Swap stretching for a dynamic warm-up. Remember that these high-intensity workouts aren't for people who are just starting out. You should build a base of resistance before doing high-intensity cardio and start the weights with lighter weights, emphasizing good form. Do you have little time in the gym? Reduce your rest intervals.
By resting as little as possible, you automatically increase the intensity of your training and keep your heart rate elevated during your weightlifting or interval training session. This cardiovascular challenge trains the body (and mind) to work efficiently and persevere despite fatigue. Rob Sulaver, C, S, C, S. When you do regular cardiovascular training, your body gets better at supplying fresh oxygen to your muscles, so you can perform your workouts better even when you're tired.
Cheer yourself up on your way to the gym and during your workout with songs that make you feel strong, powerful and that you can do anything. You can easily find dumbbells, TRX bands, kettlebells, weighted medicine balls and sliding discs at every gym (or on the Internet if you like to work out at home), and they increase the intensity of standard movements, such as push-ups, squats and sit-ups. Foaming before exercising (and when you have free time) is a good habit to make every gym session more effective.