Physical training uniform
The physical training uniform is a military uniform used during calisthenics drills and, in some cases, very casual periods of time (off-duty time during Initial Entry Training in the U.S. Army, for example). The United States Army, U.S. Marines, U.S. Navy, and U.S. Air Force require use of a physical training (PT) uniform during unit exercise (including formation runs, calisthenics, and conditioning exercises). Some units will purchase a unique t-shirt with the unit insignia and motto. For special events, this shirt is part of the uniform. Occasionally, exercise will be conducted in that branch's utility uniforms, normally with the blouse removed and the undershirt exposed (also known as "boots and utes").
Physical Training Uniforms of the U.S. Armed Forces
The U.S. Army currently uses the Army Improved Physical Fitness Uniform (IPFU), manufactured by UNICOR. It is essentially a tracksuit, marked with the ARMY name. Optional compression shorts (called "spankies" by soldiers) may be worn under the IPFU trunks provided they are black or do not extend past the trunks. The main advantage of this new uniform over its older counterpart is being highly reflective at night while keeping its tactical colors during the daytime hours. The other noticeble advantages are more water- and windproof, and a bit lighter.
- T-shirt: Grey Army-marked long-sleeve or short-sleeve T-shirt; large reflective ARMY symbol on front of shirt and stylized reflective A on back. A Physical Fitness Badge may be worn for soldiers who excel at the A.P.F.T (270 or higher, with a 90 in each event).
- Trunks: Black trunks, multipurpose: can be worn alone for swimming, worn with longsleeve or shortsleeve shirt and under the black IPFU trousers.
- Trousers: Black trousers, lined with breathable, pored nylon fabric.
- Jacket: Grey jacket, zipped, with ARMY embroidered on left chest, and inverted (reflective) chevrons extending from shoulders to mid-stomach and lower back, with hidden vents in back and zippable hidden vents in armpits. The Physical Fitness Badge can be worn on this as well.
- Socks: Commercial calf-length or ankle-length, plain white socks with no logos.
- Shoes: Approved, well-fitting, comfortable running shoes. U.K. Gear Pt - 03 Military 
- Foliage green microfleece cap and black leather gloves (with gray-green wool inserts) : optional for inclement weather.
All of these items are issued to a soldier while in processing through BCT (Basic combat training) but replacements must be purchased from AAFES stores.
The following items that are still issued, but only worn during Initial Entry Training:
- Sweatpants: White sweatpants with ARMY down the left and right legs.
- Sweatshirt White with ARMY centered on the front chest. It used to be a hoodie with a zipper and draw string closure for its hood.
Due to its white nature, this uniform is referred to by the soldiers as the 'marshmallow suit.'
U.S. Marine Corps
All items worn by U.S. Marines conducting PT as a group are subject to uniformity, at the commander's discretion.
- Shirt: Plain green cotton t-shirt, though synthetic brands are authorized without any logos
- Shorts: Plain green nylon or "silky" shorts (as of October 2011, "silky" shorts are no longer authorized)
- Sweatshirt: Green sweatshirt with black USMC and Eagle, Globe, and Anchor on left chest
- Sweatpants: Green sweatpants with black USMC and Eagle, Globe, and Anchor on left thigh
- Track suit: Dark green pants and jacket with scarlet and gold "Marines" lettering, as well as reflective trim
- Shoes: appropriate civilian design, excessive bright coloring or designs are prohibited
- Socks: commercial calf-length or ankle-length, plain white or black socks with no logos.
- Watch cap: fleece, coyote brown, black, or OD green (replaced the black wool knit cap)
- Hydration pack: green or coyote brown (or subdued colors if personally-owned packs are authorized)
The uniform consists of a gold short sleeved shirt and Navy blue shorts. The shirt is moisture wicking and odor resistant polyester with Navy in reflective lettering on back and front.
The nylon moisture wicking and odor resistant Navy blue shorts come in six and eight inch lengths, providing standard appearance among different height Sailors. It also has reflective Navy lettering and side pockets with a hidden ID card pocket inside the waistband. As with the Army uniform, optional compression shorts may be worn under the PTU shorts provided they are black or navy blue in color.
Wear and Appearance of Navy Uniforms and Insignia consists of:
- T-shirt: Gold Navy-marked long-sleeve or short-sleeve T-shirt; small reflective NAVY lettering on front of shirt and larger reflective NAVY on back.
- Trunks: Navy Blue trunks with large reflective NAVY lettering on front left leg.
- Shoes: Approved, well-fitting, comfortable running shoes.
A matching gold and navy warmup suit has been announced and will be available in 2009.
U.S. Air Force
- T-shirt: Gray moisture wicking fabric with a reflective U.S. Air Force logo on the upper left corner on chest and centered on the back.
- Shorts: Air Force blue with silver reflective stripes on the sides and the AF emblem on the front left.
- Pants: Air Force blue with silver and white piping with reflective stripes.
- Jacket: Air Force blue with a silver reflective chevron on the front and back outlined by white piping. Has reflective Air Force symbol on the upper left portion of the chest. A hood is hidden in the collar, it can be pulled out during inclement weather.
- Socks: White socks, small logos are authorized.
- http://www.army.mil/usapa/epubs/pdf/r670_1.pdf AR 670-1, Wear and Appearance of Army Uniforms and Insignia
- AR 600-8-22, Army Awards, para. 8-51
- AR 670-1, para. 14-5 Insignia (on the Physical Training Uniform)
- http://www.navy.mil/search/display.asp?story_id=31271, Navy.mil: CNO Approves Physical Fitness Uniform
- http://www.e-publishing.af.mil/shared/media/epubs/afi36-2903.pdf Air Force Instruction 36-2903
New AR 670-1 14–3. Accessories= a. Commanders may authorize the wear of commercial running shoes, calf-length or ankle-length, plain white socks with no logos, gloves, reflective belts or vests, long underwear, and other items appropriate to the weather conditions and type of activity.