There is more research out that overturns the idea that exercise for older adults needs to be gentle and not very challenging (kind of like the picture above?).
The most recent issue of IDEA Fitness Journal discusses two recent studies.
One, conducted by the Norwegian University of Science and Technology, was a longitudinal study that compared the effects of 5 years of supervised exercise training among those over 70 years of age (men and women). The results showed that all types of physical activity were beneficial, but that those who participated in HIIT (High Intensity Interval Training) had a slightly lower risk of dying during those 5 years. In other words, there is a likelihood that HIIT exercises can increase longevity. The study was published in the The BMJ of the British Medical Association, and recommended that HIIT exercise be incorporated in the physical activity that seniors do.
For those unfamiliar, HIIT means that there are intervals (timed periods) of more intense exercise interspersed in more moderate exercises. For instance, someone going on walk for five minutes could walk for one minute at a regular pace followed by 20 seconds of more intense effort (faster or on an incline) then go back to regular pace, etc., until the 5 minutes are up. This elevates the heart rate and keeps it elevated throughout the workout; it is less intense that 5 minutes of straight running or speed-walking (which many people cannot sustain) but more challenging than simply walking for that time (which may provided more limited benefits).
The second study by University of Colorado researchers, published in Physical Therapy, showed that HIIT exercises can be applied to resistance (weight) training in a PT setting. It is safe and effective and can even double physical function in older adults in rehab after hospitalization; this can result in increased care and reduced costs.
All in all, this is nothing new. It only adds to the research out there that shows that there are many different approaches to training older adults. Of course, each individual is different; some older adults are frail while others are active. A good personal trainer will understand the complexities and create an appropriate plan for his/her client. This research, however, is important for the client and the trainer to take into account; going harder can have verifiable positive results.