The symptoms of any illness generally keep you out of the gym as long as the illness lasts. Once your symptoms begin to fade, your thoughts may turn back to the gym. The exercise may help you regain your strength as you recover from the illness. Listen to your body to determine when to resume gym workouts and how intensely to work out.
In general, it's OK to exercise at an easy to moderate pace if your symptoms reside "above the neck," such as sneezing or a runny nose, and you have no fever. However, you should not exercise if you have "below the neck" symptoms, like chest congestion or stomach upset, or if you have a fever.
Severity of Illness
The type of illness you have plays a role in when you can get back to the gym. In general, exercise is still possible if you only have a minor cold, as long as you are fever free and aren't coughing much. However, if you have a contagious illness, stay away from the gym until any risk of transmitting your germs has passed. A viral infection is likely to leave you with weakness in your muscles, so your usual workout may be more difficult to complete when you exercise after flu.
Returning to Training After Illness
The specific symptoms you experience with the illness affect when you can return to the gym. Always wait until a fever is gone to return to exercise. Wait for other significant symptoms to pass, including vomiting, diarrhea, abdominal cramps, severe coughing, general aches or chills. For best results, wait until you begin to feel an increase in your energy and muscle strength so you are able to complete a workout. Consult with your health care provider if you are unsure if it is safe to return to the gym.
First Workout After Illness
Your first trip back to the gym is the test of your body's strength after the illness takes its toll, so it helps to prepare with proper nutrition and a warmup. Plan for a shorter workout with lower intensity than you did before you got sick. A slower pace is less likely to make you feel worse or cause your symptoms to reappear. If you feel dizziness, nausea or pain, end the workout early or slow down even more. Take the next day off from the gym to give your body more recovery time.
Your Return to Full Training
If your trips to the gym involve intense training activities, you should allow time to build back up to your prior intensity level. Runners World suggests, as a rule of thumb, that your period of reduced exercise intensity should last two to three days for every day of sickness. For example, if your cold hung on for five days, you should take 10 to 15 days to build back up to your previous workout intensity. Start with an easy-level workout that lasts 20 to 30 minutes; then increase your time by five or 10 minutes a day for the first week.
You can then slowly increase the intensity with each workout, paying close attention to your body for signs that you are working yourself too hard. If you are recovering from a major illness, your strength may vary from day to day. One trip to the gym may allow for an intense workout, while the next day you may feel that you can't complete an easy workout. Adjust your training schedule to accommodate how your body feels each day.