This is a randomized, controlled, prospective study in normal adults comparing the efficacy of yoga with a control intervention of PE of eight weeks in 174 normal adults on changes in their personality (guna) and General health as assessed by VPI and GHQ. The results showed that there was an increase in Sattva scores (P < 0.001) in both Y and PE groups and a decrease in Rajas (P = 0.002) and tamas (P = 0.01) scores in the PE group. The scores for Tamas decreased significantly in seniors of both the groups (females in Y and males in PE) (paired samples t test).
The increase in Sattva scores was higher in the Y group

sense of self importance, desire for sense gratification, little interest in spiritual elevation, dissatisfaction with one’s position, envy of others and a materialistic
cleverness.[33] With further growth and mastery, one moves into Sattva–a dominance which includes the qualities of truthfulness, stability, discipline, sense of control, sharp intelligence, preference for vegetarianism, truthfulness, gravity, dutifulness, detachment, respect for superiors and staunch determination[21] and stability in the face of adversity and also conscious action. Thus, we can see that although both Rajas and Tamas have both positive and negative qualities, they are the manifestation of a violent state of mind in which a person lacks mastery over upsurges of emotions and impulsive behaviour.[33] Most of the qualities of Sattva which are manifestation of a calm state of mind are achievable by different yoga techniques (physical postures, pranayama and/or meditation) meant for mastery over the mind-body complex.[34] Several earlier studies have independently corroborated these notions. It has been shown that self esteem as well as the sense of control and determination improved after meditation.[35] Reduction in crime rate after transcendental meditation (TM) supported the effect of a calm state of mind on social health.[36] These positive effects also show up as better perception and memory as well as better motor performance (dexterity
and coordination tests).[37] Better academic performance has also been documented.[38] Although in this study, Yoga has shown a better effect
on the Sattva guna than PE with a better effect size, the main difference between Y and PE practices seems to be the effect on rajas guna. The reduction in this guna was significantly higher after PE than after Y (this group difference was in males and juniors). The scores for Tamas also decreased significantly in seniors of both groups (females in Y and males in PE groups) with the effect size being higher in the PE than in the Y groups. Thus, significantly greater reductions in Rajas and Tamas were worthy of note with PE than with Y. This positive effect of PE in reducing Rajas and Tamas adds to the fund of knowledge about several psycho-physiological benefits of PE. Hence, it appears that physical practices are more effective in reducing the limitations of Rajas and Tamas such as lack of mastery over upsurges of emotions and impulsive behavior, while yoga improves the softer qualities of Sattva. The mechanism of how physical exercises may reduce Rajas and tamas and how yoga may increase Sattva needs to be investigated by further studies. Thus, we may conclude that both physical activity (to reduce Rajas and Tamas) and Yoga (to improve Sattva) may be recommended for the harmonious promotion of personality.
The GHQ showed significant differences within groups in all domains in both groups. There was a significant difference in SS between the Y and PE groups (Mann Whitney Test).
Observations by Atlantis et al. on the efficacy of physical exercise practised for eight weeks in a population of Australian employees showed that the intervention significantly improved the Quality of Life as compared to a waiting list control group (measured by SF-36). They have shown an improvement of 12.8% in physical functioning, 9.90% in general health, 44.50% in vitality and 15.90% in mental health scores.[29] The significantly better reduction in SS in the Yoga group in our study may be due to deeper rest and relaxation obtained in Yoga. The results of the study seem to point out clear differences between Y and PE on VPI whereas differences between Y and PE are not found in most domains of GHQ (except SS). Hence, although GHQ is a good measure of the various aspects of health and disease, VPI seems to be a better measure to differentiate the effects of Y and PE.
In summary, this randomized, prospective, single-blind, comparative study has shown the efficacy of both Y and PE in improving all components of general health. While physical exercise has reduced Rajas and Tamas, the yogic practice has increased Sattva. Hence, yoga which is more traditionally practised in India and cost-effective, can be recommended with additional benefits of promotion of the Sattva guna.
The strength of our design is a PE intervention matched with the integrated Y module. The study population was taken from different parts of Bangalore from different socioeconomic classes of the city. The improvement observed in both groups after eight weeks of intervention in all variables in both groups not only provides hitherto undemonstrated evidence of the efficacy of physical activity in a normal South Indian adult population but also shows that yoga could be an equally effective tool. This study also brings out the subtle differences in the efficacy of the two interventions (Y or PE). It also points out the utility of the VPI as a tool for measuring the subtle dimensions of guna described in traditional texts of yoga that can measure the steps of growth of an individual.