Table 2.
Study characteristics, constant workload studies
| Study | Age (years) | VO2max (mL kg−1 min−1) or fitness level | Type of exercise (primary outcome measure) | Type of cooling | Method of cooling | Ambient conditions | Airflow | Lab/field study |
|---|---|---|---|---|---|---|---|---|
| Pre-cooling | ||||||||
|
Barwood et al. 2019 (n = 8) [65] |
22 ± 2 | Trained | Cycling test to exhaustion at 70% Pmax, (time to exhaustion) | Pre-cooling | Menthol spray (100 mL) during pre-loaded trial | 35 °C/20% RH | 1.85 m/s (fan) | Lab, indoor |
|
Choo et al. 2019 (n = 11) [66] |
30 ± 6 | 51.1 ± 8.2 | 60-min cycling trial at 15 RPE/’hard or heavy’ (mean power output) | Pre-cooling |
(a) Ice slurry ingestion (1.25 g/kg/5 min; 0.1 °C) during rest (b) Cold water immersion (22.3 °C) during rest |
33.9 °C/42.5% RH | Unknown | Lab, indoor |
|
Hasegawa et al. 2005 (n = 9) [76] |
22 ± 1 | 48.3 ± 1.7 | Cycling test to exhaustion at 80% VO2,max (time to exhaustion) | Pre-cooling | Cooling jacket during pre-loaded trial | 32.0 °C/70–80% RH | Unknown | Lab, indoor |
|
Mitchell et al. 2003 (n = 11) [77] |
24 ± 7 | 54.8 ± 4.2 | Running test to exhaustion at 100% VO2,max (time to exhaustion) | Pre-cooling | Fan cooling with water spray (100 mL/2 min) during rest | 38 °C/40% RH | 4.0 m/s (fan) | Lab, indoor |
|
Nakamura et al. 2020 (n = 8) [78] |
22 ± 1 | 42.4 | Cycling text to exhaustion at 75% VO2,max (time to exhaustion) | Pre-cooling |
a) Hand and forearm immersion in cold water (10 °C) during rest b) Ice slurry ingestion (4 g/kg BM; − 1 °C) during rest c) Hand and forearm immersion in cold water (10 °C) and ice slurry ingestion (4 g/kg BM; − 1 °C) |
35.0 °C/62.5% RH | Unknown | Lab, indoor |
|
Osakabe et al. 2021 (n = 8) [79] |
23 ± 1 | 51.8 ± 5.0 | 2 × 30-min intermittent cycling protocol, 15-min half-time (mean power output) | Pre-cooling | Fan with skin wetting (~ 20 °C) during half-time | 35 °C/50% RH | 0.8 m/s (fan) | Lab, indoor |
|
Siegel et al. 2012 (n = 8) [80] |
26 ± 4 | 54.2 ± 2.5 | Running to exhaustion at first ventilatory threshold (time to exhaustion | Pre-cooling |
(a) Ice slurry ingestion (7.5 g/kg; − 1 °C) during rest (b) Cold water immersion (24 °C) during rest |
34.0 °C/52% RH | Unknown | Lab, indoor |
|
Uckert et al. 2007 (n = 20) [81] |
26 ± 4 | Trained | Running incremental step test to exhaustion (time to exhaustion) | Pre-cooling | Cooling vest (0–5 °C) during rest | 30–32 °C/50% RH | Unknown | Lab, indoor |
|
Walters et al. 2017 (n = 22) [82] |
20 ± 2 | Recreationally active | Cycling graded exercise test | Pre-cooling | Cooling cap (5–10 °C) during rest | 35 °C/15% RH | Unknown | Lab, indoor |
|
Xu et al. 2021 (n = 7) [83] |
20 ± 1 | 60.7 ± 4.1 | Running to exhaustion at 80% VO2,max (time to exhaustion) | Pre-cooling |
