International Journal of Sports Physiology & Performance
Testing whether an accelerometer reports the same movement the same way twice
Researchers ran triaxial accelerometers on a calibration rig and then through live Australian-football matches. The combined acceleration across all three axes, the signal the field calls Player Load, stayed consistent within a single device and between devices, and still picked up real differences in how hard athletes worked.
Why it matters
This result is about the instrument rather than about an athlete. If a device reports different numbers for the same movement on two different days, nothing measured from it can be read over time. That question has been answered for accelerometers worn on the torso in Australian football. Nobody has answered it for a sensor on the upper arm in basketball, and it is one of the questions we have to answer ourselves.
Journal of Sports Science & Medicine
Accelerometer load tracks real demand in basketball
Twelve Spanish first-division players were tracked across 16 sessions. A triaxial accelerometer separated the demand of different drills cleanly: full-court 3v3 and 5v5 carried the most load, and smaller guard-type players piled up more acceleration load than bigger players running the same drill.
Why it matters
The study ran indoors, in basketball practice, with no GPS, which is the setting a private academy trains in. It found that an accelerometer separated a walkthrough from a live scrimmage. The players were adult professionals and the sensors were not worn on the upper arm. The result describes a setting we care about. It does not describe our hardware.
Scand. Journal of Medicine & Science in Sports
Jump counts checked against video across whole sessions
A wearable accelerometer was checked against video through entire training sessions and matches in elite volleyball. The comparison ran across whole sessions on court rather than across a set of isolated repetitions in a lab.
Why it matters
Jump counting is the one number on a report a trainer can check from the sideline with no equipment at all, which is why it is worth getting right. This study compared a wearable against video in volleyball, on senior athletes. Nobody has published a jump count taken from a sensor on the upper arm, where a raised arm and a jump can look similar to one sensor.
Journal of Strength & Conditioning Research
The monitoring framework elite basketball already runs on
A review of how top basketball programs monitor players. It separates external demand, the movement and accelerometer load, from internal response, the heart rate and perceived effort, and reads the relationship between the two to judge whether a player is ready to compete.
Why it matters
The review describes how professional programs monitor players. Those programs have staff and budgets a private academy does not have, and the distance between the two is the reason we are working on this.
Scientific Reports (Nature)
Why one number is never the whole picture
Sixteen players in Spain's top league were tracked across 19 sessions using planned load, heart rate, inertial devices, and perceived-effort scales side by side. Internal effort and external movement turned out to measure different, complementary parts of the same session.
Why it matters
The finding is that two ways of measuring the same session did not substitute for each other. Any single number that claims to summarise a whole session is leaving something out, and that is worth knowing before anyone builds one.
// The gap
The research itself shows youth got skipped
A systematic review sorted basketball training- and game-load studies by level. Twenty covered elite players, nine sub-elite, and only six covered youth. The monitoring evidence concentrates at the professional end of the sport, in the same place the tools that generate it do.
This is the gap, written into the literature, not just our pitch. The players with the least data are the developing ones. That is exactly who Slingshot is built for.
Every study here is independent and peer-reviewed. The plain-language summaries are ours, written for a coach rather than a journal, and each links to the original paper. Some links land on abstract or repository pages where full text needs institutional access.