Next Article in Journal
Effects of Acute Dietary Polyphenols and Post-Meal Physical Activity on Postprandial Metabolism in Adults with Features of the Metabolic Syndrome
Next Article in Special Issue
Application of Continuous Glucose Monitoring for Assessment of Individual Carbohydrate Requirement during Ultramarathon Race
Previous Article in Journal
Irritable Bowel Syndrome and Gluten-Related Disorders
Previous Article in Special Issue
The Effects of Low- and High-Glycemic Index Sport Nutrition Bars on Metabolism and Performance in Recreational Soccer Players
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

Effects of Ashwagandha (Withania somnifera) on VO2max: A Systematic Review and Meta-Analysis

Jorge Pérez-Gómez
Santos Villafaina
José Carmelo Adsuar
Eugenio Merellano-Navarro
3 and
Daniel Collado-Mateo
HEME Research Group, Faculty of Sport Sciences, University of Extremadura, 10003 Caceres, Spain
Physical Activity and Quality of Life Research Group (AFYCAV), Faculty of Sport Science, University of Extremadura, 10003 Cáceres, Spain
Facultad de Educación, Universidad Autónoma de Chile, Talca 3460000, Chile
Centre for Sport Studies, Rey Juan Carlos University, Fuenlabrada, 28943 Madrid, Spain
Author to whom correspondence should be addressed.
Nutrients 2020, 12(4), 1119;
Submission received: 15 March 2020 / Revised: 9 April 2020 / Accepted: 14 April 2020 / Published: 17 April 2020
(This article belongs to the Special Issue Nutrition and Athletic Performance)


The purpose of this study was to systematically review the scientific literature about the effects of supplementation with Ashwagandha (Withania somnifera) on maximum oxygen consumption (VO2max), as well as to provide directions for clinical practice. A systematic search was conducted in three electronic databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA). The inclusion criteria were: (a) VO2max data, with means ± standard deviation before and after the supplement intervention, (b) the study was randomized controlled trial (RCT), (c) the article was written in English. The quality of evidence was evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. A meta-analysis was performed to determine effect sizes. Five studies were selected in the systematic review (162 participants) and four were included in the meta-analysis (142 participants). Results showed a significant enhancement in VO2max in healthy adults and athletes (p = 0.04). The mean difference was 3.00 (95% CI from 0.18 to 5.82) with high heterogeneity. In conclusion, Ashwagandha supplementation might improve the VO2max in athlete and non-athlete people. However, further research is need to confirm this hypothesis since the number of studies is limited and the heterogeneity was high.

1. Introduction

Maximum oxygen consumption (VO2max) is a physiological parameter that defines the aerobic capacity of a person. It is an indicator of the cardiorespiratory fitness that describes health status [1] and sport performance [2]. Focusing on competitive sports, the VO2max, together with running economy and the anaerobic threshold, is one of the main factors that determine success in endurance activities [3], and also contributes to increase the team sports performance by increasing work intensity, distance covered, and number of sprints completed [4]. However, from the point of view of the physical training, there are still controversies about the best training intensity to enhance the VO2max [5,6].
Apart from sport performance, VO2max has special interest in the field of health. Low values of VO2max (<17.5 mL·min-1·kg-1) are associated with an increased risk of mortality and loss of independent lifestyle in adults and elderly [7], while high values of cardiorespiratory fitness have been associated with a reduced risk of cardiovascular diseases [8,9]. The VO2max level is also important in children, where a higher aerobic capacity is related to better quality of life [10].
Ashwagandha (Withania somnifera) is a plant in the Solanaceae family. The extract of the Ashwagandha root has many biological implications due to its diverse phytochemicals [11], so it has been used, singly or in combination with other natural plants, in many research studies for its properties: anti-diabetic [12], anti-inflammatory [13], anti-microbial [14], anti-tumor [15], anti-stress [16], cardioprotective [17], or neuroprotective [18]. It also displays enhanced endothelial function [11], reduces reactive oxygen species [13], regulates apoptosis [19], and modulates mitochondrial function [11], showing to be effective to treat aging effects [20], anxiety and stress [21], arthritis [22], cognitive functions and memory [23], diabetes [12], epilepsy [24], fatigue [25], neurodegenerative diseases [26], pain [27], thyroid function [28], and skin diseases [29].
In spite of the relevant benefits of supplementation with Ashwagandha, only four meta-analyses have been carried out evaluating its efficacy on anti-inflammatory effects [30], on impotence and infertility treatment [31], on neurobehavioral disorders [32] and anxiety [33]. However, there are no meta-analyses that analyze the effect of Ashwagandha on physical performance. Therefore, the purpose of this study was to systematically review the scientific literature about the effects of supplementation with Ashwagandha on VO2max and to provide practical recommendations. Besides, a meta-analysis was carried out to determine the effect sizes of Ashwagandha on VO2max.

