Many women worry when even thinking about resistance training, and starting such workouts for them is “improbable”. This mainly happens because of common beliefs. Unfortunately, many websites with “professional” articles written by “trainers” or “specialists” contain infromation, which is out-of-date or misleading. Another worry derives from the contact with men – as there are special zones or even clubs for women only.
Trap no.3: “women are weak, so they need light weights”
Many articles try to force the thesis that women should use only light weights they lift easily and do 15-20 repetitions. Such training is supposed to “tone muscles”, “firm the body”, “burn fat” and improve shape. Similar myths derive from the training methodology form the 1970s and 1980s. Unfortunately, tens of studies, which have changed the perception of such effort, have been done since then. The conviction that you need to do long sets is strongly rooted – I have seen ladies, who did endless sets with pink dumbbells, e.g. biceps curl standing, in clubs many times. The most influencial on the body composition (body fat reduction) are the multi-joint exercises, which engage the biggest muscle groups, e.g. deadlift, squats, lunges, pull-ups, climbing the rope, pulling weight, bench press lying or sitting. The influence of isolated exercises (e.g. bending and extending arms on cables, exercises on the preacher, crossing cables) is negligible. There is a belief that “free weights exercises cause injuries” and are “very complicated”. Because of those reasons ladies are directed to the machines, where they can train “safely”. Instead of developing strength and mass and improve the body composition using free weights (by decreasing the amount of body fat and increasing the amount of muscles) – ladies lose their time.
Why are the low working loads not a good solution?
Everything would be good, if not for the adaptation of the body to a particular kind of effort and the knowledge of the response for training. The body gets used to a particular stimulus very quickly. It's the first and most important reason for aerobic training to be ineffective in the perspective of 5-10 years (what was proven in research concerning almost 13,000 runners).
Why? The body adapts to endurance work, gathers larger amount of glycogen and intramuscular fat (IMTG) – which makes the amount of subcutaneous fat decrease. With time, the energy expenditure during aerobic exercises gets smaller. The efficiency is getting worse. What can be done about that? Use the interval training instead of long-lasting “cardio” sessions.
The same rule concerns resistance training. Too small working load is not a challenge after a while, it neither causes proper “metabolic stress”, nor stimulates muscle fibres to grow. The hormonal influence of this kind is negligible. That's the reason why body-resistance workouts are no longer effective within few months, even for the beginning women and men (examples: calisthenics, workout programs by E. Chodakowska, “convict conditioning”, “100 push-ups program”, ABS, A6W, etc.) What can be done? Increase the working load regularly and wisely using e.g. line progress (e.g. you may add 2-2.5 kg of load to the last working set of a particular exercise, within a month that would mean the improvement by 8-10 kg, within a year – if you manage to keep the progress: even 96-120 kg!).
A word of introduction: what does it mean – 80-85% of maximal load? If you are able to do 1 full squat with the load of 50 kg, 80% of the maximal load is 40 kilos for you, while 85% is 42.5 kg... In general, the bigger the load, the less repetitions you are able to do. The load of 100% lets you do only one repetition.
Scientific studies on this matter and conclusions:
Large load cause even twice as good results concerning the increase of strength and mass, e.g. bench press in the group of 90% of maximal load was improved, on average, by 15%, in the group of 70% of maximal load it was only by 7%; the mass of the shoulder in the first group was improved by 5.2%, whereas, in the group of 70% of maximal load only by 2.2% (the study: http://physreports.physiology.org/content/3/8/e12472 ).
The range of 3-5 repetitions may be as efficient in building muscle mass as 9-11 repetitions (the study: http://www.ncbi.nlm.nih.gov/pubmed/12436270 ) 
The range of 20-28 repetitions is inefficient .
Too small working load (30-50% of maximal load) has insignificant influence on the development of strength, although, it may influence building muscle mass among poorly-trained people (the study: http://www.ncbi.nlm.nih.gov/pubmed/25853914 ).
Large load influences the resting metabolism much stronger after finishing training (read: FAT BURNING), the influence on REE was noticed (resting energy expenditure) even 48-72 hours after finishing training in the group with 80-85% of maximal load, and only for 24-48 hours after finishing training with the load of 45-50 or 60-64% of maximal load  (the study: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2782969/ )
Summary: small load may be inefficient, use working load, which would let you do at most 8-10 repetitions. If you are able to do 20-25 repetitions with a particular load – such exercise changes the resistance training into aerobic one. It's not about that. On the other hand – do not use the load, which would let you do only 1-3 repetitions – leave it to the powerlifters, weight lifters or strongmen.
Trap no.4: “ignoring the importance of diet”
There are two tendencies – visiting a dietitian and... putting the diet on a shelf, or using strict diet for a short time – and then “compensating the sacrifice” in the next weeks and gaining few kilos of weight. If you are going to exercise – and then consume large amount of calories - “as I am after workout and I can do it” - it will end up with a failure. In the same way, there is a misunderstanding of the importance of sweetened, fizzy drinks, juice or snacks – these may be count in hundreds of additional calories! The only thing you can drink safely is water, unsweetened - without sugar, juice, or sweeteners. Also tea and coffee are advised, but without any sugar or milk. Isotonic beverages are harmful, just like energy drinks and other sweetened drinks (e.g. a can of red bull contains 27.5 grams of carbohydrates – it's over 4 teaspoons of sugar).
Those, who are interested in more precise calculations, may read to following article: http://afterworkout.com/articles/3418/how-much-do-i-need-to-train-to-burn-a-big-mac-fries-and-a-coke
On the same basis, diets like 1,000 kcal are useless – as they lead to gigantic yo-yo effect and blocking burning fat (slowing down metabolism).
Summary: diet is responsible for your shape. Physical exercises, without any changes in diet are 3.5 times less efficient, according to scientific studies! 
Trap no. 5: “using toxic slimming pharmaceuticals”
Women often use “Chinese herbs” intoxicated with heavy metals, pharmacology, often by sibutramine, phentermine (e.g. adipex), pure sibutramine (meridia, zelixa), clenbuterol, salbutamol, ephedrine, or even DNP (chemical warfare agent), which killed a 20-year-old from Warsaw. If you don't change your lifestyle and diet – start doing resistance, aerobic and interval training – pharmaceuticals will be ineffective.
According to studies, decreasing body weight, even after using the strongest pharmaceuticals, is not that impressive, e.g.:
“during the treatment with pharmaceuticals (sibutramine, 15 mg per day), 1001 patients lost only 8 kg of body mass (not body fat!) during 48 weeks (one year). During the first 4 weeks they lost: 4.2 kg, in the following ones – averagely 3.8 kg of body mass. As you can see, it is the loss of only 0.66 kg of body mass per month!”
“during 24 weeks (6 months) of observing 180 obese patients it was pointed, that using caffeine simultaneously with ephedrine (600 mg of caffeine + 60 mg of ephedrine) caused significant loss of body mass by 16 +/- 6.8 kg (in the placebo group by 13.2 +/- 6.6 kg). During the next 26 weeks further loss of body mass was observed. As you can see, the difference between the placebo group and the ephedrine with caffeine group was only over 3 kg... It means the reduction, on average, of ~2.7 kg per month (pharmaceuticals) and 2.2 kg (placebo)”. 
Summary: it's not worth using forbidden or those of unknown origin pharmaceuticals. Slimming depends on the change in diet and proper training. It's not worth risking your health for uncertain results.
Woman at the gym – or the iron traps – Part III