This guide is for high school pitchers and the parents and coaches who help them. It covers what is realistic, what research says actually moves velocity at this age, and how to lay out a year so the gains keep coming. If you want the general version for any age, read our guide on how to increase pitching velocity. If you just want the short list, start with how to throw harder.
What is realistic in high school
There is no official velocity chart by grade, and anyone who gives you one without a source is guessing. What we do have are data points from published studies and from training facilities that report their own numbers:
- In-game velocity, ages 13 to 18. Zaremski and colleagues (2024) followed 71 pitchers aged 13 to 18 over several seasons. In-game velocity averaged 71.3 mph and ranged from 46.8 to 85.7 mph. That spread is the point: high school rosters include pitchers at very different stages.
- A national high school sample. Bowman and colleagues (2023) measured 115 high school pitchers from four US regions. Average fastball velocity was 66 mph in pitchers who had not used a weighted ball program and 71 mph in those who had.
- Adolescent vs. college. Kageyama and colleagues (2015) measured pitchers aged 12 to 15 at 30.7 m/s (about 69 mph) and college pitchers aged 18 to 22 at 35.2 m/s (about 79 mph).
- Year-over-year gains. Driveline's academy data (2021) showed expected average gains of around 3 mph per year for 14U to 16U players, compared with around 5 mph per year for 9U to 11U players. That is one facility's training population, not a guarantee, but it is a useful benchmark.
The practical message: compare yourself with yourself. A sophomore who goes from 68 to 72 mph in a year is making real progress, even if a teammate already throws 80.
Growth and maturation set the timeline
Two 15-year-olds can be several years apart biologically. Earlier maturers often throw harder sooner simply because they are bigger and stronger, and later maturers often catch up or pass them. Our article on bio-banding in youth baseball explains why chronological age is a poor yardstick during these years.
Fleisig and colleagues (1999) compared youth, high school, college and professional pitchers and found that body positions and timing were mostly similar across levels, while joint torques and arm speeds rose with level. The authors concluded that higher-level pitchers most likely produced more velocity because of greater strength and muscle mass, and that the natural progression is to learn sound mechanics early and build strength as the body matures. That is close to a blueprint for high school training.
Strength, power and body mass
Bigger, more powerful athletes tend to throw harder. In 33 Division I college pitchers, King and colleagues (2025) found that body mass was the strongest single predictor of peak fastball velocity, followed by lean mass, and that absolute lower-body power (not jump height) also predicted velocity. In 32 junior high pitchers, Hsiao and Lee (2025) found that absolute braking force in a countermovement jump and body height together explained 43% of the variance in fastball velocity.
For a high school pitcher, that points to a simple priority list:
- Lift two or three days a week, year-round, with lower-volume maintenance work in season. Squat, hinge, lunge, push, pull and carry patterns, progressed under supervision.
- Train power, such as jumps, med ball throws and sprints, in small doses with full rest between reps.
- Eat enough to grow. Many high school pitchers are trying to add muscle while undereating. Our nutrition guide for pitchers covers the basics.
Oyama and Myers (2018) also found that push-off force from the back leg was only weakly related to ball speed in 52 high school pitchers, much less than in adults. Their interpretation was that high school pitchers may gain more from learning to use their body's momentum than from simply pushing harder. Strength is necessary, but it has to show up in the delivery.
Mechanics: use the whole body
A 2023 systematic review by Kew and colleagues pooled 12 studies covering 930 pitchers from youth to professional. Hip and shoulder separation was associated with about 2.6 mph more velocity, and trunk timing, trunk tilt, a firmer front knee at release and a quieter glove-side shoulder were all linked with faster pitches. Our deep dive on pitching velocity biomechanics walks through the kinetic chain, the lead leg block and arm action.
For a high school pitcher, the useful version is narrow: find the one or two movement priorities that limit you most, work on them with drills, and check progress on video every few weeks. Changing five things at once usually changes nothing. Our article on video review for pitching mechanics covers how to film so the comparisons are fair.
Intent and a real throwing program
Velocity is a skill that has to be practiced at speed. Pitchers who only ever play easy catch and throw bullpens at 80% are not giving their bodies a reason to adapt. At the same time, throwing hard every day is not a plan. A good high school throwing program mixes easy days, moderate days and a small number of high-intent days, and it builds those high-intent days on top of a base of volume.
- Build the base first. After the yearly break, rebuild catch play and long toss volume over several weeks before adding hard throws. Our long toss guide explains how to add distance gradually.
- Add intent on purpose. One or two high-intent days a week (compression throws, pulldowns for mature pitchers, or hard bullpens) is plenty for most high schoolers in the offseason.
