High intensity interval training vs steady state cardio
There has been debate for many years now over which cardio is best. High intensity training or the long duration medium intensity. A recent trend that people keep asking me about is this ‘new’ high intensity interval training (HIIT).
Exercise trends in the fitness industry get recycled from the media to the public A LOT. It’s a good story for them and a good opportunity for a supplement sale. In fact HIIT was created in 1912 by Hannes Kolehmainen, a famous Olympic long-distance runner . That’s over a hundred years ago. Studies are still being conducted on what the best training mode is.
There has been recent research on the mitochondrial protein results of both training intensities. Increasing mitochondrial density can be considered a skeletal muscle and metabolic adaptation. One focal point of interest for metabolic adaptations is with the metabolism of fat for fuel during exercise. One particular study by Bishop DJ1, Granata C2,Eynon N is looking at two samples of cross sectional data of muscles. 1 The data of the muscles following 20-30 mins of high intensity training such as sprinting. 2. The cross sectional data of the same muscle group of another person who performed 45-60 minutes of medium intensity exercise such as jogging. The results state that following the session the muscles will look almost identical. Both high intensity interval training and continuous steady state exercise produce the same adaptation in those muscles that were worked. The high intensity mode just hurts a lot more while the steady state mode just takes longer.
Another study done at the Faculty of Health and Sport Sciences, University of Agder, Kristiansand, Norway found that doing steady state exercise in a fasted state attacked fat cells much greater than HIIT. Exercise in a fasted state also prevented the drop of blood glucose concentration as opposed to the other group they studied who induced carbohydrates before they trained.
However, high intensity interval training seems to give greater results in the long term.
Perry et al. (2008) showed that fat oxidation, or fat burning was significantly higher and carbohydrate oxidation (burning) significantly lower after 6 weeks of interval training. In as little as two weeks Talanian et al. (2007) showed a significant shift in fatty acid oxidation with HIIT. Boutcher (2011) did a research review with the High intensity training and found that it can increase cardiorespiratory fitness anywhere between 4% and 46%. Also insulin sensitivity can be improved 23% to 58% for those who are insulin resistant. It can improve HDL cholesterol after a minimum of 8 weeks of training. Atleast 12 weeks of HIIT training can also reduce lower blood pressure from 2% to 8% in both systolic anddiastolic blood pressure. Boutcher (2011) observes that the striking surge in epinephrine and norepinheprine from HIIT training may serve a catalyst role for improving fat loss. Both of these fight or flight hormones (also known as adrenaline and noradrenaline) have been shown to drive lipolysis (the breakdown in fat), and are largely responsible for fat release from both subcutaneous and intramuscular fat stores (to be used for fuel in exercise). Boutcher asserts that High intensity may thus have the potential to specifically lower abdominal fat stores, which have been implicated as the unhealthy fat depots in the human body.
Another metabolic benefit of HIIT training is the increase in post-exercise energy expenditure referred to as Excess Post-exercise Oxygen Consumption (E.P.O.C.). Following an exercise session, oxygen consumption (and thus caloric expenditure) remains elevated as the working muscle cells restore physiological and metabolic factors in the cell to pre-exercise levels. This translates into higher and longer post-exercise caloric expenditure. In their review article, LaForgia, Withers, & Gore (2006) note that exercise intensity studies indicate higher E.P.O.C. values with HIIT training as compared to continuous aerobic training.
So which is the better one for fat loss?
The answer is both! And here is why I have come to this conclusion. I have showed the benefits of both. Steady state definitely attacks the fat cells, while HIIT has more benefits over time. However, HIIT requires training intensity intervals of 90-95% of maximal effort. How many times a week do you think you could train at 95% of you maximal intensity? The answer would be not many. You could be trying to train at 95% but your recovery time from a high intensity session is much greater than the steady state cardio session. You may find it ends up being more of medium intensity cardio session because of your previous high intensity bout.
To get the best results of fat loss from cardio try 1-2 HIIT sessions a week and also 1-2 steady state sessions . You will be reaping the rewards of all the physiological and metabolic factors.
Here are 2 examples of HIIT to try.
Treadmill workout
Warm-up: 10 min of light jogging.
Interval: Set treadmill incline at 5% grade and speed at 5 km/h. During each high intensity interval increase speed to 8 km/h – 12 km/h, while keeping grade at 5%. The length of the interval should be 1 min.
Rest Interval: 2-minute rest interval with the walking speed set to 5 km/h. Do not adjust incline.
Work/Rest Ratio: 1 to 2 ratio. The work interval is 1-minute and the rest interval is 2-minutes
Frequency: 6-8 repetitions of this sequence.
Cool Down: 5 – 10-minutes of easy jogging
Comments: This is a hill running interval session. Incline, running speed, interval length, and rest interval can be adjusted during the interval session.
Adapted from Seiler and Hetlelid, 2005.
Sprint training workout
Warm-up: 10 min of light running.
Interval: 20-second sprints at maximal running speed.
Rest interval: 10 seconds of rest between each sprint. Light jogging or walking
Work/Rest ratio: 2 to 1 ratio. The work interval is 20-sec and rest interval is 10-sec.
Frequency: 3 groups or sets of 10-15 intervals. Take 4 min of rest between each set
Cool Down: 10 min easy jog
Comments: This is a sprint workout. The first few intervals should be slower allowing muscles to adapt to the workout. It is important to be safe and careful avoiding muscle damage during maximal sprinting exercise. The warm-up session is very important.
Adapted from Tabata et al. 1996.
I have created a system of implementing High intensity interval training using bodyweight and resistance based movements then followed by steady state cardio in my sessions with my clients. With the correct program design you can get all of these fat burning modes in just the one session. Just put your thinking cap on!
Stay tuned for part 3. Should women train the same as men? and what are some training strategies that women can use to further enhance their results?
Troy
