Table 2.
Included studies on chronic exercise (N=18 samples reported in N=12 articles)
| Type | First author (year) | Condition | Strain of animal | Sample size (n) | Age (mean±SD) | Gender (% female) | Race/ethnicity (%) | Type of exercise | Exercise modality | Exercise duration | Exercise intensity | eCB collection method | eCB collection timepoints | Significant reported change in AEA | Significant reported change in 2-AG | Significant reported change in other eCBs | Additional outcomesa |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Human studies | |||||||||||||||||
| Patients, including those with pre-existing conditions | |||||||||||||||||
| Stensson (2020)45 | Patients with FM | N/A | HC: n=33 FM: n=37 |
HC: 50.3±12.8 FM: 50.1±10.5 |
HC: 100% F FM: 100% F |
N/R | Strength | RE | 60-min sessions of RE, 2 times/week for 15 weeks | Weeks 1–2: 40% of one rep max, 15–20 reps, 1–2 sets Weeks 3–5: 60% one rep max, 10–12 reps, 1–2 sets Weeks 6–15: 80% one rep max, 5–8 reps, 1–2 sets |
Standard blood draw | Collected before (within 1–7 days) the start of the 15-week exercise interventions and after the intervention (within 1–7 days) | HC: No AEA changes FM: AEA ↑ |
HC: No 2-AG changes FM: No 2-AG changes |
HC: No OEA, PEA changes SEA ↑ FM: No OEA, PEA changes SEA ↓ |
HC: No pain, depression scorings, or muscle strength changes FM: Pain ↓ Depression scorings ↓ Muscle strength ↑ |
|
| Belitardo de Oliveira (2019)95 | Patients with Episodic Migraines | N/A | HC: n=12 Migraines: n=13 |
HC: 34.7±12.0 Migraines: 37.4±13.8 |
HC: 83% F Migraine: 85% F |
HC: 92% W, 0% B, 8% A, 0% M, 0% O Migraines: 92% W, 0% B, 8% A, 0% M, 0% O |
Endurance | Treadmill jogging or walking | 40-min sessions of walking or jogging on a treadmill, 3 times/week for 12 weeks | Heart-rate equivalent to each individual's ventilatory threshold—additional information N/R | Standard blood draw | Collected before exercise and between 2 and 5 days after the last exercise session or 48 h after the last exercise session within the late follicular phase of the menstrual cycle | HC: AEA ↓ Migraines: AEA ↓ |
N/A | N/A | HC: No migraine attacks or mood changes Migraines: Migraine attacks ↓ Improvements in mood |
|
| Brellenthin (2019)44 | Patients with Substance Abuse Disorder | N/A | Treatment as usual with exercise: n=21 | 35.1±10.2 | 45% F | 64% W, 2% B, 0% A, 1% M, 1% O | Endurance | Treadmill incline walking | 30 min of moderate-intensity treadmill incline walking, 3 times/week for 6 weeks | 70–75% AAMHR | Standard blood draw | N/A | N/R | N/R | N/A | Acute improvements in mood and reductions in perceived stress and drug craving | |
| Fernández-Aranda (2014)96 | Patients who are obese | N/A | HC: n=16 Obese: n=30 Morbid obese: n=43 |
HC: 27.6±7.9 Obese: 44.9±12.9 Morbid obese: 43.5±10.2 |
HC: 100% F Obese: 100% F Morbid obese: 100% F |
N/R | Endurance | PA | PA was monitored using accelerometry for 6 days | Time accumulated in MVPA during waking hours | Standard blood draw | Collected between 8 and 9 am after at least 12 h of fasting | AEA ↑ (all groups combinedb) | No 2-AG changes | OEA ↑ (all groups combinedb) | High PA associated with low harm avoidance and high novelty seeking (temperament trait) | |
| Healthy volunteers | |||||||||||||||||
| Koay (2021)97 | Healthy, newly enlisted soldiers | N/A | n=52 | 22.0±4.0 | 0% F | N/R | Endurance and strength | Combined strength and endurance program and occupational specific activities such as marching. | 80-day physical training program with about 1.3 h of PA each day | 68% of the PA in the program was of moderate intensity (4.3–6 METs), while 32% was high intensity (METS >6) | Standard blood draw | Collected after an 80-day program | N/A | 2-AG ↓ | N/A | Indole-3-propionate ↑ Fatty acids and ketone body substrates ↓ Increases in dimethylguanidino valeric acid associated with increases in several cardiovascular risk factors Shifts in metabolism across many different substrates |
|
