Altering the network of public facilities like schools is likely to affect travel choices, in particular route and mode choice. Traveling to school is not only a major contributor to public transport demand in peak periods, but is in many instances also the trip purpose where young people are engaged in bicycling. However, in contrast to public transport, an active travel mode like bicycling needs (substantial) own physical activity as input into the ‘production’ of a trip. The objective of this paper is to improve our understanding of the substitution between bicycling and public transport in school travel focusing on an underrated determinant in the literature – the personal effort (e.g. energy input in terms of kcal) of students when traveling by bike (or walk). It is shown that a local government aiming at maximizing social welfare when making decisions on the density of public school facilities would be well advised to take this cross effect into account. We use a large unique data set of travel-to-school mode choice in the city of Dresden (Germany). We estimate a series of multivariate extreme value models and derive the elasticity of bike usage and the cross-elasticity of public transport demand with respect to the physical effort. The results reveal that effort elasticity of bike usage is significantly negative, whereas the effort cross-elasticity of public transport demand is significantly positive. In both cases, the responses are highest for school travel distances between 1 and 3 km, but relatively inelastic, meaning that a widespread adoption of pedelecs (or even e-bikes) in school travel could have only limited impacts on peak-period public transport demand.