TABLE 2.
Incidence of gastrointestinal symptoms and severity of gut discomfort, total, upper-, and lower-gastrointestinal symptoms in response to 2 h HIIT exercise (between 60 and 80% V̇O2max) in temperate ambient conditions and after consumption of dairy milk (CM) and the carbohydrate-electrolyte (CEB) recovery beverages.
| CM |
CEB |
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| Exercise |
Recovery |
Exercise |
Recovery |
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| Incidence | Severity | Incidence | Severity | Incidence | Severity | Incidence | Severity | |||
| % (severe) | % (severe) | Acute (1–2 h) | Total (1–4 h) | % (severe) | % (severe) | Acute (1–2 h) | Total (1–4 h) | |||
| Gut discomfort | NA | 5 (0–13) | NA | 5 (0–24) | 14 (0–51) | NA | 5 (0–18) | NA | 4 (0–22) | 11 (1–50) |
| Total GIS1 | 59 (0) | 6 (4–18) | 76 (47) | 6 (3–24) | 15 (3–51) | 71 (12) | 7 (2–31) | 64 (35) | 4 (1–22) | 12 (1–50) |
| Upper GIS2 | 47 (0) | 3 (3–10) | 41 (29) | 4 (10–24) | 11 (2–51) | 35 (0) | 2 (1–11) | 52 (24) | 3 (1–22) | 8 (2–50) |
| Belching | 35 (0) | 3 (3–10) | 18 (0) | 0 (1–1) | 0 (1–2) | 29 (0) | 2 (1–11) | 18 (0) | 0 – | 1 (2–4) |
| Heartburn | 6 (0) | 0 (3–3) | 6 (0) | 0 – | 0 (4–4) | 0 (0) | 0 – | 0 (0) | 0 – | 0 – |
| Bloating | 12 (0) | 0 (2–4) | 35 (29) | 4 (10–24) | 10 (2–51) | 12 (0) | 0 (1–3) | 41 (24) | 3 (1–22) | 7 (3–50) |
| Stomach pain | 0 (0) | 0 – | 0 (0) | 0 – | 0 – | 0 (0) | 0 – | 0 (0) | 0 – | 0 – |
| Urge to regurgitate | 6 (0) | 0 (1–1) | 0 (0) | 0 – | 0 – | 0 (0) | 0 – | 0 (0) | 0 – | 0 – |
| Regurgitation | 0 (0) | 0 – | 0 (0) | 0 – | 0 – | 0 (0) | 0 – | 0 (0) | 0 – | 0 – |
| Lower GIS2 | 24 (0) | 1 (1–6) | 42 (18) | 1 (3–8) | 3 (3–20) | 18 (0) | 1 (7–13) | 35 (12) | 1 (5–10) | 3 (1–25) |
| Flatulence | 12 (0) | 0 (1–3) | 12 (0) | 0 – | 0 (3–5) | 18 (0) | 1 (7–13) | 24 (0) | 0 – | 1 (1–7) |
| Lower bloating | 6 (0) | 0 (2–2) | 18 (0) | 0 – | 1 (2–11) | 6 (0) | 0 – | 6 (6) | 0 – | 0 (8–8) |
| Urge to defecate | 12 (0) | 0 (1–3) | 24 (0) | 0 – | 2 (2–12) | 0 (0) | 0 – | 12 (6) | 1 (5–10) | 1 (5–10) |
| Intestinal pain | 0 (0) | 0 – | 0 (0) | 0 – | 0 – | 0 (0) | 0 – | 0 (0) | 0 – | 0 – |
| Abnormal defecation3 | 0 (0) | 0 – | 6 (6) | 0 (6–6) | 0 – | 0 (0) | 0 – | 6 (6) | 0 – | 0 (10–10) |
| Others | ||||||||||
| Nausea | 12 (0) | 1 (1–11) | 6 (0) | 0 (5–5) | 0 (5–5) | 24 (6) | 1 (1–12) | 12 (0) | 1 (4–7) | 1 (4–7) |
| Dizziness | 29 (0) | 2 (2–12) | 24 (0) | 1 (1–7) | 1 (1–7) | 29 (6) | 1 (1–11) | 18 (0) | 0 (1–3) | 0 (1–3) |
| Stitch4 | 6 (0) | 0 (1–1) | 0 (0) | 0 – | 0 – | 6 (0) | 0 (4–4) | 0 (0) | 0 – | 0 – |
| Feeding tolerance | ||||||||||
| Appetite | NA | 13 (0–39) | NA | 21 (3–35) | 26 (5–43) | NA | 14 (0–38) | NA | 25 (8–43) | 32a (9–58) |
| Thirst | NA | 23 (0–44) | NA | 16 (4–26) | 21 (6–37) | NA | 23 (0–41) | NA | 19 (8–37) | 26 (14–51) |
Values are presented as means and range of participant reporting GIS incidence (n = 17). GIS incidence during exercise and recovery are presented as percentage of total participants reporting GIS ≥ 1 on the mVAS. GIS severity during exercise and recovery are presented as mean summative accumulation of mVAS rating scale of measured time periods and individual range of participant reporting GIS incidence (Gaskell et al., 2019, 2020b). 1Summative accumulation of upper-, lower-, and other gastrointestinal symptoms, 2summative accumulation of upper- or lower- gastrointestinal symptoms, 3abnormal defecation including loose watery stools, diarrhea and blood in stools, and 4acute transient abdominal pain. NA, not applicable. Wilcoxon signed-rank tests showed no differences between CM and CEB for GIS; however a p < 0.05 vs. CM for appetite. Hedge’s g measurement of effect size for GIS and feeding tolerance severity between CM and CEB was determined as >0.50 and >0.80 for medium and large effects, respectively; however, no medium or large effects size value were detected between CM and CEB.