Abstract
PURPOSE: To establish the extent of thermoregulatory impairment in paraplegic and tetraplegic athletes compared to able-bodied controls during exercise and passive recovery in the heat using an experimental method that accounts for differences in biophysical factors.
METHODS: Thirteen trained males were separated into three groups based on spinal cord injury (SCI) level: tetraplegia (TP; C5-C8, 26.8±5.4 y, 71.2±7.1 kg), paraplegia (PA; T4-T12, 25.6±4.6 y, 74.0±19.7 kg), and able-bodied (AB; 26.2±2.2 y, 78.8±3.9 kg). Participants exercised on an arm ergometer for 30 min at a heat production of 4.0 W/kg (AB vs. TP) or 6.0 W/kg (AB vs. PA) with 3 min rest every 10 min, followed by 45 min of passive recovery in 35°C, 50% RH. Esophageal (Tes) and gastrointestinal (Tgi) temperature and local sweat rate (LSR) on the forehead and upper back were measured throughout.
RESULTS: After 30 min exercise, ΔTgi was greater in TP (1.13±0.25°C) compared to AB (0.34±0.10°C). Similarly, a greater ΔTes was evident for TP (1.60±0.28°C) compared to AB (0.28±0.15°C). Core temperature peaked at 45 min post-exercise for TP, with ΔTgi and ΔTes reaching 1.94±0.18°C and 1.83±0.13°C, respectively. No sweating was evident in TP however in AB, end-exercise ΔLSR was 0.38±0.26 mg·min−1·cm−2 on the head and 0.36±0.15 mg·min−1·cm−2 on the upper back. Differences between PA and AB were evident after 30 min exercise for ΔTgi (0.56±0.32°C vs 0.38±0.08°C) and ΔTes (0.75±0.38°C vs 0.50±0.09°C), which is when core temperature peaked for both groups. At 45 min post-exercise, PA remained greater than AB for ΔTgi (0.45±0.16°C vs 0.38±0.15°C) and ΔTes (0.46±0.22°C vs 0.28±0.18°C). Furthermore, ΔLSR was greater in PA than in AB after 30 min exercise, both at the head (1.03±0.75 mg·min−1·cm−2 vs 0.87±0.20 mg·min−1·cm−2) and the back (1.03±0.30 mg·min−1·cm−2 vs 0.49±0.18 mg·min−1·cm−2).
CONCLUSION: The increase in post-exercise body temperature in TP demonstrates the inability to dissipate heat in hot conditions, primarily due to the lack of sweating. A greater, but less pronounced increase in body temperature during exercise was also apparent in PA compared to AB, suggesting there is a graded effect of SCI level on thermoregulatory impairment.
METHODS: Thirteen trained males were separated into three groups based on spinal cord injury (SCI) level: tetraplegia (TP; C5-C8, 26.8±5.4 y, 71.2±7.1 kg), paraplegia (PA; T4-T12, 25.6±4.6 y, 74.0±19.7 kg), and able-bodied (AB; 26.2±2.2 y, 78.8±3.9 kg). Participants exercised on an arm ergometer for 30 min at a heat production of 4.0 W/kg (AB vs. TP) or 6.0 W/kg (AB vs. PA) with 3 min rest every 10 min, followed by 45 min of passive recovery in 35°C, 50% RH. Esophageal (Tes) and gastrointestinal (Tgi) temperature and local sweat rate (LSR) on the forehead and upper back were measured throughout.
RESULTS: After 30 min exercise, ΔTgi was greater in TP (1.13±0.25°C) compared to AB (0.34±0.10°C). Similarly, a greater ΔTes was evident for TP (1.60±0.28°C) compared to AB (0.28±0.15°C). Core temperature peaked at 45 min post-exercise for TP, with ΔTgi and ΔTes reaching 1.94±0.18°C and 1.83±0.13°C, respectively. No sweating was evident in TP however in AB, end-exercise ΔLSR was 0.38±0.26 mg·min−1·cm−2 on the head and 0.36±0.15 mg·min−1·cm−2 on the upper back. Differences between PA and AB were evident after 30 min exercise for ΔTgi (0.56±0.32°C vs 0.38±0.08°C) and ΔTes (0.75±0.38°C vs 0.50±0.09°C), which is when core temperature peaked for both groups. At 45 min post-exercise, PA remained greater than AB for ΔTgi (0.45±0.16°C vs 0.38±0.15°C) and ΔTes (0.46±0.22°C vs 0.28±0.18°C). Furthermore, ΔLSR was greater in PA than in AB after 30 min exercise, both at the head (1.03±0.75 mg·min−1·cm−2 vs 0.87±0.20 mg·min−1·cm−2) and the back (1.03±0.30 mg·min−1·cm−2 vs 0.49±0.18 mg·min−1·cm−2).
CONCLUSION: The increase in post-exercise body temperature in TP demonstrates the inability to dissipate heat in hot conditions, primarily due to the lack of sweating. A greater, but less pronounced increase in body temperature during exercise was also apparent in PA compared to AB, suggesting there is a graded effect of SCI level on thermoregulatory impairment.
| Original language | English |
|---|---|
| Pages (from-to) | 19-19 |
| Number of pages | 1 |
| Journal | Medicine and Science in Sports and Exercise |
| Volume | 49 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - May 2017 |