peak height velocity (PHV) to target and improve these qualities. There however, is limited evidence to support this approach (Bailey et al., 2010; Ford et al., 2011) and every athlete is different in terms of maturation therefore, biomotor's should be trained simultaneously in terms of overall athlete development.

Figure 1 – YPDM for Males. Font size highlights importance. Light blue boxes show pre-pubescent periods of adaptation and dark blue highlight adolescent periods of adaptation (Cited from Lloyd et al., 2012).

Figure 2 – The LTAD Model (Cited in Ford et al., 2011, From Balyi & Hamilton, 2004). * ABCs = Agility, balance and co-ordination, RJT = Run, Jump and Throw, KGBs = Kinesthetics, Gliding, Buoyancy, Striking with a body part and CKs = Catching, Kicking striking with body.

The YPDM and LTAD both underline the importance of biological age alongside chronological age and emphasise the importance of individual differences through maturation and PHV. The YPDM does not change the biomotor’s trained during PHV like in the LTAD, but instead highlights the biomotors to be developed dependent on maturation (Figure 1). For example, in the YPDM mobility has increased importance pre PHV, hypertrophy post PHV and endurance post PHV but all are still trained throughout childhood.

The FMS in the YPDM are essential movements for footballers such as jumping, landing, single leg balance, change of direction, deceleration, acceleration, squat, lunge, push, pull, brace and rotate. These movements need to be trained and developed so that an athlete can perform these movements well in sport situations (Higgs et al., 2008). If an athlete can perform these movements competently then they may perform complex movements better at a latter stage of adulthood (Oliver, Lloyd, & Meyers, 2012). Athletes struggling to perform FMS or individuals that neglect these skills have been shown to display sedentary behaviors and experience negative health benefits (Biddle, Pearson, Ross, & Braithwaite, 2010; Hardy, Reinten-Reynolds, Espinel, Zask, & Okely, 2012). Therefore, FMS should be the foundation of pre PHV S&C sessions to develop key motor skills and mastery of these skills have been linked to improved physical development (Lubans, Morgan, Cliff, Barnett, & Okely, 2010). In addition, a wide range of skills and techniques can be introduced pre PHV due to periods of brain maturation and the development of the neuromuscular system (Borms, 1986; Myer et al., 2013; Ungerleider, Doyon, & Karni, 2002). Circa and post PHV athletes can be challenged by increased complexity and introduced to more SSS, however, FMS will still be apart of athletes pre training or warm up routines (Lloyd & Oliver, 2012). The LTAD model however, uses ABCs, RJT, KGBs and CKs pre PHV to provide children with a base of key skills later for adolescence (See figure 2). These skills however, are not progressed or developed further throughout childhood in contrast to the YPDM. Therefore, the YPDM provides a more complete athlete programme for FMS and overall athlete development.

Strength training (ST) in the LTAD model is implemented post PHV whereas, is used throughout adolescent in the YPDM. ST prescribed with younger athletes is deemed safe as long as undertaken with qualified professionals (Baker et al., 2007; Behm, Faigenbaum, Flak, & Klentrou, 2008; Faigenbaum et al., 2009; Lloyd, Oliver, Meyers, Moody & Stone, 2012; Pierce et al., 2008). ST has been shown to improve bone mineral density in youth athletes (Álvarez-San Emeterio, Palacios-Gil Antuñano, López-Sobale, & González-Badillo, 2011; Blimkie et al., 1996), which may benefit athletes from repeated impacts during sports (Lloyd et al., 2012). The LTAD model focuses on ST post PHV due to adolescent’s increases in cross sectional area and androgen concentrations (Viru et al., 1999). However, limiting ST to just this period misses an opportunity to target neural and mechanical adaptations with younger athletes (Aagaard, Simonsen, Andersen, Magnusson, & Dyhre-Poulse, 2002; De Ste Croix, 2007). Athlete’s pre PHV have been shown to improve muscular strength through ST (Christou et al., 2006; Faigenbaum et al., 2001; Meylan, Cronin, Oliver, Hopkins & Contreras, 2014). Faigenbaum et al. (2001) results found higher reps (13-15) of moderate load to improve 1RM chest press strength (16.8%). Furthermore, muscular strength has been shown to have strong relationships with speed, agility, FMS and injury reduction in youth athletes (Behringer, vom Heede, Matthews, & Mester, 2011; DiFiori et al., 2014; Lloyd et al., 2014; Myer et al., 2014; Pierce, Byrd, & Stone, 1999). Therefore, ST is deemed necessary throughout adolescence to contribute to athlete development as seen in the YPDM.

