Can sweating make your hair grow faster?

No, sweating has no impact on hair growth rate.

Not exactly. There is no scientific evidence that anything can make hair grow faster or slower than the rates set by inherited DNA. Hair grows at an average rate of 1/8" per week.If you have gotten a short buzzed summer style and are wondering how to grow it out, read on. Starting from a butch or short crew cut, a guy can grow out his hair and have it look great as it grows out if he keeps up with haircuts, getting a slightly longer style each haircut. Assuming an average rate of hair growth of 1/8" per week and haircuts every three weeks, the following styles are a haircut apart: butch, short crew cut; medium crew cut; short ivy league; ivy league; long ivy league; short regular haircut, regular haircut. The general idea with guy's medium to short styles is to maximize and minimize the volume of hair in various areas of the head to create the illusion of an oval face shape, considered the ideal shape, with a somewhat more boxy than rounded skull shape when the face is viewed from the front and in side profile, a somewhat more rounded than boxy skull shape at the back of the head.
http://i.imgur.com/OSCe5ZV.jpg
"Oval: The oval face is the ideal shape. It is designated as the "egg" shape. It is wider at the forehead and tapers to a well rounded chin. This type of face looks equally becoming with hair worn low or high on the head; and likewise, either a center or side part or no part at all is becoming. depending somewhat on other facial characteristics."
L.S. Trusty, "The Art and Science of Barbering" pg129.
A good barber can usually design a regular haircut or one of the short pomp(pompadour) styles-crew cut, ivy league(long crew cut), flat top crew cut- to fully suit most young guys. In contrast, relatively few guys fully suit a butch, brush cut(long butch) or burr(short butch.) The main difference between a short pomp style and a butch, burr, brush cut is that a butch, burr, brush cut is a uniform short length on top while the top hair of a short pomp style is longest at the front hairline and graduates shorter in length to the crown which allows a barber to design a short pomp style to fully suit most combinations of male skull shape, frontal hairline, face shape etc Most girls are fine with whatever standard medium to short style a guy chooses to wear as long as the style fully suits and is kept clean and looking well groomed and the guy doesn't spend a lot of time on his hair. If a guy wants to go to a shorter style for the summer or one of his sporting activities, that is fine with most girls too even when she prefers that he wear a somewhat longer style. Around here most high school and college guys are wearing regular haircuts with long tapers on the back/sides, though since last summer a not insignificant number have switched to regular haircuts with medium or semi-short tapers on the back/sides, ivy leagues or crew cuts and recently some have been growing out to regular haircuts with extra long tapers on the back/sides.
A photo is the best way to describe a style to a barber or stylist.
short crew cut:
http://www.gstatic.com/hostedimg/dfbf10e504bce8a1_large
medium crew cut:
http://books.google.com/books?id=x0EEAAAAMBAJ&lpg=PP1&rview=1&pg=PA44#v=onepage&q&f=false
http://www.gstatic.com/hostedimg/ae218215599f9a96_large
ttp://oi48.tinypic.com/2i209b6.jpg
ttp://oi49.tinypic.com/iqzl80.jpg
Some barbers consider that all crew cuts should have a flat top, so it is best to not rely on words alone for even a widely recognized style like a crew cut. A guy growing out a crew to an ivy definitely does not want a flat top crew cut as the hair at the middle of the top of the head can be buzzed nearly to the scalp on some skull shapes.
flat top crew cut:
ttp://oi48.tinypic.com/f0dumb.jpg
ttp://oi50.tinypic.com/2ymzhq8.jpg
ttp://oi48.tinypic.com/k4b29f.jpg
ttp://oi50.tinypic.com/2v33tok.jpg
ivy league(long crew cut):
worn spiked up....
http://www.gstatic.com/hostedimg/45368d8c59451f3a_large
ttp://oi50.tinypic.com/1fdywx.jpg
ttp://oi46.tinypic.com/sgpjs7.jpg
worn down and brushed to the side...
