If you do STS the way we have designed it you should not do any other strength workouts besides STS during the three month plus training cycle. This is not to say you can’t do other strength workouts, it’s just the benefits for the time spent would be minimal and in many cases your results could be less do to overtraining. However, we certainly encourage you to do cardio workouts with STS.
After completing STS you can either repeat the STS program or do something completely different. This is where you can use your other strength training DVDs. Though some people might only do STS for their strength training workouts during the year, we think it is better to do some other type of workouts for at least one month before returning to STS. This will help you to overcome boredom, prevent mind fatigue and overuse injuries and will keep your body constantly improving while trying to adapt to different types of workouts.
As for STS T-Shirts we’re actually working on this now, so keep the suggestions coming.