2. Methods

The review was conducted following the statements of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA).

2.1. Literature Search

To find the studies reported in the meta-analysis, several electronic databases were screened: PubMed (Medline), Web of Science (which includes other databases such as Current Contents Connect, Derwent Innovations Index, Korean Journal Database, Medline, Russian Science Citation Index, and Scielo Citation Index) and Google Scholar. The search was conducted in September 2019. The search terms were: (a) the type of treatment (Ashwagandha or “withania somnifera”) and (b) the outcome variable (“oxygen consumption” or “aerobic” or “VO2”). The search was conducted using the treatment and the outcome variables, separated by the Boolean operator “and”.

2.2. Study Selection

The inclusion criteria were: (a) VO2max data, with means ± standard deviation (SD) before and after the supplement intervention; (b) the study was a randomized controlled trial (RCT); (c) the article was written in English. Two independent authors selected the potentially eligible articles from the databases. There were no disagreements.

2.3. Quality of the Evidence and Risk of Bias

The quality of the evidence was categorized using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. The risk of bias was assessed by the Cochrane Collaboration’s tool for assessing risk of bias. This tool classified the selection, performance, detection, attrition, and reporting bias into low, high, or unclear risk of bias.

2.4. Data Collection

Two authors independently extracted data from the studies. The information included: participants, interventions, comparisons, outcomes, and study design (PICOS), following the recommendations from the PRISMA statement. Table 1 shows age, sex, sample size, and condition of the participants. Table 2 presents intervention and the comparison groups, including type of supplementation with the doses, duration of the study, and the daily frequency of the supplementation. Figure 3 displays results for the different outcomes. Study design was not included in any table because all studies were RCT.

2.5. Statistical Analysis

The main outcome of this meta-analysis was VO2max. The meta-analysis was conducted using the Revision Manager (RevMan) software (version 5.3) obtained from Cochrane Collaboration web. Post-intervention mean and SD were extracted and used for meta-analyses. All articles reported VO2 max as mL/kg/min. Mean difference was calculated using a random model. The heterogeneity between the studies was calculated using Tau2, I2, and Chi2 tests. Although there is no consensus about the definition of “mild”, “moderate”, or “severe” heterogeneity, Higgins and Thompson [34] suggested that values for I2 higher than 56% would mean large heterogeneity while values lower than 31% would be related to low heterogeneity.

3. Results

3.1. Study Selection

The PRISMA flow diagram is showed in Figure 1. A total of 129 records were identified, 9 of which were removed because they were duplicated. Of the remaining 120 articles, 92 were excluded because they were not related with the topic, 4 studies were not written in English, and 4 were reviews. After reading the remaining 20 articles, another 15 studies did not meet the inclusion criteria and were excluded. Therefore, 5 studies were included in the systematic review. However, the article by Sandhu et al. [35] was excluded from meta-analysis due to the odd results. In this regard, they evaluated healthy young males and females aged between 18 and 25 with body mass index between 18 and 25. Their mean peak VO2max was lower than 14mL/kg/min, which is so much lower than expected for healthy young people and less than half the mean of the rest of the included studies (46.18 mL/kg/min). We tried to contact with the authors in order to obtain a reason for that, but at the time this article was considered for publication, we did not receive a response. Considering that in the article authors did not explain an incremental test to obtain the VO2max, we believe that they measured the gas exchange at rest, reporting the oxygen consumption (VO2). Therefore, this article was included in systematic review but not in the meta-analysis.

3.2. Quality of Evidence and Risk of Bias

The evidence of the effects on VO2max was initially classified as “high quality” due to all the selected articles were RCT, but the evidence dropped twice because of the small sample size and due to the high degree of heterogeneity. Therefore, the final quality of the evidence was low. The Cochrane Collaboration’s tool for assessing risk of bias (Figure 2) showed that the poorer scores were obtained in the performance and detection bias due to unclear reporting.

3.3. Study Characteristics

Study characteristics are summarized in Table 1. The total number of participants included in this systematic review were 162. Of these, 81 belonged to the Ashwagandha group and 81 were the placebo (control) group. The age ranged from 16 to 45 years old. The sample was comprised exclusively of healthy adults and athletes.

