I would like to comment on three articles on yoga published recently in IJPP. Regarding the article on the effect of yoga on reaction time, respiratory endurance and muscular strength (1) :
1. The names of asanas like Navasan, Naukasan and Mukhabhastrika are not mentioned anywhere in the traditional texts on yoga.
2. The duration of 18 yoga exercises was 30 min and the total practice session was also held for 30 min. How was this done? Was there no interval at all between exercises?
3. A control group should have been studied and matched for such parameters which are dependent upon age and since the pre and post measurements are separated by 3 months.
Regarding the letter on heart rate alterations in pranayamas (2):
1. Names of Pranayama have no traditional support from ancient texts, except Nadisuddhi Pranayama. The readers will therefore have no idea about the technique of Vibhaga, Mahat Yoga and Savitri Pranayama.
2. If a person is well trained and has been practising for 4 years, heart rate should not increase so much. Marginal increase of 5 to 7 beats/min is understandable. That means the present subject was practising with muscular exertion.
3. The ratios given for Vibhaga and Mahat yoga are objectionable; i.e., 1: 1:0.20 and 1:1:0.25 respectively. The traditional ratios are 1:2:2, 1:4:2 (Hathapradipika) and 6:8:5 (Goraksha Samhita Ch. II : 4) for Purak, Kumbhak and Rechak.
Regarding the letter on heart rate and respiratory changes accompanying single thought and thought less states (3) :
1. How did the investigator confirm whether the subject was really in
"single thought" or "no thought" state of mind? Thoughtless condition is almost difficult to achieve since it is related to the degree of arousal of the brain.
2. From the respirogram it appears that the subject was not in the
"No thought" state because mainly the expiratory phase of the respiratory cycle is seen disturbed, indicating cortical interference in the autonomic function. In single thought at least it is minimum.
3. The scale of 20 sec given in the graph and rate of respiration given in the Table do not correspond. From the scale it seems to be 12/min in normal, 8/min in the first single thought state, (upper line), 10/min in next single thought state (third line) and 7 to 11/min in
"no thought" state. Increased respiratory rate and decreased amplitude indicate sympathetic predominance and an anxious state of mind.
M. M. Gore
Scientific Research Department,
Kaivalyadhama, Lonavla - 410 403
Madanmohan, Thombre DP, Balakumar B, Nambinarayanan TK., Thakur S, Krishnamurthy N, Chandrabose A. Effect of yoga training on reaction time, respiratory endurance and muscle strength. Indian J Physiol Pharmacol 1992; 36: 229-233.
Telles S, Desiraju T. Heart rate alterations in different types of pranayamas. Indian J Physiol Pharmacol 1992; 36: 287-288.
TELLES S, DESIRAJU T. Heart rate and respiratory changes accompanying yogic conditions of single thought and thoughtless states. Indian J Physiol Pharmacol 1992; 36: 293-294.