Table 1.

Overview of approaches to prescribing physical interventions (PI) and their assumed influence on comparability across different individuals (CAI) and interindividual heterogeneity (IH) with respect to external load, internal load, dose, and outcome. ↓ indicates a relatively low comparability across different individuals or a relative low interindividual heterogeneity, whereas ↑ represents a relatively high comparability across different individuals or a relatively high interindividual heterogeneity; ? shows that we do not currently have enough knowledge to make valid assumptions. Green-shaded field: indicates a relative high compatibility across different individuals and a low interindividual heterogeneity with respect to the specific category; yellow-shaded field: illustrates a relatively low comparability across individuals and a relative high level of interindividual heterogeneity concerning the specific category; grey-shaded field: shows that it is currently not possible to make assumptions about the level of comparability across individuals and the level of interindividual heterogeneity.

	External Load		Internal Load		Dose		Outcome
	CAI	IH	CAI	IH	CAI	IH	CAI	IH
(i) Comparable external load	↑	↓	↓	↑	↓	↑	↓	↑
(ii) Comparable internal load	↓	↑	↑	↓	↓	↑	↓	↑
(iii) Comparable dose	↓	↑	↓	↑	↑	↓	?	?
(iv) Comparable outcome	↓	↑	↓	↑	?	?	↑	↓