(a) Cooling vest (4 °C) during rest (b) Cold fluid ingestion (2.3 mL/kg BM; 4 °C) during rest (c) Cooling vest (4 °C) and cold fluid ingestion (2.3 mL/kg BM; 4 °C) during rest |
38.1 °C/55.3% RH | Unknown | Lab, indoor |
| Per-cooling | ||||||||
|
Cuttel et al. 2016 (n = 8) [67] |
24 ± 4 | Recreationally active | Cycling to exhaustion at 60% Wmax (time to exhaustion) | Per-cooling |
(a) Cooling vest (stored at − 24 °C) during whole trial (b) Neck cooling collar (stored at − 24 °C) during time trial |
35 °C/50.1% RH | Unknown | Lab, indoor |
|
Flood et al. 2017 (n = 8) [68] |
26 ± 5 | 55.4 ± 6.0 | Cycling to exhaustion at 16 RPE/’hard or very hard’ (time to exhaustion) | Per-cooling | Menthol mouth rinse (25 mL every 10 min; 19.8 °C) during whole trial | 35.0 °C/47.8% RH | Unknown | Lab, indoor |
|
Jeffries et al. 2018 (n = 10) [69] |
33 ± 9 | 52.4 ± 5.3 | Cycling to exhaustion at 70% Wmax (time to exhaustion) | Per-cooling |
(a) Ice slurry ingestion (1.25 g/kg; 0.3 °C) at 85% of baseline time to exhaustion (b) Menthol mouth rinse (25 mL; 19.5 °C) at 85% of baseline time to exhaustion |
35 °C/40% RH | Unknown | Lab, indoor |
|
Luomala et al. 2012 (n = 7) [70] |
32 ± 3 | 56 ± 3 | Cycling in 10-min cycles until exhaustion; 9 min at 60% VO2,max, 1 min at 80% VO2,max (time to exhaustion) | Per-cooling | Cooling vest (− 20 °C) from 30 min into exercise until the end | 30 °C/40% RH | Unknown | Lab, indoor |
|
Mündel et al. 2006 (n = 8) [71] |
26 ± 7 | 54 ± 5 | Cycling to exhaustion at 65% Wmax (time to exhaustion) | Per-cooling | Cold drink ingestion (≥ 300 mL; 3.6° C) during whole trial | 33.9 °C/27.9% RH | 0.5 m/s (fan) | Lab, indoor |
|
Mündel and Jones 2010 (n = 9) [72] |
25 ± 7 | 54 ± 5 | Cycling to exhaustion at 65% Wmax (time to exhaustion) | Per-cooling | Menthol mouth rinse (25 mL every 10 min; 19 °C) during whole trial | 34 °C/27% RH | 0.5 m/s (fan) | Lab, indoor |
|
Parton et al. 2020 (n = 11) [73] |
20 ± 1 | 53.9 ± 6.9 | Cycling to exhaustion at 16 RPE/’hard or very hard’ (time to exhaustion) | Per-cooling | Menthol mouth rinse (25 mL every 10 min; 31.8 °C) during whole trial | 34.9 °C/40.6% RH | Unknown | Lab, indoor |
|
Scheadler et al. 2013 (n = 12) [74] |
23 ± 4 | 53.8 ± 5.2 | Running to exhaustion at 75% VO2,max (time to exhaustion) | Per-cooling | Palm cooling device during whole trial | 30 °C/50% RH | Unknown | Lab, indoor |
|
Tyler et al. 2011 (n = 8) [75] |
26 ± 2 | 56.2 ± 9.2 | Running to exhaustion at 70% VO2,max (time to exhaustion) | Per-cooling | Neck cooling collar (stored at − 80 °C for 24–28 h, 10 min in ambient conditions) during whole trial | 32.2 °C/53% RH | Unknown | Lab, indoor |
BM body mass, lab laboratory, min minutes, PCM phase change material, RH relative humidity, RPE rate of perceived exertion, VO2max maximal oxygen consumption, Wmax maximal workload