|This would unquestionably be at the lower end of contest BF% levels (avg. 12%) the women in this study achieved,|
Speaking of fitness, ... you probably already guessed it: There's study #4 by Juha J. Hulmi, et al. (2017). The study that was conducted by researchers from Finland and Estonia has the telling title "The Effects of Intensive Weight Reduction on Body Composition and Serum Hormones in Female Fitness Competitors" and was, as its authors point out, designed at least partly in response to the "worries about the potential negative consequences of popular fat loss regimens for aesthetic purposes in normal weight females have been surfacing in the media" (Hulmi. 2017).
Since longitudinal studies investigating these kinds of diets are lacking, Hulmi et al. studied the effects of a 4-month fat-loss diet in 50 (initially) normal weight females competing in fitness sports. This means we are dealing with a large-scale observational study, not an experimental study in which parameters such as the daily or weekly caloric deficit, the protein intake or related variables were set by the researchers. Rather than that, the 27 females (27.2 ± 4.1 years | 15 newbies, 12 women who had competed before) who dieted for ~4 months, and their 23 (27.7 ± 3.7 years) peers, who were acting as weight-stable controls, managed their diet and exercise regimen as they saw fit (note: with only 3 dropouts from the diet group and 6 from the control group the adherence was pretty good).
- Resistance training: Split routines were used for resistance training by all competitors in the diet group meaning that they focused on single muscle groups per session as is often the case also in bodybuilders (Hackett et al., 2013). The main muscle groups trained included thighs, hamstrings, buttocks, chest, shoulders, arms, upper and lower back, calves, and abdominals. Dividing training into separate body parts per session did not differ significantly throughout the training. At baseline the 3-, 4-, 5-, and 6-split training was used by 3, 10, 13, and 1 of the 27 participants, respectively, while the same numbers were during the diet on average 5, 8, 14, and 0 and during the recovery period 7, 8, 12, and 0. In addition, the competitors also practiced their posing routines. Training sessions lasted between 40 and 90min.
- Cardio: Aerobic training for the participants was almost uniquely either high-intensity interval training (HIT) with a bicycle, cross trainer or other gym equipment or both HIT and steady-state low to medium intensity aerobics (usually walking/running or with cross trainer). During the competition week the participants did not report doing HIT, but instead lower intensity aerobics. Typical HIT-exercise was 10–25 min in total including high intensity 15–45s intervals with 30–60s of recovery between the sets. Steady state lower intensity aerobics was typically 30–60 min in duration. Part of the females completed their aerobic training mainly together with their resistance exercise workouts while most of the participants completed also separate aerobic workouts, especially during the diet.
Why would you taper before the competition? A competitor would probably answer that he, or, as in this case, she, did not "want to come in flat". Accordingly you taper, i.e. reduce the training intensity and (re-)introduce carbs into your diet to restore muscle glycogen and get rid of the "flat" look of which Hulmi et al. argue that it will "occur with low carbohydrate diets as ∼2.7g of water per each gram of glycogen is stored in skeletal muscle" (Hulmi. 2017).Speaking of the subjects' energy deficit. The latter was - as it is currently in vogue - achieved almost solely by a drastic reduction in carbohydrate intake while keeping protein intakes high and fat intakes moderate. You can see the result in form of a diet that lacked, during contest prep/dieting, ca. 20% of the habitual energy intake of the subjects in my plot in Figure 2 reduced (see Figure 6 for data on the energy balance, i.e. calories in vs. calories out from exercise = cardio + weights).
|Figure 2: Energy intake expressed as protein, carbohydrates and fats rel. to body weight (g/kg | Hulmi. 2017).|
|Table 1: Tabular overview of the exercise levels in the diet and control groups; learn more about METs (Hulmi. 2017).|
- lower body muscles were trained during the diet 1.4 ± 0.5 times per week, and
- upper body muscle groups were trained 1.1 ± 0.3 times per week,
|Figure 3: Changes in body composition; for fat and lean mass I used the average of all three measuring methods, i.e. DXA, body impedance and skinfold; * p < 0.05 and *** p < 0.001 (Hulmi. 2017)|
- a small decrease in lean mass (bioimpedance and skinfolds) and in vastus lateralis muscle cross-sectional area (ultrasound) were observed in diet (P < 0.05) -- in that, it is certainly interesting that the scientists found that some competitors even managed to gain lean mass during the contest prep
- the total bone mass decreased by −1.3 ± 1.8% (DXA) in the competitors,
- the subject's leg strength, measured as the isometric maximal strength and explosive strength of their leg extensors remained unchanged during dieting, their bench press performance, on the other hand, declined,
- a sign. changes in the hormonal system with decreased serum concentrations of leptin, triiodothyronine (T3), testosterone (P < 0.001), and estradiol (P < 0.01) coinciding with an increased incidence of menstrual irregularities (P < 0.05),
- the surprisingly small (and non-significant) changes in mood-related parameters of which only the subjects' vigor showed a significant decline during the pre-contest phase,
- the normalization of all body weight/composition parameters and all hormones except T3 and testosterone which did not fully recover during the 3–4 month recovery period
|Figure 5: Active thyroid hormone (fT3) concentration at baseline (pre), before the contest (mid) and after recovery (post). The number at the x-axis depicts participant numbers ordered based on the pre-value (Hulmi. 2017).|
- Dulloo, Abdul G., J. Jacquet, and Lucien Girardier. "Autoregulation of body composition during weight recovery in human: the Minnesota Experiment revisited." International journal of obesity and related metabolic disorders: journal of the International Association for the Study of Obesity 20.5 (1996): 393-405.
- Hulmi, Juha J., et al. "The effects of intensive weight reduction on body composition and serum hormones in female fitness competitors." Frontiers in Physiology 7 (2017): 689.
- Keys, Ancel, et al. "The biology of human starvation.(2 vols)." (1950).