Total training load may explain similar strength gains and muscle hypertrophy seen in aged rats submitted to resistance training and anabolic steroids

Figures & data

Figure 1. Sample of myofibers from the soleus muscle of Wistar rats histochemically stained for myosin ATPase following acidic preincubation at pH 4.6. Darker myofibers are type I and lighter type II. Original magnification of 400×.

Figure 2. Experimentation period scene.

Figure 3. Testicles weight (g) from groups 20 months-old control (C), 24 months-old control (CF), anabolic steroid control (CAS), resistance-trained (RT), and resistance trained plus anabolic steroid therapy (RTA). ^arepresents difference from group C (p < 0.05). ^brepresents difference from group CF (p < 0.05). ^drepresents difference from group RT (p < 0.05).

Figure 4. Maximum load carrying test (MLCT) data of testing sessions 1 (T1) and 2 (T2) from groups initial control (C), final control (CF), control with anabolic steroid (CAS), resistance-trained (RT) and resistance trained with anabolic steroid (RTA).

Table 1. Maximum load carrying test (MLCT) data before (PRE) and after (POST) 15 weeks of experimentation from groups initial control (C), final control (CF), control with anabolic steroid (CAS), resistance-trained (RT) and resistance trained with anabolic steroid (RTA).

MLCT	Groups					F	p Value
	C	CF	CAS	RT	RTA
PRE (g)	384 ± 53	445 ± 60	401 ± 73	391 ± 46	384 ± 47	1,144	0.353
POST (g)	–	414 ± 64	574 ± 92^a	706 ± 114^a	639 ± 139^a	8,247	0.001
Delta %	–	−7	+43	+81	+66	–	–
p Value	–	0.453	0.001	0.000	0.005	–	–
Attempts
PRE (n°)	2 ± 1	3 ± 1	2 ± 1	2 ± 1	3 ± 2	1,144	0.353
POST (n°)	–	2 ± 1	5 ± 1a	7 ± 2a	7 ± 2a	8,247	0.001
Delta %	—	+50	+150	+250	+133	–	–
p Value	–	0.412	0.001	0.000	0.006	–	–

Data are shown as mean and standard deviation.

^aindicates significant difference in relation to CF (p ≤ 0.05).

Figure 5. Description of the mean absolute (g) and relative load (% BW) initial and final of the trained groups (RT) and trained with anabolic steroid (RTA).

Figure 6. Total training load and average training load per session evolution during 15 weeks of training on groups resistance trained (A and B) and resistance training with anabolic steroids (C and D).

Table 2. Effects of 15 weeks of experimentation on the average total volume (g), total climbing volume (g), relative total volume (%), relative total climbing volume (%) and mean climbing volume (n°) from groups resistance-trained (RT), and trained with anabolic steroid (RTA).

Variables	Groups		p Value
	RT	RTA
Average total volume (g)
Initial	1550 ± 493	1624 ± 544	>0.05
Final	3924 ± 516	3243.33 ± 430	>0.05
Delta (%)	+153	+100	–
p Value (pre vs post)	0.005	0.016	–
Total climbing volume (g)
Initial	284 ± 28	295 ± 28	>0.05
Final	655 ± 18	613 ± 23	>0.05
Delta (%)	+130	+108	–
p Value (pre vs post)	0.000	0.000	–
Relative total volume (%)
Initial	229 ± 73	287 ± 96	>0.05
Final	630 ± 83	674 ± 89	>0.05
Delta (%)	+175	+134	–
p Value (pre vs post)	0.003	0.007	–
Relative total climbing volume (%)
Initial	42 ± 4	53 ± 4	≤0.05
Final	105 ± 3	127 ± 5	≤0.05
Delta (%)	+150	+139	–
p Value (pre vs post)	0.000	0.000	–
Mean climbing volume (n°)
Initial	5 ± 1	5 ± 1	>0.05
Final	6 ± 1	5 ± 0	>0.05
Delta (%)	+17	0	–
p Value (pre vs post)	0.417	0.877	–

Data are shown as mean and standard deviation.

Figure 7. Total load and average load per session after 15 weeks of experimentation for groups resistance-trained (RT) and resistance trained with anabolic steroid (RTA).

Table 3. Morphometry of the soleus and plantaris muscle of aged Wistar rats after 15 weeks of experimentation in the initial control (C), final control (CF), control with anabolic steroid (CAS), resistance-trained (RT) and resistance trained with anabolic steroid (RTA).

Groups
Variables	C	CF	CAS	RT	RTA	F	p Value
Soleus
Type I CSA (µm^2)	2851 ± 698	3067 ± 745	3665 ± 973^a^,b	3698 ± 912^a^,b	3896 ± 1014^a^,b	15,574	0.000
Type II CSA (µm^2)	3397 ± 885	3290 ± 1171	3760 ± 1097	3707 ± 1123	4220 ± 683^a^,b	3,286	0.013
Nuclear ratio	1.57 ± 0.25	1.89 ± 0.37	2.54 ± 0.63^a^,b	3.01 ± 0.63^a^,b	2.99 ± 0.4^a^,b	25,217	0.000
Plantaris
Type I CSA (µm^2)	2023 ± 631	2179 ± 443	2647 ± 526^a	2880 ± 475^a^,b	2974 ± 712^a^,b	9,817	0.000
Type II CSA (µm^2)	3123 ± 998	3196 ± 855	3373 ± 928	3557 ± 1144	3735 ± 1292^a^,b	3,929	0.004
Nuclear ratio	1.24 ± 0.35	1.4 ± 0.19	1.51 ± 0.25	2.22 ± 0.4^a^,b,c	2.2 ± 0.69^a^,b,c	18,622	0.000

Data are show as mean and standard deviation.

CSA: cross-sectional area; Nuclear ratio: number of nuclei/muscle fiber.

^aindicates a significant difference in relation to C (p ≤ 0.05).

^bindicates significant difference in relation to CF (p ≤ 0.05).

^cindicates a significant difference in relation to CAS (p ≤ 0.05).