Table 1 Effect of neck cooling on thermoregulatory responses and physical performance in the heat
Study | Subjects | Ambient conditions | Cooling interventions | Exercise protocol | Tneck | Perceptual outcomes | Thermoregulatory outcomes | Performance outcomes |
|---|---|---|---|---|---|---|---|---|
Tyler et al. [13] | 8 males | 30 °C, 50% RH | Cooling collar (120 g gel, frozen at − 80 °C for 24–28 h [left in air 5 min before application]) | 15-min TT running | ↓ | ↓ TS, → RPE | → Tcore, → HR & SR, ↓ Wc | → Distance (3180 vs. 3239 m) |
Tyler et al. [13] | 9 males | 30 °C, 50% RH | Cooling collar (120 g gel, frozen at − 80 °C for 24–28 h [left in air 5 min before application]) | Running 75 min at 60% VO2max & 15-min TT running | ↓ | ↓ TS, → RPE | → Tcore, → HR & Bla & Gluc & Cortisol & Dopamine & Serotonin & S100β & PRL & PV & Wc | ↑ Distance by 146 m (5%) |
Tyler and Sunderland [14] | 8 males | 32.2 ± 0.2 °C, 53 ± 2% RH | Cooling collar (120 g gel, placed at − 80 °C for 24–28 h) | Running TTE at 70% VO2max | ↓ | ↓ TS, → RPE | ↑ Tcore, ↑ HR → SR & Wc & WL | ↑ Time by 5 min (14%) |
Tyler and Sunderland [15] | 7 males | 30.4 ± 0.1 °C, 53 ± 2% RH | Cooling collar (no change, or change every 30 min) (120 g gel, frozen at − 80 °C for 24–28 h [left in air 10 min before application]) | Running 75 min at 60% VO2max & 15-min TT running | ↓ | ↓ TS, → RPE | → Tcore (a & b), → HR & Bla & Gluc & Wc & SR (a & b) | (a) ↑ Distance by 182 m (7%) (b) ↑ Distance by 179 m (7%) |
Sunderland et al. [18] | 7 males | 33 ± 0.2 °C, 53 ± 2% RH | Cooling collar (120 g gel refrigerant frozen at − 80 °C for 24 h) | Repeated sprint exercise(5 × 6 s) before & after two 45-min bouts of football-specific intermittent treadmill protocol | ↓ | ↓ TS & RPE | → Tcore & Tsk, → HR & Bla & Gluc & PRL & Cortisol & PV & Wc & WL | ↑ Work load by 39 W (6%) |
Minniti et al. [19] | 8 males | 30.5 ± 0.1 °C, 53 ± 2% RH | Cold collar (120 g gel, frozen at − 80 °C for 24–28 h) | Running 75 min at 60% VO2max & 15-min TT running | NA | ↓ TS & RPE | → Tcore, → HR & VO2 & Gluc & Cortisol | ↑ Distance by 153 m (5%) |
Moss et al. [20] | 9 males | 40 °C, 50% RH | Cooling collar (155 g, 13.9 °C, replace every 15 min) | Cycling 45 min at 50% VO2max followed by 15-min cycling TT | ↓ | → TS & TD & RPE | → Tcore & Tsk, → HR | → Distance |
Bright et al. [21] | 4 females & 8 males | 34.4 ± 0.7 °C, 33 ± 1% RH | Cooling collar (frozen at − 1.3 °C replace every 20 min) | Cycling 90 min at RPE = 16 | ↓ | ↓ TS | → Tcore & Tsk, ↓ SR | → Work load |
Cuttell et al. [22] | 8 males | 35 ± 0.1 °C, 50.1 ± 0.7% RH | Cooling collar (155 g, frozen at − 24 °C for 45–60 min, 1.1% cooling area) | Cycling TTE at 60% PPO | ↓ | ↓ TS, → RPE | → Tcore & Tsk, → RPE & HR & SR | → Exercise time (30 vs. 28 min) |
Galpin et al. [23] | 13 males | 25 ± 1 °C, 53 ± 1% RH | Wet ice bag (1 quart ice & 600 mL room-temperature water) was applied second times among three exercise bouts | Two, 5-min HEX bouts (20 s maximal cadence cycling, & 15 s passive rest) at 50% PP, & TTE at 30% PP | ↓ | ↓ TS & RPE | → HR & VO2 | Exercise time (66 vs. 74 s) |
