Sunday, November 9, 2014

No Time? No Excuse! Three Minutes (One Minute All Out, Only) Exercise Per Week Suffice to Increase One's Skeletal Muscle Oxidative Capacity and Improve Metabolic Health!

HIIT your weaker self hard, with a total of one minute all out cycling.
It's the most often heard excuse you get, when you ask your sick overweight neighbor if he'd like to accompany you to the gym to do something for his health, first, and his physique, second. "Ah, I don't have the time to work out!"

Obviously, this is a "perceived lack of time" that is not real for 99.9% of the people, even if we're talking about 30 minutes of exercise every other day. And even if it was not, the results of a recent study from the McMaster University in Hamilton, Ontario, will totally steal their non-existent thunder and provide you with convincing arguments to drag them to the gym for a quick HIIT session (Gillen. 2014).

Why? Well, as the headline of today's SuppVersity article says, the study shows that three (=3) minutes of all-out exercise per week (no typo or other mistake here!) will "Suffice to Increase Skelet al Muscle Oxidative Capacity and Improve Metabolic Health" (Gillen. 2014).
You can learn more about HIIT at the SuppVersity

Never Train To Burn Calories!

Tabata = 14.2kcal /min ≠ Fat Loss

30s Intervals + 2:1 Work/Rec.

Making HIIT a Hit Part I/II

Making HIIT a Hit Part II/II

HIIT Ain't For Everyone
Slackers, beware! The subjects of Gillen's study, fourteen overweight or obese men and women, who were recruited by poster advertisement from the McMaster Univerisity community, were not even as short in time as you were. While they still qualified as "sedentary based on their self-reported habitual physical activity", they actually did <2 data-blogger-escaped-u="">not "=zero" exercise sessions per week that lasted on average ≤ 30 min.

Participants were allocated into the male or female intervention group and matched for age, body mass index and VO2 peak. The experimental protocol, itself consisted of familiarization and baseline testing that was followed by a 6 wk training intervention and post-training measurements. Over the course of the 6 week intervention period the subjects hit the gym only once a week, where they did
  • 3x20 s all-out cycling efforts
  • against a load corresponding to 0.05 kg/kg body mass,
  • separated by 2 min of low intensity cycling (50 W)
The exercise was performed on an electronically braked ergometer (Veletron, RacerMate, Seattle, WA, USA). With the obligatory 2 min warm-up and 3 min cool-down at 50 W, the sessions lasted 10 minutes. That's more than just three minutes, but if you think about the exhausting part of the workout, only, it's actually not a three, not a ten, but a one minute workout.
Figure 1: Changes in BMI, parameters of blood glucose management (FPG - fasting peak blood glucose; FPI - fasting peak insulin; HOMA-IR, Gmax - maximal glucose levels in 24h; blood pressure (systolic & diastolic); MAP - mean arterial pressure; power output) in response to six weeks of once a week 3 min all out HIIT exercise (Gillen. 2014)
As you can see the once weekly workouts had a significant impact on both the parameters of glucose management and the cardiovascular and muscular fitness parameters (see Figure 1). The additional skeletal muscle biopsy samples the scientist obtained before and 72 h after training revealed that the above changes went hand in hand with an increase in maximal activity of citrate synthase and protein content of cytochrome oxidase 4 (p < 0.01, main effect) and increases in the maximal activity of b-hydroxy acyl CoA dehydrogenase in men only (p < 0.05).

All the aforementioned changes in protein expression will allow the participants to burn additional amounts of fat during exercise and at rest and could, in conjunction with the improvements in glucose management that was brought about by increases in GLUT4 glucose transporter activity on the muscle specifically, slow down their weight gain - in conjunction with dietary lifestyle changes, they would even favor fat over muscle loss.
If you've missed Saturday's HIIT vs. LISS efficacy comparison, check the article out now! And/or learn more about HIIT at the SuppVersity.
Bottom line: There is no debating, the "[s]hort-term interval training using a 10 min protocol that involved only 1 min of hard exercise, 3x/wk, stimulated physiological changes linked to improved health in overweight adults." (Glenn. 2014) Changes that may pay off in form of a handful of additional years on earth, if the subjects (a) stick to their new exercise protocol and (b) stop eating everything in sight, relatively indiscriminately.

Without dietary intervention, though, I am not sure if the relatively small amount of exercise will do anything but turn a profoundly unhealthy overweight individual into a slightly more healthy overweight individual. Moreover, it's unlikely that the protocol will produce similar benefits in lean, athletic individuals. For them it probably requires some more effort to stimulate fitness gains | Comment on Facebook.
References:
  • Gillen, Jenna B., et al. "Three Minutes of All-Out Intermittent Exercise per Week Increases Skeletal Muscle Oxidative Capacity and Improves Cardiometabolic Health." PLOS ONE 9.11 (2014): e111489.