Hypertrophy is targeted in the YPDM and LTAD model towards the end of the PHV period. During this periods levels of testosterone and growth hormones increase quickly in line with an athletes growth spurt (Malina, Bouchard, & Bar-Or, 2004; Viru et al., 1999). ST after PHV would target hypertrophy aimed at morphological adaptations to training as suggested in both models (Balyi & Hamilton, 2004; Lloyd et al., 2012). This is due to increases in muscle mass and force production post peak weight velocity (PWV) and PHV in athletes (Beunen & Malina, 1988; Ford et al., 2011). It has been shown that increases in cross sectional area as a result from ST can lead to increases in force production (Aagaard et al., 2001). Both models are similar in their training approach for hypertrophy and they work well in terms of an athlete’s development and maximising training opportunities.

Power considerations are not included in the LTAD model however, are apart of the YPDM. The ability to express high levels of power is crucial for team sports such as football (Young, 2006). Power should be trained throughout adolescence as improvements are seen as athletes mature and their ability to express force is improved (Beunen & Malina, 1988). Youth athletes have been shown to improve power performance measures (Chiodera et al., 2008; Lloyd, Oliver, Hughes, & Williams, 2012; Wong, Chamari, & Wisloff, 2010). Lloyd et al. (2012) results found a plyometric programme to improve leg stiffness and reactive strength index in athletes aged 12. Therefore, power training needs to be considered and the LTAD fails to mention this physical quality, which should be trained throughout adolescence as seen in the YPDM.

Speed is trained in two parts in the LTAD model. Speed one focus on efforts less than 5 seconds pre PHV and efforts of up to 20 seconds around PHV. In contrast, the YPDM trains speed throughout childhood and suggests that sprint and plyometric training are important components of speed (Lloyd et al., 2012). Speed improvements are generally a result of neural adaptations (Borms, 1986) but also maturation will impact this as well (Rumpf, Cronin, Pinder, Oliver, & Hughes, 2012). Neural factors such as motor unit recruitment, firing rates, and co-activation have been shown to develop with maturation and may improve sprint performance (Whitall, 2003; Lambertz, Mora, Grosset & Petot, 2003).

Rumpf et al. (2012) found athlete’s pre PHV to improve speed from plyometric and speed training. Results also found athletes post PHV to improve speed following a programme of ST, sprint training and plyometrics (Rumpf et al., 2012). Similarly, Diallo et al. (2001) found plyometric training to improve 20m running velocities in athlete’s pre PHV. Kotzamanidis et al. (2005) results showed 30m sprint times to improve (-3%) with a combined programme of strength and plyometric training in athlete’s post PHV. Plyometric training has also been shown to be beneficial for athletes sprint times circa PHV. Meylan and Malatesta (2009) found 10m sprint times to improve (-2.1%) with an 8-week plyometric programme (jumping, skipping and hurdling). Therefore, as shown in the YPDM speed and power training through plyometrics have to be trained throughout childhood as are beneficial to sprint performance but a combined approach may be preferred post PHV. Other considerations around PHV have to be considered as with increasing limb lengths and coordination challenges may lead to running technique being changed and speed decreases as an effect (Beunen & Malina, 1988; Philippaerts et al., 2006). Therefore, FMS such as running technique drills have to be apart of the athletes programme and may have to be developed again circa PHV. The LTAD does not consider plyometrics in its model and this has been shown to improve speed in younger athletes (Rumpf et al., 2012; Diallo et al., 2001; Kotzamanidis et al., 2005; Meylan & Malatesta, 2009). Therefore, the YPDM offers a more complete developmental model. A breakdown of how speed training may be implemented for youth athletes can be seen in figure 3.

