Table 2

Trials evaluating exercise intervention alone on NAFLD-related outcomes

Author (year); countryInterventionAge range; sample size (% male)Study durationOutcome measuresChanges to outcome measures postintervention
Johnson (2009);18
Australia
Cycle ergometer 30–45 min 3×/week, increasing from 50–70% pretraining VO2 max43–51;
23 (65%)
4 weeksPrimary: IHTG, SI, ALT
Other: WT, BMI, Cholesterol, IMTG, SAT, VAT
↓ IHTG* 1.76%
No significant change SI, ALT, WT, BMI ↓ VAT*
St George (2009);26
Australia
Counselling sessions; low-intensity: 3 fortnightly consultations; moderate-intensity: 2 groups received 6 fortnightly consultation, with 1 group receiving additional telephone support35–60;
141 (61%)
3 monthsPrimary: ALT, AST
Other: WT, BMI, LDL, HDL, GLC, TC, TG, GGT, physical activity
↓ ALT*, and ↓ AST* in all groups, greatest seen in moderate-intensity intervention
↓ WT* and ↓ BMI*, greatest in moderate-intensity intervention
Hallsworth (2011);27
UK
Resistance exercise 45–60 min, 3×/week33–72;
21 (NS)
8 weeksPrimary: IHTG (MRS), ALT
Other: WT, BMI, WC, HC, WHR, TC, TG, HbA1C, VAT, SAT, FM, GLC, INS, HOMA-IR
↓ IHTG* 13%; 3 participants moved from clinical NAFLD to normal (<5% IHTG)
No change ALT, WT, BMI
Sullivan (2012);28
USA
Brisk walk 30–60 min, 5×/week44–51;
18 (38%)
16 weeksPrimary: IHTG (MRS), ALT
Other: WT, BM, FM, FFM, VO2 peak, TC, HDL, LDL, TG, FFA, VLDL
↓IHTG* 10.3% , ↓ ALT*
No change WT
Bacchi (2013);16
Italy
Aerobic exercise (AER) at 60% VO2 max, 60 min 3×/week or, resistance exercises (RES) 60 min, 3×/week54–58;
31 (70%)
4 monthsPrimary: IHTG (MRI), ALT, AST
Other: BMI, HbA1c, GGT, TC, LDL, HDL, TG, FFM, IATG, SAT
↓ IHTG* ∼35% in both groups; hepatic steatosis resolved in 3 AER and 4 of RES participants
↓ BMI* in both groups
No change ALT, AST
Zelber-Sagi (2014);29
Israel
Resistance training (RT) 40 min 3×/week or, stretching exercises 3×/week35–57;
82 (53%)
3 monthsPrimary: HRI score (ultrasound), ALT, AST
Other: WT, BMI, BP, GLC, INS, HOMA, TC, TG, HbA1C, HDL, LDL, GGT, FER
↓ HRI score* 11% in RT group
↓ WT* and ↓ BMI* compared with stretching
No change ALT, AST
Keating (2015);19
Australia
Cycling ergometer and walking at either high intensity/low volume, 45 min 3×/week (HI/LO); low intensity/high volume, 60 min 4×/week (LO/HI); or low intensity/low volume, 45 min 3×/week (LO/LO)25–59;
48 (35%)
8 weeksPrimary: IHTG (MRS), ALT, AST, SI, WT, BMI
Other: WT, BMI, BP, WC, VO2 max, TG, TC, HDL, LDL, FFA, INS, GLC, VAT
↓ IHTG* 2.4% (HI:LO), 2.6% (LO:HI), 0.8% (LO:LO)
↓ WT* 1.3% (HI:LO), 1.5% (LO:HI); ↓BMI*
No change ALT, AST, SI
Balducci (2015);17
Italy
Low-intensity resistance and aerobic exercise 2×/week or; high-intensity resistance and aerobic exercise 2× /weekAge NS;
606 (58%)
12 monthsPrimary: AST, ALT, FLI
Other: BMI, VAI, GGT, TG, WC, HOMA-IR, HbA1c
↑ AST*, ↑ ALT*, in exercise and control groups
↓ FLI*, ↓BMI*, ↓VAI* in exercise group*
Takahashi (2015);30
Japan
Regular resistance exercise 20–30 min 3×/week (RES) or education programme on benefits of dietary restrictions and regular physical activity36–68;
53 (35%)
12 weeksPrimary: Steatosis (ultrasound), AST, ALT
Other: FM, MM, LDL, HDL, TG, ALP, GGT, FER, GLC, INS, HOMA-IR, HbA1c
Primary:
↓ steatosis* in RES group
No change AST, ALT, WT, BMI
Cuthbertson (2016);31
UK
Supervised moderate-intensity aerobic exercise progressing from 30 min 3×/week to 45 min 5×/week(AER) or control of conventional counselling50 years (AER)
52 years (Ctrl)
50 (78%)
16 weeksPrimary: IHCL (MRS), AST, ALT
Other: WT, BMI, BP, TC, LDL, HDL, VO2 max
Primary:
↓ IHCL* 48% in AER only; ↓ AST*, ↓ ALT* in both; greatest in AER
↓ WT* and ↓ BMI* in AER group
  • *Statistically significant.

  • ALP, alkaline phosphatase; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BM, body mass; BMI, body mass index (kg/m2); BP, blood pressure; FER, ferritin; FFA, free fatty acids; FFM, fat free mass; FLI, Fatty Liver Index; FM, fat mass, GGT, gamma glutaryl transferase; GLC, glucose; HbA1c, glycosylated haemoglobin; HC, hip circumference; HDL, high-density lipoprotein; HOMA-IR, Homeostasis Model Assessment-Insulin Resistance Index; HRI, hepatorenal-ultrasound index; IATG, intra-abdominal triglyceride; IHCL, intrahepatocellular lipid; IHTG, intrahepatic triglyceride; IMTG, intramyocellular triglyceride; INS, insulin; LDL, low-density lipoprotein; MM, muscle mass; MRS, magnetic resonance spectroscopy; NAFLD, non-alcoholic fatty liver disease; NS, not stated; SAT, subcutaneous adipose tissue; SI, hepatic lipid saturation index; TC, total cholesterol; TG, triglyceride; VAT, visceral adipose tissue; VLDL, very low density lipoprotein; VO2 max, peak oxygen consumption (mL/kg/min); WC, waist circumference; WHR, waist:hip ratio; WT, weight.