Advanced Strength and Power Training for the Elite Athlete : Strength & Conditioning Journal (2024)

INTRODUCTION

The demands of elite sport are such that the time dedicated to developing physical qualities such as strength, power, and speed is delicately balanced with the need to compete and recover. Balyi and Hamilton (⁷) proposed a long-term athlete development model in which athletes progress through training phases such as the “fundamental” phase, “training to train” phase, “training to compete” phase, with the peak of their career in the “training to win” phase. Essentially, athletes in the “training to win” phase must prioritize their time well and develop highly efficient training means to compete successfully in their sport. The law of diminishing returns is well reported in the literature and states that as strength levels and training age increase, the returns from training diminish (^5,19,21). Baker and Newton (⁵) reported increases of just 5% in peak power over a 4-year period in well-trained rugby league players. Appleby et al. (²) reported that further significant increases in strength and power in this population are only likely to occur with an increase in muscle mass. However, with athletes in the “training to win” phase, it is likely that most will have found their optimal body composition for competing in their sport. Furthermore, the training volume required to gain an increase in lean mass must be balanced carefully with other training and competition demands. Alternative training means that provide a new stimulus without the need for an increase in training volume may be warranted in elite-level athletes.

Strength adaptations after a period of training are largely attributed to changes in neural function (improved motor unit recruitment, firing frequency, synchronization, and reflex activity) and an increase in muscle cross-sectional area (⁸). Other possible morphological adaptations include hyperplasia, substrate and enzyme adaptations, changes in fiber type, muscle architecture, myofilament density, and the structure of connective tissues and tendons (¹⁷). The intensity and duration of the muscular contraction, as well as the total volume load (repetitions × load) completed, are thought to be the important drivers of these adaptations (^2,8). Maximal or near maximal loads are traditionally administered when promoting changes in muscular strength because they tend to produce a greater intensity and duration of contraction, as well as contributing to greater amounts of total volume load performed (see reference ¹² for an extensive review). Lighter loads are typically used in the development of maximal power. Specific adaptations to power training are attributed to changes in neural control factors, such as reflex inhibition and facilitation, coactivation of antagonists, and greater synergistic involvement during multijoint movement patterns (⁸). Velocity-specific adaptations are also reported after power training (⁸).

The goal of this article is to summarize some of the research on advanced methods of training that may allow the elite athlete to attain significant gains in strength and power that may not occur with repeated exposure to traditional methods. For the purposes of this report, traditional methods are those exercises involving constant external resistance such as the squat, deadlift and bench press; ballistic methods such as Olympic-style lifts and jump squats; and plyometric exercises. These traditional methods have been reported to be effective in improving performance in trained and untrained individuals. Although some of the methods described in this review can be used with subelite athletes, it is suggested that pursuing more advanced or varied training methods may only be warranted when the effectiveness of traditional methods diminishes. This tends to occur with more experienced or elite-level athletes. The proposed advanced methods do not require any additional training volume or training time. They simply involve a manipulation of the traditional force-time and power-time curves to provide a new stimulus for adaptation. A multitude of proposed advanced or varied methods of preparation have been used by elite athletes, such as partial reps, occlusion training, functional isometrics, and electromuscular stimulation. The focus of this article will be on only 3 advanced methods: variable resistance training (VRT), eccentric training, and overspeed training (OST). Advanced athletes may be classified as those with a minimum of 5 years of resistance training experience; those who have demonstrated advanced strength levels (e.g., relative strength of 2 times bodyweight in the squat and 1.5 times bodyweight in the bench press); or those who have demonstrated a plateau in strength and power gains from traditional training methods.

VARIABLE RESISTANCE TRAINING

The goal of varying the resistance throughout the repetition is to match the strength curve for that exercise. There are 3 major types of strength curves: ascending, descending, and bell-shaped curves (¹⁶). An ascending strength curve is one in which it is possible to lift more load in the latter quarter or half of the repetition than when performing a complete repetition. An example of an exercise with an ascending strength curve would be the bench press, squat, or deadlift. A descending strength curve is one in which it is possible to lift more load in the initial quarter or half of the repetition than when performing a complete repetition. An example of an exercise with a descending strength curve is a bench pull or upright row. Finally a bell-shaped curve, typical of most single-joint exercises, is one in which the most load can be lifted in the mid range of the exercise. An example of this type of exercise would be an arm curl.

