Summary of the interventions’ characteristics.
| Author, year, condition | Defined intensity | AHIIT, + AMICT + LBHIIT characteristics | Descriptions of AHIIT | Descriptions of comparison groups | ||
| Times per week | Number of weeks (total sessions) | Time per session (min) | ||||
| Musculoskeletal conditions | ||||||
| Andrade et al61 (2017) (FM) | VAT | 2 | 16 (32) | 45 | Lower limb exercises sitting on floats (80% VAT HR) (level 1), jumping on a trampoline (110% VAT HR) (level 2), exercises in aquatic cycle with resistance adjustment (100% VAT HR) (level 3). Resistance exercise of upper limbs using floats | Control group did not receive any intervention. |
| Assis et al62 (2006)(FM) | HRAT | 3 | 15 | 60 | DWR: running in place, upper limbs alternating shoulder flexion–extension movements, hands held tightly clenched, lower limbs in a bicycling action | LBHIIT: Aerobic training according to the desired intensity for 40 min. Walking or jogging. Heart rate (HR) was readjusted after week eight based on the second test. |
| Carvahlo et al63 (2020) (CLBP) | RPE 11–15 | 2 | 918 (18) | 60 (40+20) | DWR, week 1–2: 20 min, RPE 11, week 3–9: 20 min, RPE 15. Walking forwards/ sideways/ backwards, Lumbar spine stabilisation, dynamic exercises, transversal rotations, method Bad Ragaz Ring. Lumbar and axial tractions | AMICT: Aquatic exercise 40 min without DWR. Sets: 1×60 s, 1×30 s, 2×30 s; Lumbar spine stabilisation, dynamic exercises, transversal rotations, method Bad Ragaz, Lumbar and axial tractions. |
| Kanitz et al64 (2021) (CLBP) | HRVT2 | 2 | 12 | 45 | DWR: week 1–4: 7 x (3 min 95% HRVT2 + 2 min < 85% HRVT2) week 5–8: 7 x (4 min 100% HRVT2 + 1 min < 85% HRVT2) week 9–12: 7 x (3 min 100% HRVT2 + 1 min 105 HRVT2 + 1 min < 85% HRVT2) | AMICT: DWR: week 1–4: 7 x (3 min 85% HRVT2 + 2min < 85% HRVT2) week 5–8: 7 x (4 min 90% HRVT2 + 1min < 85% HRVT2) week 9–12: 7 x (4 min 95% HRVT2 + 1min < 85% HRVT2) |
| Munukka et al44 (2016) (OA) | As ‘hard and fast as possible’ | 3 | 16 | 60 (48) | Exercises progressed from barefoot, small fins to large resistance boots (no contact with pool walls or bottom): 2 set x 30 rep- 3 set x 30–45 reps, with rest period 30–45 s. From week 3 to 16: Borg >15 | Control group did not receive any intervention. |
| Olkoski et al65 (2021) (CLBP) | 80% of HR, RPE 15 | 2 | 9 | 20 (DWR) 50 (AMICT) | DWR: week 1–2: 50% hour work, RPE 11 (20 min), week 3–9: 80% of HR work, RPE 15. Walking forwards/sideways/backwards, Lumbar spine stabilisation, dynamic exercises, transversal rotations, method Bad Ragaz Ring. Lumbar and axial tractions | AMICT: 1–2 reps, 30–60 s, walking different directions, dynamic exercises hip joint muscles: walking forwards/sideways/backwards, Lumbar spine stabilisation, dynamic exercises, transversal rotations, method Bad Ragaz Ring. Lumbar and axial tractions. |
| Metabolic conditions | ||||||
| Costa et al43 (2018) (dyslipidaemia) | RPE 9–15 | 2 | 12 (24) | 45 | Water aerobics exercises for upper and lower limbs (abduction/adduction, flexion/extension) including flexion of trunk, interval method was adopted throughout the training period | Control group did not receive any intervention |
| Delevatti et al70 (2020) (DM2) | 50 min 85–90% HRAT-(50 min 95–100% HRAT | 3 | 15 | 56 | Lower limb exercises: stationary running, front kick, cross-country skiing, backward stationary running, and hip extension, accompanied with upper limbs movements. 2 min of lower limb exercise, combined with two upper limb exercises (1 min each) | Control group: stretching and relaxation sessions. COMBI group (NIA): resistance: RPE 19+greatest possible velocity of motion and resistance. Intervals, sets of 15–30 s. |
| Samadi et al45 (2019) (PCOS) | 80–95% hour ‘all-out’ max work intervals | 3 | 12 | 30 | Quick movements of body (20 min): 4×4 min bouts, 8 rounds of 20 s intervals. 1 min of rest between intervals (75% HRmax) | Control group did not receive any intervention (only Metformin) |
| Respiratory conditions | ||||||
