You do not need a ten thousand dollar GPS system to coach load. You need a pen, a whiteboard, a stopwatch, and the discipline to look at the number every Wednesday.
The 90-Second Teaching
Every practice and every game has a load. Load is the sum of distance, intensity, contact, and acceleration over time. Bodies adapt to load when load progresses; bodies break when load spikes. The job of weekly programming is to keep the week-to-week load in a sustainable band. Not zero. Not max. The band.
GPS is mainly an objective load number you can trust on Wednesday at six a.m. when the head coach asks if Friday's practice should be physical. It is not a sprint-volume tool, not a recruiting tool, not a teaching slide. It is a load-management tool. The job is one thing: catch the acute spike before it costs you a player.
If you do not have GPS, the principle does not change. The technology just makes the principle visible faster. Time on feet, a jump mat, a Monday-vs-Thursday sprint, and a 1-10 RPE log will get you eighty percent of the way home.
1.Foundations
Internal load vs. external load
You cannot manage load without knowing which load you are measuring. The distinction is the entry point to everything else on this page.
What the body did
- Examples
- Distance run, weight lifted, sprints completed, yardage covered, accelerations counted.
- Measured by
- GPS, accelerometer, set-rep-load logs, video. Objective.
- Use
- Confirms what the plan said happened actually happened.
How the body responded
- Examples
- Heart-rate response, perceived exertion, soreness, sleep quality, mood.
- Measured by
- Session RPE (Foster method), wellness questionnaire, HRV. Athlete-reported.
- Use
- Tells you whether adaptation is actually happening or whether the kid is grinding into a hole.
Session RPE — the formula a $2 pencil delivers
Developed by Carl Foster. The athlete rates workout difficulty 1-10, thirty minutes after the session ends. Multiply that number by the session duration in minutes. That is your load number. No GPS required.
Session RPE in three lines
Example: a 60-minute session rated a 4 equals 240 arbitrary units. Log it. Sum the week. Compare this week to the rolling 4-week average. That single number gets you eighty percent of what an expensive GPS system delivers. Pen. Paper. Two bucks.
The Acute-to-Chronic Workload Ratio (ACWR)
Divide this week's training load by the rolling 3-to-4-week average. The number tells you whether you are spiking volume faster than the athletes can absorb it.
| ACWR Range | Zone | Coach action |
|---|---|---|
| 0.8 – 1.3 | Sweet spot | Train as planned. This is the safe band. |
| 1.3 – 1.5 | Yellow | Plan the next week down. Spike is forming. |
| > 1.5 | Red | Injury risk spikes significantly. Pull volume now, not next week. |
The Reinhardt band: 2.75 to 3.25 game loads per practice week
Joel Reinhardt (Lafayette, formerly San Jose State) published the cleanest season-long anchor in football. A typical practice week should total 2.75 to 3.25 times the load of one game.
- Below 2.75 across a season: athletes detrain. They show up Saturday under-prepared.
- 2.75 to 3.25: the band. San Jose State ran 2.85 season-long and athletes felt fresh every Saturday.
- Sustained above 3.5: injury debt accumulates. Reinhardt has watched FBS programs hit 3.5 to 3.8 and end the season hurt.
"How can we play as much game intensity as possible in our practices, while still being fully fresh on Saturday?" That is the question every weekly plan is trying to answer.
Academic stress is the invisible load
The CNS does not sort stress by category. Bryan Mann's data is loud: student-athletes are two-to-three times more likely to be injured during high school academic stress periods. Training camp that overlaps with finals is not a toughness challenge. It is a bad plan. Subtract academic load from the training load every week.
2.Without GPS — Four Free Proxies
Most high schools do not have GPS. Do not pretend you do. The four proxies below cost nothing and deliver most of the signal. Use all four, log them all in one place, and you have a load-management system.
Proxy 1 — Total time on feet per week
Count minutes. Practice plus lifting plus conditioning plus walkthroughs. Sum it. Compare this week to last. If this week is up more than twenty percent and you did not earn it with a planned progression, you have spiked. Pull volume the next week.
