“Blur the distinction between strength training and metabolic conditioning for the simple reason that nature’s challenges are typically blind to the distinction.”
-Coach Gassman founder of CrossFit
For many years the general consensus on improving one’s cardiovascular health was to simply increase the volume of endurance exercise such as running or cycling. The thinking was some is good but more is better. Marathon runners and long distance cyclist graced the cover of fitness magazines being touted as the fittest people on earth. While very impressive, research is finding that the benefits we seek from an improved cardiovascular system such as lower resting heart rate, lower body fat, greater endurance, better sleep and overall improved health can be accessed much more rapidly with High Intensity Interval Training (HIIT) and with less of the downside often associated with chronic endurance training.
More Cardio Isn’t Always Better
In a 2008 training study by Burgomaster et al at the National Center for Biotechnology Information subjects were divided into two groups of 5 men and 5 women per group. For 6 weeks one group performed 4-6 repeats of 30 second all out sprints on a stationary bike followed by 4.5 minutes of rest 3 times per week. The other group performed 40-60 minutes of cycling at 65% of their V02 Max 5 days per week. At the end of the study both groups experienced similar metabolic adaptations responsible for effective breakdown of carbohydrates and fats along with an improved V02 Max, but the striking difference between these two groups is the amount of time actually spent training. The 40-60 minute endurance group spent approximately 4.5 hours per week cycling in order to see the same results the sprinting group achieved with only 1.5 hours per week of cycling. Using the same model you could replace cycling with any movement to achieve greater metabolic adaptations than with endurance training alone. In addition to improved cardiovascular health, HIIT enables you build muscle and improve athleticism.
Keep Your Stress Hormones Low and Stay Lean
One of the potential downside of chronic endurance training is prolonged levels of metabolic stress. Training sessions lasting over an hour induce higher cortisol levels that can undue many of the positive effects from exercise. High levels of this hormone promotes fat storage and leads to the breakdown of muscle tissue as the body converts it to glucose for fuel. This explains why many marathon runners and cyclists struggle to keep body fat low. Contrary to popular belief, more hours spent training doesn’t equal greater results. Short, intense and consistent bouts of high intensity interval training continually beats endurance training as the optimal prescription for healthy biomarkers.
Get Better Results With Less Time
Running and cycling are great tools that we should all be proficient in and incorporate into our program on a regular basis. However, with a limited amount of time available for exercise each week I’d much rather spend it developing my strength and athleticism than on a bike or treadmill for an hour. Especially if I can get the same health benefits in a fourth of the time.