| Emtner et al60 (1998) (asthma) | 80–100% hour | 5 2 | 2 8 | 45 45 | Intervals (5×2 min): 2 min intense exercise, separated by 1½ min periods of low-intensity exercise. Varied repetitive large-muscle dynamic exercises. Arm and leg exercises | LBHIIT: Intervals (5×2 min): 2 min intense exercise, separated by 1 ½ min periods of low intensity exercise. Varied repetitive large-muscle dynamic exercises. Arm and leg exercises. |
| Felcar et al66 (2018) (COPD) | 85% of baseline max workload, and 110% of baseline 6MWT velocity, RPE 4–6. | 3 2 | 12 12 (60) | 60 | Both groups: endurance training (cycling and walking), strength training for lower (quadriceps) and upper (biceps and triceps) (3 sets x eight reps) limbs and stretching. eight educational sessions | LBHIIT: Both groups: endurance training (cycling and walking), strength training for lower (quadriceps) and upper (biceps and triceps) (3 sets x eight reps) limbs and stretching. 8 educational sessions. |
| Gallo-Silva et al67 (2019) (COPD) | RPE 6 | 3 | 8 | 60 | Moderate intensity to high intensity, aim RPE 4–6 in six steps, 1 min break between. Duration: 20 min, progression to 40 min. Main exercise: aerobic exercises for the trunk, upper limbs and lower limbs involving the hips, feet, ankles, hands/wrists and shoulders | Control group did not receive any intervention. |
| Wadell et al68 (2004) (COPD) | 80–100% HRpeak RPE 15 | 3 | 12 | 45 | Endurance (3×4 min) + 3 min strength (legs, arms, torso), repetitive large-muscle exercises intending to increase the load on the cardiovascular system and increase heart rate | LBHIIT: Both land and water training programme were designed to have the same intensity profile. Control group: no training intervention. |
| Neurological conditions | ||||||
| Chu et al71 (2004) (chronic stroke) | 80% HRR±5 beats/min | 3 | 8 | 60 | Moderate to high aerobic activities: shallow water walking, running, side stepping, 30 min | AMICT: Gross+fine motor movements for upper limbs while sitting. |
| Gorman et al72 (2019) (CMISCI) | 65–75% HRR, RPE 16–17 | Up to 3 | 12 | 45 | Cardiorespiratory and strengthening components with rest periods of 1 to 3 min. Hip flex/ext/abd/add, knee flex/ext. Lunge walking/semireclined paddling/kickboard. Step ups, push-ups, push off wall tethered, cycling UE and LE seated/semireclined. Adapted swim strokes. Work at 65–75% intensity level throughout each aquatic exercise sessions | LBHIIT: Lokomat training; 20–45 min. Walking. |
| Kargarfard et al73 (2018) (MS) | 75% of HRR | 3 | 8 | 60 | Walking at different intensities, joint mobility, functional exercises, balance. 10–12 reps of movements in a circuit class format | Control group: no training intervention. Weekly educational sessions for both groups. |
| Cardiovascular conditions | ||||||
| Mohr et al46 (2014) (HT) | All-out intervals | 3 | 15 | ~15–25 60 (AMICT) | Swimming ~15–25 min (3–5 min); 6–10 30 s all-out freestyle swimming (front crawl), 2 min passive recovery | AMICT: 1 hour, front crawl swimming, encouraged to swim as far as possible in every session. Control group: (NIA) no training intervention. |
| Park et al69 (2019) (PAD) | 70–85% HRR, RPE 6–8 | 4 | 12 | 60 | Main exercise: Hip flexion-extension, hip abduction-adduction, knee flexion-extension and water walking (forward, backward, lateral) 50–60% HRR +6–8 RPE, to 70–85% HRR +6–8 RPE | Control group did not receive any intervention. |
Bold types indicate comparison intervention.
AHIIT, aquatic high-intensity interval training; AMICT, aquatic moderate-intensity continuous training; CLBP, chronic low back pain; CMISCI, chronic motor incomplete spinal cord injury; COPD, chronic obstructive pulmonary diesase; DM2, diabetes mellitus type 2; DWR, deep water running; FM, fibromyalgia; HR, heart rate; HRAT, heart rate at anaerobic threshold; HRR, heart rate reserve; HRVT2, heart rate of the second ventilatory threshold; HT, hypertension; LBHIIT, land-based high-intensity interval training; LE, lower limb; MS, multiple sclerosis; MWT, 6–12 min walk test; NI, no information; NIA, not included in analyses; OA, osteoarthritis; PAD, peripheral artery disease; PCOS, polycystic ovary syndrome; RPE, rate of perceived exertion; UE, upper limb; VAT, ventilatory anaerobic threshold.