Table 3.
Summaries of study characteristics and findings from nine [6,10,11,15,23,25,26,27,28] studies using other types of exercise designs.
| Investigators Year Published | Study Population | Analytical Platform/Matrix | Research Design | Key Findings Exercise Effect Separate from Other Interventions | Intensity |
|---|---|---|---|---|---|
| Danaher et al., 2015 [23] | 7 active males (aged 22.9 ± 5.0 years) | GC-MS; Plasma |
Randomized, cross-over design; two supramaximal low volume high-intensity exercise protocols (1-week washout) (HIE); (1) HIE150%: 30 × 20 s cycling at 150% VO2peak, 40 s rest (348 ± 27W); (2) HIE300%: 30x 10s cycling at 300% VO2peak, 50 s rest (697 ± 54 W); blood samples timepoints: pre- and post-exercise (0-h, 1-h) | 55 chemically identified metabolites detected; HIE300% produced greater metabolic perturbations compared to HIE150%; Changes more pronounced during recovery than exercise, with ↑ glycolytic pathway and fatty acids and lipid metabolism. | High-intensity, short-duration |
| Zafeiridis et al., 2016 [28] | 9 healthy young men (aged 20.5 ± 0.7 years). Soccer training 4−5 times per week. | 1H NMR; Plasma |
Randomized, cross-over design; three running protocols (2-week washout): intense continuous (18-min, 80% of maximum aerobic velocity (MAV)), long-interval (29-min, 3 min at 95% of MAV, 3 min recovery at 35% of MAV) and short-interval (18-min, 30 s at 110% of MAV, 30 s recovery at 50% of MAV); blood sample timepoints: pre- and post-exercise (5-min). | 17 metabolites identified using internet databases; No detectable difference in metabolites; ↑ carbohydrate/lipid metabolism and activation of the TCA cycle in all three protocols. |
High-intensity, short-duration |
| Jacobs et al., 2014 [6] | 19 healthy physically active males (aged 21 ± 2 years) | GC-MS and LC-MS/MS; Plasma |
Double-blind, randomized, cross-over design; 6-day supplementation with decaffeinated green tea or placebo ingestion (28-day washout) 2-h before a 30 min cycle exercise at 55%VO2max | 152 chemically identified metabolites changed with exercise; ↑ metabolites related to adrenergic and energy metabolism (e.g., lactate, pyruvate, malate, succinate, glycerol, cortisol); ↓ 2-hydrxobutyrate. | Moderate-intensity, short-duration |
| Hodgson et al., 2012 [10] | 27 healthy physically active males (aged 22 ± 5 years) | GC-MS and LC-MS/MS; Plasma |
Double-blind, randomized, parallel design; 7-day supplementation with caffeinated green tea or placebo ingestion 2-h before 60-min cycle exercise at 50%VO2max | 238 metabolites chemically detected changed with exercise; ↑ ratio > 2: lactate, pyruvate, succinate, noradrenaline and glycerol; ↓ 2-hydroxybutyrate, trans-4-hydroxyproline, mannose, certain triacylglycerides (TAGs) and nicotinamide. | Moderate-intensity, long-duration |
| Karl et al., 2017 [11] | 25 male highly trained soldiers (aged 19.0 ± 1.0 years) | UPLC-MS/MS; Plasma |
Double-blind, randomized, parallel design; 4-day, 51-km cross-country ski march carrying 45 kg pack; blood sample timepoints: pre- and post-exercise (early completers: 8 to 10-h or late completers: 2 to 3-h). | 478 chemically identified metabolites changed pre- and post-exercise ↑ 88% of the free fatty acids; ↑ 91% of the acylcarnitines; ↓ 88% of the mono- and diacylglycerols detected within lipid metabolism pathways; Smaller ↑ 75% of the tricarboxylic acid cycle intermediates; ↑ 50% of the branched chain amino acid metabolites | Moderate-intensity, long-duration |
| Peake et al., 2014 [26] | 10 well-trained male cyclists and triathletes (aged 33.2 ± 6.7 years) | GC-MS; Plasma |
Randomized, cross-over design; HIIT (60-min, ≈ 82% VO2max,) and a moderate-intensity continuous exercise (MOD) (61-min, ≈ 67% VO2max); blood samples timepoints: pre- and post-exercise (0-h, 1-h, 2-h). | 49 metabolites chemically identified; 29 changed with exercise (11 changed with both HIIT and MOD; 13 changed with HIIT only; 5 changed with MOD only); ↑ in carbohydrate oxidation and ↓ in fat oxidation in HIIT exercise compared to MOD; Glucose and lactate higher at 0-h in HIIT compared to MOD. | High and moderate-intensity, long-duration |
| Al-Khelaifi et al., 2018 [15] | 191 elite athletes (171 males, 20 females) | UPLC-MS/MS; Serum |
Cross-sectional design using elite athletes from various sport disciplines being monitored for doping; blood samples collected IN or OUT competition (1 timepoint) | Metabolites chemically identified; ↑ Oxidative stress common to both high-power and high-endurance sports alike; ↑ steroids and polyamine pathways more prominent in endurance; ↑ sterols, adenine-containing purines, and energy metabolites most evident with power. | Cross-section elite athletes |
| Neal et al., 2013 [25] | 12 male cyclists (aged 36 ± 6 years) | 1H NMR; Urine |
Randomized, cross-over design; 6-week training of polarized training-intensity (80% low intensity, 0% moderate-intensity, 20% high-intensity) and a training-intensity distribution (57% low intensity, 43% moderate-intensity, 0% high-intensity) (4-week washout); urine samples timepoints: pre- and post- each training period. | Method used to identify metabolites not reported; metabolites identified as ↓ hippuric acid, ↑ creatinine, ↑ dimethylamine, ↑ 3-methylxanthine, ↓ hypoxanthine. | Chronic training, Low, moderate and high-intensity |
| Pechlivanis et al., 2013 [27] | 14 young moderately trained healthy males (aged 21 ± 2 years) | 1H NMR; Serum |
Randomized, parallel group design; two 8-week programs (3 sessions/week), two and three sets of two 80-m maximal runs (interval between runs: group A = 10 s; group B = 1 min), 20 min interval between sets; blood timepoints: pre- and post-training. | 18 chemically identified metabolites changed after training period; separation after training mainly due to ↓ lactate, ↓ pyruvate, ↑ methylguanidine, ↑ citrate, ↑ glucose, ↑ valine, ↑ taurine, ↑ trimethylamine N-oxide, ↑ choline-containing compounds, ↑ histidines, ↑ acetoacetate/acetone, ↓ glycoprotein acetyls, and ↓ lipids; no significant difference between training intervals. | Chronic training, high-intensity |
GC-MS: gas chromatography mass spectrometry; LC-MS: liquid chromatography mass spectrometry; UPLC-MS: ultra-performance liquid chromatography mass spectrometry; 1H NMR: proton nuclear magnetic ressonance; UPLC-MS: ultra-performance liquid chromatography mass spectrometry; HIE = high-intensity exercise; HIE150% = high-intensity exercise at 150% of VO2 peak; HIE300% = high-intensity exercise at 300% of VO2 peak; W = watts; MAV = maximum aerobic velocity; TCA = tricarboxylic acid cycle; HIIT: high-intensity interval training; MOD = moderate-intensity continous exercise.