The Clinical Case — Infection, Return to Sport, and the Exposé

The Case
Two Modes of Regulation
A Return-to-Sport Plan
Writing the Exposé

Learning objectives:

Compare exercise-induced and infection-associated immune regulation on the same parameters
Construct a structured return-to-sport plan with explicit cut-offs and a functional retest
Write a scientific exposé with NLM referencing and an author contribution statement
Apply the assessment criteria of the module to your own draft before submission

1 The Case

The clinical part of the dataset contains one female participant with symptoms following an upper respiratory tract infection, sampled on two days:

Day 1 — upper respiratory tract infection, subfebrile temperature (< 38.5 °C), sore throat, feeling of illness and malaise, headache, resting heart rate elevated by more than 8 beats·min⁻¹ compared with the preceding week.
Day 4 — upper respiratory tract infection, no fever, very mild feeling of illness, no malaise, no headache, resting heart rate elevated by more than 2 beats·min⁻¹.

The task is to compare panels 1A and 1C–F between the exercise-induced and the infection-associated condition. Panel 1B (lactate) is deliberately excluded from the comparison, and the reason is worth stating: lactate indexes metabolic strain from a mechanical load, not an immunological state, and the two conditions do not share that axis.

2 Two Modes of Regulation

Exercise-induced leucocytosis is a rapid, catecholamine- and shear-mediated redistribution that peaks within minutes and largely resolves within an hour: cells are moved, not made. Infection-associated changes are slower, driven by cytokine signalling and marrow output, and they persist across days; the accompanying resting heart rate elevation is a systemic autonomic signal rather than a haematological one. Two different time constants, two different mechanisms, partly overlapping readouts — which is precisely why a single blood count without a time axis and without symptoms cannot distinguish them. Students are expected to make this argument from their own figures rather than to assert it.

3 A Return-to-Sport Plan

The deliverable is a simple, defensible return-to-sport plan for this case, built on the parameters and symptoms available and integrating the one-minute sit-to-stand test as the functional retest. The plan must state explicit, falsifiable cut-offs rather than general advice. A defensible structure has four elements:

Absolute pause criteria — for example fever, systemic symptoms, marked malaise, resting heart rate elevation beyond a stated threshold. No load while any is present.
Re-entry criteria — symptom-free for a stated number of days, resting heart rate returned within a stated band of the individual baseline.
Graded progression — stepwise increase in duration before intensity, with a defined minimum time at each step and a defined response to symptom recurrence (step back, not stop).
Functional retest — the 1-STST with pre-defined criteria on heart rate response and recovery, and on subjective exertion, as the gate between steps.

The scoping review by Haunhorst et al. (2023) is the reference frame from an exercise immunology perspective; students are asked to state which of their cut-offs are supported by it, which are extrapolated, and which are their own reasoned proposals. Marking that boundary honestly is scored more highly than a plan that hides it. The caution from Lecture 3 applies: where post-exertional malaise is suspected, a graded progression is not the correct instrument and the plan must say so.

4 Writing the Exposé

Assessment: this is the clinical part of the module examination (Prf.-Nr. 141673), worth 25 % of the sports medicine share.

Assessment criteria for the written assignments. All members of a group receive identical marks, so the group’s weakest section determines the outcome — a fact worth acting on when dividing the work.

Criterion	Weight
Completeness	10 %
Scientific rigour	20 %
Factual accuracy	20 %
Level of difficulty	20 %
Creativity	10 %
Innovation	10 %
Form	10 %

The exposé follows the template supplied with the task: title and acronym, authors with the seminar affiliation, the non-clinical and clinical sections, the reference list in NLM style, alphabetically ordered, an explicit author contribution statement (idea and conceptualisation, manuscript writing, tables and figures, revision), and the signed confirmation. Submission is as a PDF via the Moodle assignment on the examination server.

Two weaknesses recur in these assignments. The first is describing figures instead of interpreting them — a results paragraph that restates the axis labels adds nothing. The second is citation drift: a claim attributed to a source that the source does not make. Both are avoidable with a single habit: for every sentence containing a citation, name the specific statement in the cited paper that carries it.

One-Minute-Paper Topics

A One-Minute-Paper (OMP) is a short, focused prompt that students answer in ~60 seconds at the end of a session to consolidate learning, surface misconceptions, and provide formative feedback. When answering, be concise, specific, and use terminology from today’s session.

Name two mechanisms that distinguish exercise-induced from infection-associated leucocytosis, and one readout in which they look alike.
Why is lactate excluded from the exercise-versus-infection comparison?
State one absolute pause criterion and one re-entry criterion, each with a number, and justify the number.
How would you integrate the 1-STST as a gate between two steps of a return-to-sport progression?
Take one sentence from your draft that carries a citation and name the exact statement in the source that supports it.

References