Table 2.
Participants’ characteristics at baseline.
| 4 × 30:180 HIIT | 4 × 30:30 HIIT | |||
|---|---|---|---|---|
| Females (n = 12) | Males (n = 5) | Females (n = 14) | Males (n = 7) | |
| Age, years | 23.4 ± 4.4 | 23.6 ± 1.3 | 23.1 ± 1.4 | 22.1 ± 1.8 |
| Height, cm | 169.3 ± 5.6 | 181.2 ± 7.7 | 171.6 ± 7.56 | 187.3 ± 7.7 |
| Body mass, kg | 61.73 ± 6.71 | 74.38 ± 8.10 | 64.86 ± 6.53 | 83.26 ± 11.07 |
| BMI, kg × m−2 | 21.51 ± 1.94 | 22.60 ± 0.98 | 22.09 ± 2.42 | 23.70 ± 2.56 |
| Muscle mass, kg | 44.13 ± 2.59 | 61.38 ± 6.81 | 46.89 ± 3.36 | 67.90 ± 8.25 |
| Leg muscle mass, kg | 14.28 ± 0.77 | 21.06 ± 2.08 | 14.87 ± 0.97 | 23.26 ± 2.37 |
| Fat mass, kg | 15.26 ± 4.62 | 9.80 ± 1.58 | 15.48 ± 3.48 | 11.84 ± 5.07 |
| Total body water, kg | 33.50 ± 1.93 | 46.50 ± 4.62 | 35.59 ± 2.52 | 51.33 ± 5.55 |
| Resting HR, beats·min−1 | 95.5 ± 20.2 | 95.2 ± 17.7 | 97.4 ± 19.2 | 84.0 ± 11.3 |
| Resting LA, mmol·L−1 | 1.3 ± 0.5 | 1.4 ± 0.4 | 1.2 ± 0.4 | 1.2 ± 0.3 |
| Speed at LT, km h−1 | 10.52 ± 0.83 | 12.62 ± 1.07 | 10.76 ± 0.87 | 12.26 ± 0.98 |
| HR at LT, beats·min−1 | 175.7 ± 10.7 | 171.4 ± 12.4 | 175.9 ± 13.0 | 172.6 ± 9.4 |
| Maximal speed, km h−1 | 14.40 ± 0.97 | 17.40 ± 0.90 | 14.67 ± 1.14 | 17.41 ± 0.56 |
| Maximal LA, mmol·L−1 | 12.0 ± 2.1 | 11.9 ± 1.7 | 12.1 ± 2.9 | 11.5 ± 2.4 |
| Maximal HR, beats·min−1 | 195.8 ± 9.9 | 189.8 ± 8.9 | 195.4 ± 10.0 | 192.9 ± 11.4 |
| HR recovery, beats·min−1 | 68.8 ± 12.7 | 67.4 ± 13.1 | 63.5 ± 13.8 | 63.7 ± 8.0 |
BMI, body mass index; HR, heart rate; HR recovery, HRmax − HR3min; LA, blood lactate concentration; LT, individual lactate threshold (baseline lactate +1.5 mmol L−1); resting HR, HR determined before start of the exercise test.
Data are mean ± SD. Exercise parameters were determined during maximal performance test (incremental running test). Group 4 × 30:180 HIIT, high-intensity interval training with 4 all-out runs of 30-s duration and 180-s active recovery; Group 4 × 30:30 HIIT, high-intensity interval training with 4 all-out runs of 30-s duration and 30-s active recovery. No statistical between-group (i.e., HIIT group) differences were detected.