Sports Medicine (2021) 51:1619–1628
The Importance of‘Durability’ inthePhysiological Proﬁling
EdMaunder1 · StephenSeiler2· MathewJ.Mildenhall3· AndrewE.Kilding1,3· DanielJ.Plews1
Accepted: 29 March 2021 / Published online: 22 April 2021
© The Author(s), under exclusive licence to Springer Nature Switzerland AG 2021
Proﬁling physiological attributes is an important role for applied exercise physiologists working with endurance athletes.
These attributes are typically assessed in well-rested athletes. However, as has been demonstrated in the literature and
supported by ﬁeld data presented here, the attributes measured during routine physiological-proﬁling assessments are not
static, but change over time during prolonged exercise. If not accounted for, shifts in these physiological attributes during
prolonged exercise have implications for the accuracy of their use in intensity regulation during prolonged training sessions
or competitions, quantifying training adaptations, training-load programming and monitoring, and the prediction of exercise
performance. In this review, we argue that current models used in the routine physiological proﬁling of endurance athletes
do not account for these shifts. Therefore, applied exercise physiologists working with endurance athletes would beneﬁt from
development of physiological-proﬁling models that account for shifts in physiological-proﬁling variables during prolonged
exercise and quantify the ‘durability’ of individual athletes, here deﬁned as the time of onset and magnitude of deterioration
in physiological-proﬁling characteristics over time during prolonged exercise. We propose directions for future research and
applied practice that may enable better understanding of athlete durability.
Applied exercise physiologists working with endurance
athletes routinely proﬁle a number of physiological traits
for purposes of training programming and monitoring.
The common models for these assessments do not
account for changes in proﬁled variables over time
during long-duration exercise, and, therefore, athlete
‘durability’, which we deﬁne and discuss here.
Using existing data and ﬁeld measures from a range of
endurance athletes, we propose that applied exercise
physiologists would beneﬁt from development of models
that incorporate interactions between exercise intensity
and duration, and therefore quantify athlete ‘durability’.
* Ed Maunder
1 Sports Performance Research Institute New Zealand,
Auckland University ofTechnology, Auckland, NewZealand
2 Faculty ofHealth andSport Sciences, University ofAgder,
3 High Performance Sport New Zealand, Auckland,