Low-intensity steady state (LISS)

Low-intensity steady state (LISS) is continuous aerobic exercise at an easy effort that a client can sustain for a long session.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 452.} NSCA textbooks call it long slow distance (LSD) training: a client capable of 6-minute miles might run 8-minute miles over a longer distance.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 452.} Use the talk test to check the effort: the client should be able to talk without getting short of breath.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 452.}

The NSCA’s program design guide describes base training at about 60% to 70% of VO2 max or maximum heart rate as a way to accumulate volume with little musculoskeletal stress.^{2Hoffman, NSCA’s Guide to Program Design, p. 158.} Benefits include better cardiovascular and thermoregulatory function, more mitochondrial energy production and more fat used as fuel.^{3Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 584.} These changes likely raise lactate threshold by improving lactate clearance.^{3Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 584.}

In practice

• For lifters, Helms and colleagues recommend easy cardio on a low-impact machine, such as a bike or elliptical, to stay below the effort that interferes with strength and muscle gains.^{4Helms et al., The Muscle & Strength Pyramid: Nutrition, 2nd ed., p. 57.},^{5Helms et al., The Muscle & Strength Pyramid: Nutrition, 2nd ed., p. 58.} The lower calorie burn means it takes more time to add up.^{4Helms et al., The Muscle & Strength Pyramid: Nutrition, 2nd ed., p. 57.},^{5Helms et al., The Muscle & Strength Pyramid: Nutrition, 2nd ed., p. 58.}
• Fatigue per calorie burned rises with intensity.^{6Israetel et al., Scientific Principles of Hypertrophy Training, p. 361.} Israetel and colleagues suggest starting fat loss with more everyday movement and little fatiguing cardio, then testing whether low-intensity cardio or fewer calories suits the client better.^{6Israetel et al., Scientific Principles of Hypertrophy Training, p. 361.}
• Endurance athletes can do too much LISS: it’s slower than race pace and doesn’t train the muscle fiber recruitment a race demands.^{3Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 584.}