Jogging is a prolonged and casual exercise, and this degree of physical exertion has been proven to lower your testosterone levels. As well as affecting performance in the bedroom, a lack of the hormone can be responsible for slow muscle recovery and an acute lack of energy. Which means that despite thinking that by taking it slow you’re having it easier, your body might be running itself into the ground.
Hormones help regulate our physiology and behaviour, and an imbalance can affect everything from respiration to digestion, metabolism and sensory perception.
Researchers at Laval University in Québec presented evidence suggesting that short, intense bouts of exercise were much better for maintaining ideal levels of testosterone. However, exercising more strenuously can affect the body in other adverse ways, so it is important to acknowledge the limits of your own body.
The Immune System
Dr. Zen P. Lin of the Mingdao University, Taiwan, published a report in 2010 displaying yet more evidence that extended sessions of leisurely exercise could be detrimental to one’s health. According to his study, not only can jogging affect your testosterone levels, it also has the potential to lower the defences of your immune system.
The study found that while shorter runs may raise the effectiveness of your immune system, “prolonged bouts of strenuous exercise cause a temporary depression of various aspects of immune function”. As a result, those jogging for longer than the recommended two to three hours a week are statistically more vulnerable to contagious diseases and illness.
Professional athletes, with their meticulously worked-out schedules and phalanxes of personal nutritionists are largely exempt from this – but for an average person, who doesn’t weigh out everything they eat and work out to a scientifically-formulated exercise schedule, too much jogging might be building your thighs, but harming your insides.
The more minor effects of running or jogging over long periods, many times a week, can mount up surprisingly quickly. Your bad form may not be fatal on its own, but persistent repetition of a flawed stride may put unwanted pressure on blood vessels, or put misplaced weight onto joints.
‘Runner’s knee’ is a common complaint of the amateur jogger, and can wear down cartilage, reduce your body’s natural shock absortion and generally weaken two of your key joints. The condition can worsen if exercise is pursued regardless and may result in chronic pain attacks and permanent damage.
The ‘optimal dose’
Obviously running or jogging of any type cannot be branded ‘unhealthy’ by definition, as it is exercise and therefore will ultimately physically benefit you. However, Dr Martin Matsumura of the Cardiovascular Research Institute in Pennsylvania has observed that “what we still don’t understand is defining the optimal dose of running for health and longevity.”
So whilst your muscle mass may rise, and your cardio performance improve, there are many small-scale factors that are, nonetheless, damaging. And from joint erosion and falling testosterone levels to trapped nerves and a weaker immune system, these side effects may contribute to or aggravate considerably more serious problems.