In the Lab – Training Tonnage Based on Throwing Velocity

Tom House’s 1991 classic, Nolan Ryan’s Pitcher’s Bible, introduced a deceptively simple idea: throwing a baseball hard, repeatedly, creates a measurable physical stress load — and the weight room’s job is to build the capacity to absorb that load without breaking down. More than thirty years later, that core idea still holds up. But the tools we use to measure and manage that load have evolved dramatically, and if you’re a strength coach still thinking in terms of flat weekly tonnage, you’re missing most of what actually keeps a high-velocity arm healthy.

Here’s how the thinking has evolved—and what it means for how you should structure an off-season program.

Where It Started: Tonnage as a Proxy for Throwing Stress

House’s formula was straightforward physics: kinetic energy equals one-half mass times velocity squared. Take a 5-ounce baseball thrown at 90 mph, scale it up across a week’s worth of pitches, and you get a number representing total weekly “work” the arm has to produce. The idea was to translate throwing demand into a strength-training target—if the arm produces X amount of force weekly, the weight room needs to build toward a program that can support it. Not going to bury the lead – higher throwing velocity requires higher training tonnage. 

House also introduced a mechanical efficiency adjustment. Nolan Ryan was rated at roughly 93% mechanical efficiency, meaning almost all of his generated force converted directly into ball velocity, with very little “leaking” through poor sequencing. A less efficient thrower needs more raw strength to hit the same velocity, because he’s compensating for energy lost in movement rather than getting it for free through clean mechanics — think of it like a leaky hose needing more water pressure to deliver the same flow out the end.

Mathematically, velocity is the more powerful lever in this equation, since it’s squared while efficiency is a linear multiplier — a given percentage increase in velocity raises the energy demand more than the same percentage change in efficiency. But in the real world, mechanical inefficiency varies far more between pitchers than velocity does, which is probably why so much of modern pitching development still starts with cleaning up mechanics before chasing added strength. As a strength coach, we should understand our role. Both high velocities and low efficiency require greater training stress, for different reasons. A high velocity needs more braking forces to decelerate the arm/body while throwing. Low efficiency requires improving the requisite force to throw higher velocities in the future.

Why Flat Tonnage Falls Short for a Modern High-Velocity Pitcher

Ryan’s actual program — 3 sets of 12 reps, total body, three days a week — reflects the training philosophy of its era: moderate load, structural balance, general durability. It’s a reasonable base-building approach, but it’s a blunt instrument. Tonnage (sets × reps × load) tells you how much work was done; it says almost nothing about what quality that work developed.

That distinction matters enormously for a pitcher throwing 92+ mph. Two programs can carry identical total tonnage and produce completely different athletes:

• Moderate-load, high-rep volume work builds general structural capacity but does little to develop rate of force development or neural drive — the ability to express strength fast, which is what a throw actually demands, since the entire kinetic chain sequence happens in well under half a second.
• Max-strength and explosive/ballistic work (low-rep heavy lifting paired with medicine ball throws, jumps, and other high-velocity, low-load movements) builds the force ceiling and ensures that strength actually transfers to throwing speed.
• Eccentric and isometric work targets something neither of the above really touches: connective tissue. The structures that actually fail in high-velocity throwers — the UCL, labrum, rotator cuff, joint capsule — adapt specifically to sustained tension and heavy, controlled eccentric loading, not to moderate-load volume work. This mirrors what’s well established in tendon rehabilitation research and has increasingly moved into throwing programs as a deliberate training target, not just a rehab tool.

The practical shift: total tonnage for a 92+ mph thrower usually isn’t higher than Ryan’s program — it’s redistributed toward the qualities a flat, moderate-load model never touched, and it’s dosed non-uniformly across the year rather than delivered as a constant template. You may come across an athlete with raw throwing ability who will benefit from moderate load, higher-rep-volume work. Throwing athletes are increasingly specialized and the product of specific, deliberate work. In this case, having a bag of training options such as developing absolute force or rate of force in the off-season, or eccentric and isometric work at various parts of the year for connective tissue or lower systemic stress, is going to be needed.

The Real Lesson: Tonnage Is a Monitoring Tool, Not a Programming Target

Tonnage remains useful for tracking whether volume trends up or down across a training block—a reasonable check on aggregate fatigue. But it was never built to capture peak force, rate of force development, or connective tissue-specific loading, which are the variables that actually predict whether a high-velocity arm survives a season. Judging a throwing program by tonnage alone is a lot like judging a diet by calorie count while ignoring macronutrients.

Enter Acute: Chronic Workload Ratio (ACWR)

This is where modern sports science offers a genuinely better framework — one already validated directly in baseball populations, not just borrowed from other sports.

