What Is A ‘SIT’ Workout?

If you’ve dabbled in fitness in recent years, you’ve likely encountered the concept of high-intensity interval training, or HIIT. This approach to working out involves alternating short bursts of exercise with brief periods of recovery.

But have you heard of SIT workouts?

Despite the name, SIT does not revolve around sitting down (as much as we wish it did). But it’s an approach to fitness that can have great results for your health and longevity.

Below, experts break down what SIT workouts entail, the benefits of this kind of exercise and what you should keep in mind if you want to incorporate it into your fitness regimen.

“SIT stands for sprint interval training,” Laura Morris, a certified personal trainer and nutrition consultant, told HuffPost. “It is a workout that involves short, high-intensity bursts of exercise followed by a longer period of rest.”

Many different types of exercise can be adapted into SIT workouts, including running, cycling, battle ropes, wall balls, rowing and swimming. Other common modalities are bodyweight exercises like burpees, jump squats, pushups and mountain climbers.

“Unlike traditional cardio that keeps you at a steady pace, SIT focuses on maximizing intensity for brief intervals, often lasting 20-30 seconds,” said fitness and wellness coach Kylie Larson. “The rest interval should be long enough for you to recover completely so you can attack the next interval with the same intensity.”

She noted that a typical SIT session might start with a five-minute warmup with light cardio like brisk walking or cycling. Then, you would sprint at your maximum effort for 20-30 seconds using your modality of choice and recover with one to two minutes of low-intensity movement or rest.

This sprint-recovery cycle repeats for at least four rounds, though you can build up to 10. Then, you can cool down with light activity or stretching.

“It’s designed to push your limits during the sprint phases, allowing you to blend fitness results with increased power output and athletic performance,” said Scott Brown, the vice president of fitness at Orangetheory Fitness.

“SIT is similar to HIIT in that periods of higher intensity are offset with periods of rest, both with the goal of inducing high-quality and high-output work during the high intensity,” he added. “The main difference is that HIIT does not necessarily mean ‘as fast as possible.’ It simply means high intensity. SIT protocols are designed to focus on top-end speeds.”

“SIT workouts are powerhouse workouts with incredible benefits for your fitness, health and building resilience,” Morris said. “Athletes of all backgrounds use SIT workouts to enhance their abilities.”

As with exercise in general, sprint interval training is good for your cardiovascular health.

“When your heart and lungs work hard, you increase your VO2 max ― your body’s ability to use oxygen ― thus increasing your cardiovascular fitness,” Morris explained. “The bursts of effort in SIT workouts improve circulation, which benefits both your heart and your brain. It’s been linked to reduced risks of cardiovascular disease and better cognitive function.”

She added that this type of fitness can help build muscular power and endurance as well.

“Sprint intervals activate your fast twitch muscle fibers, also known as Type 2b muscle fibers,” Morris explained, noting that these muscle fibers are important for power, speed and athletic performance.

“For those training for half and full marathons, adding SIT is an often-overlooked training tool that, when applied properly, can unlock the ability to sustain higher speeds at lower heart rates,” Brown said.

SIT can help with short distance running, as well as marathon racing.

“Unlike traditional interval training, SIT demands maximum intensity during these sprints, which helps me build explosive power, improve my anaerobic threshold, and increase my overall running efficiency,” said fitness coach and celebrity trainer Kollins Ezekh. “For my marathon prep, I often do track sprints, hill sprints, or treadmill sprints to simulate the effort required on race day.”

SIT workouts can support muscle retention, which is particularly beneficial for people in menopause.

“The high-intensity nature of sprints stimulates muscle fibers and growth hormone response, helping you maintain or even build lean muscle mass ― a crucial factor as muscle loss accelerates during perimenopause,” Larson said.

This type of fitness can also boost your metabolism.

“SIT improves mitochondrial function and increases your post-exercise oxygen consumption, meaning you burn more calories even after your workout is done,” Larson said, noting that this kind of fitness helps your cells more efficiently convert food into energy.

Another benefit is enhanced insulin sensitivity. Morris pointed to research that found SIT can improve your body’s ability to regulate blood sugar levels and noted that it can thus “reduce the risk of type 2 diabetes and improve overall metabolic health.”

Beyond the physical benefits, this challenging approach to exercise can also boost your mental toughness.

“Pushing through those intense sprints helps build resilience, focus and confidence in your ability to tackle challenges,” Morris said.

Alternating short bursts of all-out effort and low-intensity recovery makes for an incredibly efficient workout as well.

