For the uninitiated, HIIT involves short bursts of movement at a near-to maximum heart rate level (around 80 to 90 per cent), followed by recovery.
What is the best HIIT ratio?
The most effective ratio of time spent working versus time spent resting? New research has found that 60 second interval interventions are the most effective for improving health outcomes.
The small study published in Future Physiology put 26 previously sedentary adults through HIIT three times a week for six weeks, half the group did 60HIIT (six to ten 60-second intervals with 60 seconds of rest), and the other did 30HIIT (four to eight 30-second intervals with 120 seconds of rest).
Researchers measured results by tracking the aerobic capacity, body composition and arterial stiffness of the participants through out the experiment. Although neither group experienced changes in body composition or arterial stiffness, they found that the 60HIIT group saw greater aerobic capacity suggesting improved fitness.
"In order for people to get the most out of HIIT, which may be the answer to the difficulties of paying for and getting to the gym, we need to get the timing right," Researcher Hannah Church said. "Our research showed just how important this is, because we found that 30-second intervals with 120 seconds of rest meant that participants' heart rates didn't stay up. One hundred twenty seconds is just too long to be resting for!"
How often should women be doing HIIT per week?
"Women should be aiming for around two to three HIIT sessions per week to get maximum benefits, in conjunction with two to three resistance or weights-based workouts," Flow fitness expert and trainer Camilla Bazley told Women's Health. "This will ensure that you are getting a sound balance between cardio and strength training, and allow the body to recover from sessions. A great way to program training week would be to complete HIIT sessions every second to third day, or reduce the length of HIIT workout and increase frequency by adding a small session on to the end of a full body weights session."
What are some common mistakes that are made with HIIT?
We hate to break it to you, but you're probably not working hard enough.
"The most common mistakes made with HIIT training is that they are quite simply, not HIIT training," Bazley says. "To get the benefit of this anaerobic style of cardio, it needs to be all about the intensity."
While it's important to keep intensity high, you don't need to do so for long.
"Typically speaking, a good HIIT workout will be no longer than 20 to 30 minutes max," Bazley explains.
"For anaerobic activity you need to be working at approximately 80 to 90 per cent of your max HR for the burst of repeated efforts. If you are in your aerobic zone, you'll be closer to 65 to 75 per cent which can be sustained for a longer period of time, but doesn't burn as many calories in a short period. Becoming familiar with your heart zones is highly beneficial to get the most out of your workouts."
Considering the benefits of HIIT it can be tempting to smash it out on the reg, but Bazley says you don't want to over do it.
"HIIT can be quite taxing on the nervous system, and it is important to ensure that recovery measures are taken to avoid over training," she says. "This can lead to an increases production in stress hormones such as cortisol, and just cause fatigue in general. The golden rule, train smarter not harder!"
