Evidence from HIIT studies conducted under controlled laboratory conditions has provided proof-of-concept of efficacy [9]. However, it has been argued that HIIT has high efficacy but low effectiveness [16], and long-term exercise interventions carried out under free-living conditions have been asked for to investigate whether HIIT is feasible as a public health initiative among older adults [9, 16]. Our data showed that both training groups reported on average more than two exercise sessions per week throughout the year. Approximately 60% of the sessions in the HIIT group were performed with a self-reported high-intensity (≥15 Borg scale), indicating that older adults are able to perform HIIT over a long time-period without strict supervision. However, women had a lower proportion of sessions with high-intensity exercise compared to men. This result is in line with previous findings that women (aged 60–67 years) are less likely than men to prefer vigorous physical activity [23].

I believe we are coming around to the conclusion that what was recommended for years by the medical community (30 minutes of "aerobic exercise" 3-5 times a week, getting the heart rate up to 80% max. for age, etc.) has been inadequate, and of too low an intensity level. When an activity is of sufficient intensity, and not of a certain duration or repeated a certain number of times, the body will initiate a total-body response (metabolic, HDL, glucose tolerance, blood pressure, bone mineral density, immune competency, etc.) It appears that if this level of intensity is never reached, regardless of the amount of time spent or the frequency it is repeated, the beneficial response by the body never occurs, or is at least blunted.

This exercise is similar in movement to the back squat; however, the bar sits in the front rack position across the collarbones and shoulders of the athlete. HOW TO DO IT: As you drive back up, it is imperative that you raise your elbows to the sky to keep the bar in the correct position. The core should be tight to prevent the back from rounding. If you have mobility issues in the front rack position, you can cross your forearms in front of your body, parallel to the ground. MUSCLES USED: Glutes, quads, hamstrings, calves and core.

Since this move is more difficult, you may sometimes use a kipping motion to propel your body higher into the air in order for your chest to touch the bar. HOW TO DO IT: Start by hanging from a secured bar with your hands slightly wider than shoulder-width apart. While squeezing the traps together and engaging the abs, pull yourself up to the bar and touch your chest to the bar. MUSCLES USED: Back, core, shoulders and chest.
Tabata Intervals. The great thing about many of these techinques is the time saving aspect, and Tabata Intervals are definitely time savers. Developed by Dr. Izumi Tabata for Olympic athletes, Tabata Protocol is a form of High Intensity Interval Training (HIIT) where 20 seconds of work is coupled with 10 seconds of rest then repeated for 8 total rounds Metabolic profile of high intensity intermittent exercises. Tabata, I., Irisawa, K., Kouzaki, M., et al. Department of Physiology and Biomechanics, National Institute of Fitness and Sports, Kanoya City, Japan. Medicine & Science in Sports & Exercise 1997 Mar;29(3):390-5.. The 20 seconds work/10 seconds rest pattern has been shown to tax both aerobic and anaerobic pathways more — and in less time — than intense exercise with longer rest periods, meaning improved overall cardiovascular fitness. This protocol can be done with running/rowing/swimming, bodyweight exercises, or weighted movements.
Exclusion criteria included major diseases or conditions such as severe heart disease, uncontrolled hypertension, obesity, osteoarticular pathology, and neurological disease. Criteria were evaluated on the basis of clinical history, resting ECG, and physical examination. Participants maintained their lifestyles and were instructed not to take part in any other physical programs throughout the study. At the time of the initial design, the study consisted of a 12-week randomized controlled trial with a frequency of 3 times a week, 36 sessions in all, ending with a new assessment of their wellness and the potential persistence of the results on functional/physical capacities.