3.4. Interventions

The characteristics of the Ashwagandha supplementation and placebo group are displayed in Table 2. The doses varied from 300 to 500 mg and the daily frequency intake was once or twice a day. The total duration of the intervention varied from 2 to 12 weeks.

3.5. Outcome Measures

The study of Choudhary et al. [36] found a significant group*treatment interaction in the VO2max. The remaining four articles only found within-group improvement in VO2max after the supplement intervention [35,37,38,39].
Regarding meta-analysis results, a significant (p = 0.04) mean difference was observed. Figure 3 showed a mean difference of 3.00 (95% CI from 0.18 to 5.82). The heterogeneity level was large according to the I2 = 84%. The quality of the evidence was low according to the GRADE classification.

4. Discussion

The purpose of this study was to systematically review the scientific literature about the effects of supplementation with Ashwagandha on VO2max and to carry out a meta-analysis to determine the overall effect. After 20 articles were assessed for eligibility, 15 articles were excluded since they did not report VO2 max. A total of 5 articles were included in the systematic review [35,36,37,38,39]. However, one article was excluded from the meta-analysis [35] since the reported mean VO2max was abnormally low for healthy young people and less than half the mean of the rest of the included studies (46.18 mL/kg/min), which may indicate that they were not actually reporting VO2max but VO2 at rest. The results of this meta-analysis showed that supplementation with Ashwagandha may be useful to improve VO2max in athletes [36,38,39] and healthy adults [37]. Table 2 displayed the amount of Ashwagandha used in each study, which varied from 330 up to 1000 mg/day, which is inside the limits, 750 to 1250 mg/day, found to be well tolerated and safe [40]. In this regard, none of the five articles reported any relevant side effect as a consequence of the treatment, achieving a high compliance with the treatment and very low number of dropouts.
The two studies that achieved the highest treatment effect and effect size [36,39] were those with the highest Ashwagandha intake (>50 g in the whole program). Therefore, it seems like the higher the dose, the higher the improvement in VO2. However, the study by Tripathi, Shrivastava, Ahmad Mir, Kumar, Govil, Vahedi, and Bisen [14] did not observe any significant difference between the effects of a 330 mg intake and the effects of a 500 mg intake after 2 weeks. Therefore, further studies comparing the effect of different doses, as well as studies with longer duration are needed.
In general terms, the overall effects were better in those studies with a sample comprised of athletes [36,38,39] compared with the studies with healthy adults [14,39]. This is interesting since, as expected, baseline levels were higher in athletes and, consequently, larger improvements were expected in non-athlete healthy adults. It could be that the effects of supplementation with Ashwagandha might be linked to the physical activity levels of the participants, promoting and increasing the physiological adaptations to physical exercise. However, this hypothesis should be explored in future studies. The VO2max defines the body’s ability to transport and utilize oxygen, so this physiological parameter is associated with endurance performance. Many factors contribute to the VO2max values, including genetic predisposition [41], enzymes [42], muscle fiber type [43], or training [44]. It is also known that nutritional supplementation can improve the effects of training and reach higher performance [45]. Previous studies with Ashwagandha administration observed improvement in working capacity test in rats by increasing the swimming endurance test [46]. As endurance performance is determined by mitochondrial function, some reasons for the Ashwagandha to improve cardiorespiratory fitness can be the significant effects observed on mitochondrial and energy levels, by reducing the succinate dehydrogenase enzyme activity in the mitochondria and benefiting Mg-ATPase activity [47]. Previous studies showed that Ashwagandha significantly enhanced the hemoglobin concentration and red blood cells in animals [48] and also in humans [38], with the subsequent increase in the capacity to transport oxygen to the muscles. Moreover, it should be considered that Ashwagandha has shown to have anti-fatigue [49,50] and anti-stress [51] actions. This could be connected to the significant improvement in the time to exhaustion of the experimental group that could be observed in the study of Shenoy, Chaskar, Sandhu, and Paadhi [39]. Some of the chemical constituents of Whitania somnifera [52] such as flavonoids, alkaloids, and steroidal lactones (withanolides) or the antioxidants (superoxide dismutase, catalase, and glutathione peroxidase) could be behind the improvements of VO2max. Therefore, further studies are needed to explore which are the chemical constituents and mechanism that may explain the potential improvement in the VO2max.
Although all mechanisms by which Ashwagandha can improve the VO2max have not been described yet and future studies are needed to elucidate that improvement, it is known that Ashwagandha exhibits little or no associated toxicity [53], so it seems that this Ayurvedic herb “Ashwagandha” (Withania somnifera) can be safely used for improving cardiovascular fitness in healthy adults and also in athletes, offering an additional alternative as a nutritional supplement to enhance VO2max.
Some limitations in the present meta-analysis can be mentioned. The first one is related to the search strategy, only articles published in English were included and a few databases were used. Another limitation can be the large heterogeneity in the included articles. Different doses, levels of physical activity, or the inclusion of both women and men in the protocols make it very difficult to achieve a high level of evidence. In addition, the systematic review and meta-analysis was not prospectively registered in any public database. Furthermore, in order to have a better understanding of long-term ergogenic benefit and potential side effects from Ashwagandha root extract, longer duration studies are needed.