Variable resistance is usually provided by the use of heavy elastic bands or chains. The length-tension relationship is such that a muscle provides maximal force close to its resting length (¹⁵). However with traditional exercises, such as the squat or bench press, the load lifted is determined by the strength at the weakest point in the range of motion. Essentially, for much of the concentric phase, the neuromuscular system is being stimulated submaximally, even at so-called “maximal” loads. Variable resistance training aims to redress this situation by increasing load exposure progressively throughout the range of motion. In this way, the VRT compliments the length-tension relationship and the strength curve of the exercise. The athlete, as a consequence, works closer to maximal contraction levels throughout the concentric phase.

The nature of the band properties are such that the resistance increases in a curvilinear fashion throughout the range of motion (²⁰). However, the chain resistance increases in a linear fashion throughout the concentric range (²⁰). Furthermore, as the chain hangs, it will oscillate, adding further to the variability in the resistance. Therefore, while both bands and chains provide a form of VRT, each method exposes the athlete to a somewhat unique stimulus. Each will produce slightly different kinematic and kinetic responses for a given exercise. There are a number of companies that now manufacture resistance bands with different bands appropriate depending on the exercise selected and the amount of tension required. The use of chain resistance, although common in the powerlifting community, has received less attention in the literature than band resistance. Further research is required to validate their use in the resistance training program in athlete populations.

Wallace et al. (²⁹) have shown that band resistance in the squat exercise, which produces 10% more resistance at the end of the concentric phase and 10% less at the start (bottom of squat), produced greater levels of peak force and power than an equivalent constant resistance load (85% 1 repetition maximum [1RM]). Using a similar protocol in a 7-week training study, Anderson et al. (¹) reported combined elastic band and resistance training to improve 1RM squat and bench press by 16 and 8%, respectively. This was in contrast to the traditional training group who experienced a 6 and 4% increase in squat and bench press, respectively. The differences between the 2 training groups reached statistical significance (p < 0.05). The magnitude of the difference between the groups is of particular significance for the practitioner.

Similarly with lighter loads in the range of 40–60% 1RM, the addition of band resistance has shown superior improvements in strength, power, and rate of power development in comparison with traditional methods (^19,24). Positive results have also been demonstrated with VRT for the bench press exercise in both strength and power after training periods (^18,19). Baker and Newton (⁶) reported a 10% increase in concentric lifting velocity with the use of a 17.5-kg chain resistance added to a 60% 1RM load in the bench press in comparison with a standard bench press in professional rugby league players. These research reports add support to the anecdotal evidence of the effectiveness of VRT training with elite athletes (²⁸). More research is required to provide firm recommendations on exercise selection, repetition, and set schemes. However, based on the research evidence to date, Table 1 outlines the author's recommended guidelines for a training program design for VRT as a component of a periodized plan. More training studies are required to verify the positive benefits of chain resistance. It must be highlighted that although manufacturers of band products often state training guidelines for their products, differences in band set-up from facility-to-facility will affect the magnitude of the tension. Therefore, each facility should measure resistance of bands and chains using their own unique set-up.

ECCENTRIC TRAINING

The submaximal performance throughout much of the concentric phase of the traditional lifts is not the only mechanical disadvantage of these exercises. Individuals can reportedly produce 20–60% more force eccentrically than concentrically (¹¹). However, load selection in the traditional lifts is determined by the concentric ability of the athlete. Therefore, the athlete is trained submaximally throughout the eccentric phase. A recent report by Cook et al. (¹⁰) demonstrated superior gains after a period of maximally loaded eccentric training (with the assistance of spotters concentrically) in comparison with traditional methods of training. They attributed the greater gains to the higher absolute forces experienced by the neuromuscular system. This type of loading is referred to as supramaximal eccentric training, in which one attempts to lift maximal or close to maximal eccentric loads. Bette et al. (⁹) reported an increased recruitment and hypertrophy of the highest threshold fast-twitch fibers in response to heavy eccentric training in a group of strength-trained athletes. This type of training is therefore likely to also result in an improvement in high-velocity contractions. It is important, however, to highlight that eccentric contractions cause greater muscle damage than concentric contractions (²³). The increase in eccentric intensity could be tempered by a reduction in training volume to control the overall muscle soreness response. This training type should be progressed gradually to prevent a sudden and steep increase in training-related muscle damage.

