In this Article

• What is interval training?
• How are interval-training sessions designed?
• How do I determine how hard to work?
• How often should I increase the intensity of the intervals?
• How do I know how high my heart rate is?
• Can I do intervals inside or outside, with or without exercise equipment?
• How often should I do intervals?
• What are the advantages of interval training?
• Are there any disadvantages to interval training?
• What are the physiological effects of interval training and how do they increase fitness and performance?
• How do I know if I should do intervals?
• Will interval training help me burn more calories and more fat?
• Will interval training help me lose weight?
• Is circuit training an interval-training workout?
• Is interval training the same as cross-training?
• I'm a bodybuilder. Should I do intervals?
• Should I warm up before interval training?
• What should I do for a cool-down after interval work?
• Interval Training Index

Are there any disadvantages to interval training?

Intervals are tough on your body. If performed too often they increase the risk of overtraining. Overtraining is uncomfortable and a set back and so it's important to prevent it by allowing time for recover and growth between sessions. I recommend at least two days of rest between sessions and even more if you suspect you are overtrained. Symptoms of overtraining are

• loss of strength speed, endurance, or other elements of performance,



• loss of appetite,



• inability to sleep well,



• chronic aches and pains or soreness,



• chronic colds or respiratory infections,



• overuse injuries like tendinitis,



• unusual fatigue,



• occasional increase in resting heart rate,



• irritability, and



• malaise and you don't feel like exercising anymore.

If you have any of these symptoms and it's from overtraining and not a medical condition (for which you should see your doctor), then you will need to either take a break from working out (generally seven to 10 days) or experiment with fewer intervals. Don't worry about losing your fitness if you take a break. Virtually everyone comes back stronger after a break.

NOTE 1: If you have trouble with your knees, then speeding up for work intervals of walking, jogging, or running, might be too tough. You don't want to irritate your joints, and so stop the exercise that hurts and modify your workout to make it pain-free (or as close to pain-free as you can. You never want to work through pain, and especially pain that gets worse during your workout. See your doctor if pain persists.

NOTE 2: Check with your doctor before starting interval training if you have any questions about the health of your heart or other medical conditions that might be affected by high-intensity workouts.