5. Conclusions

Ashwagandha supplementation might improve the VO2max in athlete and non-athlete people. The analyzed studies used oral administration of Ashwagandha which varied between 2 and 12 weeks with intakes between 300 to 1000 mg/day. Due to the limited number of studies included in this systematic review and meta-analysis, further research is needed to confirm the effects and the recommended dose.

Author Contributions

Conceptualization, J.P.-G., J.C.A. and D.C.-M.; methodology, J.P.-G., S.V., E.M.-N. and D.C.-M.; software, J.C.A., and D.C.-M.; formal analysis, J.P.-G., S.V., J.C.A., E.M.-N., and D.C.-M.; investigation, J.P.-G., S.V., J.C.A., E.M.-N., and D.C.-M.; data curation, J.P.-G., J.C.A. and S.V.; writing—original draft preparation, J.P.-G., S.V. and D.C.-M.; writing—review and editing, J.P.-G., S.V., J.C.A., E.M.-N. and D.C.-M.; supervision, J.P.-G., S.V., J.C.A., E.M.-N. and D.C.-M. All authors have read and agreed to the published version of the manuscript.


S.V. is supported by a grant from the regional Department of Economy and Infrastructure of the Government of Extremadura and European Social Fund (PD16008).

Conflicts of Interest

The authors declare no conflict of interest.


