“No Time to Exercise” is No Excuse With HIIT

interval1_380Research has consistently shown that high intensity interval training (HIIT) is not only time-efficient but also very effective in improving health and fitness. The duration used for some of the early HIIT research may have utilized brief work periods (like 20 seconds) but the intensity level used to get results was extremely high (i.e. 170% VO2 max).

In 2010 Martin Gibala, PhD and colleagues from McMaster University took HIIT research to the next level, showing significant results could be obtained by using a lower intensity during the interval stages. His group used a protocol that involved 8-12 one-minute sprints on a bike with 75 seconds of recovery in between the sprints, 3 times week for 2 weeks. The intensity used during each work stage was about 100% of peak power output (an average output of about 350 Watts).

The “secret” to why HIIT is so effective is unclear. However, the study by Gibala and co-workers also provides insight into the molecular signals that regulate muscle adaptation to interval training.

It appears that HIIT stimulates many of the same cellular pathways that are responsible for the beneficial effects we associate with endurance training.

The great thing about a well-designed HIIT training session is that it can be fast but yet effective in producing health benefits. Here are a few examples of HIIT that I used in a recent workout. This template can be adapted for your needs depending on your fitness level and goals. The first interval example was performed on a stationary cycle using a 1:3 work-to-rest ratio while the second example was performed on an erg (Concept 2 rowing machine) using a 1:2 work-to-rest ratio. Try this type of protocol using other modalities that may fit your needs like running or other cardio equipment like an elliptical machine or treadmill.

The key take away is that the duration should be short and the intensity should be high. Use this type of HIIT protocol 1-3 times a week. The higher the intensity, the higher the excess-post oxygen consumption (epoc). EPOC is a “measurably increased rate of oxygen intake following strenuous activity intended to erase the body’s oxygen deficit.” In recovery, oxygen is used in the processes that restore your body to a resting state. It is possible to expend a few hundred extra calories (depending on body weight and intensity of the workout) over the course of 24 hours or more following strenuous exercise.

 Example of HIIT Bike Protocol

2:00 Warm-up

20 seconds of all-out work (300-700 Watts) >100 rpm

1:00 recovery (<50 rpm)

Repeat x 3 then cool-down

 

Example of HIIT Rowing Protocol

2:00 Easy Rowing (damping set at 4-5, 20-25 spm)

30 seconds of all out work (damping set at 4-5 and >30 spm)

1:00 recovery

Repeat x 3 and cool-down

Reference

Jonathan P Little, Adeel S Safdar, Geoffrey P Wilkin, Mark a Tarnopolsky, and Martin J Gibala (2010). A practical model of low-volume high-intensity interval training induces mitochondrial biogenesis in human skeletal muscle: potential mechanisms. The Journal of Physiology, DOI: 10.1113/jphysiol.2009.181743

Have You Tried the 10-20-30 High Intensity Interval Protocol Yet?

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Source: http://dailyhiit.com

There are many effective high intensity interval training (HIIT) protocols that have been used by exercise physiologist and researchers over the years. One such interval protocol (10-20-30) was tested and published in the Journal of Physiology by two researchers from Copenhagen. Researchers, Gunnarsson and Bangsbo, had very promising results on a group of moderately trained runners who used this particular protocol. The study compared training results on a control group and an interval group using the 10-20-30 protocol. The 10-20-30 training concept consisted of a standardized ∼1.2 km warm-up at a low intensity followed by 3–4 × 5 minute running interspersed by 2 minutes of rest. Each 5-minute running period consisted of five consecutive 1 minute intervals divided into 30, 20, and 10 seconds at an intensity corresponding to <30%, <60%, and 90–100% of their maximal intensity, respectively.

Study results showed the 10-20-30 group, significantly reduced systolic blood pressure by 5 ± 2 mmHg, and total and low-density lipoprotein (LDL) cholesterol was significantly lowered by 0.5 ± 0.2 and 0.4 ± 0.1 mmol/l, respectively. No changes were observed in control group. The study also showed that interval training with short 10-second near-maximal bouts can improve performance and V̇O2max despite a ∼50% reduction in training volume. In addition, the 10-20-30 training regime lowered resting systolic blood pressure and blood cholesterol, suggesting a beneficial training effect on the health profile of trained individuals.

Following the 7-week study the runners experienced an average increase in their VO2max of 4% (mean 52 ml/kg/min. VO2max) and improved running times in a 1,500-m and a 5-km run by 21 and 48 seconds, respectively. Four weeks prior to as well as before and after the intervention period each subject (n = 18) underwent a series of tests that included: (1) a treadmill test to determine V̇O2max and maximal aerobic speed, (2) a 1,500-m run, and (3) a 5-km run.

This type of training protocol suggest that adding 1:00 intervals using the 10-20-30 protocol to your current training routine would be ideal not only for runners but the general population as well. It would be prudent to try this only after a solid aerobic conditioning base is established.

Recommended Reading

Gunnarsson TP, Bangbo J. (2012). The 10-20-30 training concept improves performance and health profile in moderately trained runnersJournal of Applied Physiology, 113(16-24) DOI: 10.1152/japplphysiol.00334.2012

Bangsbo J, Gunnarsson TP, Wendell J, Nybo L, Thomassen M. (2009) Reduced volume and increased training intensity elevate muscle Na+-K+ pump alpha2-subunit expression as well as short- and long-term work capacity in humans. J Appl Physiol 107: 1771–1780