Table 2.
Ghrelin response to short-term (< 12 weeks), long-term (≥ 12 weeks), and very long-term (≥ 12 months) chronic exercise
| Study, year [reference] | Participants, number, characteristics (age in years) | Exercise, type, intensity, frequency, duration | Ghrelin form, method (intra-assay CV) | Mean ghrelin change (P) | Body mass or body fat change |
|---|---|---|---|---|---|
| Short-term training with unchanged circulating ghrelin | |||||
| Rämson et al. 2008 [98] | 8 college trained male rowers (20.2 ± 1.6) | Aerobic training, volume about 10 h/wk 1 | Ghrelin, RIA (< 10%) | + 7.9% (NS) | Unchanged |
| Aerobic training, volume about 15 h/wk 2 | + 0.4% (NS) | Unchanged | |||
| Aerobic training, volume about 10 h/wk 4 | + 12.6% (NS) | Unchanged | |||
| Hedayati et al. 2012 [99] | 19 healthy female students (22.2 ± 1.74) | Circuit resistance training | Total ghrelin, EIA (7.4%) | ||
| 9 students at 40% of 1 RM, 4 wks | + 7.7% (NS) | Unchanged | |||
| 10 students at 80% of 1 RM, 4 wks | + 13.6% (NS) | Unchanged | |||
| Morishima et al. 2014 [100] | 20 normal weight healthy sedentary individuals (33 ± 2) | Cycling exercise, 55% of VO2max, 3 times/wk, 4 wks | Active ghrelin, EIA (4.2%) | Unchanged | |
| Hypoxic training (n = 9), FiO2 = 15%) | + 14.7% (NS) | ||||
| Normoxic training (n = 11), FiO2 = 20·9%) | − 12.1% (NS) | ||||
| Short-term training with decreased circulating ghrelin | |||||
| Rämson et al. 2012 [101] | 12 highly trained national and international male rowers (22.2 ± 3.4) | Training volume about 10 h/wk 1 | Ghrelin, RIA (< 10%) | ||
| Training volume about 15 h/wk 2 | + 0.7 (NS) | Decreased | |||
| Training volume about 10 h/wk 4 | − 11.3 (P < 0.05) | Decreased | |||
| Cho et al. 2017 [102] | 40 normal weight healthy females (22–28) | Intensive military training, 6 times/wk, 8 wks | Ghrelin, RIA (< 15%) | − 10% (< 0.01) | Decreased |
| Short-term training with increased circulating ghrelin | |||||
| Tremblay et al. 2019 [103] | 100 inactive overweight adults/elderly with MetS (56 females, 44 males) (50–70) | High-resistance/low-aerobic training, 3 wks | Total ghrelin, EIA (1.1%) | DNM (P < 0.05) | Decreased |
| Low-resistance/high-endurance training, 3 wks | DNM (P < 0.05) | Decreased | |||
| Low-resistance/low-endurance training, 3 wks | DNM (P < 0.05) | Decreased | |||
| Liao et al. 2020 [104] | 19 obese children (12.7 ± 1.94) | Exercise + diet intervention (moderate exercise (50–60% of HRmax), high-intensity interval exercise (80–90% of HRmax), and resistance training (12–15 RM), 6 times/wk, 6 wks | Ghrelin, ElA | DNM (P < 0.05) | Decreased |
| Long-term training with unchanged circulating ghrelin | |||||
| Jones et al. 2009 [105] | 13 overweight adolescents (7 females and 5 males) (12–18) | Aerobic training, 45 min, 60–85% of VO2peak, 3 times/wk, 32 wks | Active ghrelin, EIA (9.2%) | − 6.7% (NS) | Decreased |
| Martins et al. 2010 [106] | 22 sedentary overweight/obese individuals (14 females, 8 males) (36.9 ± 8.3) | Treadmill walking or running, 75% of HRmax, 5 times/wk, 12 wks | Total ghrelin, RIA (< 10%) | + 14.2% (NS) | Decreased |
| Guelfi et al. 2013 [107] | 12 inactive overweight and obese middle-aged males (49 ± 7.0) | Aerobic training,70–80% of HRmax, 40–60 min, 3 times/wk, 12 wks | Active ghrelin, LIA, | + 20% (NS) | Unchanged |
