Variation benefits your gains!
We have all heard that variation in training gives better results, but how true is really this statement, and what is the best type of variation?
This study compared four different 12-week leg-exercise regimes:
1. Doing the same exercises, keeping the load the same.
2. Varying exercises, keeping the load the same.
3. Doing the same exercises, varying the load.
4. Varying exercises, varying the load.
When it came to hypertrophy, there was no significant difference between the groups.
When it came to strength however, the groups which varied their exercises had significantly higher increases in strength. The greatest strength gains were seen in the group which kept weights constant, but changed exercises (group 2 above). Strength was measured using a 1 rep max test for squat.
Thus we can say that varying exercises for a certain muscle may yield better results than varying your weight.
The problem here is, however, that the load was only varied between 6RM and 10RM, when it would have been more interesting to see variations between at least 4-20RM as these rep ranges stimulate the muscles in different ways. The safe bet for now is that you should vary weight and exercises, but if you had to choose one, vary your exercises!
Fonseca RM et al. Changes in exercises are more effective than in loading schemes to improve muscle strength. J Strength Cond Res. 2014 Nov;28(11):3085-92.