How much cardio do you recommend for someone looking to lose body fat while maintaining muscle mass and strength?
The short answer would be, the minimum amount necessary to see results. I am a firm believer that nutrition should be responsible for as much of one’s fat loss progress as possible. Cardio should be used as an ‘adjunct therapy’ as needed and weight training should be used to preserve muscle mass and strength – not for fat loss.
Some people will have to do more than others to achieve the desired results – typically females of lighter bodyweight. The reason for this is that since their maintenance intake tends to be relatively low (due to a lighter bodyweight), creating the appropriate caloric deficit requires a painfully low caloric intake, which in addition to the obvious hunger issues, also has the potential risk of not meeting one’s nutritional needs. So in these cases, it might be better to eat more, and do a bit more cardio to create the necessary deficit. For the most part, a deficit is a deficit whether created by caloric restriction, energy expenditure by way of exercise, or some combination of both.
As to the type of cardio, you generally see people fall into one of two camps – lots of low intensity, long duration cardio (steady state cardio) or some form of interval training (HIIT). I fall somewhere in the middle and think utilizing both is the best approach. HIIT is great for fat loss and also has the side benefit of being a short, albeit intense, workout. However, it’s also a very demanding workout, particularly for the legs if you’re choosing running or stationary cycling as your exercise of choice. Coupled with one or two intense lower body sessions a week, too much HIIT might result in some localized overtraining of the legs. So, this is an instance where more is not necessarily better, especially if you’re trying to hold on to your strength and size. So depending on how your lower body workouts are structured, I’d say a couple HIIT sessions is going to be sufficient more often than not. I often choose two and when doing so might reduce leg volume and also consider reducing the weekly lower body training sessions from two to one.
While still on the subject of interval training, and having made mention of the potential issues with localized overtraining of the legs, I think that the optimal positioning of one’s interval training workouts would be on leg days, but in a session separate from the leg training workout. This has the benefit of allowing the legs to have more complete rest days. If a person had their training set up as two upper body workouts and two lower body workouts for example, and they positioned their HIIT workouts on upper body, or even off days, you’re looking at four intense lower body days per week, which for some might be a bit much.
So in terms of a recommendation? I’d probably start with 1-2 HIIT sessions per week and another couple low/moderate steady state sessions and adjust accordingly from there. However, remember to look to your nutrition first when plateaus hit. Don’t automatically assume you have to do more cardio. Might you have to do more? Perhaps, but again, look to your diet first and then start looking at the other elements of your training program second. I do not believe that anyone has to resort to the nonsensical approach you see so many competitors these days following – twice a day steady state sessions of 45-60 minutes. I think anyone who has to do that much cardio to lose fat is a dieting moron.
One last thing to hit on is the issue of whether cardio should or even needs to be done in a fasted state. The short answer is no it doesn’t. You’ll hear it preached in bodybuilding and fitness circles that to ‘burn more fat’ you have get up early and do your cardio fasted. It’s not necessary, and in the case of intense HIIT sessions, definitely not recommended. While you might use more fat as fuel during fasted cardio, at the end of the day it’s irrelevant. What’s important is the caloric deficit you created during activity, not where that deficit (fat vs carbs) came from and fasted vs fed cardio doesn’t change that. In fact one might argue that eating first might be a better option since performance generally will improve with a full tank, which could translate into greater expenditure during the workout.