| Resistance training, 75–85% of 1 RM, 40–60 min, 3 times/wk, 12 wks | − 9% (NS) | Unchanged | |||
| Gibbons et al. 2017 [108] | 16 inactive overweight/obese individuals (18–55) | Aerobic training, 70% of HRmax, 5 times/wk, 12 wks | Total ghrelin, RIA (5.9%) | ||
| Exercising with weight loss | DNM (NS) | Decreased | |||
| Exercising with no weight loss | DNM (NS) | Unchanged | |||
| Bowyer et al. 2019 [109] | 49 normal weight older females (60–75) | Low-dose aerobic training, 50–55% of HRR, 105 ± 9 min/wk, 16 wks | Acyl ghrelin, EIA (< 10%) | + 25% (NS) | Unchanged |
| Fico et al. 2020 [110] | 19 inactive obese middle-aged and older adults (18 females, 1 male) | Swimming training, 20–45 min, 40–70% of HRR, 3 times/wk, 12 wks | Ghrelin | DNM (NS) | Decreased |
| 20 inactive obese middle-aged and older adults (18 females, 2 males) | Cycling training, 20–45 min, 40–70% of HRR, 3 times/wk, 12 wks | DNM (NS) | Decreased | ||
| Long-term training with decreased circulating ghrelin | |||||
| Plinta et al. 2012 [79] | 50 professional female players (21 ± 2.4) | Moderate aerobic training, 120 min (pulse 140–160/min) 5 times/wk, 12 wks | Total ghrelin, EIA (6.0%) | ||
| 15 basketball players | − 44.6 (P < 0.01) | Unchanged | |||
| 35 handball players | − 31.4 (P < 0.01) | Unchanged | |||
| Gibbons et al. 2017 [108] | 16 inactive overweight/obese individuals (18–55) | Aerobic training, 70% of HRmax, 5 times/wk, 12 wk (exerting with weight loss) | Acyl ghrelin, RIA | DNM (P < 0.05) | Decreased |
| Yu et al. 2018 [111] | 39 centrally obese MetS individuals (32 females, 7 males) (58 ± 8) | Yoga training, 60 min, 5 times/wk, 52 wks | Acyl ghrelin, EIA | − 33% (vs.− 7% in controls) | Decreased |
| Bowyer et al. 2019 [109] | 49 non-obese elderly females (60–75) | high-dose aerobic training, 50–55% of HRR, 160 ± 14 min/wk, 16 wks | Acyl ghrelin, EIA (< 10%) | − 17.6 (P = 0.019) | Decreased |
| Long-term and very long-term training with increased circulating ghrelin | |||||
| Leidy et al. 2004 [112] | 15 normal-weight healthy females (20.2 ± 1.4) | Aerobic training 70–80% of HRmax, 5 times/wk, 12 wks | Total ghrelin, RIA (< 2.7%) | ||
| 5 exercising with weight stable | − 15.1 (NS) | Unchanged | |||
| 10 exercising with weight lost | + 71% (P < 0.05) | Decreased | |||
| Foster-Schubert et al. 2005 [113] | 87 overweight post-menopausal females (60.7 ± 6.75) | Aerobic training, 45 min, 60–75% of HRmax, 5 times/wk, 12 wks/48 wks | Total ghrelin, RIA (3.5%) | + 24%/ + 32% (P < 0.05) | Decreased |
| Kelishadi et al. 2008 [114] | 100 obese boys and girls (7–9) | Moderate aerobic exercise, 40 min, 5 times/wk, 24 wks | Total ghrelin, RIA (9%) | DNM (P < 0.05) | Decreased |
| Mizia-Stek et al. 2008 [115] | 37 middle-aged obese premenopausal females (29–52) | Cycling, 60 min, 65% of HRmax + diet of 1,000 kcal/day, 12 wks | Ghrelin, EIA (< 6.0%) | + 10.5 (P = 0.005) | Decreased |
| Konopko-Zubrzycka et al. 2009 [116] | 21 obese females and males (20–60) | Moderate aerobic exercise, 45-min walk, 5 times/wk, 24 wks + intragastric balloon placement + diet | Ghrelin, RIA (17.8%) | DNM (P < 0.01) at 4 and 24 wks | Decreased |