  1. Dela, F.; Finkenzeller, T.; Ingersen, A.; Potzelsberger, B.; Muller, E. Trajectories of cardio-metabolic health in successful aging. Scand. J. Med. Sci. Sports 2019, 29 (Suppl. 1), 44–51. [Google Scholar] [CrossRef]
  2. Mooses, M.; Hackney, A.C. Anthropometrics and Body Composition in East African Runners: Potential Impact on Performance. Int. J. Sports Physiol. Perform. 2017, 12, 422–430. [Google Scholar] [CrossRef] [PubMed]
  3. Brandon, L.J. Physiological factors associated with middle distance running performance. Sports Med. 1995, 19, 268–277. [Google Scholar] [CrossRef] [PubMed]
  4. Helgerud, J.; Engen, L.C.; Wisloff, U.; Hoff, J. Aerobic endurance training improves soccer performance. Med. Sci. Sports Exerc. 2001, 33, 1925–1931. [Google Scholar] [CrossRef] [PubMed]
  5. Midgley, A.W.; McNaughton, L.R.; Wilkinson, M. Is there an optimal training intensity for enhancing the maximal oxygen uptake of distance runners? Empirical research findings, current opinions, physiological rationale and practical recommendations. Sports Med. 2006, 36, 117–132. [Google Scholar] [CrossRef] [PubMed]
  6. Steele, J.; Butler, A.; Comerford, Z.; Dyer, J.; Lloyd, N.; Ward, J.; Fisher, J.; Gentil, P.; Scott, C.; Ozaki, H. Similar acute physiological responses from effort and duration matched leg press and recumbent cycling tasks. PeerJ 2018, 6, e4403. [Google Scholar] [CrossRef] [Green Version]
  7. Myers, J.; Prakash, M.; Froelicher, V.; Do, D.; Partington, S.; Atwood, J.E. Exercise capacity and mortality among men referred for exercise testing. N. Engl. J. Med. 2002, 346, 793–801. [Google Scholar] [CrossRef]
  8. Blair, S.N.; Kampert, J.B.; Kohl, H.W., 3rd; Barlow, C.E.; Macera, C.A.; Paffenbarger, R.S., Jr.; Gibbons, L.W. Influences of cardiorespiratory fitness and other precursors on cardiovascular disease and all-cause mortality in men and women. JAMA 1996, 276, 205–210. [Google Scholar] [CrossRef]
  9. Rebollo-Ramos, M.; Velazquez-Diaz, D.; Corral-Perez, J.; Barany-Ruiz, A.; Perez-Bey, A.; Fernandez-Ponce, C.; Garcia-Cozar, F.J.; Ponce-Gonzalez, J.G.; Cuenca-Garcia, M. Aerobic fitness, Mediterranean diet and cardiometabolic risk factors in adults. Endocrinol. Diabetes Nutr. 2019. [Google Scholar] [CrossRef]
  10. Galvez Casas, A.; Rodriguez Garcia, P.L.; Garcia-Canto, E.; Rosa Guillamon, A.; Perez-Soto, J.J.; Tarraga Marcos, L.; Tarraga Lopez, P. Aerobic capacity and quality of life in school children from 8 to 12. Clin. Investig. Arterioscler. 2015, 27, 239–245. [Google Scholar] [CrossRef]
  11. Dar, N.J.; Hamid, A.; Ahmad, M. Pharmacologic overview of Withania somnifera, the Indian Ginseng. Cell. Mol. Life Sci. 2015, 72, 4445–4460. [Google Scholar] [CrossRef] [PubMed]
  12. Chukwuma, C.I.; Matsabisa, M.G.; Ibrahim, M.A.; Erukainure, O.L.; Chabalala, M.H.; Islam, M.S. Medicinal plants with concomitant anti-diabetic and anti-hypertensive effects as potential sources of dual acting therapies against diabetes and hypertension: A review. J. Ethnopharmacol. 2019, 235, 329–360. [Google Scholar] [CrossRef] [PubMed]
  13. Sun, G.Y.; Li, R.; Cui, J.; Hannink, M.; Gu, Z.; Fritsche, K.L.; Lubahn, D.B.; Simonyi, A. Withania somnifera and Its Withanolides Attenuate Oxidative and Inflammatory Responses and Up-Regulate Antioxidant Responses in BV-2 Microglial Cells. Neuromol. Med. 2016, 18, 241–252. [Google Scholar] [CrossRef] [PubMed]
  14. Tripathi, N.; Shrivastava, D.; Ahmad Mir, B.; Kumar, S.; Govil, S.; Vahedi, M.; Bisen, P.S. Metabolomic and biotechnological approaches to determine therapeutic potential of Withania somnifera (L.) Dunal: A review. Phytomedicine 2018, 50, 127–136. [Google Scholar] [CrossRef]
  15. Hassannia, B.; Logie, E.; Vandenabeele, P.; Vanden Berghe, T.; Vanden Berghe, W. Withaferin A: From ayurvedic folk medicine to preclinical anti-cancer drug. Biochem. Pharm. 2019. [Google Scholar] [CrossRef]