Proxy 2 — Jump mat or vertical-jump check on Wednesday
This is the cheapest GPS proxy available. Use the 90% jump rule: an individual below 90% of his summer baseline is fatigued. A team where fewer than 50% of guys hit 90% is over-trained. Scott's URI data: by season end without proper load management, 27% of the roster was too fatigued to produce a valid jump reading at all. Those are athletes who were not available to perform — on a playoff-bound team.
Proxy 3 — Sprint-time decay across the week
Time a 10 or a 20 on Monday. Time the same sprint on Thursday. A drop of more than 0.05 seconds on the 10 or 0.10 seconds on the 20 means the kid is carrying fatigue into Friday. Pull the Friday physical periods for him.
Proxy 4 — RPE 1-10 per practice, logged
Have the position coaches rate each practice 1-10 on physical demand. Sum the week. Compare to the rolling 4-week average. Same 30% spike rule applies. RPE is subjective but consistent enough at the team level to flag a spike.
3.With GPS — Three Metrics That Matter
If you own Catapult, GPSports, Polar, or similar, here are the three metrics worth your Wednesday morning. In priority order. Everything else the system reports is noise until you have these three under control.
1 · Total weekly load (yards or meters)
The base number. Sum all movement Monday through Friday. Track the rolling 4-week average. The week-to-week change is the signal.
Red flag: any week where total load is 30% above the rolling 4-week average. That is the soft-tissue spike. Either you screwed up the plan or the head coach added a period without telling you. Find it. Fix the next week down.
Target band: 2.75 to 3.25 game loads, season-long average (Reinhardt).
2 · High-speed running meters (above 5.5 m/s)
The speed-preservation number. High-speed meters above 5.5 m/s (roughly 18 ft/sec, a true sprint) is what protects max velocity across a season. Most football players de-train speed in season because nobody makes them sprint. GPS tells you who has and who has not.
Target: each skill player should hit at least one practice per week with meaningful high-speed exposure. Reinhardt's Thursday speed check — 90% of max velocity in the team warm-up — is the cleanest install. Linemen: 10-yard sprints count. Non-linemen: a 30-yard build-up to full speed, twice.
Red flag: any skill player who has not hit 5.5 m/s in a week. He is not training speed; he is losing it. Schedule one period of speed work for him before Friday.
3 · Hit Score / collision count / acceleration count
The physicality number. The count of high-intensity contact and acceleration events per session. Different systems name it differently — Catapult calls it Player Load plus a collision algorithm; GPSports calls it Hit Score. The metric matters because contact load drives the long-tail fatigue and the rehab cost of football.
In-season use: flag the kid taking too much contact relative to the rest of his position group. Often it is the WR or RB who cannot help himself in skelly periods. Reduce his contact reps. Preserve his game day.
Off-season use: during the Contact Prep block, the Hit Score should be climbing on schedule. If it is flat, athletes are not being asked to deliver real contact in training and they will arrive at camp soft.
What about Player Load, Body Load, Training Impulse, Equivalent Distance, Metabolic Power?
Most of these are composite metrics the vendor invented to sell the system. They are not bad. They are just not where to start. Pick total load, high-speed meters, and Hit Score. Get those three reliable. Then layer in one composite metric if a question demands it. A dashboard with twenty metrics that nobody reads is worse than a notebook with three metrics the head coach trusts.
4.The Metric Library
Once you have the three core metrics dialed, the rest of the vendor dashboard becomes useful. Every metric on every system maps to one of four categories. Learn the categories. Then pick one metric from each that answers a question you already have.
| Category | What it answers | Common metrics | How to use it |
|---|---|---|---|
| Volume | How much work got done. | Player Load, Total Distance, Total Contacts, Time on Feet | The weekly fatigue load and the ACWR input. Track rolling 4-week. |
| Intensity | How hard was the hardest work. | High-Speed Running, Sprint Distance, Accels, Decels, IMA, Hit Score | The signal that you are training game-speed, not just running around. |
| Density | Work per unit time. | Player Load per minute, HSR per minute, m/min | Detects practice creep. Same yardage in less time = harder day. |
| Performance | The peak the body reached. | Max MPH, Max Velocity, Peak Player Load, Max Accel | Speed-preservation check. Compare to summer baseline. |
Velocity bands (vendor-agnostic)
Different systems label the speed zones differently. The research-backed thresholds for American football are remarkably consistent. Use these numbers as your translation table when a vendor rep tries to upsell you on their proprietary "high-intensity yards" definition.