Ando et al. [24] | 8 males | 35 °C, 70% RH | Wet towel (21 °C water & fanning back neck of with a small fan) | Ergometer cycling (30–32 W [first 5 min], increased at 20–21 W/min until HR = 160 bpm), cycling 10 min at 160 bpm | ↓ | → RPE | ↓ Tsk, → Bla & WL | → Cognitive function during strenuous exercise |
Lee et al. [25] | 12 males | 30.2 ± 0.3 °C, 71 ± 2% RH | Cooling collar (120 g gel refrigerant frozen at − 80 °C for > 24 h [left in ambient condition for 5 min before use]) | Running TTE at 70% VO2max | ↓ | ↓ TS, → RPE | → Tcore & Tsk, → HR & S100β & WL | → Exercise time (71 vs. 67 min) |
Desai and Bottoms [26] | 8 male players | 21.3 ± 3.4 °C, 44.5 ± 4% RH | Ice bag (310 g ice) was applied three times in each trial (1-min pre-exercise & after the 1st & 2nd bout) | Table-tennis-specific protocol (3 bouts, 660 s) | ↓ | → TS & RPE | → HR & VO2 | ↑ TPS (15%) |
Zhang et al. [27] | 6 males, 1 female | 36 °C, 50% RH (running) & 20.7 °C, 45%RH (recovery & 6 × 15 m sprint & YYIR1) | Half-time cooling using a neck towel (placed in 5 °C ice water for 10 min) | 45-min running & 15-min recovery | NA | ↓ TS | → Tcore & HR, ↓ SR & dehydration | ↑ YYIR1 distance |
Tyler and Sunderland [28] | 9 females | 30.5 ± 0.1 °C, 53 ± 2% RH | Cold collar (120 g gel, frozen at − 80 °C for 24–28 h) | Running 75 min at 60% VO2max & 15-min TT running | ↓ | ↓ TS & RPE | → Tcore, → HR & SR & Wc | ↑ Distance by 146 m (5%) |
Colvin and Lokody [29] | 1 triathlon runner | 41 °C, 50% RH | Cooling collar (454 g, 18 °C) | Running TTE | ↓ | NA | ↓ Tcore | ↑ Time by 17 min (51%) |
Gabrys et al. [30] | 11 males | 40 °C, 80% RH | Water cooling collar (300 cm2, Tin = 14.8 °C, Tout = 18.4 °C, flow rate: 1.2 L/min) | Graded cycloergometer exercise at 50 W, increased by 50 W every 3 min (till 200 W) | NA | ↓ TD | → Tcore, → VO2, ↑ SV & CO | ↑ Work load by 50 W (33%) |
Chalmers et al. [31] | 12 football players | 35 °C, 55% RH, WBGT = 30 °C | Ice towel (2.5 kg ice) was applied 2.5 min at the 30-min mark of each half | Simulated football match (45 min + 15-min rest + 45 min) | NA | → TS, ↓ RPE | ↓ Tcore, → Tsk, ↓ HR | NA |
Hamada et al. [32] | 7 males | 30 ± 1 °C, 40% RH | Ice pack cooling at bilateral carotid (500 g, change every 10 min; applied at 20th min) | Cycling 40 min at 60% VO2max | ↓ | ↓ TS | → Tcore & Tsk, → SkBF, ↑ HR, ↓ SR | NA |
Torii et al. [33] | 7 males | 30 °C, 40% RH | Ice pack cooling at bilateral carotid after 20-min exercise | Cycling 40 min at 60% PPO | ↓ | ↓ TS | → Tcore & Tsk, → HR & SKBF, ↓ Tty, ↓ SR | NA |
Bouskill and Parsons [34] | 8 males | 39.9 ± 0.2 °C, 27.1 ± 0.3% RH | Water cooling collar (Tin = 18.7 ± 0.2 °C, Tout = 19.4 ± 0.7 °C, flow rate: 0.8 L/h) | 50-min exercise (step test to 25 cm height at 60 bpm) | ↓ | → TS | ↓ Tsk, ↑ HR, → SR & WL | NA |
Gordon et al. [35] | 10 male athletes | 21 °C, 66.9% RH | Cooling collar (T unknown) | Running 45 min at RPE = 15 | NA | → RPE | ↓ Tcore, ↓ SR, → HR | NA |
Kielblock et al. [36] | 5 males | 40 °C, 70.5% RH | Instant cold pack (T unknown) | 54 W external work until ΔTcore =  + 2 °C | NA | NA | → Tcore, → HR & BP | NA |