A second method of eccentric training receiving research attention is that of augmented eccentric training. Augmented eccentric training involves fewer loads than supramaximal eccentric training; however, exercises are designed such that the eccentric load is superior to the subsequent concentric load. For example, Sheppard et al. (²⁶) demonstrated an increase in countermovement jump peak power with the use of an eccentric overload using dumbbells. The dumbbells were dropped at the bottom of the countermovement before the athletes immediately jumped upwards. Sheppard and Young (²⁷) reported an increase in bench throw performance with an eccentric overload facilitated with the use of weight releasers. Doan et al. (¹⁴) have also demonstrated an augmented eccentric load to acutely enhance 1RM bench press. Although lacking in research evidence at this time, the authors suggested that the likelihood of the acute findings improves performance chronically after a period of training.

The mechanisms behind the enhancement with augmented eccentric training are believed to be similar to those, which cause drop jump height to be superior to countermovement jump height. Namely, an increase in storage of elastic energy, stimulation of afferent nerve impulses, increase in tendon elongation allowing muscles to act closer to optimal length for tension generation, and an increase in the active state of the muscle tendon unit (²²). Regardless of the mechanisms, both augmented and supramaximal eccentric training show potential for a varied stimulus for the elite athlete showing limited gains with traditional methods. More research is required to prescribe firm scientific guidelines on how to program appropriately when designing eccentric training programs. Based on the evidence to date, however, the author outlines recommendations for program prescription when designing eccentric training programs in Tables 2 and 3.

OVERSPEED TRAINING

Power is the product of force and velocity. In a fluid of low density such as air, an inverse relationship exists between the two. Therefore, the addition of extra load to an exercise tends to result in an increase in force but a reduction in velocity. When attempting to improve unloaded athletic movements, such as jumping, sprinting, and changing direction, most strength and power training practices focus on improving aspects of force production. However, an increase in resistance load will tend to result in an acute reduction in concentric shortening velocity. The practice of OST, however, allows the athlete to train at supramaximal concentric shortening velocity, providing a unique stimulus for the athlete. This form of training is also thought to result in a reduction in antagonist coactivation and a possible increase in high threshold fast-twitch fiber recruitment (¹⁰). Adapted from overspeed sprinting, assisted jumping involves a reduction in body mass with a resultant increase in concentric movement velocity. The reduction in body mass is typically facilitated by the use of an overhead bungee or heavy elastic band attached to a total body harness. Cronin et al. (¹³) reported an 8.4% increase in peak velocity and a 14.3% increase in single leg jump peak power after 10 weeks of assisted jump training. Argus et al. (³) performed an acute and chronic study comparing assisted, resisted, and traditional jump training. The acute study demonstrated a higher peak velocity in the assisted jump, which off-set 10% of the athlete's body mass in comparison with the other 2 jump types. To offset 10% of the athlete's bodyweight, each individual is required to stand on a force plate or weighing scales with band assistance progressively applied until the bodyweight is reduced by the required amount. Furthermore, after 4 weeks of training in professional rugby players, assisted jumping provided superior gains in countermovement jump performance in comparison with the resisted or traditional jumping program. Sheppard et al. (²⁵) have also demonstrated an 11% increase in vertical jump height after 5 weeks of assisted jump training in elite volleyball players. The results of these studies are particularly significant, considering the advanced levels of the athletes involved. Positive results with this type of training have been reported with a 10–30% reduction in body mass in the standing position. Further research is required to provide firm scientific guidelines on the appropriate design of OST programs. However, the author outlines some guidelines based on the research to date for the design of OST programs in Table 4.

CONCLUSION

In summary, by manipulating the typical force-time and power-time curves of traditional training methods, VRT, eccentric training, and OST provide a varied and novel stimulus for advanced athletes that may allow them to break through strength and power plateaus. Including these methods in the periodized plan of advanced athletes or prescribing methods based on an individual needs, assessments are likely to improve the athletic performance of this population. In the yearly plan of an elite athlete, the addition of VRT in the first mesocycle (i.e., 2–6 weeks) followed by the introduction of some supramaximal or augmented eccentric training in the second mesocycle may provide a greater stimulus for strength and power adaptations than traditional methods. Subsequent to this, the addition of VRT in a power training cycle with some OST may provide further novel stimuli to allow the athlete progress to new levels of athletic performance.

REFERENCES