| Zone | Threshold | What it represents |
|---|---|---|
| Sprint | > 18 mph (> 8.0 m/s) | True max-velocity. The kid is opening up. This protects speed. |
| High-speed running | 15 – 18 mph (6.7 – 8.0 m/s) | Game-speed running zone. Where most plays live. |
| Research sprint cut | > 14.3 mph (> 6.4 m/s) | Common literature definition of "sprinting." Use if your system runs metric. |
| Moderate | 12 – 15 mph (5.4 – 6.7 m/s) | Sub-game-speed. Filler running. Not protective of max velocity. |
| Accel/decel threshold | > 3.5 m/s² | Counts a meaningful start or stop. Below this is jogging. |
A field-tested 9-metric Catapult package
If you already own Catapult and want the deeper dashboard, here is a published college-S&C 9-metric set. Build a one-page report around these and ignore the other forty fields the platform offers.
The 9 (per published Catapult user @ college level)
- Player Load — total work accumulated. Baseline + ACWR input.
- Acute-to-Chronic Ratio — >1.5 = elevated injury risk. The single most important derived number.
- Running Symmetry — return-to-play tool. Goal: ≤2% asymmetry before clearance.
- Movement Efficiency — Player Load per yard. Spikes signal altered gait (tendonitis, shin splints).
- Player Load (daily) — top of every daily report.
- Acceleration Total Efforts — counts the 3-4 step explosive bursts that are football.
- Acceleration Distance — sustained accel = consistency. Drops first when tired.
- Max MPH — speed preservation. Players love it. Caveat: in-season, requires opportunity.
- Sprints & Sprint Distance — at 14+ MPH threshold. Effort signal.
5.Position-Specific Monitoring
Monitoring linemen the same way you monitor skill players is the most common GPS mistake. They move differently. They get hurt differently. They need different metrics.
WR · DB · RB · LB
- Primary metric
- High-Speed Running distance (> 6.7 m/s / 15 mph).
- Secondary metric
- Max MPH per week. Sprint count.
- Red flag
- No 5.5 m/s touch in 7 days = losing speed.
- Why it matters
- Soft-tissue injuries (especially hamstring) cluster here. Skill players' GPS data predicts the trainer's table.
OL · DL · TE
- Primary metric
- Inertial Movement Analysis (IMA) — accel/decel events > 3.5 m/s². Hit Score / Player Load Slow.
- Secondary metric
- Total Player Load. Contact count. Low-zone distance (still moving — body weight matters).
- Red flag
- Hit Score 2× position-group average for the week = contact debt.
- Why it matters
- Linemen barely sprint. Velocity zones miss everything they do. Monitoring on HSR makes them look "under-loaded" when they are actually grinding.
Position-specific dashboard template
| Position | Top 3 metrics | Weekly target | Pull-the-player rule |
|---|---|---|---|
| WR / DB | HSR distance · Max MPH · Sprint count | ≥ 1 session above 90% Max MPH | No HSR touch in 7 days OR Max MPH down 5% |
| RB / LB | HSR distance · Player Load · Accel total efforts | Total load within 0.8 – 1.3 ACWR band | ACWR > 1.5 OR Player Load 30% above 4-wk avg |
| QB | Player Load · Throw count · Accel efforts | Manage throw volume + sprint exposure separately | Throw count spike OR shoulder soreness flag |
| OL / DL / TE | IMA / Hit Score · Player Load · Contact count | Hit Score climbing in off-season, plateau in-season | Hit Score 2× position-group avg OR contact count spike |
6.The Weekly Plan (Reinhardt template)
Three physically demanding days, each with a different stress signature. Monotony is the silent killer. When every practice day feels the same, the body cannot distinguish hard from easy and chronic injury risk climbs.
