Effects of interval training on endurance and heart mass

(12-19-2013) Interval training is Spinningincreasingly done to improve endurance or lose weight effectively. Research has shown that it is more effective in those areas than regular endurance training at moderate intensity. There are however different forms of interval training. Researchers from the Japan Aerospace Exploration Agency and the Universities of Tsukuba and Kyoto have performed a study in which the effects of interval training using two different protocols are compared to endurance training at a moderate intensity.

What did the researchers do?

The researchers recruted 42 healthy inactive men. The subjects were divided into three groups: The Sprint Interval Group, the Aerobic Interval Training Group and the Continuous Endurance Group. All three groups performed their respective training protocols on five times a week for eight weeks on a stationary bicycle. The Sprint Interval Training consisted of a 2 minute warm up after which seven 30 second sprints were performed alternated with 15 seconds of rest. Sprint training intensity was set at 120% of maximum oxygen uptake (VO2max). The Aerobic Interval Training protocol consisted of the same 2 minute warm up followed by three spirtins of three minutes each at 80-85% VO2max alternated by two minute rest periods at 50% VO2max. The Continuous Endurance Training protocol consisted of a 2 minute warm up followed by 40 minutes of cycling at 60-65% VO2max. Before and after the eight week training period a maximum oxygen uptake test was done. In addition, an MRI scan of the heart was made to see if the changes in endurance were caused by an increase in the mass of the left heart chamber (left ventricle).

What where the results?

The results are depicted in the figures below:


Effects interval training on VO2max

Figure 1: Effects on VO2max in ml/kg/min.












Effects of interval training on heart mass

Figure 2: Effects on left ventricular mass in g.












Relative changeafter 8 weeks Sprint Interval Training Aerobic Interval Training Continuous Aerobic Training
VO2Max: 16.7% 22.5% 10.0%
Lef Ventricular Mass: 6.5% 8.0% 2.5%


After eight weeks of training all groups had increased their VO2max. There was however a large difference between the Aerobic Interval Training group and the Continuous Aerobic Group. Both interval training groups showed similar increases in left ventricular mass. The Continuous Aerobic Training group did not have a significant increase in left heart chamber mass.

What did the researchers conclude?

The researchers concluded that all three training protocols were effective in increasing VO2max, but the Aerobic Interval Training was particularly effective. Although left ventricular mass increased in both interval training groups, it could only explain a small part of the increase in VO2max and other factors are likely to play a larger role in heart chamber mass.

What does this mean for me?

-To increase endurance 10 minutes of interval training is more effective than 40 minutes of continuous aerobic training.

-Aerobic interval training consisting of three minute sprints at 80-85% VO2max is more effective in increasing endurance and VO2max than 30 second sprints at an intensity of 120% VO2max.

See also:

-Cardio training for weight loss

-How to lose weight and fat effectively


-Matsuo, T., Saotome, K., Seino, S., et al. Effects of a Low-Volume Aerobic-Type Interval Exercise on VO2max and Cardiac Mass. Medicine & Science in Sports & Exercise 2014, 46, 1, 42-50.