http://www.gstatic.com/hostedimg/d2e97250e0614ff6_large
regular haircut, short taper on the back/sides:
ttp://www.gstatic.com/hostedimg/
daaea942199baad0_large
regular haircut, semi-short taper on the back/sides:
http://www.gstatic.com/hostedimg/067a2a8e87978148_large
regular haircut, medium taper on the back/sides:
http://www.gstatic.com/hostedimg/55c5c155a74bf22b_large
ttp://oi54.tinypic.com/1445gn5.jpg
regular haircut, long taper on the back/sides:
ttp://www.gstatic.com/hostedimg/
80803651238e0738_large
ttp://oi60.tinypic.com/2hdczr8.jpg
regular haircut to summer crew cut:
http://books.google.com/books?id=gEwEAAAAMBAJ&lpg=PP1&pg=PA46#v=onepage&q&f=false
Pg 27, two sixteen year old guys with crew cuts; pg 26, same guys with regular haircuts:
http://books.google.com/books?id=Xg6dEKlEnr4C&lpg=PA1&pg=PA27#v=onepage&q&f=false
Butch v Crew:
ttp://oi57.tinypic.com/23iawiw.jpg
This is a brush cut around 5/8" on top with the sides tapered down to around 2/8" at the top of the ears on a guy who fully suits a brush cut, most guys don't:
ttp://oi60.tinypic.com/ff0ncp.jpg
This is a butch, around 3/8" on top, sides tapered down to around 2/8" on a guy who fully suits a butch:
ttp://oi58.tinypic.com/qrisn8.jpg
Forward Brush:
ttp://i.imgur.com/tyQYoKW.jpg
ttp://i.imgur.com/QlZ0OFB.jpg
A minute dab of control wax aka butch wax will keep the hair looking well groomed at crew cut and ivy league length. A butch comb also helps with grooming the short pomp styles- the small, flat, plastic, oval, pocket brushes that one finger fits through and barbers sell for about a dollar. A boar bristle military brush is usually available for a few dollars and while too large for a guy to carry in his pocket, is nice to have at home.
ttp://oi55.tinypic.com/xf83tc.jpg
here are a few regular haircuts:
ttp://oi60.tinypic.com/ivvorn.jpg
ttp://oi59.tinypic.com/10pxb7p.jpg
ttp://oi61.tinypic.com/t558cl.jpg
ttp://oi62.tinypic.com/206kg2h.jpg
Same guy as above, hair groomed with a little dab of brylcreem...
ttp://oi60.tinypic.com/uo603.jpg
An ivy league, is considered to be a convertible haircut as it can be styled several ways...
1) Lightly waxed, side parted and brushed to the side with a short pompadour at the front hairline.
2)) Lightly waxed, side parted and brushed to the side without a short pompadour at the front hairline.
3) Lightly waxed and brushed back off the forehead like a crew cut.
4) Lightly waxed with the top hair brushed forward and the short bangs on the forehead like a forward brush.
5) Lightly waxed with the top hair brushed forward and the short bangs brushed back off the forehead like a crew cut.
here are a few ivy leagues...
ttp://oi43.tinypic.com/15nnb06.jpg
ttp://oi39.tinypic.com/28hq5nq.jpg
ttp://oi41.tinypic.com/1ktcl.jpg
ttp://oi42.tinypic.com/15f6kif.jpg
ttp://oi41.tinypic.com/15pq0w0.jpg
ttp://oi40.tinypic.com/rcvfcx.jpg
ttp://oi42.tinypic.com/rarptx.jpg
ttp://oi39.tinypic.com/2hd2lbl.jpg
ttp://oi41.tinypic.com/dqiq0z.jpg
The flat top crew cut is practically not seen at all on young guys at the moment but has usually been the most popular short style. In the 50's and 60's at least the first half till the beatles influence made short styles almost anathema, it was the most popular short style and then from the mid 80s to around 2000, was practically the only short style worn by young guys.
A few flats....
ttp://oi58.tinypic.com/2j19942.jpg
ttp://oi59.tinypic.com/16kqhle.jpg
ttp://oi60.tinypic.com/2ibdggi.jpg
ttp://oi60.tinypic.com/2n7dvub.jpg
ttp://oi62.tinypic.com/htwj12.jpg
ttp://oi58.tinypic.com/dwxw20.jpg
ttp://oi62.tinypic.com/23itj4z.jpg
ttp://oi60.tinypic.com/5u4hau.jpg
ttp://oi59.tinypic.com/fmoutg.jpg
ttp://oi57.tinypic.com/4pypsw.jpg
Flats and Crews...
ttp://oi39.tinypic.com/2vafpsn.jpg
ttp://farm8.staticflickr.com/
7123/7881261778_8155883af4_o.jpg
ttp://oi39.tinypic.com/nujie.jpg
ttp://oi44.tinypic.com/5b348y.jpg
ttp://oi39.tinypic.com/2wf1xrq.jpg
ttp://oi41.tinypic.com/29p2hqo.jpg
ttp://oi44.tinypic.com/ip169y.jpg
ttp://oi58.tinypic.com/21o1t2c.jpg
ttp://oi60.tinypic.com/f8dvd.jpg
ttp://oi59.tinypic.com/1zdsldi.jpg