Figure 3 – Long term model to maximise speed qualities through childhood and adolescence (Cited in Oliver, Lloyd & Rumpf, 2013).

Agility is a fundamental component in football and needs to be trained throughout childhood. However, research studies of agility and childhood trainability are lacking (Lloyd et al., 2012). Lower body reactive strength and sprint speed both influence change of direction in athletes (Young, James & Montgomery, 2002). In addition, plyometrics have positive effects on change of direction performance (Thomas, French & Hayes, 2009). Thomas et al. (2009) results found training drop jumps and countermovement jumps in athletes post PHV to improve change of direction times. Therefore, it seems appropriate to train agility alongside plyometrics, speed and strength training before and after maturation. Basic technique and FMS of agility may be trained during early childhood due to neural plasticity and the chance to develop key motor skills (Myer et al., 2011). Furthermore, as athletes mature and are able to produce more force and rate of force development (RFD) then agility can become more complex and progress to more SSS during adolescence. However, if some athletes experience a period of adolescent awkwardness (Philippaerts et al., 2006) during PHV then these key movements may have to be re-mastered (Lloyd, Oliver, Faigenbaum, Myer, & De Ste Croix, 2014).

Mobility or suppleness as referred to in the LTAD model is shown to be trained pre and post PHV but not during the windows of opportunity. In contrast, the YPDM trains mobility throughout childhood and extra emphasis was placed during early childhood (ages 5 to 11), as this is a key period to develop flexibility (Malina, 2007). In addition, another key opportunity is the time around PHV where some athletes may experience changes in motor skills and performance (Philippaerts et al., 2006) and the need to reestablish full range of motion (Lloyd & Oliver, 2012). However, the LTAD model and YPDM did not place increased importance for mobility circa PHV, which is just as important for athlete’s pre PHV. Mobility exercises can be used in warm ups to establish and develop key positions and ranges of motion without the presence of fatigue (Brooks & Cressey, 2013). The mobility drills used may reflect the sport and also certain movements that may be needed for the training session (Fletcher & Jones, 2004; Gambetta, 1997). Fletcher and Monte-Colombo (2010) found dynamic mobility exercises to be superior to static stretching exercises for improving 20m sprint and agility times. Therefore, mobility should be trained throughout childhood especially pre and circa PHV and then used in warm ups, recovery sessions and pre training routines post PHV.

Endurance and metabolic conditioning have been shown to develop throughout childhood and adolescence linearly with maturation (Bacquet, van Praagh, & Berthoin, 2003; Viru et al., 1999). During childhood the YPDM suggests the youth athlete will be exposed to enough of a metabolic stimulus through training and matches, therefore, does not need extra emphasis (Lloyd & Oliver, 2012). Moreover, in adulthood and professional football aerobic capacity can determine an athlete’s performance and level (Helgerud et al., 2001). Hence, an increased importance to develop aerobic capacity post PHV is shown in both models.

In conclusion, the LTAD models can be used by S&C coaches to structure their practice for athlete development. In terms of overall holistic development for the youth footballer the YPDM offers a more in depth model that provides all the key skills necessary for an athlete to progress through childhood. Overall athletes should engage in a programme tailored around the YPDM to ensure they remain injury free and increase levels of performance (Faigenbaum et al., 2001; Pierce, Byrd, & Stone, 1999; Rumpf et al., 2012; Wong, Chamari, & Wisloff, 2010). Both models provide a good framework to work from however these models can be adjusted to provide a more specific and individual approach.

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