Jumping tasks, whether they are vertical or horizontal, should be included regularly in strength and conditioning programs.  Jumps are part of a larger skill set needed to be successful in sport competitions. In some instances, the ability to jump higher or farther than another competitor will determine who wins the competition, while the repetitive nature of jumping tasks in other sports does not determine the winner. In team sports, jumping tasks may be used during rebounding in basketball, spiking/blocking in volleyball, diving in baseball, etc. While impulse may ultimately determine the jumping performance of an individual [1], distinct force-time characteristics may determine the spike and magnitude of the impulse created [1,2]. Greater maximal muscular strength may modify the force-time characteristics of an individual. Specifically, increasing maximal muscular strength achieved through resistance training can alter both peak performance variables as well as the shape of the force-time curve [3-6]. 

1. Garhammer J, Gregor R. Propulsion forces as a function of intensity for weightlifting and vertical jumping. J Strength CondRes. 1992;6(3):129–34
2. Sole CJ. Analysis of countermovement vertical jump force-time curve phase characteristics in athletes [Doctoral Dissertation].Digital Commons: East Tennessee State University; 2015.T. J. Suchomel et al.123
3. Mizuguchi S. Net impulse and net impulse characteristics in vertical jumping: East Tennessee State University; 2012. 
4. Cormie P, McGuigan MR, Newton RU. Adaptations in athletic performance after ballistic power versus strength training. MedSci Sports Exerc. 2010;42(8):1582–98
5. Cormie P, McBride JM, McCaulley GO. Power-time, force-time, and velocity-time curve analysis of the countermovement jump: impact of training. J Strength Cond Res. 2009;23(1):177–86
6. Cormie P, McGuigan MR, Newton RU. Changes in the eccentric phase contribute to improved stretch-shorten cycle performance after training. Med Sci Sports Exerc. 2010;42(9):1731–44.

There is previous literature that has examined the influence of muscular strength on various factors associated with athletic performance and the benefits of achieving greater muscular strength. Greater muscular strength is strongly associated with improved forcetime characteristics that contribute to an athlete’s overall performance. Much research supports the notion that greater muscular strength can enhance the ability to perform general sport skills such as jumping, sprinting, and change of direction tasks. Further research indicates that stronger athletes produce superior performances during sport specific tasks. Greater muscular strength allows an individual to potentiate earlier and to a greater extent, but also decreases the risk of injury. Sport scientists and practitioners may monitor an individual’s strength characteristics using isometric, dynamic, and reactive strength tests and variables. Relative strength may be classified into strength deficit, strength association, or strength reserve phases. The phase an individual falls into may directly affect their level of performance or training emphasis.

Based on the extanted literature, it appears that there may be no substitute for greater muscular strength when it comes to improving an individual’s performance across a wide range of both general and sport specific skills while simultaneously reducing their risk of injury when performing these skills. Therefore, sport scientists and practitioners should implement long-term training strategies that promote the greatest muscular strength within the required context of each sport/event. Future research should examine how force-time characteristics, general and specific sport skills, potentiation ability, and injury rates change as individuals transition from certain standards or the suggested phases of strength to another.

Suchomel, Timothy J., et al. “The Importance of Muscular Strength in Athletic Performance.” Sports Medicine, vol. 46, no. 10, Feb. 2016, pp. 1419–1449.

 

We prefer to utilize a variation of contrast training to elicit a higher level of explosive strength and reactiveness in the athletes that train here at Zelos Athletics. The method is designed to apply more stress on the athletes, provoking greater neurological and physiological adaptations to maximize explosive strength and speed. It works by performing a heavy, multi-jointed exercise followed by a plyometric movement that is biomechanically similar. A heavy set followed by an explosive exercise that is typically deloaded, meaning you can use assistance, or resist the jump. This combination of exercises that are paired together increases the amount of muscle fibers that are recruited to perform a movement, as well as the speed at which those fibers are recruited; bringing about potentiation. For example, the multi jointed lift can be a squat, followed by a box jump. This increases the speed at which your muscles can produce force; leading to an increase in the rate of force development the athlete can produce.

