Ashwagandha Boosts Size & Strength Increases, Augments Fat Loss & Recovery in 8-Week Resistance Training Study
|Ashwaghanda may be for gymrats, too.|
There's a study by Raut, et al. that evaluated the "tolerability, safety, and activity of Ashwagandha (Withania Somnifera) in healthy volunteers" from 2012; a study by Sandhu, et al. in which the researchers probed the "effects of Withania somnifera (Ashwagandha) and Terminalia arjuna (Arjuna) on physical performance and cardiorespiratory endurance in healthy young adults" and found an increase in velocity [+3%], relative power [+9%] and VO2 max [+7%] in response to 500mg/day for 8 weeks; a study by Choudhary et al. (2015) which found both, increases in VO2max and quality of life of 50 "athletic" individuals in response to a commercial Ashwaghanda product that goes by the cryptic acronym KSM-66 Ashwagandha; as well as a study by Shenoy, et al. (2012) which found 11%, 16% 16% and 2% increases in time to exhaustion, VO2, metabolic equivalents (METs) and respiratory exchange ratio (RER), respectively (note: the benefits were sign. lower in female study participants, see Table 1), in response to the same amount, i.e. 500 mg/day, of an aqueous root extract of Ashwagandha that has been used by Sandhu et al. two years before.
"prospective, double-blind, placebo-controlled parallel group study to measure the possible effects of ashwagandha extract on muscle strength/size, muscle recovery, testosterone level and body fat percentage" (Wankhede. 2015)in young men who participated in a standardized resistance training regimen, it is thus not totally impossible that the next best Ashwaghanda product from the internet will produce significantly different results. I guess you should keep that in mind if you plan to go shopping after reading this article. The product Wankhede, et al. used, by the way, was provided by Shri Kartikeya Pharma and Ixoreal BioMed and happened to be the same KSM-66 high-concentration root extract Choudhary et al. used in their likewise very recent study.
|Figure 1: Overview of the study design as it is visualized in Wankhede et al. (2015)|
BIA and CK - not the best ways to measure body fat and recovery: What should be noted about these measurements, though, is the fact that body fat levels were measured via bio impedance (BIA) and the recovery was judged based on creatine kinase (CK) values. With BIA being susceptible to variations in hydration status and other sources interference (Kyle. 2004) and the CK-values showing extreme inter-individual variability (learn more), the validity of these outcomes remains somewhat questionable.Both, the subjects who received the active treatment in form of 2x300 mg/day Ashwagandha, as well as those who received the placebo treatment, underwent identical 8-week resistance training programs; programs, the scientists describe as follows:
"The resistance training program consisted of sets of exercises over major muscle groups in both the upper body and the lower body. [...] Each subject in both groups was asked to come to a training session every other day, with one rest day pe week, for three days per week. Every session began with a warm up consisting of five minutes of low-intensity aerobic exercise. The subjects were instructed to perform, for each set as many repetitions as they could until failure. The subjects were asked to go through the full range of motion and were demonstrated the proper technique for safe and effective weight lifting" (Wankhede. 2015).The workouts were periodized with increasing number of sets from 1-2 to 3. More specifically, the subjects performed barbell squats, the leg extensions, seated leg curls, machine chest presses, barbell chest presses, seated machine rows, one-arm dumbbel rows, machine biceps curls, dumbbel biceps curls, cable triceps press-downs, dumbbell shoulder presses, and the straight-arm pull-downs in the first two weeks and barbell squat (3 sets) the leg extension (3 sets), the leg curl (2 sets), one chest exercise (flat, incline or decline press or fly, cable cross over, 3 sets), one back exercise (rows, pull up, pull down or seated cable row, 3 sets), another chest exercise (3 sets) another back exercise (3 sets), one biceps exercise or one triceps exercise (curls or extensions, 3 sets), and one shoulder exercise (raises or presses, 3 sets) for the rest of the 8-week study.
|Figure 2: Absolute increases in thigh, arm and chest size and reduction in body fat (%) over the course of the 8-week study; the figures above the bars denote the inter-group difference in %, * denotes significant differences (Wankhede. 2015).|
|Figure 3: Changes in 1RM (kg) strength and testosterone (ng/dL) over the course of the 8-week study; the figures above the bars denote the inter-group difference in %, * denotes significant differences (Wankhede. 2015).|
"[...] the following limitations which should lead us to interpret the findings with some caution: the subjects are untrained and moderately young, the sample size of 50 is not large and the study period is of duration only 8 weeks" (Wankhede. 2015)Accordingly, Wankhede et al. rightly demand that further "[r]esearch studying the possible beneficial effects of ashwagandha needs to be conducted", research that spans "longer periods of time" and includes "different populations including females and older adults of both genders" (Wankhede. 2015). In this regard, I would like to remind you that the previously discussed results Shenoy et al. published three years ago, in which the sex of the participants had a major impact on the study outcome, make studies comparing male to female resistance trainees particularly appealing - from a science perspective, obviously ;-)
- Choudhary, Bakhtiar, A. Shetty, and Deepak G. Langade. "Efficacy of Ashwagandha (Withania somnifera [L.] Dunal) in improving cardiorespiratory endurance in healthy athletic adults." AYU (An international quarterly journal of research in Ayurveda) 36.1 (2015): 63.
- Kyle, Ursula G., et al. "Bioelectrical impedance analysis—part II: utilization in clinical practice." Clinical nutrition 23.6 (2004): 1430-1453.
- Patel, Dhaval, Harisha C. Rudrappa, and Proshanta Majumder. "A comparative pharmacognostical, physicochemical, and heavy metal analysis on Ashwagandha root obtained from natural and polluted sources." International Journal of Green Pharmacy 9.1 (2015): 14.
- Raut, Ashwinikumar A., et al. "Exploratory study to evaluate tolerability, safety, and activity of Ashwagandha (Withania Somnifera) in healthy volunteers." Journal of Ayurveda and Integrative Medicine 3.3 (2012): 111.
- Sandhu, Jaspal Singh, et al. "Effects of Withania somnifera (Ashwagandha) and Terminalia arjuna (Arjuna) on physical performance and cardiorespiratory endurance in healthy young adults." International journal of Ayurveda research 1.3 (2010): 144.
- Shenoy, Shweta, et al. "Effects of eight-week supplementation of Ashwagandha on cardiorespiratory endurance in elite Indian cyclists." Journal of Ayurveda and integrative medicine 3.4 (2012): 209.
- Wankhede, Sachin, et al. "Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial." Journal of the International Society of Sports Nutrition 12.1 (2015): 43.
- West, Daniel WD, and Stuart M. Phillips. "Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training." European journal of applied physiology 112.7 (2012): 2693-2702.