| Day | Stress signature | GPS focus | If no GPS |
|---|---|---|---|
| Mon | High Force — big plays, full-speed contact | Highest total load + Hit Score | Longest minutes, hardest RPE |
| Tue | Non-Sprint / Helmets | Lower total, low high-speed meters | Mid minutes, mid RPE |
| Wed | High Speed — open field, full velocity | High high-speed meters, moderate total | Sprint emphasis, jump-mat check |
| Thu | Walkthrough + 90% speed check | Lowest total load, brief high-speed touch | Walkthrough + Monday sprint re-test |
| Fri | Low Volume High Speed | Low total, short sharp high-speed | Sharp, short, dial-the-engine |
| Sat | GAME | Baseline = 1 game load | 1 game = the reference unit |
"If somebody just teleported into our building and watched all three of our practice days, they would say, okay, there was something different about those three days. Just a little bit of a change-up goes a long way." — Joel Reinhardt
Why Thursday is a walkthrough, not a hard day
Reinhardt's posted data from Lafayette: in every off-day cycle across a season, skill positions had higher Vmax on the second day back than on the first. Conclusion: giving athletes a day to ramp up before expecting highest outputs is the correct sequencing. Thursday is the ramp. Friday is the sharp output. Saturday is the bill.
"You can bang your head against the wall expecting Tuesday to be very high speed, but it probably won't be." — Joel Reinhardt
Fall camp loading
Camp is where the whole year is won or lost. The temptation in camp is to load every day because excitement is high. Build camp in blocks: three on, one off, two on, one off. The biggest camp week Reinhardt has run was 3.6 to 3.7 game loads — but only for six days before pulling back. Get overall volume and ebb-and-flow right and you have accounted for ninety percent of team availability across the season.
Monitoring cadence — what to look at, when
The data is only useful if you are actually looking at it at the right grain. Daily for the kid. Weekly for the team. Block for the plan. Season for the program. Mix the grains up and you will either pull a kid you should not have or miss the spike that mattered.
| Cadence | What you check | Statistical lens | Decision |
|---|---|---|---|
| Daily | Individual Player Load + wellness score | Daily z-score vs. 30-day individual baseline | Flag > ±2 SD. Talk to the kid. |
| Weekly | Team total load + ACWR + HSR per skill player | Weekly z-score vs. 4-week rolling average | Plan next week. Walk in with one chart, not twenty. |
| Block (3-4 wk) | Cumulative game-load ratio + Hit Score trend | Compare block average to prior block + Reinhardt band | Adjust the macrocycle. Build the back-off. |
| Season | Season-long game-load ratio + injury count | Season average vs. 2.75 – 3.25 target band | Off-season program audit. Sell the AD the system worked. |
The kid wins on the daily. The team wins on the weekly. The plan wins on the block. The program wins on the season. Look at the wrong grain and you make the wrong call.
7.Wednesday Morning Red-Flag Checklist
Run this every Wednesday before Thursday's plan is finalized. Four checks. Five minutes if the data is on a dashboard. Worth a player.
- Any player 30% above his rolling 4-week average? Reduce his Friday volume by 50%, no contact.
- Any skill player without a 5.5 m/s touch in the prior 7 days? Add one speed period before Friday. He is losing speed, not preserving it.
- Any player whose Hit Score is 2× his position-group average for the week? Reduce his contact reps. Preserve game day.
- Any team-wide weekly total above 3.5 game loads (or its proxy equivalent)? Mandatory back-off built into next week. Not optional.
What GPS does NOT tell you
- It does not tell you if the play call is right. It tells you how the play got run.
- It does not tell you if conditioning is enough. That is decided by game demand, not load math.
- It does not replace the eye. A coach who can see fatigue in a kid's third step does not need GPS to tell him to pull the kid.
- It does not score effort. A lazy kid running fewer meters is not necessarily under-loaded. He may just be loafing.
8.Vendor Library — Who Makes What, and What They Are Good For
The wearable market is consolidating. Catapult bought GPSports. Football has settled on a small set of credible vendors at the college and HS level. Here is the working landscape, with what each system is actually built for and what to download or read from each one before you buy.
