@article{Astorino2026, 
author = {Todd A. Astorino and Madison Mower and Armando Flores and Marissa Flannery},
title = {Cardiometabolic response to high intensity functional training versus rowing-based high intensity interval training},
year = {2026},
journal = {Sports Medicine and Health Science},
volume = {8},
number = {3},
pages = {311-318},
keywords = {High intensity interval training, Circuit training, Blood lactate concentration, Oxygen uptake, Calorie expenditure},
url = {https://www.sciopen.com/article/10.1016/j.smhs.2025.01.003},
doi = {10.1016/j.smhs.2025.01.003},
abstract = {This study compared the cardiometabolic response between rowing high intensity interval training (HIIT) and high intensity functional training (HIFT). Twenty two adults (age and                      V            ˙                  O        2                m      a      x       ​= ​[25 ​± ​7] yr and [40 ​± ​9] mL/kg/min) underwent incremental exercise on a rowing ergometer to assess                      V            ˙                  O        2                m      a      x       and peak power output (PPO). Subsequently, they underwent rowing HIIT (six 1 minutes [min] efforts at 85% PPO with 75 seconds [s] recovery) or HIFT (six 1 ​min efforts including pushups, jump squats, mountain climbers, and air squats with 75 ​s recovery). Gas exchange data, heart rate (HR), and blood lactate concentration (BLa) were acquired during exercise and post-exercise. These regimens elicited 92%–96% HRmax, with higher peak HR ([174 ​± ​14] b/min vs. [167 ​± ​15] b/min, p ​= ​0.002) and time spent ≥ 85% HRmax ([6.1 ​± ​2.2] min vs. [5.0 ​± ​2.8] min, p ​= ​0.03) for HIFT versus rowing HIIT. Results showed similar peak                      V            ˙                  O        2   between HIFT and HIIT ([81 ​± ​9] vs. [82 ​± ​8]                      V            ˙                  O        2                m      a      x      , p ​= ​0.72), yet lower mean                      V            ˙                  O        2   ([1.73 ​± ​0.38] L/min vs. [1.93 ​± ​0.50] L/min, p ​< ​0.001). Mean and peak ventilation    (                              V                ˙                    E        ) was significantly higher (p ​< ​0.05) with HIFT ([62 ​± ​13] L/min and [84 ​± ​18] L/min vs. [53 ​± ​15] L/min and [73 ​± ​19] L/min). BLa was significantly higher with HIFT versus rowing HIIT (p ​< ​0.001) and was elevated 15 ​min post-exercise ([7.0 ​± ​3.0] mM vs. [3.5 ​± ​1.1] mM). In healthy, active adults, HIFT elicits vigorous intensities similar to traditional HIIT.}
}