[quote]Lion of War wrote:
Hi, i found this very interesting study on cardio and loss of lean body mass,wanted to share with you.
What did the researchers do?
The researchers managed to track down five competitive female bodybuilders who agreed to have their body fat measured at 12-weeks out, 6-weeks out and just prior to a competition. They also agreed to provide details about their training routines during this period. The researchers also recruited five female athletes to serve as controls. They took the body fat measurements when the subjects were post-absorptive, were normally hydrated and had not exercised for 36 hours.
The researchers were keen to make sure that they produced reliable results. So they used a very sophisticated way of measuring body fat and lean body mass. They used an under-water weighing process called hydrodensitometry, where the volume of inspired air was measured by oxygen dilution and the densities of fat mass and lean mass were assumed to be constants across all subjects. They noted that the potential error in their measurements from this process was just 0.4% body fat.
What happened?
Cardio routine
The bodybuilders detailed that at 12-weeks out they spent 5.8 �± 1.1 days per week performing aerobic training for 344 �± 110 minutes (5 hours 44 minutes �± 1 hour 50 minutes). They also reported that approximately 4 weeks before the competition, they increased their time performing aerobic exercise to 590 �± 139 minutes (9 hours 50 minutes �± 2 hours 19 minutes). So in the second 6-week phase, the bodybuilders were performing almost twice as much cardio as in the first 6-week phase.
Weight training routine
The bodybuilders detailed that throughout the 12-week period, they performed weight-training 5.0 �± 1.2 days per week and for 342 �± 164 minutes (6 hours 4 minutes �± 2 hours 24 minutes). They used 2-3 sets of 10-12RM loads for each body part in addition to a single set of 6RM. Four of the five bodybuilders noted that they lost either some repetitions or some load over the 12 weeks on some or all exercises.
Dietary practices
The researchers did not ask for the bodybuilders to complete diet diaries but four of the five bodybuilders stated that they did not reduce their energy intake at all over the 12 weeks, which was estimated as 6.41 �± 0.80 MJ per day (1,531 �± 194kcal per day).
Body fat percentage at 12-weeks out
The researchers noted that at the outset of the study, the body fat percentages of the bodybuilders and athletic female control subjects were very similar (17.8% vs. 17.4%). They also noted that these figures were similar to those reported in a large-scale study of female body fat percentages by Withers (1987), who found that body fat in 182 athletic females averaged 18.5%.
This is very interesting, as it suggests that when female bodybuilders are not preparing for competition, they are walking around at normal, athletic female body fat percentages.
Body fat percentage changes
The researchers found that the bodybuilders reduced their body fat percentage by an average of 5.6% over the 12-week period. Unsurprisingly, an average of 68% (range: 66 â?? 70%) of this loss occurred in the second 6-week period, when the bodybuilders were performing twice as much cardio. The following chart shows the reductions in body fat percentage for each bodybuilder:
Reductions in body fat
Lean body mass changes
The researchers found that the bodybuilders reduced their lean body mass by an average of 1.34kg (3lbs) or 2.4% over the 12-week period. Despite the much greater loss of fat mass in the second 6-weeks than in the first 6-weeks (and double the amount of cardio), the amount of lean mass in both 6-week periods was almost identical, with an average of 51% (range: 38 â?? 61%) of the overall lean mass lost occurring in the second 6-week block. The following chart shows the reductions in lean body mass for each bodybuilder:
Reductions in lean body mass
What did the researchers conclude?
The researchers concluded that bodybuilders at 12-weeks out displayed a similar level of body fat to other athletic females. They also concluded that the 12-week contest preparation period led to a 5.75kg (13lbs) reduction in body mass, made up of a 1.34kg (3lbs) reduction in lean mass and a 4.41kg (10lbs) reduction in fat mass. This means that the weight loss was 76.7% fat and 23.3% lean tissue, despite the relatively lean status at the outset.
The researchers also concluded that the weight and fat lost were greater in the second 6-week period than in the first. This was probably because in the second 6-week period, the bodybuilders performed an average of 9 hours 50 minutes cardio per week while they â??onlyâ?? performed an average of 5 hours 44 minutes per week in the first 6-week period.
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Interesting study, thanks for sharing.
There’s a few issues here: Theres no mention of the actual steroid cycle which would greatly effect any muscle loss. The study talks about the amount of cardio, general training and diet but misses this very important part. It’s hard to come to a conclusion without knowing what they were using.
As a very general thought…as long as your diet and drug use are smart then cardio won’t burn as much muscle as people tend to think. Obviously when you are losing a lot of weight some muscle will be lost but as long as you give the muscle a reason to stay (ie. training, nutrition & drugs) the body will try to retain it as much as possible regardless of the amount of cardio you are doing.
You don’t need to look far because there are a lot of high level bodybuilders that still do 2 hours of cardio a day and they’re still able to bring a decent package to stage. Cardio isn’t the devil it just a tool that needs to be used properly alongside the drugs, training and diet. One of the most beautiful things in bodybuilding is you need to master so many different aspects and bring them all together in a perfect combination. When you can figure this out then you will see how even doing 2 hours of cardio a day cannot hurt you. Obviously there’s many ways to skin a cat but this is definitely one of them.