Too much exercise has been shown to disrupt immune function. There are several instances where regular long runs for weight loss have resulted in weight gain, fatigue and unhealthy drops in blood glucose. In this case, the issue can be traced to a rise in cortisol – a stress hormone – which has been linked to a gain in abdominal fat, weakened immune function and compromised cognitive function. As high cortisol surges can occur during and after exercise, it is advisable not to switch on this natural stress response mechanism on a daily basis.
Studies reveal that certain workout behaviors can suppress immune function: (a) workouts lasting 1.5 hours or more, particularly when you don’t refuel in between (b) a reasonably high intensity but not a very difficult exercise regimen (c) not enough recovery period between workouts.
In fact, endurance athletes who push themselves to their limit are often diagnosed with depressed immunity. Elite athletes tend to have more severe symptoms of the common cold that also last longer; the incidence of upper respiratory issues in this group is also high. Recreational athletes are the healthiest while those who seldom exercise are prone to weight loss and lifestyle diseases.
Exercising in moderation can be understood in the following ways:
•Keep your body active and aligned to your natural rhythm. If possible, do simple household chores where you stand on your feet, bend down or stretch to reach top shelves. Do 10 push-ups in your recreation or exercise room at work, take one or more walk breaks with colleagues and engage in movements that are light intensity and pleasurable.
•If you have recently lost weight after being on a strenuous training program, you will need to watch your diet carefully. As you may start burning fewer calories, you may want to cut down on junk food (sources of empty calories) and continue nourishing your body with proteins and vegetables.
•Consider burst training, where you exercise at 90-100 percent of your maximum heart rate for 30-60 seconds followed by 30-60 seconds of rest or a lower-intensity exercise. Some ideas for burst training at home include:
i) Jumping jacks
ii) Squat pulses
iii) High jumps (raise your arms above your head and jump as fast as you can for 60 seconds)
iv) Take your bike out for a quick spin
v) If you have a pool at home, dip in for a few laps
•Sleep at least 7-8 hours a day. During restful sleep, your body heals and repairs its blood and heart vessels.
•Allow for an adequate recovery period after and between workouts.
With careful exercise, diet and sleep management, you should be able to keep your weight at a healthy level without compromising your immune system.