INTRODUCTION

This case study examines the progress of a 15-year-old male athlete specializing in football training over a structured 14-month training program. The program, consisting of 4 days a week of training, was designed to improve explosiveness, speed, and overall strength. 

Key results from the program include:

Speed

• 40 Yard Dash (laser tested): Decreased from 4.92 seconds to 4.58 seconds (-0.34 seconds)

• 20 Yard Shuttle (laser tested): Decreased from 4.47 seconds to 4.32 seconds (-0.15 seconds)

Explosiveness

• Vertical Jump: Increased from 27 inches to 37 inches (+10 inches)

• Clean: Increased from 205 lbs to 300 lbs (+95 lbs)

• Broad Jump: Increased from 9’ 1” to 10’ 3” (+14 inches)

Strength

• Single Leg Squat: Increased from 180 lbs to 365 lbs (+185 lbs)
• Back Squat: Increased from 285 lbs to 385 (+100 lbs)
• Bench Press: Increased from 242 lbs to 325 lbs (+83 lbs)
• Body Weight: Increased from 207 lbs to 230 lbs (+23 lbs)

These improvements highlight significant gains in lower-body explosiveness, full body strength, and athletic ability, all of which are critical for success in football. This case study provides a detailed analysis of the athlete’s training program, methodology, and outcomes, demonstrating the effectiveness of following a structured strength and power development in young athletes. 

ATHLETE PROFILE

• Name: George Parkinson IV
• Primary Sport: Football
• Training Duration: 14 months
• Frequency: 4 days per week

“I feel 100% confident that this training system will help George get to the next level. Based on what college players are doing right now, his testing numbers alone prove he’s on that trajectory.” - George Parkinson III

TRAINING FOCUS

The athlete’s primary goals were to:

• Increase explosiveness and speed for better performance in football.

• Improve absolute strength to support the demands of his sport.

• Improve general athletic profile while gaining weight.

METHODOLOGY

The athlete followed a comprehensive, sport-specific training plan designed to enhance explosiveness, strength, speed, and coordination. The program integrated key elements of strength training, Olympic weightlifting, plyometrics, and speed training. Each training session included the following components:

Strength Training: Emphasis on squat variations, bench press, and upper body hypertrophy.

Technical Coordination: Dynamic Olympic weightlifting movements such as cleans from various positions to develop coordination and train fast twitch muscle fibers. 

Plyometrics: Drills designed to improve movement patterns, balance, and explosiveness.

Accessory Work: Core strengthening exercises, mobility drills, and isolation exercises for hypertrophy.

Speed Training: Max intensity speed drills to improve acceleration and top end speed.

“I’ve seen month over month improvement in George’s strength, speed, and overall athleticism. Along with a huge boost in confidence with his abilities on the field” - George Parkinson III

TRAINING PROGRESS AND RESULTS

Speed

40 Yard Dash: 

• Starting Point: 4.92 seconds 

• End Point: 4.58 seconds

• Improvement: -0.34 seconds (7%)

Analysis: The 40-yard dash improvement is a combination of maximal intensity training, locomotive technique, and foundational strength development. It is primarily supported by key lifts that boost explosiveness, stride power, and ground force production. This improvement reflects enhanced athleticism that directly boosts a rusher’s ability to win pass-rush reps, impact plays more consistently, and handle a wider range of responsibilities on the field.

Additional Context: A 40-yard dash time of 4.58 seconds would have been the 4th fastest result among defensive ends that attended the 2025 NFL Combine. This puts a 15 year old in the top 3% of all collegiate defensive ends tracked by the MathBomb 2025 Relative Athletic Score. 

20 Yard Shuttle: 

• Starting Point: 4.47 seconds

• End Point: 4.32 seconds

• Improvement: -0.15 seconds (3%)

Analysis: The improvement in the 20-yard shuttle is a direct result of increased lateral agility and enhanced reactivity. Strength gains in single-leg work, explosive lifts like the clean, and foundational lower-body power have improved the athlete’s ability to decelerate, change direction quickly, and reaccelerate with control. These improvements translate to sharper footwork, quicker reactions to offensive movement, and more effective execution of pass-rush counters and pursuit angles.

Additional Context: Both the 40-yard dash and shuttle tests were conducted with the VALD SmartSpeed Laser Timing Gate System on NCAA-compliant football fields. The use of the laser timing gates and proper facilities minimizes human error and ensures the most accurate results for the athlete. 

Explosiveness

Vertical Jump: 

• Starting Point: 27 inches

• End Point: 37 inches

• Improvement: +10 inches (37%)

Analysis: An increase in vertical jump height is a direct indicator of improved explosiveness and power, particularly in the lower body. A 10-inch increase is significant, as it suggests enhanced force production and efficiency during dynamic movements.

Additional Context: The vertical jump test was conducted using a Vertec Vertical Jump Trainer on a level surface. To ensure accuracy of testing results the Vertec Vertical Jump Trainer was selected over a force mat to minimize human error. 

Clean: 

• Starting Point: 205 lbs

• End Point: 300 lbs

• Improvement: +95 lbs (46%)

Analysis: The clean is a crucial lift for developing power and explosiveness. A 95-pound increase in the clean is a remarkable gain that showcases the athlete’s enhanced ability to generate force quickly. Additionally, the ability to receive and control a 300 lbs clean shows an elite level of force absorption which is crucial for a lineman. 