| System | Price band | What it is built for | Signature metric | Where it lives |
|---|---|---|---|---|
| Catapult Vector / S7 | $$$$ premium | Football-first vest + LPS option. The college standard. Best collision algorithm. Reinhardt + most FBS run it. | Player Load + Session Score (Hit Score) | FBS / FCS / Power-4. Pro. |
| Catapult One | $$ mid | HS-friendly cousin of Vector. Subscription model. Designed for programs without an analyst on staff. | Player Load + simplified dashboard | HS programs scaling up to college-grade data. |
| STATSports Apex / APEX Athlete Series | $$$ premium | 24 metrics. Strong global brand from soccer + rugby. Western Michigan runs it. Big HS academy installs. | High-Intensity Distance + High-Speed Running | College FBS/G5. Soccer-heavy HS programs. Youth academies. |
| Polar Team Pro | $$ mid | Most HS-affordable serious option. Heart rate + GPS + accel in one unit. iPad-first dashboard. | Training Load (HR-weighted) | HS programs that want one box for HR and GPS together. |
| Kinexon Perform GPS Pro | $$$ premium | Lightest unit on the market (~30g). 100+ live metrics. Strong real-time dashboard for game-day. | Player Load + real-time intensity zones | NFL. Pro soccer. Some Power-4. |
| Playermaker | $$ mid | Foot-mounted, not vest. Built for soccer technical metrics (touches, ball use). Niche use for football skill-position foot-work. | Movement signature + technical events | Skill-position individual development. Not a team-monitoring tool. |
| Zebra MotionWorks | $$$$ enterprise | The NFL's official tracking system. RFID-based, stadium-installed. Not sold to HS — listed for context only. | Next Gen Stats (NFL) | NFL stadiums only. |
| No GPS | $0 | The four proxies above. Eighty percent of the signal for zero dollars. The honest starting point for most HS programs. | Session RPE × duration | Any program. Required for any program even with GPS. |
Vendor-published guides — read these before you buy
Every vendor publishes free coach-facing content. Most of it is marketing. Some of it is genuinely useful. The reading list below is the working signal-to-noise filter.
9.How to Pitch Your AD
Most high school programs that want GPS get told no the first time. Sometimes the second time. The play here is not to ask for a budget on day one. The play is to build the case with free data first, then bring the AD a problem the tech solves.
The four-step ramp
- Season 1 — pen and paper. Run Session RPE, the three-question wellness check, and a weekly jump-mat number. Log everything in one Google Sheet. Cost: zero.
- Off-season 1 — show the chart. Build the rolling 4-week chart. Highlight every week you spiked above 30%. Tie those weeks to soft-tissue injuries. The AD does not respond to theory. He responds to dates and names.
- Season 2 — ask for a free trial. Most vendors (Catapult, Polar, STATSports, Kinexon) will run a free 30-day trial. Get 12-24 units in for a month. Layer the GPS data on top of your existing RPE log. Show how the two agree.
- End of trial — pitch the budget against a number. Cost per soft-tissue injury at your level (lost game weeks, ATC time, parent calls) is the comparison line. Not "GPS is cool." Not "the big schools have it."
"It took four years to get GPS. We got a free trial for 24 catapults. And then our AD was like, well, what if one breaks? That's the problem with the state school — there's so many hoops to jump through." — Scott, on the URI procurement story
10.Coach Objections — Honest Answers
"My head coach is old school. He won't look at the numbers."
Common. The play is not to wave a chart at him. The play is to find the deeper lesson in his old-school method, so you can explain the data in language he already trusts. Then introduce changes one nudge at a time. Start with the kid who got hurt. Show him the spike that came the week before. Not the whole roster. Not the whole system. One kid. One week. One number.
"We just sprint everyone the same. Why do I need GPS to tell me they ran 2,400 yards?"
You don't. If your whole team runs 24 hundred-yard sprints, GPS is wasted. The vest earns its keep when positions diverge — when your linemen and your slot receivers are working different movement signatures in the same practice. If your conditioning is uniform, skip GPS and run the four free proxies.
"I have a $500 budget. Where should it go?"
One Just Jump mat (or a Vertec) for the weekly readiness check. That single tool earns its budget in your first prevented soft-tissue injury. Pair it with a Google Sheet running the Session RPE math and you have a system better than most college programs had in 2015.
"My kids are exhausted from finals week. Do I still hit the plan?"
No. Bryan Mann's data: student-athletes are two-to-three times more likely to be injured during academic stress periods. The CNS does not sort stress by category. Cut volume during finals, re-ramp the week after. The training plan serves the athlete, not the other way around.
"My athletes lie on the RPE scale. How do I trust the number?"