“It’s a great way to build strength and power while saving time ― a huge plus for anyone with a busy schedule,” Brown noted. “What’s also great about it is that it’s accessible to anyone with both low-impact and high-impact options, and you don’t have to be an elite athlete to reap the benefits.”

“Sprint interval training is an excellent workout, but it can come with some challenges,” Morris noted. “With all high-intensity workouts, there is an increased risk of injuries, especially without proper form, warmups or recovery. Overtraining, mental burnout and plateaus can occur if your workout schedule isn’t managed properly.”

Because SIT is so physically demanding, she recommended that people with health issues consult with a medical provider before starting this kind of high-intensity exercise for the first time.

“While excellent for cardiovascular health and fat loss, SIT isn’t ideal for building muscle mass and may exacerbate stress or fatigue if the body isn’t well-rested,” Morris added.

Forgetting to build in adequate rest and recovery can therefore be a critical error.

“SIT can be incredibly taxing on your nervous system,” Brown explained. “When working with high-end athletes, I learned a few tricks to monitor their times against their best. As soon as they fell below a certain threshold, we would stop the session to preserve energy and avoid overuse.”

Heart rate monitoring can also help you ensure proper pacing and avoid overtraining.

“This is not a beginner workout ― in fact, it is not an intermediate workout,” said Denise Chakoian, a certified personal trainer and founder of CORE Cycle.Fitness.Lagree. “Someone needs a good baseline to avoid injury and overdoing a particular exercise or exercises in an ‘all out’ method.”

Basically, if you never cycle or do box squats, don’t start doing these exercises with a SIT workout.

“The benefits of this kind of fitness would be for someone that is already conditioned, and has already been training for a while to build themselves up to do a workout like this,” Chakoian said. “This would be for a more advanced training session.”

You risk getting hurt if you don’t start with smaller and slower workouts geared toward beginners.

“SIT is incredibly effective but also intense, so it’s essential to approach it thoughtfully,” Brown emphasized. “Typically, I would reserve this specific interval training style for those with a fitness base already established and performance athletes. It is safer and more beneficial with that solid base fitness established in both your cardiorespiratory system and your musculoskeletal system.”

“SIT workouts are a fantastic way to increase your fitness, tone up and challenge your athletic abilities, and they are one of my favorites to incorporate for increasing athletic performance,” Morris noted.

If you want to make SIT part of your fitness regimen, she advised starting with an activity you already enjoy.

“Do you love to cycle? Try adding in sprint intervals on your bike,” Morris explained. “Love body weight exercises? Add in four rounds of 30-second mountain climbers at max effort, resting for one minute between sets.”

The key is to start slowly and progress gradually. If diving in with 20-30 seconds of all-out intensity is too much, begin with shorter sprints, longer rest periods and fewer rounds at the beginning.

“Think of it as an introduction period to SIT workouts,” Morris said. “Allow your muscles and mind to understand the intensity and rhythm of this type of workout. As your fitness improves, gradually increase intensity, duration and number of intervals.”

Start each set slowly with a proper warmup as well. Just five to 10 minutes of light jogging or cycling can prepare your muscles for the big sprints.

“Focus on form ― proper technique is key to avoiding injury, especially during all-out sprints,” Larson said. “And listen to your body. It’s normal to feel breathless during sprints, but stop if you experience dizziness or pain.”

Remember there’s a difference between discomfort and pain.

“Discomfort in exercise is a sign of growth, as it lets you know you are pushing beyond your comfort zone,” Morris said. “If you experience high amounts of pain in your muscles or joints, back off from the intensity and let your body recover.”

Between sprints, you should always take one to three minutes to rest or recover with low-intensity movement. The higher the intensity, the longer rest period needed.

“As your heart, lungs and muscles become more efficient, you can increase intensity and speed and decrease rest time,” Morris explained. “But rest is probably the most important component to seeing gains with SIT workouts. Think of recovery as the time you actually get stronger and repair.”

Don’t forget to incorporate full rest days as well.

“Allow your body to recover by spacing SIT sessions one to two days apart,” Larson recommended, adding that one or two SIT sessions per week is adequate. “You can add these short sessions to the end of a lifting day, but this can also be a stand-alone workout.”

Because this style of training is so intense, she also advised eating quick-digesting foods that can offer a fast energy hit before your SIT workouts. Fruits like bananas and dates are a good option. Remember that nutrition is part of the bigger picture of fitness.

“Healthy lifestyle habits are key to making the most of SIT workouts,” Morris emphasized. “Support your body outside your workouts with adequate sleep, hydration and a nutrient-dense diet. These factors are essential for maximizing the benefits of SIT.”