Abstract
Maximal power production of the upper body incorporating the bench throw with different loads of 1RM were analysed. Sports and exercise science student were subjects and performed a maximal 1RM bench press to determine the loads for the bench throws. Loads completed include 20,30,40,50,60 and 70% of 1RM bench press to determine where the maximal power production and maximal velocities occurred. Results showed that maximal power production occurred around the 60% of 1RM while maximal velocity occurred at 20% of 1RM. Loads at 60% of 1RM in untrained and recreational subjects is best used when training to overcome an external load as in rugby league, rugby union or wrestling. Loads at 20% of 1RM is best used when training athletes in striking, throwing and hitting sports that require greater velocity of movement. When training for power and velocity a minimum of 2 to 3 repetitions and a maximum of 5 to 6 repetitions is suggested.

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Introduction of power training for athletic development programs typically reveal a majority of Olympic lifting (e.g., clean, power clean, snatch) or plyometric exercises (e.g., bounding, jumping) to increase muscular power (1,2). While these exercises are a great way in developing lower body power, methods for developing upper body power have not been explored in the same extent.

Maximal upper body power production is an important aspect of training for sports that require a pushing (e.g., rugby league, rugby union) or striking movement (e.g., boxing, martial arts) as well as hitting sports (e.g., tennis and baseball) (3).

The purpose of this study is to outline the different requirements sports have in regards to the most effective way to employ the bench throw into a periodised training program to develop maximal power production in their chosen sport.

Methods
Experimental Approach to the Problem: Each participant of this study was required to complete a 1 repetition maximum (1RM) bench press and complete bench throws at 20%,30%,40%,50%,60% and 70% of 1RM. Assessment of 1RM bench press was necessary to establish the relative loads for the bench throw at each percentage of 1RM. Each participant performed both the 1RM bench press and bench throws in the same session.

Subjects: Subjects included 16 men all of whom were undergraduate students in Sports and Exercise science (mean ± SD, weight =78.7 ± 9.9kg, height= 179.8 ± 7.9cm). Each participant had varying degrees of weight training experience, however it is predicted that training the majority of students have had weight training experience due to the nature of the course of study.

Procedures: 1 Repetition Maximum Bench Press To determine bench press strength, subjects underwent 1RM testing. Bench press 1RM was measured as the maximum amount of weight that could be eccentrically lowered and concentrically lifted one time throughout the full range of motion. The bench press was completed on a standard bench with an Olympic bar and standard cast iron plates.

Participants were positioned supine on the bench with their head, shoulders and buttocks in contact with the bench at all times. Both feet were placed flat on the floor. The bar was aligned with the eyes of the lifter and the subjects were asked to grasp the bar just wider than shoulder width (4). Each subject was instructed to remove the bar from the rack position and complete one repetition consisting of an eccentric and concentric contraction finishing with full extension of the arms.  If the participant was successful, the weight on the bar was increased and another attempt was completed until a failed 1RM attempt occurred where the previous lift was recorded as the subjects 1RM.

Bench Throw: Upper body power production was assessed using a bench throw that was set up in a smith machine (Elite Fitness) that only allows vertical movement. The subject was set up in the same fashion as the bench press however the bar was set up parallel to the nipple line. In each of the lifts the bar was set up with a predetermined weight accounting for a percentage of the subjects 1RM. After each throw weight, power production (watts) and velocity (m/sec) was recorded. The Power production and velocity was recorded using a GymAware power production unit (Kinetic Performance Technology, Australia). Each subject worked in a group of four to allow for adequate recovery between each throw.

Statistical Analysis: The following values were used to determine the relationship between two variable, r values: 0.0 to 0.29 = weak; 0.30 to 0.59 = moderate; 0.60 to 0.84 = strong; 0.85 to 0.99 = very strong; 1.00 = perfect relationship. The statistical analyses uses means ± standard deviation (mean±SD).

Results
Peak power (PP) production occurred between 50-70% 1RM and ranged from 193W and 577W (Table 1). PP plateau at around 60% of 1RM (Figure 1). Velocity showed an inverse relationship as power production increased when comparing means at each throw (Figure 1).There was a weak inverse relationship (r= -0.17) when comparing the power of every throw with the velocity.

11 subjects recorded 1RM loads equal to or greater than their measured body weight, while 5 subjects recorded less than their measured body weight. A significant difference (p=<0.05) was shown between subjects with a 1RM≥ Body weight (BW) and subjects with a 1RM<BW when comparing 1RM, no significant difference occurred when comparing body weight of both groups (Figure 2). A significant difference was shown when comparing peak power (p=0.039) and peak relative power (p=0.007), however peak velocity showed no significant difference (p=0.134).

Body weight and peak power production showed a very strong positive relationship (r=0.937), while body weight and peak relative power (PRP) showed a strong positive relationship (r=0.879) when looking at all subjects. Weight and 1RM of all subjects showed a moderate positive relationship (r=0.546).

