Research Quarterly for Exercise and Sport, November 2014
Here's something for all of the 10 miles/day people who suffer from "chronic cardio" disease. A recent study out of British Colombia has found that high intensity interval training may be an effective tool for improving postprandial hyperglycemia (the rise in blood sugar following a meal) in individuals with, or at risk for type 2 diabetes. HIIT is defined as, "repeated vigorous-intensity efforts lasting from a few seconds up to several minutes, separated by short periods of rest or recovery" (Little & Francois, 2014, p. 452). When compared to traditional "steady-state," continuous moderate-intensity exercise, HIIT has been shown to offer a more favorable exercise stimulus for improving postprandial hyperglycemia by: (a) promoting a higher degree of muscle fiber recruitment (Edgett et al., 2013), (b) causing greater depletion of muscle glycogen (Shiose, Tobina, Higaki, Kiyonaga, & Tanaka, 2012), (c) promoting a greater activation of 5’ adenosine monophosphate-activated protein kinase (Chen et al., 2003), and/or (d) promoting an increase in skeletal muscle glucose transporter 4 (Hood, Little, Tarnopolsky, Myslik, & Gibala, 2011; Little et al., 2011). In addition to the scientific jargon, other potential long-term benefits of HIIT include: better body composition, cardiorespiratory fitness, as well as greater increases in muscle mass and reduction in abdominal fat when compared to "steady-state" cardio. Definitely food for thought as you re-assess your exercise goals for 2015!
You can access the study here.
Chen, Z. -P., Stephens, T. J., Murthy, S., Canny, B. J., Hargreaves, M., Witters, L. A., . . . McConell, G. K. (2003). Effect of exercise intensity on skeletal muscle AMPK signaling in humans. Diabetes, 52, 2205–2212.
Edgett, B. A., Foster, W. S., Hankinson, P. B., Simpson, C. A., Little, J. P., Graham, R. B., & Gurd, B. J. (2013). Dissociation of increases in PGC-1a and its regulators from exercise intensity and muscle activation following acute exercise. PloS One, 8, e71623.
Hood, M. S., Little, J. P., Tarnopolsky, M. A., Myslik, F., & Gibala, M. J. (2011). Low-volume interval training improves muscle oxidative capacity in sedentary adults. Medicine & Science in Sports & Exercise, 43, 1849–1856.
Little, J. P., & Francois, M. E. (2014). High-Intensity Interval Training for Improving Postprandial Hyperglycemia. Research quarterly for exercise and sport, 85(4), 451-456.