The toll that aging takes on a body extends all the way down to the cellular level. But the damage accrued by cells in older muscles is especially severe, because they do not regenerate easily and they become weaker as their mitochondria, which produce energy, diminish in vigor and number.

A study published this month in Cell Metabolism, however, suggests that certain sorts of workouts may undo some of what the years can do to our mitochondria.

Exercise is good for people, as everyone knows. But scientists have surprisingly little understanding of its cellular impacts and how those might vary by activity and the age of the exerciser.

So researchers at the Mayo Clinic in Rochester, Minn., recently conducted an experiment on the cells of 72 healthy but sedentary men and women who were 30 or younger or older than 64. After baseline measures were established for their aerobic fitness, their blood-sugar levels and the gene activity and mitochondrial health in their muscle cells, the volunteers were randomly assigned to a particular exercise regimen.

Some of them did vigorous weight training several times a week; some did brief interval training three times a week on stationary bicycles (pedaling hard for four minutes, resting for three and then repeating that sequence three more times); some rode stationary bikes at a moderate pace for 30 minutes a few times a week and lifted weights lightly on other days. A fourth group, the control, did not exercise.

After 12 weeks, the lab tests were repeated. In general, everyone experienced improvements in fitness and an ability to regulate blood sugar. There were some unsurprising differences: The gains in muscle mass and strength were greater for those who exercised only with weights, while interval training had the strongest influence on endurance.

But more unexpected results were found in the biopsied muscle cells. Among the younger subjects who went through interval training, the activity levels had changed in 274 genes, compared with 170 genes for those who exercised more moderately and 74 for the weight lifters. Among the older cohort, almost 400 genes were working differently now, compared with 33 for the weight lifters and only 19 for the moderate exercisers.

Many of these affected genes, especially in the cells of the interval trainers, are believed to influence the ability of mitochondria to produce energy for muscle cells; the subjects who did the interval workouts showed increases in the number and health of their mitochondria — an impact that was particularly pronounced among the older cyclists.

It seems as if the decline in the cellular health of muscles associated with aging was “corrected” with exercise, especially if it was intense, says Dr. Sreekumaran Nair, a professor of medicine and an endocrinologist at the Mayo Clinic and the study’s senior author. In fact, older people’s cells responded in some ways more robustly to intense exercise than the cells of the young did — suggesting, he says, that it is never too late to benefit from exercise.

With Jack Frost nipping at our toes, Canadian runners are contemplating one of two things – either hang the shoes up for the winter, or figure out how to maintain a training program over the winter months. The later is definitely a preference, however, there are innate concerns that runners may have regarding the snowy, icy and blustery conditions that we Canadians can experience.

One of the largest concerns that The SportLab hears leading into this season, is that regarding proper footing on our winter roads. This leads to the question as to whether a runner can prepare themselves for Canadian winter roads and potentially reduce their risk of injury? There are definitely some easy tips that can improve runners stability and balance while simultaneously decreasing the risk of injuring an ankle or a knee.

ONE: Increase your volume of off road running. By training in the summer months on smooth, paved surfaces, we have conditioned our bodies to have the expectation of a perfect foot strike against the road each time we take a stride. As we enter the winter season, take some time to run on grass, do some cross country or trail running. The undulations of the terrain and varying angles of the ground, will help strengthen the muscles, that otherwise, may be used minimally in road running.

TWO: Work on your balance in movement. Call up one of your construction friends and have an eight foot length of 2×4 delivered to your house! Once you have this high tech piece of training equipment, you can work through three progressions. Lay the piece of timber on the ground with the 4” surface facing upward. Walk the ‘plank’, heel-to-toe, from one end to the other, turn around, and repeat. If you are able to complete the exercise with your eyes open, progress to doing the same thing with one eye open and ultimately work towards walking the plank with your eyes closed. In working through these progressions you will be creating input into your nervous system that will ultimately improve balance and decrease your risk of falling and becoming injured.

THREE: Practice stationary stability. Time to track down another piece of high tech training equipment – a pillow. For this exercise you will stand, on one foot, on the pillow (an uneven surface). Aim for successful completion of 30 seconds on each foot. In order to progress, do the same exercise with one eye open and the final progression is being able to complete the 30 seconds with both eyes closed. It may take a few weeks to become an ‘expert’ at this!

By implementing the tips above, a runner can be well prepared for changes outdoors that may present themselves over the course of the winter. Through good preparation, we will be able to enjoy the great outdoors, decrease our risk of injury and show Old Man Winter that no matter what he throws at us, we are hearty Canadians that will continue to do what we love. Or, go jump on a treadmill for the next 6 months.