A dashboard can describe training. It cannot predict an injury for you.

I am in favour of recording training. I am much less enthusiastic about pretending that one calculated score can tell an athlete whether tomorrow is safe. Workload information can reveal what was completed, identify an unexpected change and support planning. Those are valuable functions. They do not require a claim that injuries can be reliably forecast for individuals.

Separate the work from the response

External load describes work performed: distance, speed, repetitions, weight or other task-specific outputs. Internal load describes the person’s response, often through heart rate or perceived exertion. The consensus statement by Bourdon and colleagues makes this distinction central to monitoring. Similar external work can produce different internal responses across athletes or across days.

Session rating of perceived exertion multiplied by duration offers a low-cost summary. A 40-minute session rated six produces 240 arbitrary units. That arithmetic is illustrative, not a target. Two sessions with the same total can differ markedly in sprinting, landing or local tissue demands. Aggregation makes information manageable while inevitably discarding detail.

Why the ratio became too persuasive

The acute-to-chronic workload ratio compares a recent load with a longer reference period. It appears to answer an attractive question: how large is this week relative to what the athlete is accustomed to? Unfortunately, the ratio also depends on arbitrary windows, calculation choices and a denominator that may become very small during rehabilitation.

Impellizzeri and colleagues describe conceptual and methodological problems with interpreting this metric as a causal injury-management tool. Where acute load is included in the chronic calculation, mathematical coupling adds another complication. My interpretation is that a universal “safe zone” asks much more of the evidence than it can deliver.

After a period of little training, a modest absolute increase may generate a dramatic ratio. Conversely, a reassuring ratio can conceal inappropriate task selection or an athlete who is struggling. Ratios can describe a chosen calculation, but they should not override clinical restrictions, symptoms, recovery or direct knowledge of the session.

Build the smallest useful system

A spreadsheet can capture session type, duration, perceived effort, selected sport exposures and relevant responses. The important specification is consistency: use the same definitions, record at a consistent time and distinguish missing data from zero training. If staff cannot explain what a field means, the apparent precision is not trustworthy.

Wearable tracking adds detail but also requires device management, reliable collection and time for interpretation. Hardware and software costs vary substantially, so a universal price would be misleading. Procurement should consider annual licensing, data export, ownership, validation for the intended measure and the labour required—not just the advertised number of metrics.

Monitor the exposure you actually care about

Total distance may miss the feature most relevant to a return plan. High-speed running, accelerations, change-of-direction work, jumps or contact can require separate attention. Definitions matter here too: a fixed speed threshold describes different relative intensities for athletes with different maximum speeds.

I would rather see a short report that states which demands increased and how the athlete responded than a dense page of unexplained percent changes. Monitoring should make a discussion more specific: Was the increase planned? Was it concentrated in one task? Did symptoms settle? What does the next scheduled session add?

Data should support agency

Athletes should understand why information is collected, who can see it and whether it affects selection. Wellness reports become less useful when honest answers are perceived as punishment. Access controls and retention rules are part of a responsible system, not paperwork to add after the dashboard is finished.

The sensible endpoint is a documented decision with context and uncertainty. Sometimes that means adjusting a session; sometimes it means collecting more information before changing anything. A monitoring tool earns its place by improving those decisions, not by dressing an uncertain future in a confident colour.