Throwing is a fundamental motor skill that consolidates during the first decade of life. Learning how to throw represents a landmark in the cognitive and physical development of children, especially between the age of 4-5 years old and the age of 8-9 years old, a narrow window of time also known as the “golden age of motor learning”. Overarm throwing mechanics improve throughout childhood and soon evolves into more advanced skills such as throwing a javelin or putting a shot. Youth athletes age 9-12 practice basic throwing drills with 6 pounds shot puts and 300 gr mini javelins, with no difference between boys and girls. It is not until the onset of puberty – between the age of 11 and 13 years old for the female athlete and between the age of 12 and 15 years old for male athletes – that implements progressively become heavier and young athletes start throwing the discus and the hammer.
The circa-pubertal phase represents a relatively common landmark for sports specialization among strength and power athletes. As young throwers become faster and stronger, their throwing mechanics changes to accommodate more speed. Strength – relative strength, a better estimate of the change in the rate of force development occurring during early adolescence – does, therefore, become a limiting factor in the developing elite level throwers, as stronger and more powerful athletes can better handle linear and/or rotational speed. It is not unusual for a 12-15 years old thrower to experiment with different implements, of different size, shapes, and weights. The use of overweight and underweight implements in the training of youth athletes does represent an excellent way to increase speed and strength in a time where boys and girls are more likely to adapt and improve their throwing mechanics.
However, there is only a limited amount of time that can be spent working with heavier and/or lighter implements – 10-15% heavier and/or lighter than a regular discuss or shot put, 10-14 pounds for a 14-15 years old boy and 6-10 pounds for a girl – and only a limited amount of weight that can be used before throwing mechanics starts deteriorating. Longer periods of time practicing with overweights can make athletes, especially young athletes, slower by changing their timing to the point that speed or release starts to decrease. Strength training does, therefore, become a priority in developing elite level throwers: by the time young athlete turn 13-14, heavy strength training – back squats, front squats, bench press and weighted pulls – and explosive strength training – depth jumps, drop jumps, snatch, clean and jerk – are necessary to develop a solid foundation of general strength while reinforcing fundamental motor patterns that strongly relate to throwing mechanics.
Boys and girls age 9-11 should learn how to squat – back squat and front squat – practicing with lighter weights at first: strength training should incorporate low-impact plyometrics such as jumps, hops, leaps, and bounds, and weighted pulls (pulls and high pulls) in the effort to consolidate a solid foundation in Olympic style weightlifting. By the age of 12-15 years old, male athletes with two or more years of experience in strength training should be able to squat 1.2-1.4 times their bodyweight and female should be able to squat 0.9 to 1.1 times their body weight. It’s not until puberty that the discrepancy between male and female athlete in terms of absolute strength becomes significant; however, if properly trained, pound per pound female athletes should be no more than 12-15% behind male athletes with similar training experience when it comes to relative strength.
As athletes become faster and stronger, snatch, clean and jerk should be incorporated into their training in the attempt to prioritize peak vertical bar velocity over weight, namely power over absolute strength. Throwers aged 14-17 with three to four years of strength training experience should be able to back squat 1.6-2 times their body weight. Their training includes a combination of submaximal weights (ranging anywhere between 75 and 85% of 1RM), plyometrics and only a small percentage, less than 5% of the total volume of training, of weights above 90% of the 1RM. It’s only in the late developmental stage (male and female athlete 17 years old or older) that strength training becomes a predominant aspect in the development of elite level throwers. Up to 40% of the total volume of training for athletes age 21 years old or older includes a higher percentage of heavy strength training with weights ranging between 80% and 90% of 1RM. Strength – absolute strength – does become a limiting factor among elite level throwers, and strength training per se – heavy back squat, deadlift, bench press, pull and high pulls – becomes more and more predominant as athletes approach full maturity, between the age of 19 and 21 years old.
Despite the weight of the implement – 800gr for men and 600gr for women, the lightest implements in throwing events – elite level javelin throwers need to be able to back squat anywhere between 150 and 220 Kg, snatch 85-125 Kg, clean and jerk 115-160 Kg in order for them to throw 70-75 meters (for women) and 85-90 meters (for a men). These numbers significantly increase as the weight of the implements increase. Elite level shot putters and hammer throwers back squat up to 300Kg (men) and 200Kg (women), and total more than 220-285 Kg in the snatch, clean and jerk. Discus throwers normally fall in between shot putters and hammer throwers – by far, the strongest athletes in track and field – and javelin throwers with back squats up to 200-250 Kg, snatch up to 110-130 Kg and clean and jerk up to 130-160 Kg. Strength, for these athletes, is nothing but the consequence of a process of specialization in sport that includes heavy strength training from a very young age.