| Martins et al. 2010 [106] | 22 sedentary overweight/obese individuals (14 females, 8 males) (36.9 ± 8.3) | Treadmill walking or running, 75% of HRmax, 5 times per wk, 12 wks | Acyl ghrelin, RIA (< 10%) | + 39% (P < 0.05) | Decreased |
| Cederberg et al. 2011 [117] | 552 young undergoing military service (19.3 ± 0.9) | Intensive military training, 24 wks | Des-acyl ghrelin, EIA (11.8%) | + 13.5% (P < 0.001) | Decreased |
| Gueugnon et al. 2012 [118] | 32 obese inactive adolescents (22 females, 10 males) (14–15) | Intermittent exercise, 45–60 min, 4-min of moderate work (50% of MAP and 1 min of intense work (85% of MAP) 5 times/wk, 28 wks | Ghrelin, RIA (7.9%) | DNM (P < 0.05) | Decreased |
| Ueda et al. 2013 [119] | 20 healthy mildly to moderately active females (49.1 ± 0.8) | Aerobic training, 80 min, 65% of HRmax, 3 times/wk, 12 wks | Acyl ghrelin, EIA (< 18%) | Increased, + 11% (P < 0.01) | Decreased |
| Markofski et al. 2014 [120] | 14 healthy elderly (10 females and 4 males) (71.2 ± 5) | Aerobic (60–70% of HRR) + resistance (80–85% of 1 RM) training, 20 min, 3 times/wk, 12 wks | Total ghrelin, EIA | + 46% (P < 0.05) | Unchanged |
| Campos et al. 2014 [121] | 42 post-pubertal obese adolescents (28 females, 14 males) | Aerobic training, 60 min, 3 times/wk, 52 wks | Ghrelin, EIA | + 16.1% (NS) | Decreased |
| Aerobic + resistance training, 2 × 30 min, 52 wks | + 18.5% (NS) | Decreased | |||
| Kim et al. 2014 [122] | 18 untrained healthy young males (23.6 ± 2.8) | Resistance training, 50–80 min, 60–80% of 1 RM, 6 times/wk, 12 wks | Total ghrelin, RIA (5.2%) | ||
| + high-protein diet | + 24% (P = 0.001) | Decreased | |||
| + standard diet | + 7.5% (NS) | Unchanged | |||
| Mason et al. 2015 [123] | 234 overweight/obese post-menopausal females (57.9 ± 5) | Moderate to-vigorous intensity aerobic training, 45 min, 70–85% of HRmax, 5 times/wk, 48 wks | Total ghrelin, RIA (11.8%) | + 1.0% (NS) | Decreased |
| The same training program + diet, 48 wks | + 7% (P = 0.008) | Decreased | |||
| Moraes et al. 2015 [124] | 37 hemodialysis patients (16 females, 21 males) (45 ± 12.8) | Resistance training, 60–70% of 1 RM, 24 wks | Acyl ghrelin, EIA, | + 50% (P < 0.05) | Unchanged |
| Kang et al. 2018 [125] | 13 middle-aged obese females (50.1 ± 3.8) | Aerobic + resistance exercise training, 50 min, 5 times/wk, 12 wks | Ghrelin, EIA | + 39.6% (P < 0.05) | Decreased |
| Yu et al. 2018 [111] | 39 centrally obese individuals with MetS (32 females, 7 males) (58 ± 8) | Yoga training, 60 min, 3 times/wk, 52 wks | Des-acyl ghrelin, EIA | + 14% (vs. − 27% in controls) | Decreased |
| Tremblay et al. 2019 [103] | 100 inactive overweight adults/elderly with MetS (56 females, 44 males) (50–70) | High-resistance/low-aerobic, 12 wks/24 wks | Total ghrelin, EIA (1.1%) | DNM (P < 0.001) | Decreased |
| Low-resistance/ high-endurance, 12 wks/24 wks | DNM (P < 0.001) | Decreased | |||
| Low-resistance/low-endurance, 12 wks/24 wks | DNM (P < 0.001) | Decreased | |||
CV coefficient of variation, DNM data not mentioned, EIA enzyme immunoassay, FiO2 fractional inspired oxygen, HRmax maximum heart rate, HRR heart rate reserve, LIA luminescence immunoassay, MAP of maximal aerobic power, MetS metabolic syndrome, NM not measured, NS not significant, RIA radioimmunoassay, RM repetition maximum, TV training volume, VO2max maximal oxygen uptake, VO2peak peak of oxygen consumption