End your workout before you wipe out.
Knowing when your workout is done is more than a matter of watching the clock or counting reps. Guidelines are useful, but the optimum duration of a workout depends on your sport or activity, ability level, goals and circumstances, such as how well rested you are before the workout. In order to end your workouts at that sweet spot where you've had just enough challenge without wiping yourself out, you need to pay attention to your body's signals.1.
Reach for and monitor your intensity while you are exercising. If you're strolling along instead of running, for example, you'll need to keep strolling a long time to get a workout. Performing aerobic activities at a pace where it's just possible to hold a casual conversation is considered moderate activity and is recommended for beginners. Getting warm and breaking a sweat indicates that you're exercising at a sufficient level to increase your metabolism and challenge your body to develop fitness.2.
Pay attention to your form during your workout. If you start to wobble on the treadmill, can't pump that weight like you did on the previous rep or aren't reaching as far with your swimming stroke, you've probably reached your maximum level of effort for the workout. Pushing ahead in this state won't give any further benefits. Recognize that your workout is done and move into the cooldown and stretching phase of your routine.3.
Check in with yourself -- both physically and mentally -- immediately after the workout and again several hours later in the day. If you feel positive about your effort and look forward to your next workout, as well as energized for your other daily activities, you'll know you're on the right track with the duration and intensity of your exercise sessions. But if you find yourself dragging through the day and dreading the thought of returning to the gym, you might be burning out due to excessive workout effort.4.
Keep an exercise log or journal. If, after your post-workout check-in, you decide to change your next workout's time or intensity, jot this down along with your reasons for doing so. This will help you spot trends over the long term. Occasionally pushing past your limit will probably not hurt in the long run, but wiping yourself out repeatedly could lead to injuries or other serious problems.
- Deep fatigue that develops four or more hours after the workout could indicate serious overtraining or some other health problem. You should see your doctor if you have that kind of fatigue.