- Be honest about effort. In a long toss study, throws pitchers called 75% effort still produced 93% of maximum elbow torque (Melugin et al., 2019). Your "easy" days may not be as easy as they feel.
Weighted balls in high school
Weighted balls are already common at this age. In the Bowman (2023) sample, 63% of high school pitchers had used a weighted ball program, and those pitchers threw harder on average. That study was not designed to show cause and effect, and only one injury happened during the season, so it could not compare injury rates.
The best controlled evidence in this age group is the Reinold (2018) randomized trial. Thirty-eight healthy pitchers aged 13 to 18 (mean 15.3) trained in the offseason. The weighted ball group threw 3 times per week for 6 weeks with balls from 2 to 32 ounces, and both groups did strength training. Velocity rose 3.3% in the weighted ball group, but that group also had a 24% injury rate, with four elbow injuries during training or the following season, while no one in the control group was injured.
Weighted balls are a tool, not a requirement. If a high school pitcher uses them, they belong in a supervised, gradually progressed program with every throw counted in workload, after a base of strength and regular throwing is in place. Our full review of weighted ball training covers the rest of the research, including the studies that found no velocity change.
Build workload capacity so you can keep training hard
Velocity work only pays off if you can keep doing it. Gabbett's 2016 review described a training-injury prevention paradox: athletes accustomed to higher training loads tended to have fewer injuries than those training at lower loads, and the real problem was large, sudden jumps. For a pitcher, that means the goal is not to throw as little as possible. It is to raise your chronic workload steadily so that hard weeks land on a prepared arm.
The acute:chronic workload ratio (ACWR) is one way to check that. It compares your last 7 days of throwing with your last 28. Weeks around 0.8 to 1.3 usually mean you are building on a base. Big spikes, like a showcase week after a quiet month, are where trouble tends to start. Olsen and colleagues (2006) found that adolescent pitchers who needed surgery had pitched more months per year, more pitches per game and more showcases, and threw with higher velocity. Zaremski (2024) also found that throwing harder in games and a jump in velocity from preseason to in-season were risk factors. Velocity is the goal, so the plan has to build capacity alongside it.
You can check your own numbers with the free pitching workload calculator. Count everything: catch play, long toss, drills, bullpens and games.
Sleep and nutrition are training
High school schedules are hard on sleep. Milewski and colleagues (2014) surveyed 112 middle and high school athletes and found that those who slept fewer than 8 hours a night were 1.7 times more likely to have had an injury. Sleep is also when the strength and skill work you did that day turns into adaptation. Aim for 8 or more hours, and treat a bad night as a reason to make the day's throwing lighter, not to skip it entirely.
Food matters for the same reason. A pitcher trying to add muscle needs enough total calories and protein spread across the day. Use the calorie and macro calculator as a starting point if you are 18 or older, and talk with a qualified professional for younger athletes.
Know the Pitch Smart limits for ages 15 to 18
MLB and USA Baseball's Pitch Smart guidelines for ages 15 to 18 set a daily game maximum of 95 pitches (ages 15 and 16) or 105 pitches (ages 17 and 18), with required rest that rises with pitch count. They also recommend no more than 100 combined innings in any 12 month period and at least 4 months off from competitive pitching each year, including 2 to 3 continuous months off from all overhead throwing. In a 10-year study, Fleisig and colleagues (2011) found that pitchers who threw more than 100 innings in a year were 3.5 times more likely to be seriously injured.
Treat those limits as guardrails, not targets. Use the pitch count calculator to check rest after any outing, and check your state association's rules too.
Sample year plan for a high school pitcher (example, not a prescription)
This assumes a spring high school season and a summer team. Adjust the months to your calendar and your coach's plan. The rest period is part of the plan: it is when tissue recovers and strength work can progress fastest.
| Phase | Typical months | Throwing | Strength and power | Main goal |
|---|---|---|---|---|
| Rest from overhead throwing | About 2 to 3 continuous months, often fall | None | Full program, 3 days a week if possible | Recover, gain strength and body mass |
| Offseason build | Late fall to winter, 6 to 10 weeks | Catch play and long toss, volume rising gradually | 3 days a week, add power work | Build chronic throwing capacity |
| Offseason velocity block | Winter, 4 to 6 weeks | 1 to 2 high-intent days a week on top of the base | 2 to 3 days a week | Raise velocity while ACWR stays steady |
| Preseason | Late winter, 4 to 6 weeks | Bullpens and live at-bats ramp toward game length | 2 days a week | Turn velocity into game readiness |
| In-season | Spring and summer | Games plus light catch and short bullpens between outings | 1 to 2 short sessions a week | Maintain strength and capacity, follow pitch counts |
Our free 6-week high school velocity building program gives you a printable version of the offseason foundation, with two strength sessions a week and an organized throwing week.
