Yes, exercise with sweating and friction may aggravate acne in susceptible people, especially on shoulders, back and chest.
One important step is to shower straight after the workout (don’t travel home first and shower at home!).
It is also important to use a cleanser suitable for your skin type. I can recommend NeoStrata’s Clarifying Facial Cleanser*, which is perfectly fine for back, shoulders and chest also, or SkinCeuticals’ Simply Clean*.
I also like zinc-containing mists, e.g. La Roche Posay’s SeroZinc* spray, however, they don’t replace cleansing properly with a suitable cleanser AND water (avoid waterless cleansing with wet wipes!).
After cleansing, apply a very light, oil-free moisturizer, if your skin feels dry, for example La Roche Posay’s Toleriane Fluide*. However, if your skin does not feel dry or tight, skip the moisturiser (and never use rich body lotions on any breakout prone areas!).
In summer, you can apply a sun protection moisturiser in a light base formulation in sun exposed areas, e.g. Jan Marini’s Physical Protectant*.
Also make sure to wear breathable clothing, as occlusion may aggravate acne on the body.
*Available at EudeloBoutique.com