Cardio, Weights or Both?

kettlebell training

I don’t know how many times I’ve heard a new gym member say: “I want to do more cardio to get leaner…” It seems like you must be ‘burning’ fat if you are sweaty and exhausted but is it really an effective way to get leaner? Here is a very simple study that compared changes in body composition (fat and muscle lost or gained) from two different exercise programs:

ENDURANCE TRAINING vs ENDURANCE & WEIGHT TRAINING

72 overweight individuals were divided into 2 groups that did either endurance training or endurance training with weight training for 8 weeks.

Group Results Endurance Training (30 min) Endurance (15 min) & Weight Training (15 min)
Fat Change (lbs) -3 -10
Lean Mass Change (lbs) -0.5 +2
Weight Change (lbs) -3.5 -8

-Westcott, W., Fitness Management. Nov., 1991

By doing only endurance training you can lose ‘weight’ but some of it is lean mass. Less lean mass means a slower metabolism, therefore easier fat gain as you age or if you stop training. Losing lean mass usually means losing strength, before you know it you will need someone to help you take lids off jars or carry your shopping. The best results for body composition and health are achieved through a combination of endurance and weight training.

A common objection to strength training goes along the lines of “I don’t want to do weights because I don’t want to get big and bulky”. What we are really talking about is using your body against a resistance to become stronger. You could be rock climbing, doing gymnastics, working on a building site, not necessarily heaving weights in a gym. Whatever the modality most people will plateau at close to an optimal level of muscle within a year or two of strength training. After this time it takes effort and intention to become ‘big and bulky’. I’ve never seen it happen by accident. Notice the use of the term ‘strength’ training not ‘body-building’. To the beginner they can appear to be similar, but different systems of sets, reps and rest will yield very different results.

Lean Mass Abbye Pudgy Stockton

Too Bulky? The First Lady of Iron Abbey Stockton. Pioneer of Women’s weightlifting.

STRENGTH AND ENDURANCE STUDY 6-MONTH W/WO PROTEIN SUPPLEMENT

If you want to enhance your results further, pay attention to post training nutrition. A separate study (Westcott 2007) showed that a group of exercisers consuming a post-exercise protein shake (25g protein; 37g carb;) achieved about 40 percent greater lean weight gain and about 80 percent greater fat weight loss than a group that did not supplement.

Group Results Protein Supplement No Supplement
Percent Fat (%) -4.0 -2.8
Lean Weight (lbs) +5.5 +3.9
Fat Weight (lbs) -9.0* -4.9

* Significantly different from no supplement group

“Just after exercise, the protein-building processes of muscle cells are especially receptive to amino acids.” “Muscle cells are especially efficient in absorbing carbohydrates from the blood just after exercise.” Dr. Mark Tarnopolsky, M.D. American College of Sports Medicine.