From our data, we conclude that target training HR detected by means of the %HRmax method may be overestimated in cases where the HR response is not regular, as it was found in many of our subjects.

These data suggest that competitive cross-country skiers with higher D and NE excretion may reach better competition levels compared with those with lower levels. Measures of BNCE provide objective information about competition performance, which may benefit athletes in their precompetition preparation.