Strength training has so many great things going for it that I'm a big fan -- increased strength, more muscle and body shape, better balance and bone density and improved functionality across all facets of human movement. But let’s be honest, we all need aerobic or cardio training as well. It has its own set of important functional benefits including general fitness, elastic arteries, increased heart and lung function and lower blood pressure to name a few benefits.
Lifting weights can easily move us into the high intensity exercise zone above the 75 percent effort required to get some afterburn, but it's only for short bursts. This is not consistent, steady-state effort and does not generally burn as much energy as a good run on the treadmill, cycle or row machine at moderate pace. For example, here are the energy expenditure calculations for weights versus cardio for one hour of exercise from the NAT Nutritional Analysis Tools web site. I've based this on a 150 pound person (just under 70 kilograms).
- Running at 8 minutes a mile pace (5 min/km) -- burn 852 calories (kilocalories)
- Weight lifting, vigorous, free weights or machines -- burn 409 calories (kilocalories)
I’ve tried to line these activities up for effort so that the comparison is worthwhile. Whenever I check these numbers it astounds me because I run and I lift weights, and sometimes I feel much fresher after a run than going for it in the gym with sub-10 RM (repetition maximum) and three sets of ten exercises. Nevertheless, the numbers always come out the same with any reputable energy calculator. Sustained aerobics always spends about twice the energy of weight training in a comparable comparison. You can see from this why cardio sessions are important for fat loss.
Should I Exercise Before Breakfast to Burn More Fat?
The answer is 'not necessarily', because even though you will burn more fat on an empty stomach, ultimately this will probably make little difference because your energy intake and expenditure and metabolism balances out, more or less, over the 24-hour period. What really matters is your total energy intake and expenditure, that is, how much you eat and how much you exercise and move in general.
However, stay tuned on this because until this is examined further scientifically, how much meal timing manipulation could help with fat loss is not certain. One thing that seems clear is that people who eat breakfast maintain weight better and lose fat quicker, so don’t skip breakfast.
The Best Strategy for Fat Loss
So where are we at with our fat burning project? Here is a summary.
Increase muscle with weight training. Extra muscle helps to burn more energy at rest, even if only a little. This is called the resting metabolic rate of muscle or RMR. Extra muscle will also burn more fat in active phase, the active metabolic rate if you like, or the AMR, so having more muscle will definitely help burn more energy and fat.
Lift heavier weights. What I suggest is that the weights workout should be vigorous, with the number of repetitions kept at the low to medium end of the scale between 8 and 12 RM. To remind you, the RM is the repetition maximum, which means the most weight you can lift for this number of reps before fatigue. The 8-12 is within a range that should provide strength and bigger muscle growth, which is called hypertrophy.
If you go higher than this, say 15 to 20 repetitions to a set, or more, you are getting into the range where you would probably be better off doing cardio because the return on effort, the energy burn, is better spent jogging, cycling, stepping or rowing. At that number of repetitions you won’t build much muscle either, so very high-repetition training with weights has minimum value in my view.
Do aerobic exercise. Considering how much energy you would use in an hour of either type of exercise, weights or cardio, you must do some consistent aerobic or cardio work to burn fat.
Try high-intensity cardio. High-intensity exercise, even if only in short bursts, may rev up the metabolism and get that fat mobilized in the post-exercise period. Do some high intensity as well, but don’t overdo it, because burning the fat is a long-term project and you don’t want to get ‘burned out’. A group exercise program such as a solid cycle spin class might match this requirement. In fact, I highly recommend group cycle spin classes where you are encouraged to go fast, yet with the option to slow down if you need to.
Weights and Cardio Circuit Training Programs
Combining weights and cardio in a circuit interval session is also an excellent approach to fat burning. The weights circuits are based on the idea of mixing high and low-intensity weights and cardio in a circuit. This idea is not new, but what I've designed uses basic equipment and is easy to follow.
Check it out and let me know if it works for you.
Owen O. Resting metabolic requirements of men and women. Mayo Clin Proc 1988;63:503-510.
LaForgia J, Withers RT, Gore CJ. Effects of exercise intensity and duration on the excess post-exercise oxygen consumption. J. Sports Sci. 2006 Dec;24(12):1247-64.