Low intensity steady state cardio, commonly called LISS, is any form of aerobic exercise performed at a consistent, easy pace for an extended period, typically 30 to 60 minutes. Your heart rate stays in a narrow zone throughout the session, generally 50 to 60 percent of your maximum heart rate. Think of it as the opposite of interval training: no bursts, no recovery periods, just a sustained effort you could maintain while holding a conversation.
How LISS Differs From HIIT
The most common comparison is between LISS and high intensity interval training (HIIT), and the differences go beyond how hard you’re breathing. A study comparing the two methods found that both significantly increased VO₂ max (a measure of aerobic fitness) and lowered resting heart rate. However, the HIIT group saw a greater VO₂ max improvement. Both methods were equally effective at reducing systolic and diastolic blood pressure.
That doesn’t make LISS the lesser option. HIIT demands more recovery time, places greater stress on joints and the nervous system, and isn’t realistic as a daily habit for most people. LISS fills a different role: it’s the type of exercise you can do five or six days a week without accumulating fatigue, making it the backbone of federal physical activity guidelines that recommend 150 to 300 minutes per week of low to moderate intensity movement.
What Happens in Your Body During LISS
At lower intensities, your muscles rely heavily on fat as fuel. The exercise intensity where your body burns the most fat per minute is sometimes called “Fatmax.” Research on healthy young adults found this peak fat-burning zone occurs around 44 to 67 percent of maximum aerobic capacity, depending on fitness level and whether you’re using your upper or lower body. Fitter individuals tend to hit their peak fat oxidation at higher intensities. LISS keeps you squarely in this range for the entire session, which is why it’s often recommended for people focused on body composition.
Over weeks of consistent training, LISS drives changes at the cellular level. Aerobic exercise has been shown to increase the volume of mitochondria (the structures inside muscle cells that produce energy) by roughly 19 percent, with even larger increases in the internal surface area of those mitochondria, up to 43 to 92 percent depending on the specific membrane measured. More mitochondria with greater surface area means your muscles become more efficient at converting oxygen and fat into usable energy. This is the foundation of aerobic endurance.
Effects on Insulin Sensitivity
One of the most practical benefits of LISS happens after the workout ends. During exercise, muscle contractions trigger a chain of signals that move glucose transporters to the surface of muscle cells, allowing them to absorb sugar from the bloodstream without relying as heavily on insulin. This effect persists well beyond the session itself.
In a study of sedentary, obese adults, a single 70-minute session at 50 percent of peak aerobic capacity (a pace consistent with LISS) increased insulin sensitivity by 35 percent the following morning compared to a rest day. A shorter, harder session at 65 percent intensity for 55 minutes didn’t produce a statistically significant improvement. Repeated training sessions over time have been shown to increase the concentration of these glucose transporters in people with metabolic syndrome and type 2 diabetes, creating lasting improvements in blood sugar regulation. For people concerned about metabolic health, the longer duration of LISS appears to matter as much as, or more than, the intensity.
Recovery and Stress
LISS doubles as active recovery. After intense exercise, blood lactate (a byproduct of hard effort) clears faster with light activity than with complete rest. Research found that active recovery at around 80 percent of your lactate threshold, which corresponds to an easy, conversational pace, produced the fastest lactate clearance. This is why many athletes use LISS sessions the day after a hard workout rather than taking a full rest day.
There’s also a stress-regulation component. About 60 percent of studies examining the relationship between physical activity and the body’s stress hormone response have found that higher fitness levels are associated with a blunted cortisol reaction to psychological stressors. Regular aerobic exercise appears to help normalize the activity of the hormonal system that governs your stress response. Unlike intense training, which itself acts as a significant stressor, LISS keeps the physical demand low enough that it calms the nervous system rather than taxing it further.
Common LISS Activities
Almost any aerobic movement can become LISS if you control the pace. The most accessible options include:
- Walking or hiking: The simplest entry point. Walking on an incline adds intensity without impact. Hiking on softer trail surfaces reduces joint stress even further.
- Cycling: Sitting on a bike seat keeps weight off your feet and minimizes stress on your knees, ankles, and hips.
- Swimming: Water buoyancy makes this essentially zero-impact. It’s one of the few options that works the entire body while being gentle on joints.
- Rowing: Exercising from a seated position limits joint stress while engaging both upper and lower body.
- Elliptical workouts: The smooth, gliding motion eliminates the jarring ground contact of running.
The best choice is whichever activity you’ll actually do consistently. LISS only works as a long-term strategy if you enjoy it enough to show up repeatedly.
How Long and How Often
If you’re new to exercise, starting with 20 to 30 minutes per session is enough to build a base. As your endurance improves, the goal is to work up to 60-minute sessions several days per week. For people whose entire exercise routine is LISS, aiming for 30 to 60 minutes on most days of the week aligns with the 150 to 300 weekly minutes recommended by federal guidelines.
Pacing matters more than duration in the beginning. If you can’t maintain a conversation during your session, you’re working too hard for it to qualify as LISS. Keeping your heart rate between 50 and 60 percent of your maximum (a rough estimate is 220 minus your age) ensures you stay in the right zone. A heart rate monitor or fitness watch makes this easier to track, but the talk test is a reliable low-tech alternative: if you can speak in full sentences without gasping, you’re in the right range.