  16. Kaur, P.; Mathur, S.; Sharma, M.; Tiwari, M.; Srivastava, K.K.; Chandra, R. A biologically active constituent of withania somnifera (ashwagandha) with antistress activity. Indian J. Clin. Biochem. 2001, 16, 195–198. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  17. Kaur, G.; Singh, N.; Samuel, S.S.; Bora, H.K.; Sharma, S.; Pachauri, S.D.; Dwivedi, A.K.; Siddiqui, H.H.; Hanif, K. Withania somnifera shows a protective effect in monocrotaline-induced pulmonary hypertension. Pharm. Biol. 2015, 53, 147–157. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  18. Yenisetti, S.C.; Manjunath, M.J.; Muralidhara, C. Neuropharmacological Properties of Withania somnifera - Indian Ginseng: An Overview on Experimental Evidence with Emphasis on Clinical Trials and Patents. Recent Pat. CNS Drug Discov. 2016, 10, 204–215. [Google Scholar] [CrossRef]
  19. Ahmed, W.; Mofed, D.; Zekri, A.R.; El-Sayed, N.; Rahouma, M.; Sabet, S. Antioxidant activity and apoptotic induction as mechanisms of action of Withania somnifera (Ashwagandha) against a hepatocellular carcinoma cell line. J. Int. Med. Res. 2018, 46, 1358–1369. [Google Scholar] [CrossRef] [Green Version]
  20. Pradhan, R.; Kumar, R.; Shekhar, S.; Rai, N.; Ambashtha, A.; Banerjee, J.; Pathak, M.; Dwivedi, S.N.; Dey, S.; Dey, A.B. Longevity and healthy ageing genes FOXO3A and SIRT3: Serum protein marker and new road map to burst oxidative stress by Withania somnifera. Exp. Gerontol. 2017, 95, 9–15. [Google Scholar] [CrossRef]
  21. Chandrasekhar, K.; Kapoor, J.; Anishetty, S. A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian J. Psychol. Med. 2012, 34, 255–262. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  22. Khan, M.A.; Ahmed, R.S.; Chandra, N.; Arora, V.K.; Ali, A. In vivo, Extract from Withania somnifera Root Ameliorates Arthritis via Regulation of Key Immune Mediators of Inflammation in Experimental Model of Arthritis. Antiinflamm. Antiallergy Agents Med. Chem. 2019, 18, 55–70. [Google Scholar] [CrossRef] [PubMed]
  23. Choudhary, D.; Bhattacharyya, S.; Bose, S. Efficacy and Safety of Ashwagandha (Withania somnifera (L.) Dunal) Root Extract in Improving Memory and Cognitive Functions. J. Diet. Suppl. 2017, 14, 599–612. [Google Scholar] [CrossRef] [PubMed]
  24. Anju, T.R.; Smijin, S.; Jobin, M.; Paulose, C.S. Altered muscarinic receptor expression in the cerebral cortex of epileptic rats: Restorative role of Withania somnifera. Biochem. Cell Biol. 2018, 96, 433–440. [Google Scholar] [CrossRef]
  25. Singh, A.; Naidu, P.S.; Gupta, S.; Kulkarni, S.K. Effect of natural and synthetic antioxidants in a mouse model of chronic fatigue syndrome. J. Med. Food 2002, 5, 211–220. [Google Scholar] [CrossRef]
  26. Kuboyama, T.; Tohda, C.; Komatsu, K. Effects of Ashwagandha (roots of Withania somnifera) on neurodegenerative diseases. Biol. Pharm. Bull. 2014, 37, 892–897. [Google Scholar] [CrossRef] [Green Version]
  27. Ramakanth, G.S.; Uday Kumar, C.; Kishan, P.V.; Usharani, P. A randomized, double blind placebo controlled study of efficacy and tolerability of Withaina somnifera extracts in knee joint pain. J. Ayurveda Integr. Med. 2016, 7, 151–157. [Google Scholar] [CrossRef] [Green Version]
  28. Sharma, A.K.; Basu, I.; Singh, S. Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial. J. Altern. Complement. Med. 2018, 24, 243–248. [Google Scholar] [CrossRef]
  29. Li, W.; Zhang, C.; Du, H.; Huang, V.; Sun, B.; Harris, J.P.; Richardson, Q.; Shen, X.; Jin, R.; Li, G.; et al. Withaferin A suppresses the up-regulation of acetyl-coA carboxylase 1 and skin tumor formation in a skin carcinogenesis mouse model. Mol. Carcinog. 2016, 55, 1739–1746. [Google Scholar] [CrossRef]
  30. Cakici, N.; van Beveren, N.J.M.; Judge-Hundal, G.; Koola, M.M.; Sommer, I.E.C. An update on the efficacy of anti-inflammatory agents for patients with schizophrenia: A meta-analysis. Psychol. Med. 2019, 49, 2307–2319. [Google Scholar] [CrossRef] [Green Version]
