Does practicing hatha yoga satisfy recommendations for intensity of physical activity which improves and maintains health and cardiovascular fitness?

Abstract

Background: Little is known about the metabolic and heart rate responses to a typical hatha yoga session. The purposes of this study were 1) to determine whether a typical yoga practice using various postures meets the current recommendations for levels of physical activity required to improve and maintain health and cardiovascular fitness; 2) to determine the reliability of metabolic costs of yoga across sessions; 3) to compare the metabolic costs of yoga practice to those of treadmill walking.

Methods: In this observational study, 20 intermediate-to-advanced level yoga practitioners, age 31.4 +/- 8.3 years, performed an exercise routine inside a human respiratory chamber (indirect calorimeter) while wearing heart rate monitors. The exercise routine consisted of 30 minutes of sitting, 56 minutes of beginner-level hatha yoga administered by video, and 10 minutes of treadmill walking at 3.2 and 4.8 kph each. Measures were mean oxygen consumption (VO2), heart rate (HR), percentage predicted maximal heart rate (%MHR), metabolic equivalents (METs), and energy expenditure (kcal). Seven subjects repeated the protocol so that measurement reliability could be established.

Results: Mean values across the entire yoga session for VO2, HR, %MHR, METs, and energy/min were 0.6 L/kg/min; 93.2 beats/min; 49.4%; 2.5; and 3.2 kcal/min; respectively. Results of the ICCs (2,1) for mean values across the entire yoga session for kcal, METs, and %MHR were 0.979 and 0.973, and 0.865, respectively.

Conclusion: Metabolic costs of yoga averaged across the entire session represent low levels of physical activity, are similar to walking on a treadmill at 3.2 kph, and do not meet recommendations for levels of physical activity for improving or maintaining health or cardiovascular fitness. Yoga practice incorporating sun salutation postures exceeding the minimum bout of 10 minutes may contribute some portion of sufficiently intense physical activity to improve cardio-respiratory fitness in unfit or sedentary individuals. The measurement of energy expenditure across yoga sessions is highly reliable.

Figure 1

Mean METs and standard deviation per minute during the yoga session (n = 20). Data from the first four minutes of the 56 minute yoga practice are not displayed. The postures used within each section of the yoga practice (see Table 1) varied in sequence and timing. Minutes 1–24 were sun salutation postures with postures changing every 3–8 seconds; minutes 25–44 were standing poses with postures changing every 10–48 seconds, and minutes 45–52 were sitting and lying postures lasting 3 minutes and 4.5 minutes respectively. Readers are referred to the yoga DVD for a complete description of the yoga session [57].

Figure 2

Mean %MHR and standard deviation per minute during the yoga session (n = 18). Data from the first four minutes of the 56 minute yoga practice are not displayed. The postures used within each section of the yoga practice (see Table 1) varied in sequence and timing. Minutes 1–24 were sun salutation postures with postures changing every 3–8 seconds; minutes 25–44 were standing poses with postures changing every 10–48 seconds, and minutes 45–52 were sitting and lying postures lasting 3 minutes and 4.5 minutes respectively. Readers are referred to the yoga DVD for a complete description of the yoga session [57].