Discussion
The objectives of this study were to determine the best weight to be used when training for maximal upper body power production for a range of sports that utilize a pushing, striking, hitting or throwing movement. Taking into consideration the force required to overcome the weight of an opponent as in rugby league, rugby union or martial arts, or the best way to increase the speed and power relationship required when sticking a tennis ball or throwing a baseball requires different levels of power and velocity production.

The results showed that maximal force production occurred with a load of 60% of 1RM, therefore suggesting that power training is best utilised at this load. However research has suggested that power output is greatest at 70-80% of 1RM (5). This difference could have occurred due to the experience disparity between the subject groups with the study using elite and sub-elite rugby league players who are currently playing in the 1st division (NRL) or 2nd division and have a training history of 4 years in regards to maximal strength and power development when compared to the group used for this study where training history is not stated. This study suggest that for inexperienced athletes training at a load of 60% of 1RM will aid in the development of maximal strength and increase power production and benefit an athlete looking to overcome significant weight as in an opponent in rugby league, rugby union or martial arts as well as having the effect of increased hypertrophy (5).

Previous work relating to the force velocity relationship has demonstrated that at a load of 30% 1RM maximal mechanical power output is attained (6). Baker suggests that maximal power production may occur between 10kg to 40kg load in boxing and throwing related sports that require greater speed contribution (3). 10kg to 40kg relates to a 1RM between 11% and 46% in regards to the mean 1RM displayed in this study, therefore agreeing with the earlier recommendation that loads of 30% 1RM are best utilised to increase maximal mechanical power in sports that require greater concentration on velocity of movement when undertaking activities like throwing or hitting opposed to maximal power production to overcome an external force as in rugby league.

The difference in our data between those subjects that achieved a 1RM≥ BW and those that achieved a 1RM<BW suggests that prior training in maximal power and/or maximal strength was a factor. Body weight of the subject was not a good indicator in predicting 1RM as there showed no significant difference between both groups, therefore when prescribing strength or power training exercises for athletes individual testing is needed to predetermine training loads.

Range of repetition during power training sessions have been noted as having an effect on the outcome of achieving maximal power. With maximal power production occurring at the second or third repetition and declining rapidly after 5 or 6 repetitions when using loads between 30-45% of 1RM, it is suggested to train a minimum of 2 to 3 repetitions and a maximum of 5 to 6 repetitions when maximal power production is the goal (3,7). Power endurance based athletes may entail higher repetitions of 10 to 20 repetitions as they have different training objectives however, it is advised to remember that power levels drop significantly after 5 or 6 repetitions and may  (7).

Practical Application
This study has demonstrated that maximal power production occurs at around 60% of 1RM in untrained and recreational subjects and is best used when training to overcome an external load as in rugby league, rugby union or wrestling. Maximal velocity occurs at 20% of 1RM and is best used when training athletes in striking, throwing and hitting sports that require greater velocity of movement. Coaches need to be aware that training at maximal power or maximal velocity or somewhere in between the continuum will depend on the athlete or chosen sport and its requirements. When training for power and velocity a minimum of 2 to 3 repetitions and a maximum of 5 to 6 repetitions is suggested.

Table 1- Description of subjects and results of strength and power. Figure 1- Power and Velocity curve expressed at varying percentage of 1RM Max Bench Press. Values are Mean ± SD. N=16.

Figure 2- Body weight and 1 repetition maximum for subjects with a 1RM≥Body Weight (n=11) and 1RM<Body Weight (n=5) and the overall group (n=16). Values are means ± SD.

References

1.    Baker DG and Newton RU. Selecting the appropriate exercises loads for speed strength development. Strength Cond Coach  3: 8-16, 1995
2.    Haff, GG, Whitley, A and Potteiger, JA. A brief review: Explosive exercises and sports performance. Strength Cond. J 23: 13-20, 2001.
3.    Baker DG and Newton RU . Methods to increase the effectiveness of maximal power training for the upper body. Strength and Conditioning Journal 27: 24-32. 2005
4.    Delavier, Frederic. Strength Training Anatomy Second Edition. Champaign, IL: Human Kinetics, 2006.
5.    Baker DG and Newton RU. Adaptations in upper-body maximal strength and power output resulting from long-term resistance training in experienced strength-power athletes. Journal of Strength and Conditioning Research 20: 541-546, 2006
6.    Kaneko, M, Fuchimoto, H, Toji, H, Suei, K. Training effect of different loads on the force-velocity relationship and mechanical power output inhuman muscle. Scand. J. Sport Sci 5: 50-55, 1985.
7.    Baker DG and Newton RU . Change in power output across a high repetition set of bench throws and jump squats in highly trained athletes. Journal of Strength and Conditioning Research 21: 1007-1011, 2007.