Broad Jump: 

• Starting Point: 9’ 1”

• End Point: 10’ 3”

• Improvement: +14 inches (13%)

Analysis: The increase in broad jump distance is a powerful indicator of enhanced full-body explosiveness. As one of the most direct expressions of force production through the hips, legs, and core, the broad jump reveals an athlete’s ability to generate and transfer power efficiently. For an edge rusher, this means a more explosive first step, stronger engagement off the line, and greater ability to close ground quickly.

Strength

Single Leg Squat: 

• Starting Point:180 lbs

• End Point: 365 lbs

• Improvement: +185 lbs (102%)

Analysis: The doubling in single-leg squat exemplifies the athlete’s increasing unilateral strength and stability. This is a direct indication of strengthened hamstrings and quadriceps which supports the improvement of speed results while still gaining weight. 

Back Squat: 

• Starting Point: 285 lbs

• End Point: 385 lbs

• Improvement: +100 lbs (35%)

Analysis: The increase in the back squat demonstrates a significant improvement in lower body strength, which is critical for football. The added squat strength provides a solid foundation for developing the explosive power necessary for playing the role of an edge rusher. 

Bench Press: 

• Starting Point: 242 lbs

• End Point: 325 lbs

• Improvement: +83 lbs (34%)

Analysis: For a 15-year-old, bench pressing 325 lbs with a 34% increase is exceptional and reflects advanced physical development. This result stems from consistent upper-body hypertrophy training, which has built muscle mass and strength, enabling more powerful hand strikes and better control of blockers, laying a strong foundation for future elite performance.

Body Weight: 

• Starting Point: 207 lbs

• End Point: 230 lbs

• Improvement: +23 lbs (11%)

Analysis: This 11% increase in body weight reflects healthy, purposeful growth fueled by hypertrophy training that has specifically developed muscle critical for performance. The added muscle mass enhances strength, power, and durability. These are key qualities that help the athlete engage blockers effectively, maintain leverage, and deliver explosive movements on the field. This targeted muscular development supports continued progress and improved athletic performance.

TRAINING OBSERVATIONS

• Absolute Strength: The strength gains in the back squat (35% increase), single leg squat (102% increase), and bench press (34% increase) demonstrate substantial improvements in total body strength, which provide a strong foundation for continued strength, power, and explosive development for the rest of his adolescent maturity. It additionally supports an elevated level of on-field performance compared to other individuals in his age range as these strength levels are above average compared to his peers. 

• Explosiveness: The athlete’s exceptional results in clean (300 lbs) and vertical jump (37 inches) both point to a significant enhancement in explosive power. This is crucial for the athlete’s performance in functional movement patterns such as running, jumping, and physical contact against opponents. 

• Speed and Agility: The improvements in the 40-yard dash (4.58s) and 20-yard shuttle (4.32s) reflect stronger acceleration, quicker lateral movement, and better control when changing direction. These gains are the result of increased lower-body strength and explosive power developed through targeted strength and speed training. On the field, this means the athlete will be faster off the line and more agile when reacting to offensive blockers. These qualities are essential for an edge rusher and will give him a clear advantage as he continues working toward competing at the collegiate level.

• Overall Athleticism: George Parkinson’s overall athleticism has advanced significantly, with major improvements in strength, explosiveness, and body composition. His 10-inch vertical jump increase, 14-inch broad jump gain, and 95-pound improvement in the clean demonstrate exceptional power development, particularly in the lower body. With increases in all areas of power expression, the athlete has significantly enhanced his athletic capacity for competing at a more advanced level of football.

CONCLUSION

Over the 14-month period, the 15-year-old defensive edge rusher demonstrated impressive improvements in key strength, explosiveness, and speed metrics. These metrics, combined with a 23-pound increase in lean mass, reflect a more explosive, durable, and physically dominant athlete. On the field, this translates to stronger engagements, quicker reactions, and more forceful movements in all directions. These gains will have direct applications in his performance on the field and provide a strong indication to keep him on track for a professional post-collegiate athletic career. Even at 15 years old, his current results would put him in the top 12% of collegiate defensive end/edge players tracked by MathBomb’s 2025 Relative Athletic Score. 

Additional Context: MathBomb’s 2025 Relative Athletic Score is a percentile-based system which compares verified the top athletes in the NCAA. Often composed of 3rd, 4th, and 5th year players, the 1-10 rating in each category is related to the percentile of an athlete’s performance compared to the other athletes in that position.

FUTURE RECOMMENDATIONS

• Continued Strength Development: Maintaining consistent strength training and getting the athlete physically stronger with an emphasis on lower body strength. A heavier squat result will allow for a stronger foundation for absolute strength against opponents. A 385 lbs squat is a great result for a rising sophomore in high school, but the goal is to exceed 500 lbs by the end of high school. 

• Maintain/Improve Speed: Continue to incorporate speed training into the overall program structure to maintain physical capabilities as he matures physically and gains weight. Improve rate of acceleration to attain top speed sooner and subsequently lower 40 time while enhancing on field performance. 

• Increase Muscle and Weight: Looking at the future demands of this athlete for his sport, he will need to increase his bodyweight to be competitive with other athletes at the collegiate level. Strength training and proper nutrition will play a key role in how much of any future weight put on is muscle, which will have a direct effect on strength and maintained athleticism.