ACWR compares a pitcher’s recent (“acute,” typically 7-9 days) throwing load against his longer-term (“chronic,” typically 28 days) rolling average. The principle: tissue adapts to a chronic load, and injury risk climbs sharply when acute load suddenly exceeds what that tissue has been prepared for. The research backing this in pitchers is substantial:

• Collegiate pitchers with an ACWR of 1.27 — acute load 27% above chronic — were roughly 15 times more likely to sustain an injury.
• A separate study found athletes whose ACWR shifted more than 33% in either direction were about 8 times more likely to suffer a throwing overuse injury the following week.
• A recent cross-sport meta-analysis found injury incidence was lowest when ACWR stayed in the 0.8-1.3 range.
• In elite fast bowling (a similar shoulder/elbow stress profile to pitching), high acute: chronic spikes were associated with substantially higher injury risk — but a well-built chronic base meaningfully blunted that risk, meaning a bigger aerobic-adjacent foundation makes an athlete more resilient to a given spike.

Modern systems have also solved the biggest flaw in older workload tracking: treating every pitch as equal. Wearable-sensor platforms now calculate per-throw workload from elbow torque and ball velocity, weighted by the pitcher’s size, then roll that into acute and chronic averages — a far better proxy than raw pitch counts, since a 95 mph fastball and a 78 mph get-me-over changeup clearly don’t cost the arm the same amount. One caveat worth building into any program: ACWR has drawn real methodological criticism — mathematical coupling issues between the acute and chronic windows, and a growing recognition that external load (what was prescribed) means little without internal response (how the athlete’s body actually reacted — soreness, velocity decay, grip strength, perceived exertion). Track both.

Nolan Ryan said “pitching is 50% mental,” which supports the idea that raw acute load is incomplete. The emotional stress of being alone on the mound parallels a sport like tennis or golf, but with the added pressure of representing the team. The only other comparable would be a kicker in football, with a fraction of the acute load. A pitcher has to throw a ball 70-100 times with maximal intent and extreme precision; the mental load is immense. Training loads develop the physical, but you need to account for the emotional. Chances are the person they are throwing against is really talented and only needs to be successful 1 out of 3 times. The pitcher needs to be successful more than 2 out of 3 times; if they give up 9 hits in a single game, chances are they will be pulled.

Where Strength Training Fits — and Where It Doesn’t

Here’s a distinction that trips up a lot of off-season programming: squats and deadlifts don’t show up in a pitcher’s throwing ACWR, but weighted balls, pulldowns, and long toss absolutely do. Strength training builds the chronic capacity that determines how well an athlete tolerates a given throwing ACWR — it’s the mechanism behind that fast-bowling finding above, where a bigger chronic base blunted the harm of an acute spike. It’s foundational, but it isn’t throwing-specific load.

Weighted balls, pulldowns, and long toss are a different story entirely. Pulldowns — max-intent, long-distance throws — frequently generate arm speeds and torques at or above game-level pitches, precisely because the format lets an athlete cut it loose without mound mechanics constraints. Weighted balls shift joint stress in both directions: underload work increases arm speed, overload work increases torque at a given velocity. Long toss, especially at max distance, is functionally a high-volume, high-intent throwing session even though it’s often framed as conditioning. The joint doesn’t distinguish between a mound pitch and a max-effort pulldown. If you’re only tracking bullpen pitch counts for ACWR purposes while weighted-ball work and pulldowns ramp up separately, you can miss a serious acute spike entirely — the stress is real even when it’s filed under a different mental category.

There’s a second, quieter risk here too: heavy lifting and high-intent throwing development often get ramped simultaneously in the off-season, because that’s when an athlete has the most training bandwidth. Stack a max-effort lower-body day against a max-intent pulldown session, and systemic fatigue can degrade throwing mechanics — which, per the mechanical efficiency discussion above, means each throw at a given velocity now costs the arm more than it would if the athlete were fresh. Tapering research shows that max-intent work like throwing requires systemic support through volume and training duration in the weight room. This is why tonnage and raw acute loading are incomplete when preparing a throwing athlete. The perceived stress of training maximally with reduced volume while increasing throwing intensity is the ultimate measure of preparation for throwing a baseball consistently hard from the beginning to the end of the season.

A Periodized Off-Season Framework

Here’s how to structure a program that treats throwing load — bullpen, weighted balls, pulldowns, long toss — as one integrated stream, with lifting playing a supporting, not competing, role.

