Need to Spring clean your fitness routine? Self  asked top trainers and athletes how they turn up the heat on their workouts — and how you can use their secrets to get serious results.
Admit it: the polar vortex forced you to miss more than one spin class this winter. Don't worry— we've asked a few of the country's fittest professionals for some advice on how to shape up A.S.A.P. Here's how to give your everyday routine a boost.
When you have NO time. Nike master trainer Holly Rilinger  says all you have to do is HIIT it — that's high-intensity interval training —with these five functional movements: Push, pull, squat, lunge, rotate. That could be push-ups, a plank with a row (hold a plank while you row a dumbbell with one arm, then the other) jump squats, side-to-side lunges, and a dumbbell wood chop. Do each move for 45 seconds, going all-out, and rest 15 seconds at the end; immediately start the next exercise. It only takes five minutes! Have a little more time? Double down.
When you think you can't make it a second longer. Basketball star and guard for the WNBA's Tulsa Shock Skylar Diggins  thinks of this phrase whenever it seems impossible to do one more rep, "'You may feel winded, but your muscles are ready.' A coach told me that a long time ago, and it stuck with me. Your brain always wants to stop before your body."
When you want to hoff that donut. You know all the smartest training in the world can be undone by eating bad food— but that doesn't stop you from wanting to inhale cupcakes at work. How do you beat the urge? Take this advice from Sadie Lincoln, creator of barre3 , which she says works for preventing mindless eating: "Simply say in your head: 'This is important to me.' Once you remind yourself why you want to act a certain way, it's much easier to actually do it."
When you know you're half-assing it. Once, when choreographer Derek Hough  was leading a crowd through a cardio dance session, he noticed a few dancers who were just going through the motions. His quote? "Hey! Doing this [mimes a lackluster shuffle and hip pop] won't get you anywhere. If you're not in it, it's not worth it. And if you want to burn, if you want to change, if you want to have fun, you've gotta work it." His point rings true for any session: You made the time to be here! Give it all you've got.
When you've hit a plateau. You have to kick your movements up a notch. Doing the same exercises over and over and expecting new body results IS insanity. That's why Nike Master Trainer Marie Purvis  always includes progressions in her workouts, and you should too. How to do it? Say you've started with a backward lunge. Now add a kick at the top. Easy? Make it a jumping lunge. You can bang out 20? Take it back to a standard lunge, but hold 10-pound dumbbells in each hand. You can gradually progress any movement you're doing to refresh your go-to workout. For more ideas, check out the Nike Training Club app; Marie designs every workout.
When you're tempted to do more, more, more. If a good amount of working out is healthy, then a ton of working out must be uber-healthy. That's the fraught workout trap we can all fall into. Take it from gold-medal gymnast Gabby Douglas , an athlete who's constantly judged on her form, body and performance, that reserving rest days isn't just smart— it's part of training: "If I don't take a day off to relax and let my muscles bounce back, my training suffers. My performance suffers. I start to feel sluggish, and I'll start slacking in the gym." Remember, more isn't more when it comes to exercise. If you're tired, if you're second-guessing whether you need a workout, take a day and get back at it hard the next time.
When you need to make a workout a little more fun. Grab a friend for these tag-team exercises designed by Marie Purvis. And before you roll your eyes and think, "Partner moves?!" know this: These babies are a challenge. You use each other's resistance and bodyweight (and enthusiasm!) to get even more of a burn than you could on your own.
TUG OF WAR SQUAT
Get into a wide, low squat three feet away and facing your partner, extend your opposite arms (your right arm, her left arm), and grab hands. Begin to pull, increasing the resistance until you're both trying to throw each other off balance, while maintaining the squat. Continue for 30 seconds. Repeat twice.
UP AND OVERS
One partner holds a plank with legs together, while the other partner hops back-and-forth over her legs. Up the challenge: Have the partner holding plank go up and down onto her forearms. Continue for 30 seconds, and then switch roles. Repeat twice.
HOLD THE BRIDGE
One partner lies faceup on the ground and holds a bridge with hips high; the second partner plants her palms on her partner's knees, facing away, and starts doing triceps dips. Continue for 30 seconds, then switch roles. Repeat twice.