| Sadhasivam (2020)98 | Healthy volunteers | N/A | n=148 | ≥18.0 | Blood draws only: N/R Full sample: 49% F |
16% W, 2% B, 74% A, 2% M, 6% O | Balance | Yoga (BSP) | 4-day, 3-night yoga retreat | N/R | Standard blood draw | Collected before (up to 2 days before program began) and after exercise (within 2 days after program ended) | AEA ↑ | 2-AG ↑ | DEA ↑ 1-AG ↑ OEA ↑ |
BDNF levels ↑ Depression ↓ Anxiety ↓ Happiness ↑ |
|
| Belitardo de Oliveira (2019)99 | Healthy volunteers | N/A | n=17 | 39.0±13.4 | 60% F | 41% W, 1% B, 1% A, 0% M, 35% O | Endurance | Treadmill running or walking | 40 min of treadmill running or walking, 3 times/week for 12 weeks | Heart rate equivalent to each individual's ventilatory threshold—additional information N/R) | Standard blood draw | Collected before program and within 2–5 days after the last exercise session in program | AEA ↓ | N/A | N/A | Reduction in AEA associated with weight loss Improvements in mood |
|
| Animal studies | |||||||||||||||||
| Dos Santos (2019)100 | Mice that received carrageenan injection | C57BL/6 female mice | Exercise: n=6 Cg+ exercise: n=6 |
8–10 weeks | Exercise: 100% F Cg+ exercise: 100% F |
N/R | Endurance | Swimming | 5 days/week of swimming for 3 weeks: Week 1: 15 min Week 2: 30 min Week 3: 45 min |
N/R | Mice spinal cord tissue | Collected immediately after exercise program | Exercise: No AEA changes Cg+ exercise: AEA ↑ |
N/A | N/A | Spinal CB2R participate in exercise-induced antinociception in mice | |
| Thompson (2017)101 | Mice from HR lines | Trained mice from HR lines | HC: n=50 HR: n=50 |
N/R | HC: 50% F HR: 50% F |
N/R | Endurance | Wheel running | Wheel running access for exercise group for 6 days | N/R | Cardiac puncture | Collected after exercise program | HC: AEA ↑ HR: AEA ↓ |
HC: 2-AG ↓ HR: 2-AG ↓ |
N/A | HC: Female mice had ↓2-AG levels and ↑ AEA levels compared with male mice HR: Female mice had ↓2-AG levels and ↑ AEA levels compared with male mice |
|
| Biedermann (2016)39 | Mice | C57BL/6 mice | Runners: n=10 Restricted runners: n=10 |
10 weeks | Runners: 0% F Restricted runners: 0% F |
N/R | Endurance | Wheel running | Free access wheel running (all day) or restricted access wheel running (6 h/day) for 9 weeks | N/R | Cardiac puncture | Collected after exercise program | Runners: AEA ↓ Restricted runners: AEA ↓ |
Runners: No 2-AG changes Restricted runners: No 2-AG changes |
Runners: No OEA, PEA, 1-AG, and AA changes Restricted Runners: No OEA, PEA, 1-AG, and AA changes |
Runners: Hippocampal gray matter volume ↑ Immature hippocampal neurons ↑ Restricted runners: Immature hippocampal neurons ↑ |
|
| Gamelin (2016)102 | Rats | Male Winstar rats | HC: n=7 HFD: n=7 |
15 weeks | HC: 0% F HFD: 0% F |
N/R | Endurance | Treadmill running | Treadmill running 1 h/day, 5 days/week for 12 weeks | 70–80% of the maximal aerobic velocity | Cardiac puncture | Collected after exercise program | HC: No AEA changes HFD: No AEA changes |
HC: No 2-AG changes HFD: No 2-AG changes |
HC: No OEA and PEA changes HFD: No OEA and PEA changes |
HC: No CB1R, CB2R, or FAAH changes HFD: No CB1R, CB2R, or FAAH changes |
|
| Hill (2010)32 | Rats (treated with CB1R antagonist in experiment 2) | Sprague/Dawley rats | n=35 | 12 weeks | 0% F | N/R | Endurance | Wheel running | Access to wheel for 8 days | N/R | Brain tissue in rats | Collected after exercise program | AEA ↑ | No 2-AG changes | N/A | Voluntary exercise ↑ proliferation of progenitor cells in the dentate gyrus of the hippocampus Effect of proliferation was prevented following AM251 treatment |
|
a
Outcomes, including mood, anxiety, stress, pain, fear, hunger, cravings, etc., were all self-reported unless otherwise stated.
b
Did not report separate results for groups, treated as one sample.
1-AG, 1-arachidonoylglycerol; BSP, Bhava Spandana Program; CBR2, cannabinoid type 2 receptor; DEA, docosatetraenylethanolamide; FM, fibromyalgia; HFD, high-fat diet; HR, high runner; MVPA, moderate-vigorous physical activity; OEA, oleoylethanolamide; PA, physical activity; SEA, stearoylethanolamide.