Heart rate (HR), minute ventilation (V˙ E), oxygen consumption
(V˙ O2), and carbon dioxide production (V˙ CO2) were measured
during the exercise with an automated system.b Blood
pressure was monitored every 3 minutes by an automatic blood
pressure system.c Mean arterial pressure (MAP) was calculated
as the diastolic pressure plus one third of the pulse pressure,
and oxygen pulse values as V˙ O2 divided by HR. Peak oxygen
uptake (VO2peak) was defined as the peak VO2, according to at
least 3 of the following 4 criteria: (1) the increase of V˙ O2 was
less than 2mL kg1 min1 in the last 2 minutes of exercise21;
(2) HR exceeded the maximal predicted HR; (3) the respiratory
exchange ratio exceeded 1.1022; and (4) venous lactate concentration
after the termination of exercise exceeded 50mg/dL.23