The possibilities when setting up high intensity interval training (HIIT) protocols are very high. Different studies in recent years have shown that there is no single valid configuration, but that the proposed goal can be achieved with different HIIT configurations.
The results of a study have recently been published (Wommer et al, 2021; Int J Sports Med 14-Jul; doi: 10.1055 / a-1550-9977) with the objective of comparing the time spent above 90% of V̇O2max (tV̇O2max) during 3 combined-work HIIT protocols establishing exercise efforts of 8 x 60 seconds with a decreasing, increasing, or constant work rate distribution within each exercise interval.
Ten healthy male subjects (age: 27.6 ± 5.0 years; V̇O2max: 3.82 ± 0.52 L / min) performed an incremental test to determine V̇O2max and maximum power (Pmax). During visits 2, 3 and 4, three work interval training sessions were performed that established efforts of 8 x 60 s: active recovery of 60 s with constant power production (100% Pmax; ITCON), decreasing (from 110 to 90% Pmax; ITDEC), or increasing (from 90 to 110% Pmax; ITINC) linearly throughout each work interval. Sustained time above 90% of V̇O2max (tV̇O2max) or HRmax (tHRmax), blood lactate concentrations (BLC), and index of perceived exertion (RPE) were measured.
The results showed that the tV̇O2max (ITCON: 274 ± 132; ITDEC: 313 ± 102; ITINC: 310 ± 113 s, P = 0.37), tHRmax (ITCON: 396 ± 180; ITDEC: 441 ± 207; ITINC: 390 ± 212 s, P = 0.47), BLC (P = 0.73) and final RPE (P = 0.75) were similar between the protocols.
The authors concluded that HIIT induced a similar time near VO2max and associated physiological responses regardless of manipulation of the workload distribution.
JL. Chicharro (PhD) Opinion:
The main goal of aerobic HIIT is to improve VO2max and / or maximum aerobic speed / power. For this, it is necessary that in the training session the subject reaches a sufficient total time at or very close to VO2max.
The configuration of the protocols is indifferent as long as the objective is reached. In any case, due to the response kinetics of VO2, it is difficult to reach VO2max with intervals of less than 2 min, with an interval time of 3 min as the ideal duration.
In any case, if the duration of the intervals is shortened, the duration of recovery must also be shortened, which would make it possible to achieve high VO2 values.