Frequently asked questions
How much velocity can a high school pitcher gain in a year?
It varies a lot with growth and training. Driveline's academy data (2021) showed expected gains of roughly 3 mph per year for 14U to 16U players, down from about 5 mph per year at 9U to 11U. Treat those as averages from one training population, not a promise.
How hard do high school pitchers throw?
Published studies give a rough picture. In a 2024 study of 71 pitchers aged 13 to 18, in-game velocity averaged 71.3 mph with a range of 46.8 to 85.7 mph. In a 2023 survey of 115 high school pitchers, average fastballs were 66 mph for pitchers who had not used weighted balls and 71 mph for those who had.
Should high school pitchers use weighted balls?
They can raise velocity, but the evidence is mixed on safety. A 2018 randomized trial in pitchers aged 13 to 18 found a 3.3% velocity gain and a 24% injury rate in the weighted ball group versus no injuries in the control group. If a high school pitcher uses them, it should be inside a supervised, progressive program with workload tracking, not as a shortcut.
What matters most for high school velocity?
Growth, strength and body mass, efficient mechanics, regular high-intent throwing, and enough built-up workload capacity to train hard week after week. Sleep and nutrition support all of it. No single drill matters as much as a consistent plan across the year.
How many innings should a high school pitcher throw per year?
Pitch Smart recommends no more than 100 combined innings in any 12 month period for ages 15 to 18, and at least 4 months off from competitive pitching each year, including 2 to 3 continuous months off from all overhead throwing.
A velocity plan that fits high school
Let Pitch AI build your throwing week
Pitch AI builds a personalized throwing program from your age, level, years pitching, recent pitch counts, schedule, equipment, season phase and goal, then progresses it in blocks. Daily readiness check-ins adjust the day's work, logged throws feed an acute:chronic workload trend, and Pitch Smart rest days are applied after logged games. You can also upload a short clip for AI mechanics feedback and add strength and conditioning to the same plan.
Sources and further reading
- Zaremski JL, et al. Workload Risk Factors for Pitching-Related Injuries in High School Baseball Pitchers. American Journal of Sports Medicine, 2024
- Bowman EN, et al. Most high school baseball pitchers are using weighted ball throwing programs to increase ball velocity: cross-sectional analysis of US high school pitchers. JSES Reviews, Reports, and Techniques, 2023
- Kageyama M, et al. Difference between adolescent and collegiate baseball pitchers in the kinematics and kinetics of the lower limbs and trunk during pitching motion. Journal of Sports Science and Medicine, 2015
- Driveline Baseball: Youth Baseball Player Development, Velocity Aging Curves (2021)
- Fleisig GS, et al. Kinematic and kinetic comparison of baseball pitching among various levels of development. Journal of Biomechanics, 1999
- King BW, Snow TK, Millard-Stafford M. Peak Lower-Extremity Power Unadjusted for Body Mass Predicts Fastball Velocity in Collegiate Baseball Pitchers. Journal of Strength and Conditioning Research, 2025
- Hsiao HW, Lee HJ. Countermovement Jump Analysis as a Predictor of Overhead Pitching Velocity in Adolescent Baseball Pitchers. Journal of Human Kinetics, 2025
- Oyama S, Myers JB. The Relationship Between the Push Off Ground Reaction Force and Ball Speed in High School Baseball Pitchers. Journal of Strength and Conditioning Research, 2018
- Kew ME, et al. Kinematic Parameters Predictive of Pitch Velocity in Youth to Professional Baseball Pitchers: A Qualitative Systematic Review. Orthopaedic Journal of Sports Medicine, 2023
- Melugin HP, et al. Baseball Pitchers' Perceived Effort Does Not Match Actual Measured Effort During a Structured Long-Toss Throwing Program. American Journal of Sports Medicine, 2019
- Reinold MM, et al. Effect of a 6-Week Weighted Baseball Throwing Program on Pitch Velocity, Pitching Arm Biomechanics, Passive Range of Motion, and Injury Rates. Sports Health, 2018
- Gabbett TJ. The training-injury prevention paradox: should athletes be training smarter and harder? British Journal of Sports Medicine, 2016
- Olsen SJ 2nd, et al. Risk factors for shoulder and elbow injuries in adolescent baseball pitchers. American Journal of Sports Medicine, 2006
- Milewski MD, et al. Chronic lack of sleep is associated with increased sports injuries in adolescent athletes. Journal of Pediatric Orthopaedics, 2014
- Fleisig GS, et al. Risk of serious injury for young baseball pitchers: a 10-year prospective study. American Journal of Sports Medicine, 2011
- MLB and USA Baseball. Pitch Smart guidelines, ages 15 to 18