What a great message from Taylor Cummings on Body Image! Love it!!! 

I wanted to make some points about hydration so you have some scientific reasoning as to the why your youth athlete should be drinking water every day.  First, water is the largest component of our bodies, accounting for about 45-75% of our total body weight.  Second, water acts as a lubricant, shock absorber, and solvent.  Maintaining a positive fluid balance aids in nutrient transport, which means getting the converted sugars from food to the right places for when we are training and recovering.  Third, it is essential for the body’s temperature regulation; during training we lose water through sweat which helps keeps our skin cool once we reach a certain threshold.  Post training your youth athlete should be hydrating 150% of what he/she sweats out; we don’t have the tools at our facility to objectively measure what the athletes loses pertaining to sodium and nitrogen during a single training bout.  However, if your youth athlete is unable to complete their training for the day, this may be caused by dehydration.  What can happen is (if not taking in fluids) they may exceed his/her hydration status, which means once he/she starts to sweat from training, he/she may be sweating out more than what is available for that function. 

A couple things about dehydration, adolescents and kids are at greater risk of dehydration than adults are resulting from an increase in gaining heat from the environment because of the greater surface ratio compared to adults.  Increased heat production during training, a decreased ability to dissipate heat through sweat, and a decreased sense of thirst compared to adults. This all can lead to a decrease in athletic performance, increasing fatigue; can lead to a decrease in motivation in some cases, decrease in neuromuscular control, accuracy, muscular strength, muscular endurance, and overall general performance.  Dehydration can increase the core body temp, reduce stroke volume (the amount of blood pumped per beat), cardiac output, decrease in blood pressure, reduction in blood flow (thickening of the blood), increase in heart rate, increase the risk of heat stroke, and rhabdomyolysis (which is very dangerous). 

What I can recommend for your youth athlete is that they drink water daily to satisfy their body being in a hydrated state every day.  Signs they can monitor for themselves is what color their urine is when they goes to the bathroom. If dark yellow, he/she should drink 12oz of water ASAP.  A lighter the color is a good indication of chronic hydration.  What may skew their assessment of hydration can be consuming beets, blackberries, B vitamins, and certain medications may turn the urine dark yellow, bright yellow, pink, red, or orange. 

A quick way to estimate hydration status can be having your youth athlete weigh in at the begin training, and again concluding training.  Preferably with minimal clothes on to get an objective estimate of his/her bodyweight.  An example of this can be without a shirt, or shoes.  This is something he/she can do on their own, privately in a bathroom here at our facility, and recording his/her weight on the daily workout card.  Additionally, tracking bodyweight over time can assess changes over time which may help to identify chronic dehydration.  For example, losing several pounds over the course of a few days. 

To wrap this up, your youth athlete should be aiming to avoid losing more than 2% of their bodyweight at the conclusion of every training bout, and hydrating during training.  He/she should be prehydrating before training to allow for fluids to be absorbed, and post training replacing fluid and electrolyte (sodium, potassium, chlorine) loses, by way of drinking water and post workout meals (protein, and carbs).  For an aggressive approach, if dehydrated, he/she can consume 1.5L of fluid per kilo (1lbs = 2.2KG) of bodyweight lost immediately.

Recommendations for youth athletes   

Four hours before event (training session, or athletic event): 

• Consume appx 5-7ml (0.16-0.23oz) water or sports drink per KG bodyweight
• Example, if he weighs 100lb, that’s 45kg x 0.19 = 8.56oz of fluids

Two hours before event recommendations:

• If not adequately hydrated, sip on 3-5ml (0.1-0.17oz) of fluid per KG bodyweight

During event recommendations:

• Adolescents weighting 60KG (132lb) should drink 9oz every 20 minutes even if they don’t feel thirsty 

Journal of Applied Physiology 1992 73:4, 1340-1350