Two fixes. First, collect from the position coach, not the athlete — position coaches see the practice, athletes see only their own reps. Second, use the team-level trend, not the individual number. The team RPE is consistent enough to flag a spike even when individual numbers wobble.
"What about Hawkin Dynamics force plates and the 2-axis readiness model?"
That is the next-level layer. Coach T42 (Sac State Football) published the canonical 2-axis readiness model: Eccentric Peak Force as the consistency anchor, Modified RSI as the sensitivity sensor, traffic-light flagging. It is the rigorous upgrade to the 90% jump rule. If your program has access to force plates, run it. If you do not, the jump mat plus a Nordic curl monthly gets you most of the way.
"Can I use GPS to test conditioning levels?"
GPS confirms conditioning is matching actual game demand. It does not replace conditioning testing. The decision tree: (1) define game demand from the GPS data of your actual games, (2) build conditioning to match that demand, (3) use the GPS data from practice to confirm you are reaching it. The data closes the loop. It does not start it.
Glossary
- ACWR (Acute-to-Chronic Workload Ratio)
- This week's load divided by the rolling 3-4 week average. Sweet spot is 0.8 to 1.3.
- External load
- What the body actually did. Distance, sprints, contact, accelerations. Objective. GPS measures this.
- Internal load
- How the body responded. Heart-rate, perceived exertion, soreness. Athlete-reported. Session RPE measures this.
- Session RPE
- Carl Foster method. RPE (1-10, collected 30 min post-session) multiplied by duration in minutes equals load.
- High-speed running (HSR)
- Distance covered above a velocity threshold (commonly 5.5 m/s, or ~18 ft/sec). The speed-preservation metric.
- Player Load
- Catapult's proprietary composite metric — accelerometer-based total movement intensity. Useful as a single team-level dashboard number.
- Hit Score
- GPSports' contact-impact metric. Counts and quantifies high-intensity collisions and accelerations.
- Game load
- The load of one game, used as a reference unit. Reinhardt's season-long band is 2.75 to 3.25 practice-week game loads.
- 90% jump rule
- Scott's no-tech readiness proxy. Athlete below 90% of summer best on weekly jump test = fatigued. Team below 50% hitting threshold = overtrained.
- Monotony
- The condition where every practice day delivers the same stress signature. Drives chronic injury risk. Reinhardt's "silent killer."
- Spike
- A week-over-week jump in load above the 4-week average. The 30% spike is the cleanest single predictor of soft-tissue injury.
Deeper Reading
References
- Foster C. Monitoring training in athletes with reference to overtraining syndrome. Med Sci Sports Exerc, 1998;30(7):1164-1168. PubMed ↗
- Gabbett TJ. The training-injury prevention paradox: should athletes be training smarter and harder? Br J Sports Med, 2016;50(5):273-280. PubMed ↗
- Hulin BT, Gabbett TJ et al. The acute:chronic workload ratio predicts injury: high chronic workload may decrease injury risk in elite rugby league players. Br J Sports Med, 2016;50(4):231-236. PubMed ↗
- Drew MK, Finch CF. The relationship between training load and injury, illness and soreness: a systematic and literature review. Sports Med, 2016;46(6):861-883. PubMed ↗
- Malone S, Roe M, Doran DA et al. High-speed running and sprinting as an injury risk factor in soccer: can well-developed physical qualities reduce the risk? J Sci Med Sport, 2018;20(3):250-254. PubMed ↗
- McGuigan M (ed). Monitoring Training and Performance in Athletes. Human Kinetics, 2017. Primary reference for sRPE, ACWR, internal/external load framework.
- Mann B. Monitoring Fatigue from A to Z. Source for academic-stress × injury data and HS wellness questionnaires.
- Buddy Morris. American Football GPP. Source for the "stimulate don't annihilate" minimum-effective-dose framing.
- Reinhardt J. Practice layout data, Lafayette College (FCS). Posted @joelreinhardt, Instagram, April 2026. Vmax-second-day-back finding.
Talk About It Inside
Running into an ACWR spike you can't explain? Trying to pitch a Catapult trial to a skeptical AD? Got a kid whose jump number dropped 12% in a week and you're not sure if it's fatigue or finals? Drop it in the Insiders thread. I answer every one.