Regression values and swimming energetic parameters.

Oxygen consumption (MO2, mgO2 kg−1 h−1) was expressed as a function of swimming speed (U, Body lengths s−1) with the formula f = abUb+SMR. Swim trials without (control) and with a tag (trials 2, 3) were performed on the same individual. Abbreviations: SMR, standard metabolic rate; AMR, active metabolic rate; Uopt, optimal swimming speed; COTmin, minimum cost of transport; Ucrit, critical swimming speed. Values are mean±SD. Different superscripts indicate significant differences per row (repeated measurements ANOVA, pN = 9).