  31. Durg, S.; Shivaram, S.B.; Bavage, S. Withania somnifera (Indian ginseng) in male infertility: An evidence-based systematic review and meta-analysis. Phytomedicine 2018, 50, 247–256. [Google Scholar] [CrossRef] [PubMed]
  32. Durg, S.; Dhadde, S.B.; Vandal, R.; Shivakumar, B.S.; Charan, C.S. Withania somnifera (Ashwagandha) in neurobehavioural disorders induced by brain oxidative stress in rodents: A systematic review and meta-analysis. J. Pharm. Pharmacol. 2015, 67, 879–899. [Google Scholar] [CrossRef] [PubMed]
  33. Pratte, M.A.; Nanavati, K.B.; Young, V.; Morley, C.P. An alternative treatment for anxiety: A systematic review of human trial results reported for the Ayurvedic herb ashwagandha (Withania somnifera). J. Altern. Complement. Med. 2014, 20, 901–908. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  34. Higgins, J.P.; Thompson, S.G. Quantifying heterogeneity in a meta-analysis. Stat. Med. 2002, 21, 1539–1558. [Google Scholar] [CrossRef] [PubMed]
  35. Sandhu, J.S.; Shah, B.; Shenoy, S.; Chauhan, S.; Lavekar, G.S.; Padhi, M.M. Effects of Withania somnifera (Ashwagandha) and Terminalia arjuna (Arjuna) on physical performance and cardiorespiratory endurance in healthy young adults. Int. J. Ayurveda Res. 2010, 1, 144–149. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  36. Choudhary, B.; Shetty, A.; Langade, D.G. Efficacy of Ashwagandha (Withania somnifera [L.] Dunal) in improving cardiorespiratory endurance in healthy athletic adults. Ayu 2015, 36, 63–68. [Google Scholar] [CrossRef] [Green Version]
  37. Tripathi, R.; Salve, B.; Petare, A.; Raut, A.; Rege, N. Effect of Withania somnifera on physical and cardiovascular performance induced by physical stress in healthy human volunteers. Int. J. Basic Clin. Pharmacol. 2016, 5, 2510–2516. [Google Scholar]
  38. Malik, A.; Mehta, V.; Dahiya, V. Effect of ashwagandha (withania somnifera) root powder supplementation on the vo2 max. and hemoglobin in hockey players. Int. J. Behav. Soc. Mov. Sci. 2013, 2, 91–99. [Google Scholar]
  39. Shenoy, S.; Chaskar, U.; Sandhu, J.S.; Paadhi, M.M. Effects of eight-week supplementation of Ashwagandha on cardiorespiratory endurance in elite Indian cyclists. J. Ayurveda Integr. Med. 2012, 3, 209–214. [Google Scholar] [CrossRef] [Green Version]
  40. Raut, A.A.; Rege, N.N.; Tadvi, F.M.; Solanki, P.V.; Kene, K.R.; Shirolkar, S.G.; Pandey, S.N.; Vaidya, R.A.; Vaidya, A.B. Exploratory study to evaluate tolerability, safety, and activity of Ashwagandha (Withania somnifera) in healthy volunteers. J. Ayurveda Integr. Med. 2012, 3, 111–114. [Google Scholar] [CrossRef] [Green Version]
  41. Williams, C.J.; Williams, M.G.; Eynon, N.; Ashton, K.J.; Little, J.P.; Wisloff, U.; Coombes, J.S. Genes to predict VO2max trainability: A systematic review. BMC Genom. 2017, 18, 831. [Google Scholar] [CrossRef]
  42. Honig, C.R.; Connett, R.J.; Gayeski, T.E. O2 transport and its interaction with metabolism; a systems view of aerobic capacity. Med. Sci. Sports Exerc. 1992, 24, 47–53. [Google Scholar] [CrossRef]
  43. Pette, D.; Staron, R.S. Cellular and molecular diversities of mammalian skeletal muscle fibers. Rev. Physiol. Biochem. Pharmacol. 1990, 116, 1–76. [Google Scholar]
  44. MacInnis, M.J.; Gibala, M.J. Physiological adaptations to interval training and the role of exercise intensity. J. Physiol. 2017, 595, 2915–2930. [Google Scholar] [CrossRef] [Green Version]
  45. Dominguez, R.; Cuenca, E.; Mate-Munoz, J.L.; Garcia-Fernandez, P.; Serra-Paya, N.; Estevan, M.C.; Herreros, P.V.; Garnacho-Castano, M.V. Effects of Beetroot Juice Supplementation on Cardiorespiratory Endurance in Athletes. A Systematic Review. Nutrients 2017, 9, 43. [Google Scholar] [CrossRef] [Green Version]
  46. Dhuley, J.N. Adaptogenic and cardioprotective action of ashwagandha in rats and frogs. J. Ethnopharmacol. 2000, 70, 57–63. [Google Scholar] [CrossRef]
  47. Begum, V.H.; Sadique, J. Effect of Withania somnifera on glycosaminoglycan synthesis in carrageenin-induced air pouch granuloma. Biochem. Med. Metab. Biol 1987, 38, 272–277. [Google Scholar] [CrossRef]