1. Step 1 — Build one combined load number. Before programming anything, get bullpen pitches, pulldown throws, weighted ball reps, and long toss onto a single intensity-weighted metric. A once-a-week bullpen is often the smallest piece of a pitcher’s total weekly arm stress; pulldowns and long toss frequently do more.
2. Step 2 — General prep (weeks 1-4): build tolerance, not intensity. Low-intent long toss and moderate weighted-ball work, minimal pulldown intent. Pair with higher-volume, moderate-load strength and hypertrophy training. Keep week-to-week arm load increases under roughly 10%, and hold the acute: chronic ratio near 1.0-1.2.
3. Step 3 — Specific prep (weeks 5-9): ramp throwing intent, shift lifting toward strength and power. This is where pulldowns hit real intent and weighted ball and long toss progressions climb. Lifting shifts from volume toward max-strength and rate-of-force-development work. Never stack max-effort lower-body work with max-intent throwing on the same day — if they’re close together, lift after throwing, not before. Build in a deload every third or fourth week, dropping total arm load 30-40%, so the chronic average reflects adapted capacity rather than an artificially depressed one.
4. Step 4 — Ramp to camp (final 3-4 weeks): mirror what spring training will actually ask. Increase bullpen frequency if possible, and structure rest between high-intent sessions to match camp’s rhythm — a 4-5 day between-outing cycle rather than a full week, so the tissue has already adapted to that recovery window before camp starts. Taper lifting volume here; its job shifts from building capacity to preserving it without adding stress. The target: a chronic throwing baseline heading into camp high enough that camp’s demands land inside that 0.8-1.3 ratio range, rather than hitting as a 1.5-2x shock in February.
5. Step 5 — Track internal response throughout. Track weekly grip strength, shoulder and elbow soreness, session RPE, and sleep quality alongside the external load numbers. If those markers trend worse while the external load still looks “in range,” that’s the signal to hold or deload — not the spreadsheet.

What Tapering Research Adds to the Ramp-to-Camp Phase

The final phase of the off-season framework above — cutting volume while sharpening intensity heading into camp — has a name in the sports-science literature: tapering. And the foundational work here, led by Iñigo Mujika, gives that phase far more precision than “back off a bit before camp starts.”

Mujika’s core, repeatedly replicated finding is that training volume can be cut substantially—commonly by 40-60%, and in some tapering protocols as much as 60-90%—without hurting performance, provided training intensity stays close to or at pre-taper levels. The mechanism matters: cutting intensity causes detraining and erodes the adaptations already built; cutting volume mainly sheds accumulated fatigue while those adaptations stay intact. In practice, athletes achieve that volume reduction mainly by shortening session duration, not by dropping how often they train or how hard each remaining session is. For highly trained athletes, the effective taper window is generally 8-14 days, and a progressive (exponential) reduction in load tends to outperform a single abrupt step down.

This isn’t just endurance-sport theory transplanted onto throwing athletes — it’s been tested directly in track and field throwers, and the findings translate cleanly onto a pitcher’s ramp into spring training:

• A study of collegiate track and field throwers (hammer, discus, and javelin) found that a one-week planned overreach followed by a three-week taper improved both explosive ability and competitive throwing performance — and did so despite no measurable change in muscle architecture. The gains came from the nervous system arriving fresh and ready to express force, not from new muscle tissue. That parallels the mechanical-efficiency discussion earlier: a fatigued system leaks force through poor sequencing, and tapering is largely about arriving at competition with that leak closed.
• A separate study comparing light-load versus heavy-load tapering in track and field throwers found both approaches produced similar improvements in throwing performance, though heavy-load tapering produced larger gains in strength, whole-body power, and rate of force development. That’s a real programming choice for a strength coach: light-load tapering may be the gentler, lower-fatigue-cost option if the priority is simply arriving fresh, while heavy-load tapering banks additional strength and power gains at a slightly higher fatigue cost.
• Later work from the same research group that produced the throwers studies (with Mujika as a co-author) compared step versus exponential tapers in strength athletes and found the step taper favored muscle-tissue-level adaptations, while the exponential taper favored neuromuscular performance — reinforcing that taper shape, not just taper amount, changes what an athlete arrives with on competition day.

The Bottom Line

House’s original tonnage formula wasn’t wrong — it was a first attempt at quantifying something real: throwing hard and often is a physical stress load, and the weight room exists to build the capacity to absorb it. What’s changed is the resolution. Modern tools let us separate how much work was done from what quality it built, weight-throwing stress by actual intensity rather than raw counts, and track acute spikes against chronic baselines with real predictive power. For a strength coach managing a high-velocity arm into spring training, the job isn’t hitting a tonnage number — it’s making sure the chronic base is big enough, and built specifically enough, that camp’s inevitable acute spike doesn’t turn into a March injury report.

I have met and worked with Tom. Pretty much everything we have seen today regarding throwing can be traced back to him. There is so much information out there to work off of. Formulas and drills are in endless supply. If you saw the work Tom did with his pitchers and quarterbacks, it was simple and direct. There is confidence in that. More is not better; better is better.

References

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