  48. Ziauddin, M.; Phansalkar, N.; Patki, P.; Diwanay, S.; Patwardhan, B. Studies on the immunomodulatory effects of Ashwagandha. J. Ethnopharmacol. 1996, 50, 69–76. [Google Scholar] [CrossRef]
  49. Mishra, L.C. Scientific Basis for Ayurvedic Therapies; CRC Press: Boca Raton, FL, USA, 2003. [Google Scholar]
  50. Biswal, B.M.; Sulaiman, S.A.; Ismail, H.C.; Zakaria, H.; Musa, K.I. Effect of Withania somnifera (Ashwagandha) on the development of chemotherapy-induced fatigue and quality of life in breast cancer patients. Integr. Cancer Ther. 2013, 12, 312–322. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  51. Lopresti, A.L.; Smith, S.J.; Malvi, H.; Kodgule, R. An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled study. Medicine 2019, 98, e17186. [Google Scholar] [CrossRef] [PubMed]
  52. Kumar, V.; Dey, A.; Hadimani, M.B.; Marcović, T.; Emerald, M. Chemistry and pharmacology of Withania somnifera: An update. TANG 2015, 5, 1–13. [Google Scholar] [CrossRef] [Green Version]
  53. Mishra, L.C.; Singh, B.B.; Dagenais, S. Scientific basis for the therapeutic use of Withania somnifera (ashwagandha): A review. Altern. Med. Rev. 2000, 5, 334–346. [Google Scholar] [PubMed]
Figure 1. Flow chart delineating the complete systematic review process.
Figure 1. Flow chart delineating the complete systematic review process.
Nutrients 12 01119 g001
Figure 2. The Cochrane Collaboration’s tool for assessing risk of bias.
Figure 2. The Cochrane Collaboration’s tool for assessing risk of bias.
Nutrients 12 01119 g002
Figure 3. Meta-analysis results of the effects of Ashwagandha supplementation on VO2max.
Figure 3. Meta-analysis results of the effects of Ashwagandha supplementation on VO2max.
Nutrients 12 01119 g003
Table 1. Characteristics of the sample.
Table 1. Characteristics of the sample.
Sample Size and Sex
Age (Years)CountryPopulation
Shenoy 20128AS: 20 (M and F)
CG: 20 (M and F)
18–27IndiaElite cyclists
Malik 20138AS: 16 (M)
CG: 16 (M)
16–19IndiaHockey players
Choudhary 201512AS: 25 (M and F)
CG: 25 (M and F)
Tripathi 20162AS: 10 (M)
CG: 10 (M)
18–45IndiaHealthy adults
Sandhu 20108AS: 10 (M and F)
CG: 10 (M and F)
18–25IndiaHealthy adults
RCT: randomized controlled trial; AS: Ashwagandha group; M: males; F: females; CG: control group.
Table 2. Characteristics of the interventions.
Table 2. Characteristics of the interventions.
RCTAshwagandha GroupControl GroupDose (mg)Duration
of the Study
Total Dose (g)
Type of SupplementationType of Supplementation
Shenoy 2012Ashwagandha in gelatin capsulesCapsules containing starch powder5008 weekstwice56
Malik 2013Roots of WSSugar power was filled in gelatin capsules5008 weeksonce28
Choudhary 2015One capsule of KSM-66 AshwagandhaIdentical capsules containing sucrose30012 weekstwice50.4
Tripathi 2016WS aqueous extract in the capsule formMaize starch capsule3302 weeksonce4.62
Sandhu 2010WS filled in gelatin capsulesCapsules filled with flour5008 weeksonce28
RCT: randomized controlled trial; KSM-66: commercial name of an Ashwagandha extract; WS: Withania Somnifera. Total dose was calculated as: total dose (g) = (dose (mg) × daily frequency × study duration (days))/1000.

Share and Cite

MDPI and ACS Style

Pérez-Gómez, J.; Villafaina, S.; Adsuar, J.C.; Merellano-Navarro, E.; Collado-Mateo, D. Effects of Ashwagandha (Withania somnifera) on VO2max: A Systematic Review and Meta-Analysis. Nutrients 2020, 12, 1119.

AMA Style

Pérez-Gómez J, Villafaina S, Adsuar JC, Merellano-Navarro E, Collado-Mateo D. Effects of Ashwagandha (Withania somnifera) on VO2max: A Systematic Review and Meta-Analysis. Nutrients. 2020; 12(4):1119.

Chicago/Turabian Style

Pérez-Gómez, Jorge, Santos Villafaina, José Carmelo Adsuar, Eugenio Merellano-Navarro, and Daniel Collado-Mateo. 2020. "Effects of Ashwagandha (Withania somnifera) on VO2max: A Systematic Review and Meta-Analysis" Nutrients 12, no. 4: 1119.

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop